TamoGraph Site Survey

TAMOSOFT
TamoGraph® Site Survey
Professional Wi-Fi Site Survey Software
for Microsoft® Windows® and macOS®
Help Documentation
Version 5.0
Copyright © 2010-2017 TamoSoft
Contents
Contents ........................................................................................................................................................ 2
Introduction .................................................................................................................................................. 5
Overview ............................................................................................................................................... 5
Why to Perform a Site Survey ............................................................................................................... 5
When to Perform a Site Survey ............................................................................................................. 5
Survey Types.......................................................................................................................................... 5
System Requirements ........................................................................................................................... 6
Differences Between the Windows and macOS Versions ..................................................................... 7
Driver Installation - Microsoft Windows ............................................................................................... 7
Driver Installation Troubleshooting on Windows ................................................................................. 7
Wi-Fi Capture Engine Installation - macOS ........................................................................................... 8
Trial Version Limitations........................................................................................................................ 8
License Types......................................................................................................................................... 8
Interface Overview ........................................................................................................................................ 9
Access Point List ..................................................................................................................................10
Floor Plan / Site Map ...........................................................................................................................13
Plans and Surveys, Properties, and Options Panel..............................................................................13
Main Menu ..........................................................................................................................................14
Performing a Site Survey .............................................................................................................................16
New Project Wizard.............................................................................................................................16
Calibration ...........................................................................................................................................19
Configuration.......................................................................................................................................19
Data Collection ....................................................................................................................................20
Understanding Survey Types: Passive, Active, and Predictive ............................................................22
Active Survey Configuration ................................................................................................................24
Best Practices, Tips, and Tricks ............................................................................................................28
Survey Job Splitting .....................................................................................................................................30
Predictive Surveys .......................................................................................................................................31
Drawing Walls and Other Obstructions ..............................................................................................32
Drawing Attenuation Zones ................................................................................................................33
Virtual APs Placement Methods..........................................................................................................33
Manual Placing and Configuring Virtual APs .......................................................................................34
Automatic Placing and Configuring Virtual APs ..................................................................................35
Reconfiguring Virtual APs ....................................................................................................................40
2
Contents | TamoGraph Site Survey
Working with Presets ..........................................................................................................................41
Applying Visualizations ........................................................................................................................41
Working with Multi-floor Sites ............................................................................................................41
Mixing Real and Virtual Data ...............................................................................................................43
Best Practices, Tips, and Tricks ............................................................................................................44
Analyzing Data – Passive and Predictive Surveys ........................................................................................46
Selecting Data for Analysis ..................................................................................................................46
Adjusting AP Locations After Passive Surveys .....................................................................................47
Splitting an AP into Multiple Unique APs ............................................................................................48
Working with Multi-SSID APs ..............................................................................................................49
Visualization Types ..............................................................................................................................49
Signal Level ..........................................................................................................................................49
Signal-to-Noise Ratio ...........................................................................................................................50
Signal-to-Interference Ratio ................................................................................................................51
AP Coverage Areas ..............................................................................................................................52
Number of APs ....................................................................................................................................53
Expected PHY Rate ..............................................................................................................................53
Frame Format ......................................................................................................................................54
Channel Bandwidth .............................................................................................................................55
Channel Map .......................................................................................................................................56
Requirements ......................................................................................................................................56
Analyzing Data – Active Surveys..................................................................................................................58
Selecting Data for Analysis ..................................................................................................................58
Visualization Types ..............................................................................................................................58
Actual PHY Rate ...................................................................................................................................59
TCP Upstream and Downstream Rate.................................................................................................60
UDP Upstream and Downstream Rate ................................................................................................60
UDP Upstream and Downstream Loss ................................................................................................61
Round-trip Time ..................................................................................................................................62
Associated AP ......................................................................................................................................62
Requirements ......................................................................................................................................63
Spectrum Analysis .......................................................................................................................................64
Hardware Requirements .....................................................................................................................64
Spectrum Data Graphs ........................................................................................................................65
Performing Spectrum Analysis Surveys ...............................................................................................66
3
Contents | TamoGraph Site Survey
Viewing Collected Spectrum Data .......................................................................................................66
Exporting Spectrum Data ....................................................................................................................66
Reporting and Printing ................................................................................................................................67
Customizing Reports ...........................................................................................................................68
Google Earth Integration.............................................................................................................................69
Configuring TamoGraph ..............................................................................................................................70
Plans and Surveys ................................................................................................................................70
Properties ............................................................................................................................................71
Options ................................................................................................................................................74
Configuring GPS Receiver ............................................................................................................................77
Using GPS Configuration Dialog ..........................................................................................................77
Finding the GPS Receiver Port Number ..............................................................................................79
Taking Photographs.....................................................................................................................................82
Voice Control ...............................................................................................................................................83
Using TamoGraph in a Virtual Machine ......................................................................................................84
Frequently Asked Questions .......................................................................................................................86
Sales and Support........................................................................................................................................91
4
Contents | TamoGraph Site Survey
Introduction
Overview
Welcome to TamoGraph Site Survey, a powerful and user-friendly application for collecting and visualizing
Wi-Fi data. Wireless network deployment and maintenance requires the use of a professional RF site
survey tool that facilitates otherwise time-consuming and very complex tasks, such as ongoing analysis
and reporting of signal strength, noise and interference, TCP and UDP throughput, channel allocation,
data rates, etc. By using TamoGraph, businesses can dramatically reduce the time and costs involved in
deploying and maintaining WLANs and improve network performance and coverage.
Why to Perform a Site Survey
In a word, wireless site surveys are necessary because radio wave propagation is difficult to predict,
especially in non-open space environments. Considering all the variables that might affect the health and
performance of your WLAN is virtually impossible. Changing conditions, even something as seemingly
minor as a laptop equipped with a legacy 802.11g adapter that your new employee connected to the
office wireless network, might seriously affect the WLAN performance. In addition, considering the wide
proliferation of wireless infrastructure, factors such as interference from nearby WLANs play a very
important role. This is why regular site surveys conducted with a professional tool are essential.
When to Perform a Site Survey
Pre-deployment surveys: At this stage, a site survey is necessary in order to verify that the network plan
works well in a real-world environment. Placement of temporary access points (APs) and a quick survey
of the resulting WLAN characteristics allow an engineer to fine-tune AP and antennae placement,
determine the optimal number and types of APs and antennae, and avoid poor coverage zones. Using
TamoGraph, you can also perform a simulation in a virtual environment prior to deployment.
Post-deployment surveys: Once a WLAN has been deployed, a complete verification site survey is
necessary to ensure that the WLAN performance and coverage meet the design requirements. At this
stage, the Wi-Fi equipment placement is finalized, and a site survey report should be generated so that
the historical records can be accessed at any time in the future.
Regular, ongoing surveys: Maintaining high performance and coverage requires regular “check-up”
surveys. New users, new equipment, site expansion, neighboring WLANs, and other factors can adversely
affect your WLAN. It should be monitored on a regular basis.
Survey Types
There are three types of surveys that you can conduct with TamoGraph: passive, active, and predictive.
During a passive survey, the application collects the most comprehensive data on the RF environment:
information on access points and their characteristics, signal strength, noise level, interference, etc. This
is the default and most important survey type that we recommend to conduct in every case. It is called
passive because during this type of survey, the application passively listens for packets and does not
attempt to connect to WLANs. However, to provide more insight into the real-world performance of your
WLAN, TamoGraph can also perform active surveys, during which your Wi-Fi adapter connects to the
wireless network(s) of your choice to measure actual throughput rates and a few other metrics. Unlike
5
Introduction | TamoGraph Site Survey
passive and active surveys, predictive surveys are not performed on-site. Predictive surveys are a
computer simulation in which Wi-Fi characteristics are predicted for the virtual environment model
created by the user. The process of creating and adjusting the virtual environment, selection and
placement of simulated APs, and analyzing the resulting WLAN is commonly referred to as “RF planning.”
Please refer to the Understanding Survey Types: Passive, Active, and Predictive chapter for more
information on this topic. Additionally, TamoGraph can be used to perform spectrum analysis surveys.
System Requirements
TamoGraph requires a portable computer with the following minimal system requirements:
Computers running Microsoft Windows








Microsoft Windows 7, Windows 8, Windows 8.1, Windows 10, Windows Server 2008 R2, Windows
Server 2012, Windows Server 2012 R2. Both 32- and 64-bit versions are supported.
Intel Core 2 or similar CPU. A multi-core CPU such as Intel i5 or i7 is recommended.
2 GB of RAM.
A compatible wireless adapter for passive surveys. For the up-to-date list of compatible adapters,
please visit our Web site. Any modern wireless adapter may be used for active surveys.
An NMEA-compliant GPS receiver or a Windows GPS or GLONASS sensor, if you plan to perform
GPS-assisted site surveys.
A USB spectrum analyzer, Wi-Spy by MetaGeek, if you plan to perform spectrum analysis surveys.
Internet Explorer 8.0 or higher, if you plan to import street maps from one of the online map
services.
60 MB of free disk space.
Computers running macOS






macOS Yosemite (10.10), El Capitan (10.11), Sierra (10.12), or High Sierra (10.13).
MacBook, MacBook Pro, or MacBook Air manufactured in 2011 or later.
4 GB of RAM.
An NMEA-compliant GPS receiver, if you plan to perform GPS-assisted site surveys.
A USB spectrum analyzer, Wi-Spy by MetaGeek, if you plan to perform spectrum analysis surveys.
60 MB of free disk space.
You can also run TamoGraph on a desktop computer that is not equipped with a compatible wireless
adapter. This operating mode may be feasible if you would like to collect Wi-Fi data using portable
computers and then import, merge, and analyze the data on a desktop PC or iMac based on faster
hardware and using a larger display.
6
Introduction | TamoGraph Site Survey
Differences Between the Windows and macOS Versions
The versions of TamoGraph for Windows and macOS are largely identical. In addition, TamoGraph project
files are compatible across versions. Project files created with the Windows version of TamoGraph can be
opened by the macOS version, and vice versa.
Nevertheless, there are many differences between the two operating systems and the underlying
hardware. This results in some differences in the TamoGraph versions that are summarized below:
Microsoft Windows
macOS
Compatible Adapters
Requires specific Wi-Fi adapter Works with the Wi-Fi adapter built
models for passive surveys.
into your MacBook and does not
require specific additional adapters.
Driver or Packet Capture You need to install the special You need to install the packet
Engine Installation
drivers that come with this product. capture engine.
Simultaneous
Supported, as long as two different Not supported.
Active + Passive Surveys adapters are plugged in.
Using Multiple Adapters Supported.
Not supported.
Additionally, some menu items are located in different places on the two versions.
Driver Installation - Microsoft Windows
TamoGraph is a tool for monitoring wireless 802.11 a/b/g/n/ac networks. To conduct passive surveys, you
must have a compatible wireless adapter to use this product. In order to enable the monitoring features
of your wireless adapter, you will need to use the special drivers that come with this product.
When TamoGraph is not running, your adapter will be able to communicate with other wireless hosts or
APs, just like when you are using the original driver supplied by the adapter manufacturer. When
TamoGraph is running, your adapter will be put in passive, promiscuous monitoring mode.
Prior to installing the new driver for your wireless adapter, be sure that your adapter is compatible with
this product. The list of compatible adapters can be found at the following URL:
http://www.tamos.com/products/wifi-site-survey/adapterlist.php
For detailed, illustrated driver installation instructions, please launch the program and click Help => Driver
Installation Guide in the program's menu.
If you use CommView for WiFi, another TamoSoft product, you do not need to install or change the driver,
as TamoGraph and CommView for WiFi share the same drivers.
Driver Installation Troubleshooting on Windows
If you get the “Could not start device driver” or “Could not install device driver” message, first, make sure
that the adapter is plugged in and verify that it is enabled by opening Control Panel => Network and
Internet => Network Connections and right-clicking on the adapter icon.
The next step depends on the adapter chipset:
7
Introduction | TamoGraph Site Survey
For adapters based on Atheros
chipsets:
For adapters based on other
chipsets (Intel, Dell, Broadcom):
Make sure that the special adapter driver was not
replaced by a vendor-supplied driver. This may
have happened when you ran Windows Update.
Open Control Panel => System and Security, select
the Hardware tab, and then open the Device
Manager. Your adapter is listed under “Network
adapters.” If the adapter name is not prepended
with “[CommView],” then your adapter is not
using the special driver for TamoGraph. In that
case, click Help => Driver Installation Guide in the
main application window and let the program
reinstall the special driver.
Make sure that you use the latest driver supplied
by your computer or adapter vendor. Visit the
vendor's Web site to download and install the
latest driver version.
If the problem persists even after rebooting, please contact our technical support.
Wi-Fi Capture Engine Installation - macOS
To conduct passive and active surveys, TamoGraph uses the built-in Wi-Fi adapter of your MacBook. In
order to enable the monitoring features of the Wi-Fi adapter, you will need to install the Wi-Fi Capture
Engine. You will be prompted to install it when you run TamoGraph for the first time. Alternatively, you
can do that by clicking TamoGraph => Install Wi-Fi Capture Engine in the main menu. Note that the engine
installation requires an administrative account. Once the engine has been installed, you can run
TamoGraph as a standard user.
When TamoGraph is not running, your adapter will be able to communicate with other wireless hosts or
APs as it normally does. When TamoGraph is running, your adapter will be put in passive, promiscuous
monitoring mode. If you want to restore network connectivity while TamoGraph is running, select the
Properties tab on the right panel, expand the Scanner frame and click Stop Scanner.
Trial Version Limitations
The trial of TamoGraph allows you to evaluate the software for 30 days and has the following limitations:




Watermarks are placed on all visualizations.
You cannot save projects or reports.
You cannot collect data and survey sites for longer than ten minutes.
If you perform a predictive survey, you cannot use the planning tool for longer than five minutes
or place more than five virtual APs on the floor plan.
License Types
Two TamoGraph license types are available: Standard and Pro. The more expensive Pro license allows you
to use the GPS functionality for conducting GPS-assisted site surveys outdoors, perform predictive
surveys, and customize PDF and HTML reports. The Standard license does not offer GPS, predictive survey,
or report customization functionality.
8
Introduction | TamoGraph Site Survey
Interface Overview
The application main window includes the following elements:



The resizable left-side panel displays an AP list of the APs detected by the scanner or the ones
that are present in the imported projects.
The central area is used for displaying the floor or site plan image, survey paths, and visualizations
of analyzed data.
The resizable right-side panel allows you to manage project floor plans and collected survey data,
as well as to configure various project options and settings.
You can hide and show the left and right panels using the vertical splitter or through the menu commands
View => Left Panel and View => Right Panel.
In addition to the three main elements, the application contains the main tool bar (provides quick access
to frequently used commands), the RF Planner toolbar (used in predictive surveys for drawing virtual
objects; not shown by default), and the status bar (provides information on the wireless adapter and
scanner status, current floor plan dimensions, coordinates, and zoom level, as well as the legend for the
currently selected visualization).
The following chapters describe the functionality of these elements in detail.
9
Interface Overview | TamoGraph Site Survey
Access Point List
The left application panel is used to display the list of APs detected by the application (if you have a
compatible adapter installed.) It also displays virtual APs if you perform a predictive survey. You can use
the Group by button to group APs by band, channel, SSID, name, or custom group. Grouping by SSID is
the best method in a corporate WLAN environment, where all the WLAN's APs share the same SSID.
The AP list displays key AP parameters in the corresponding columns: SSID, vendor, channel, current signal
level in dBm, supported encryption type(s), maximum data rate in Mbps, the number of 802.11n or
802.11ac spatial streams, and MAC address. If the vendor is unknown, the AP name is preceded by
“Unknown.” If the vendor name is known, the AP name is preceded by the vendor name followed by the
AP type. Additionally, for Cisco APs, TamoGraph will try to find and use AP names assigned by the
administrator. You can rename APs by right-clicking on them and selecting Rename. To restore the original
name, simply delete a user-assigned name by hitting the backspace key. If the AP uses channel bonding
(several 20 MHz channels), the channel set is shown in parenthesis after the primary channel number. For
802.11ac APs, several channel sets might be shown, e.g., for the 40 MHz and 80 MHz modes. You can
customize the columns by right-clicking on the list header or change their order by dragging them. The
APs that are not currently audible are shown in grey font, and their signal level is shown as “N/A.”
The AP icons are color-coded to reflect the 802.11 bands and standards they use:
2.4 GHz 802.11b
2.4 GHz 802.11g
2.4 GHz 802.11n
5 GHz 802.11a
5 GHz 802.11na
5 GHz 802.11ac
10
Interface Overview | TamoGraph Site Survey
The check boxes next to the APs play a very important role: They should be used for selecting the APs you
want TamoGraph to analyze. When the Selected APs mode is enabled on the tool bar, data visualizations
for passive surveys include only the APs that have checked boxes next to them.
Right-clicking on the AP list allows you to Select All or Deselect All APs, as well as to disable or enable the
Ignore APs if max. signal is below option (see AP Detection and Placement for more information.) If the
list of APs becomes too long and you prefer to not see the APs that are currently outside of the range,
select Advanced => Remove Inactive APs. This will remove the APs that have been outside of the range
for longer than two minutes.
If the AP signal is strong enough and if a sufficient number of readings has been recorded, TamoGraph
computes the AP location and places the corresponding icon on the site map. Those APs that are present
on the site map have a small blue plus (+) sign in the lower right corner of their icons. The Auto-locate
Access Points command allows you to reset the original estimated AP location(s) of either all or only the
highlighted AP if you changed them by moving AP icons with the mouse. If an AP was not automatically
placed on the site map and you want to place it there, you can drag the AP icon from the AP list to the site
map. To remove it from the site map, drag the AP icon outside of it or use the Clear Access Point Locations
command. See Adjusting AP Locations for more information. Virtual APs that were created by the user for
predictive surveys have a small blue “V” sign in the lower right corner of their icons; such APs cannot be
auto-located or dragged off the site map.
When working with dozens of APs, it might be difficult to find the corresponding entry on the AP list for a
given icon on the site map and vice versa. To help you with this task, two visual feedback mechanisms
exist:

When you select an AP icon on the site map, the corresponding item on the AP list is highlighted
in grey color. If a multi-SSID AP has been selected, multiple corresponding items on the AP list are
highlighted (one per radio).

When you double-click an item on the AP list, the corresponding AP icon on the site map blinks a
few times (assuming that the corresponding AP icon is shown on the site map). If the AP icon is
not within the site map’s visible area, the site map is automatically scrolled to ensure that the
icon is visible.
AP Ignore List
Sometimes, a surveyor might need to ignore one or several APs completely. This might be the case when
APs do not have a fixed location, e.g., APs that are installed in elevators, or when APs are used temporarily,
e.g., a laptop that is used as a hot spot. To ignore such an AP, select it on the AP list, right-click on it, and
then select Advanced => Ignore this AP. The AP's MAC address (also known as BSSID) will be added to the
ignore list and any packets from this AP will be discarded. The ignore list can be accessed via the Settings
=> AP Ignore List command of the main application menu. You can review the list and add or remove one
or multiple MAC addresses.
Custom Groups
One of the possible AP grouping methods is by “Custom Group”. This method might be used if you have
a grouping criterion that is not covered by the standard grouping methods, such as by SSID or by band.
For example, you may want group APs by their location. Initially, APs are not assigned to any group. To
create groups and assign APs to them, use the Custom Group menu. Under this menu, you can Add
11
Interface Overview | TamoGraph Site Survey
selected APs to an existing or new group (by “selected,” we mean the APs that are currently checked in
the AP list) or Clear grouping for all or selected APs. You can also Manage all groups. When you use the
Manage command, the application displays a dialog listing all APs and their membership in the groups.
Initially, all APs are marked as Ungrouped. You can create new groups, rename them, delete them, and
move one or several APs to any group via drag-and-drop. Note that an AP cannot be assigned to multiple
groups; it can be assigned either to one group or to no group. Groups are project specific, which means
that they exist only within a given project. You cannot create or manage groups when no project is open.
12
Interface Overview | TamoGraph Site Survey
Floor Plan / Site Map
This central area of the application window is used for displaying the floor plan or site map. When you
perform a passive or active site survey, you use the floor plan to mark your current location. As you move
and click on the plan, TamoGraph will show your walkabout path and the area you have covered, as shown
on the illustration below:
The application status bar displays the map dimensions and your current coordinates when you hover the
mouse over the map. To zoom in our out, use the mouse scroll wheel or the Zoom button on the status
bar. To pan the map, use the vertical and horizontal scroll bars or press and hold the space bar and drag
the map while holding the left mouse button. If you are using a computer with a multi-touch display, you
can use the two-finger pinch zoom gesture to zoom in or out and the two-finger pan gesture to pan.
When you are through surveying the site, you can use the Visualization drop-down list on the tool bar to
have TamoGraph display data visualizations for your site (e.g., signal level or AP coverage areas).
Plans and Surveys, Properties, and Options Panel
This panel gives you access to virtually all of the application and project settings. Using this panel, you can
manage floor plans or conducted surveys, configure requirements for your wireless network, change the
scanner settings, select color schemes for your visualizations, etc. For a detailed description of these
functions, refer to the Configuring TamoGraph chapter.
13
Interface Overview | TamoGraph Site Survey
Main Menu
The application menu commands are described below. Some menu items are located in different places
in the Windows and macOS versions.
Project
New – launches a new project wizard.
Open – opens a previously saved project.
Save – saves the current project.
Save As – saves the current project under a different name.
Close – closes the current project.
Generate Report – opens the report generation dialog.
Save Current Visualization – saves the currently selected visualization and legend to an image
file.
Clear Recent List – clears the list of recently opened project files.
Exit – closes the application.









Survey










Start – starts data collection.
Pause – suspends data collection temporarily.
Stop – stops data collection or site map calibration.
Continuous – turns on the continuous data collection mode.
Point-by-Point – turns on the point-by-point data collection mode.
GPS – turns on the GPS data collection mode.
Calibrate – allows you to set the map dimensions.
Export Survey Data – exports collected data when the survey job is split between several
computers.
Import Survey Data – imports collected data when the split jobs need to be merged into one
project.
Take Photo – allows you to take a photograph and add it to your project.
RF Planner



Auto-place APs – open the AP automatic placement wizard.
Reconfigure APs – open the AP automatic reconfiguration wizard.
Virtual Model – turns on or off the virtual model and, respectively, shows or hides all virtual APs
and other objects used in predictive surveys.
View






Left Panel – shows or hides the left panel.
Right Panel – shows or hides the right panel.
Main Menu – shows or hides the main application menu. To show it again, press ALT or use the
View context menu on the central pane.
Main Toolbar – shows or hides the toolbar in the main application window.
RF Planner Toolbar – shows or hides the toolbar for editing virtual objects used in predictive
surveys.
Status Bar – shows or hides the application status bar.
14
Interface Overview | TamoGraph Site Survey









Full Screen – expands the main application window and hides all other applications. To exit full
screen mode, press F11 or use the View context menu on the central pane.
Vertical Ruler – shows or hides the vertical ruler.
Horizontal Ruler – shows or hides the horizontal ruler.
Legend – shows or hides the legend on the map.
Spectrum – shows or hides the spectrum analysis pane. This item is enabled only when the project
contains spectrum data or when Wi-Spy is plugged in.
Access Points – shows or hides AP icons. This applies to both virtual APs and real-world APs.
Walkabout Paths – shows or hides survey paths.
Virtual Objects – shows or hides virtual objects (walls, attenuation areas, AP auto-placement
areas, and floor areas) that were created as part of a predictive survey.
Media Objects – shows or hides icons that represent photographs taken during surveys.
Settings





Interface Font – allows you to change the interface font.
Language – allows you to change the interface language.
GPS Settings – allows you to configure your GPS receiver.
Camera and Voice Settings – allows you to configure a camera for adding photos to your project
and voice recognition setting for controlling the application using voice commands.
AP Ignore List – allows you to configure the list of APs to be ignored by the application.
Help






Contents – displays help documentation.
Contents (PDF) – displays help documentation in PDF format.
Driver Installation Guide – displays driver installation guide.
Check for Updates – connects to the TamoSoft Web site and checks whether a newer application
version is available.
Activation – activates your registration key.
About – displays information about the application.
15
Interface Overview | TamoGraph Site Survey
Performing a Site Survey
To perform a WLAN site survey, you need to
Create a new project with the help of the Project Wizard.
Calibrate the floor plan or site map.
Configure the survey options and WLAN requirements.
Collect wireless data by walking along the planned survey path and periodically marking your
location on the map or using a GPS receiver. If you perform a predictive survey, you do not need
to collect wireless data. Rather, you need to create a virtual environment. See the chapter on
predictive surveys for more information.




The following chapters describe these steps in detail. Additionally, be sure to read Best Practices, Tips,
and Tricks to learn how to make your site surveys fast, efficient, and accurate.
New Project Wizard
To create a new project, click Project => New. A wizard window will appear.
Step 1
Specify the Name, Description (optional), and Project path. The name you give to the project is used as
the file name under which your project will be saved in the folder specified in the Project path field.
Step 2
In this step, you should Select an environment. The Environment panel allows you to configure some of
the very important project parameters that affect the way data visualizations are computed. Because
different environments have different characteristics in terms of signal attenuation, diffraction, reflection,
etc., you are asked to select the environment that best describes the site you plan to survey. For each
environment, the application recommends a Guess range. A guess range is the diameter of the circle for
which the application predicts the WLAN characteristics with a high degree of certainty. For passive
surveys, TamoGraph can also compute WLAN characteristics outside the guess range zone, although such
computations have a lower degree of accuracy. Check the Extrapolate data beyond the guess range box
to enable such computations. Enabling this option means that data visualizations will cover the entire map
rather than the areas that you actually surveyed. Enabling this option is not recommended unless you
cannot survey some areas of the map for whatever reason. Finally, the Measurement units control can
be used to choose the preferred units (feet or meters) for displaying distances and coordinates throughout
the application. See the Environment chapter for more information.
Step 3
Select the Channels to scan. The application scanner sweeps through the channels supported by the
wireless adapter to collect and analyze packets being sent on the selected channels. You may want to
modify the channel selection if you know that some of the channels supported by the wireless adapter
are not used in your WLAN or in your country. For example, if your WLAN does not use the 5 GHz band,
you may want to turn off all 5 GHz channels; this will shorten the scanning cycle and, therefore, increase
the data accuracy. However, please keep in mind that skipping some of the channels may result in the
application's inability to detect sources of interference, such as neighboring APs that work on the channels
16
Performing a Site Survey | TamoGraph Site Survey
that were skipped. It is recommended that you not modify the default Scan interval and Use the same
interval for all channels settings at this stage. See the Scanner chapter for more information. You can use
the Select channels button for selecting or deselecting all channels, as well as for selecting channels based
on the country- or region-specific allowed channel lists (e.g., choosing United States will select channels
1-11 and deselect channels 12-14 in the 2.4 GHz frequency band).
Note: This wizard step is skipped if your computer is not equipped with a compatible wireless
adapter. You might still want to create projects on such computers if you plan to conduct active
surveys or use the survey job splitting—i.e., if the data collection process is performed on other
computers and the collected data is then merged on your computer.
Step 4
In the final step, you should add an image file that contains the floor plan or site map of the facility or
area that you want to survey (you will be able to add more images if your project includes several zones
or floors later.) A floor plan or site map is required for accurate data analysis. If no image file is available,
you may want to scan a plan, if it exists on paper, create one using a drawing program, such as CorelDraw,
or even make a sketch using a ruler and pencil and then scan the sketch (be sure to follow the
proportions). The image file should be between 250 and 2,500 pixels on a side (naturally, this applies to
raster formats only; vector images, such as DWG, do not have pixel dimensions). Larger images will slow
down the application. The following image file formats are supported on Windows: BMP, PNG, JPG, GIF,
WMF, TIFF, PDF, DWG, DXF, and SVG. The following image file formats are supported on macOS: BMP,
PNG, JPG, GIF, TIFF, PDF, DWG, DXF, and SVG.
If you add an AutoCAD image (DWG or DXF), an additional import settings dialog is displayed. This dialog
allows you to select a layout to be used (if the file contains multiple layouts) and include or exclude specific
layers. For example, you may want to exclude the plan legend. You can also crop the floor plan to define
a specific zone to be used for surveying.
The application also supports PDF files. When you use a PDF file, an additional import settings dialog is
displayed. This dialog allows you to select a page to be used (if the file contains multiple pages).
Alternatively, you can use any of the images embedded into the PDF file; such images are listed on a
separate tab. You can also rotate or crop the floor plan to define a specific zone to be used for surveying.
If you plan to perform a large-area GPS-assisted survey, you may want to import a map from one of the
online map services or Microsoft MapPoint (MapPoint Europe or MapPoint North America are required
to use MapPoint maps). Click Load Street Map to open a new map loader dialog. Once the initial map
view is loaded (the application will try to guess your location based on the Wi-Fi environment), you can
navigate to the area you want to survey, using the map controls or the Navigation frame, in which you
can enter your coordinates, or read them from the GPS receiver, or enter your address. Click Go to
Location to load the map of the corresponding area. When you are satisfied with the area selection and
zoom level, click Use Map. Note that the application will use the map image as you see it, with the selected
zoom level and size in pixels as in the map loader window (the window can be resized). Be sure to select
the area correctly and to set a zoom level that meets your needs, as you will not be able to resize the map
or zoom in/out at a later time. When you open the map loader window, TamoGraph temporarily returns
control over your Wi-Fi adapter to the operating system so that you can connect to the Internet and load
17
Performing a Site Survey | TamoGraph Site Survey
the map. If a Wi-Fi connection to your AP is not established, connect your computer to the Internet over
a wired connection, close the map loader window, and open it again.
18
Performing a Site Survey | TamoGraph Site Survey
Calibration
Once the project has been created, you will be prompted to calibrate the floor plan or site map. Calibration
is the process by which you “tell” the application about the map dimensions (and coordinates, if you
perform a GPS survey). Depending on the survey mode selected on the tool bar,
clicking the Calibrate button on the tool bar (the right button on the illustration)
will allow you to perform either standard (non-GPS) calibration or GPS calibration. GPS calibration is
performed if the GPS survey mode is selected (the “satellite” button on the illustration). In all other cases,
standard calibration is performed.
Standard Calibration (non-GPS)
To calibrate the map in this mode, you need to know the distance between two points on the map. That
can be the distance between two walls or windows. Click on the first point of the distance, and move the
mouse pointer to the second point while holding down the left mouse button. Release the left mouse
button when the mouse pointer is over the second point. A red line indicating the distance will be shown.
At the bottom of the screen, enter the length of the red line and click Apply.
GPS Calibration
IMPORTANT: GPS functionality is available to Pro License users only.
To prepare the map for a GPS survey, you need to add at least three reference points with known
geographic coordinates. To create a new reference point, click Add new and drag the point marker to a
location on the map whose coordinates you want to enter. After that, you can do one of the following:

Enter the coordinates of that point if you know them, or

Walk or drive to that point and use your GPS receiver to get your current coordinates.
If you use the first method, simply enter the latitude and longitude of the new point in the corresponding
fields on the left in one of the standard coordinate formats—e.g., 50.435237, 50° 26' 6.85" N, or 50°
26.114' N. Be sure to double-check the numbers that you enter. Entering precise coordinates is extremely
important for the accuracy of the subsequent data collection and analysis. If you use the second method,
turn on your GPS receiver, connect it to your computer, and click Get from GPS Receiver. TamoGraph will
then connect to the GPS receiver (or display a GPS configuration dialog, if you have not configured it) and
read your current coordinates. Once the latitude and longitude have been entered, click Set to save the
coordinates of the first point.
Repeat these steps for all points. The points should be as far apart as possible and not located on a straight
line. You can enter more than three reference points, but this is usually not necessary if your site map has
correct proportions. Click Apply when done.
Configuration
Before proceeding to data collection, you may want to configure some of the application settings and
project properties, although this is not mandatory. Available settings and options are described in the
Configuring TamoGraph chapter. Specifically, it is recommended that you configure WLAN requirements.
19
Performing a Site Survey | TamoGraph Site Survey
This is helpful for a quick and easy evaluation of the overall health of your WLAN and detection of potential
issues.
Data Collection
Once the project configuration has been completed, you are ready to perform the actual
survey by walking the site with a laptop that runs TamoGraph (unless you perform a
predictive survey, where no on-site data collection is necessary). To facilitate the data collection process,
TamoGraph offers three survey modes that can be selected by pressing the corresponding buttons on the
tool bar: Continuous (the left button on the illustration), Point-by-Point (the middle button on the
illustration), and GPS (the right button on the illustration) for GPS-assisted outdoor surveys.
IMPORTANT: GPS functionality is available to Pro License users only.
In the default continuous mode, after you mark your initial location on the map by clicking on it, the
application scanner continuously scans the air by sweeping through the Wi-Fi channels. When you mark
the next location on the map, the data that has been collected between the two clicks on the map is
spread evenly along the path between the two data points. This means that your path should consist of
straight lines and that you should walk steadily, clicking on the map every time you change direction.
In the point-by-point mode, TamoGraph collects data only when you click on the map. In that mode, you
should stay where you are after marking your location on the map, until the scanner completes the cycle.
Then the scanner stops, until you mark your next location, where the scanner makes another full cycle.
This means that your path can have any shape, but less data will be collected, as compared to the
continuous mode, and a smaller area will be covered.
In the GPS mode, the data collection process is similar to the one in continuous mode, but the location is
automatically determined by the GPS receiver connected to the computer. Continuous and Point-byPoint surveys can be conducted both indoors and outdoors; GPS surveys can be conducted outdoors only,
as GPS receivers cannot receive location data when indoors.
Before you begin, spend some time thinking through your walkabout path. Decide which areas you need
to survey and how you are going to do that. Remember that it is quite all right to mix the three data
collection modes—that is, you can survey some areas where walking steadily in a straight line is not a
problem in continuous mode; you can then survey other areas in point-by-point mode, and then survey
the area outside the building in GPS mode. You can also stop the survey at any moment and continue
after a break, as you can select several survey segments for data analysis. Once you have thought through
your walkabout path, begin the actual survey.
TamoGraph allows you to perform two types of surveys: active and passive (or both at the same time).
Every time you start data collection, you will be prompted to select the type of survey, as shown below.
20
Performing a Site Survey | TamoGraph Site Survey
It is extremely important to understand the difference between the two survey types, as they focus on
different WLAN characteristics. Please refer to Understanding Survey Types: Passive, Active, and
Predictive for more information. When performing an active survey, an additional configuration dialog is
displayed before you can start data collection. This dialog is explained in the Active Survey Configuration
chapter. Additionally, when a compatible spectrum analysis device is connected to the computer, you will
be able to collect spectrum data either in parallel with a passive survey (the first dialog option will be titled
Passive Survey + Spectrum Survey) or in spectrum-only mode (another option titled Spectrum Survey will
be added to the dialog).
Continuous Mode: To start data collection, click on the Start button (illustrated on the left) and then mark
your initial location on the map by clicking on the corresponding spot. Walk along the planned path
at a steady pace in a straight line. You should walk a bit slower than you normally do. Every
time you reach the end of the straight line on your path (i.e., every time you need to change
direction), click on the map again to mark your current location. Data collection stops when you click on
the Stop button (illustrated on the right.) If you want to suspend data collection temporarily without
stopping your current survey (e.g. when you want to answer a phone call and then continue), click
on the Pause button (illustrated on the left) to pause the survey and then click it again to resume.
Important: if you paused the survey, you can move freely, but you must return to the exact location
where you paused the survey before you resume it, otherwise your survey data will be invalid.
Point-by-Point Mode: To start data collection, click on the Start button. Mark your location on the map
by clicking on the corresponding spot. TamoGraph will collect data by scanning the channels twice and
display a notification at the bottom of the window when all the data has been collected. Proceed to the
next point on your path and mark your location again. Repeat until you have surveyed all the planned
points. Data collection stops when you click on the Stop button.
GPS Mode: To start data collection, turn on your GPS receiver, connect it to your computer, and then click
on the Start button. Your current location will be displayed on the map with a circle. Make
sure that the displayed location matches your actual location. If it does not, you made a
mistake while calibrating the map with reference points, and you need to re-calibrate the map. Walk or
drive slowly along the planned path. The slower you drive, the more Wi-Fi data will be collected, and the
more accurate the data analysis will be. GPS surveys can be conducted outdoors only, in open areas where
a GPS receiver can see many satellites. Location data accuracy is directly related to the number of satellites
in view. As you move along the path, location data accuracy is indicated on the application status bar, as
21
Performing a Site Survey | TamoGraph Site Survey
shown on the illustration. If location data accuracy becomes poor, you may want to stop the survey until
more satellites become visible to the receiver (you can click on the data accuracy indicator to display the
GPS receiver configuration dialog that displays accuracy level and visible satellites). Data collection stops
when you click on the Stop button.
When you are through with the survey, you can proceed to the data analysis of a passive and/or active
survey. However, before you do, it is recommended that you read the next three chapters, especially if
you are new to Wi-Fi site surveys. They provide important information about the available types of
surveys, their purpose, as well as some valuable tips and tricks to make your site surveying more efficient.
Understanding Survey Types: Passive, Active, and Predictive
There are three types of surveys that you can conduct in TamoGraph: passive, active, and predictive.
During a passive survey, the application collects the most comprehensive data on the RF environment:
information on access points and their characteristics, signal strength, noise level, interference, etc. This
is the default and most important survey type that we recommend to conduct for every project. If you
need more insight into the real-world performance of your WLAN, TamoGraph can also perform an active
survey. During active surveys your Wi-Fi adapter connects to the wireless network(s) of your choice and
the application generates network traffic to measure actual throughput rates and a few other metrics. In
addition to the surveys based on actual on-site measurements, TamoGraph can be used for planning
WLANs that have not been deployed yet. This type of survey is called predictive, because Wi-Fi
characteristics are predicted for the virtual environment model created by the user. The virtual model
includes walls and other obstructions, as well as virtual APs placed by the user. In other words, it is a
computer simulation. No on-site measurements are conducted.
The table below summarizes the distinctions between the two survey types. Please read this information
carefully to make sure you fully understand which survey type you need.
When to conduct
Hardware
requirements
Additional
software
configuration
requirements
22
Passive Surveys
Highly recommended at all
times.
The
most
comprehensive survey type
that covers the most
important
WLAN
characteristics and metrics.
On Windows, a compatible
wireless adapter is required.
For the up-to-date list of
compatible adapters, please
visit our Web site. On
macOS, no specific adapter is
required; the application will
work with the built-in
adapter of your MacBook.
None
Active Surveys
Optional. Conduct when
measurement of real-world
performance characteristics
of your WLAN is required.
Predictive Surveys
Optional. Conduct before
deployment to plan your
WLAN and simulate its
characteristics.
On Windows, virtually any
modern wireless adapter
with the latest drivers
supplied by the adapter
vendor will work. On macOS,
no specific adapter is
required; the application will
work with the built-in
adapter of your MacBook.
You must create a Windows
profile for the WLAN you
plan to test. On macOS, the
WLAN you plan to test must
be listed under Preferred
Networks. If you plan to
measure TCP and/or UDP
throughput, you must also
run the throughput server
A fast multi-core CPU. Intel i7
is highly recommended. No
wireless adapter is required.
Performing a Site Survey | TamoGraph Site Survey
None
How data is
collected
The application passively
listens for packets and does
not attempt to connect to
WLANs.
Available
visualizations
Signal Level
Signal-to-Noise Ratio
Signal-to-Interference Ratio
AP Coverage Areas
Number of APs
Expected PHY Rate
Frame Format
Channel Bandwidth
Requirements
List of APs and
their
characteristics is
available
Yes
utility on the wired side of
your WLAN.
The application connects
your Wi-Fi adapter to the
wireless network(s) of your
choice to measure actual
throughput rates and a few
other metrics.
Actual PHY Rate
TCP Upstream Rate *
TCP Downstream Rate *
UDP Upstream Rate *
UDP Downstream Rate *
UDP Upstream Loss *
UDP Downstream Loss *
Round-trip Time
Associated AP
Requirements
No
No on-site data collection is
performed. Data is simulated
based on the virtual
environment
that
you
created.
Same as for passive surveys
Yes
Surveys can be
conducted
simultaneously
On Windows – yes. You can conduct a simultaneous Active + Not applicable
Passive survey if your computer is equipped with two
different Wi-Fi adapters. One of them must be compatible
with passive surveys; for the up-to-date list of compatible
adapters, please visit our Web site. On macOS – no.
* When using advanced mode with a throughput server utility connection. See Survey Type Selection for more info.
As mentioned above, some additional software configuration is required when performing an active
survey. The next chapter provides detailed information on how to configure TamoGraph for an active
survey.
23
Performing a Site Survey | TamoGraph Site Survey
Active Survey Configuration
When you click the Active Survey or Active + Passive button in the survey type selection dialog, an
additional configuration dialog is displayed as shown below.
This dialog allows you to configure TamoGraph for an active survey you are about to conduct.
Adapter Selection
The adapter selection section can be used to specify which Wi-Fi adapter to utilize for an active survey
and which one for the passive survey (if you are conducting both survey types simultaneously, in the
Active + Passive mode.)

If your computer has only one Wi-Fi adapter, you cannot change the default selection; that
adapter will be used for the active survey.

If your computer has two Wi-Fi adapters and you are conducting both survey types
simultaneously, in the Active + Passive mode, you cannot change the default selection, either;
the adapter that is compatible with passive surveys will be used for the passive part of the survey,
while the other adapter will be used for the active part of the survey.
24
Performing a Site Survey | TamoGraph Site Survey

If your computer has two Wi-Fi adapters and you are conducting an active survey only, you can
select either of the two adapters. We recommend that you use the integrated adapter for active
surveys. For example, if your laptop comes with an integrated Wi-Fi Intel adapter and you also
use a Wi-Fi USB adapter, select the integrated Intel adapter.
Please keep in mind that the WLAN metrics that are measured during an active survey depend on the
capabilities of your adapter. If your adapter's capabilities are inferior to the capabilities of your WLAN,
this will be reflected in the results obtained during the survey. For example, if your APs support the
802.11n standard with the maximum rate of 300 Mbps, whereas your Wi-Fi adapter is a legacy 802.11g
device with the maximum rate of 54 Mbps, the measured PHY rate and throughput rates will never exceed
54 Mbps, thereby giving you an underrated picture of the WLAN performance.
Connection Mode Selection
There are two connection methods for performing active surveys: the SSID method and the MAC address
method (also frequently referred to as the “BSSID method”).
1. The SSID method allows the client to associate to the selected SSID and roam between multiple
APs that share the selected SSID. This mimics real-world client roaming behavior. Note that some
adapters let you adjust roaming thresholds; these roaming settings might affect the performance
data.
2. The MAC address method locks a client into the MAC address of the AP and prevents the client
from roaming. This allows you to analyze the connectivity zone and performance metrics of a
single AP.
Note that for the MAC address method to work, support of this functionality is required from the
operating system and the driver. The combination of the adapter model, OS, and the driver
determine whether this method will work. If TamoGraph notifies you that this method is not
supported, use the SSID method and create a temporary SSID specific to a single AP, which will let
you bypass this problem.
Which of the two methods you choose depends on the specific purposes of your survey. The first method
is typically used in post-deployment scenarios, while the second one is typically used on the deployment
stage. If you use the first method, select the desired SSID from the drop-down list. If your WLAN doesn't
broadcast its SSID, select the <Non-broadcast SSID> item and you will be prompted to choose the network
profile for that WLAN at a later stage. If using the second method, select the desired AP from the dropdown list.
Because performing active surveys involves a full association to a WLAN, you must properly configure
security settings prior to the survey. Be sure to follow this checklist:

When TamoGraph is not running, make sure that the client adapter you plan to use for active
surveys can connect to the AP(s) and/or SSIDs you plan to connect to during an active survey. This
must be a single-click connection right from the Wi-Fi system icon of Windows or macOS. You
must not be prompted for any additional credentials. If a username or password is required, they
must be cached by Windows/macOS. If other authentication, such as a smart card, is required, it
too must be performed without requiring any user input.
25
Performing a Site Survey | TamoGraph Site Survey

Using third party authentication supplicants is not supported; the OS must be able to complete
authentication by itself. In other words, a valid network profile for the given WLAN and the
selected client adapter must exist in the OS.

Sometimes existing WLAN security configuration does not allow you to associate under the
conditions described above. In such cases, we suggest that you create a temporary SSID with no
or WPA-PSK security. Create a firewall rule to prevent clients using that temporary SSID from
accessing any important intranet resources and delete that temporary SSID when you are done
with the survey.
Survey Type Selection
Once an active survey has been started and the client associated to a WLAN, TamoGraph begins to
measure client performance. You can select the Basic or Advanced active survey type.
In the Basic mode, the client sends pings to the computer on the wired side of the network at the specified
IPv4 or IPv6 address. This mode is the easiest to configure: Simply enter the IP address of a host that can
respond to ping packets (this may be a computer or other ping-capable type of hardware, e.g., an AP.)
Make sure that the firewall rules on the client side and the host side permit ping (also known as ICMP)
request and response packets. The drawback of the Basic mode is that no data throughput measurements
can be performed. Only the following visualizations will be available: Actual PHY Rate, Round-trip Time,
Associated AP, and Requirements.
In the Advanced mode, TamoGraph connects to a throughput test server utility on the wired side of the
network at the specified IPv4 or IPv6 address and port. During the survey, TamoGraph is continuously
sending and receiving packets to/from the server utility and records performance data. This mode is a bit
more difficult to configure, but you get much more data as a result of throughput testing. In addition to
the Actual PHY Rate, Round-trip Time, Associated AP, and Requirements visualizations, you also get TCP
Upstream and Downstream Rate, UDP Upstream and Downstream Rate, and UDP Upstream and
Downstream Loss.
The only additional step required to use the Advanced mode is copying the throughput test server utility
from the computer where TamoGraph is installed to the host on the wired side of the network and running
the utility. On Windows, the utility executable file can be found at C:\Program
Files\TamoGraph\ThroughputTest\TTServer.exe on 32-bit Windows or C:\Program Files
(x86)\TamoGraph\ThroughputTest\TTServer.exe on 64-bit Windows. Copy this file to a host running
Windows and launch the file. You will see the utility window as shown below.
26
Performing a Site Survey | TamoGraph Site Survey
Alternatively, the throughput test server utility for Windows or macOS can be downloaded from our Web
site at http://www.tamos.com/products/throughput-test/. It is part of our freeware product, TamoSoft
Throughput Test. Install the product and use the Run Server command.
In the Active Survey Configuration dialog, select the protocols you want to test: TCP (default) or TCP+UDP,
if you are interested in UDP performance metrics, too. Advanced users may want to change the QoS traffic
type (described in the next chapter.)
You are now ready to start an active survey. Always start active surveys when you are close to the AP your
client will connect to, in the area where the signal level is high. This will allow the application to quickly
validate the settings and start data collection. DO NOT start active surveys in the areas where the signal
level is insufficient for stable connectivity. Click Verify and Start to proceed.
QoS Testing
If you are not an advanced user and not familiar with the concept of QoS, you do not need to read this
chapter; just leave the default Best Effort selection in the QoS traffic type control and begin the survey.
Advanced users might want to use the QoS traffic type control to specify the Quality of Service traffic type
that will be associated with the TCP and UDP data streams that are sent and received by the application.
A description of the use of QoS and related standards and technologies, such as WMM, 802.11e, DSCP,
and 802.11p, is beyond the scope of this manual, but in brief, you might want to use this functionality to
check how different QoS traffic types affect throughput. In a properly designed WLAN that uses
enterprise-class APs, throughput values for high-priority traffic should exceed those for normal-priority
traffic.
The table below summarizes different QoS traffic types that may be used. Please pay attention to the fact
that not all the QoS types available in the application and described below have corresponding WMM
access categories. In practice, this means that when you select a QoS type that has no WMM mapping,
your Wi-Fi adapter driver might fail to QoS-tag packets at all.
QoS Type
27
Description
Performing a Site Survey | TamoGraph Site Survey
Best Effort
Background
Flow traffic has the same network priority as regular traffic not associated with
QoS.
This traffic type is the same as not specifying priority, and as a result, the DSCP
mark and 802.1p tag are not added to sent traffic. Corresponds to the WMM
AC-BE access category.
Flow traffic has a network priority lower than that of Best Effort. This traffic
type could be used for traffic of an application doing data backup.
Excellent Effort
Sent traffic will contain a DSCP mark with a value of 0x08 and an 802.1p tag
with a value of 2. Corresponds to the WMM AC-BK access category.
Flow traffic has a network priority higher than Best Effort, yet lower than
AudioVideo. This traffic type should be used for data traffic that is more
important than normal end-user scenarios, such as e-mail.
AudioVideo
Sent traffic will contain a DSCP mark with value of 0x28 and 802.1p tag with a
value of 5. This does not correspond to any WMM access category.
Flow traffic has a network priority higher than Excellent Effort, yet lower than
Voice. This traffic type should be used for A/V streaming scenarios such as
MPEG2 streaming.
Voice
Sent traffic will contain a DSCP mark with a value of 0x28 and an 802.1p tag
with a value of 5. Corresponds to the WMM AC-VI access category.
Flow traffic has a network priority higher than AudioVideo, yet lower than
Control. This traffic type should be used for real time voice streams such as
VOIP.
Control
Sent traffic will contain a DSCP mark with a value of 0x38 and an 802.1p tag
with a value of 7. Corresponds to the WMM AC-VO access category.
Flow traffic has the highest network priority. This traffic type should only be
used for the most critical of data. For example, it may be used for data carrying
user inputs.
Sent traffic will contain a DSCP mark with a value of 0x38 and an 802.1p tag
with a value of 7. This does not correspond to any WMM access category.
Best Practices, Tips, and Tricks

If the WLAN being surveyed has SSID broadcasting disabled, enable it for the duration of the
survey, if possible. This will facilitate the identification of the APs you would like to have included
in the data analysis.

Fully charge your laptop and be prepared to recharge it. Having an extra battery on hand would
not hurt. However, if your laptop goes into standby or hibernation while you are performing a
survey, TamoGraph will save the data and stop the active survey. You will be able to continue
where you stopped.

When you conduct GPS surveys, the survey process is fully automated; normally you do not need
to touch any application controls, so you may want to close the laptop lid. If you plan to close the
lid, be sure to configure the laptop power settings to prevent the laptop from going into standby
or hibernation when you close the lid.
28
Performing a Site Survey | TamoGraph Site Survey

Plan your walkabout path in advance. You may want to write down numbers on the site map
marking your path. Then, while surveying, you would just have to walk along the path and click
on these numbers. When planning your path, be sure to plan it so that you capture the perimeters
of the rooms rather than their center. This improves data quality.

If you care about signal leakage outside the building, plan your path along the outside building
perimeter. Without this perimeter, TamoGraph will not be able to estimate the signal strength
outside the walls.

Be sure to cover places of special importance, such as conference rooms or the CEO's office.
Survey them with closed doors. Closed doors may considerably decrease the signal level, so
surveying with open doors may give you a signal coverage map that is too optimistic.

If the site is large, consider splitting the site map into several parts, as working with smaller maps
is easier. Besides, the report generated by TamoGraph will be more meaningful if separate maps
are used for separate zones. A large map just will not be legible if has to be displayed on one page.
You can have as many maps as you wish in a single TamoGraph project. The same applies to multifloor buildings.

If the site is large, you can also split the job between several people sharing the same project. The
correct way of doing this is described in the Survey Job Splitting chapter.

If you are going to survey a large facility with many employees during business hours, make an
announcement telling them that someone will be conducting a survey. Ideally, this will prevent
them from distracting you with questions.
29
Performing a Site Survey | TamoGraph Site Survey
Survey Job Splitting
While performing surveys of large sites, it is sometimes convenient to split the data collection process
between several employees who would walk the site independently, each of them surveying a separate
area. Once the data has been collected, the separate surveys can be merged into a single project. Using
TamoGraph, you can easily organize this mode of operation, as explained below.
If you plan to perform a site survey alone, using a single laptop, you do not need to read this chapter.
Step 1
Create a new project and calibrate the map. Save the project and copy the project file to the portable
computers that will participate in the data collection process. The computer that is used for creating the
project does not necessarily have to be equipped with a compatible wireless adapter. It can be a desktop
computer.
Step 2
Open the project file in TamoGraph on each of the portable computers to which you copied the project
file. Discuss how to split the survey job between your associates and assign different areas of the site map
to them so that each of them surveys a separate area.
Step 3
Using the portable computers, your associates can now walk the site and survey the designated areas.
When the area is fully surveyed, save the project and then click Survey => Export Survey Data in the main
application menu. A dialog box will appear, and the user will be able to select the survey path(s) to be
exported. Click Export to save the data to a file with the .SSTRACK extension.
Step 4
Copy the survey data files created on the portable computers back onto the main computer. Open the
project that you used for the job splitting in Step 1. Click Survey => Import Survey Data in the main
application menu, select the SSTRACK file to import, and then select the survey path(s) to be imported.
Repeat this for all the SSTRACK files you copied from the portable computers.
Step 5
The Plans and Surveys tab on the right panel now contains all the survey paths that were created by the
different users who surveyed the site in parallel. Save the project. You are now ready to analyze the data
as normal.
Tips and Tricks
When you analyze the data collected by other computers, you typically do not need TamoGraph to scan
Wi-Fi channels (if the computer is equipped with a wireless adapter) or display the driver installation guide
(if the computer is not equipped with a wireless adapter). To turn off the scanner and prevent the driver
installation guide from appearing, launch TamoGraph with the /scanneroff command line switch.
30
Survey Job Splitting | TamoGraph Site Survey
Predictive Surveys
IMPORTANT: Predictive Surveys are available to Pro License users only.
In addition to the surveys based on actual on-site measurements, TamoGraph can be used for planning
WLANs that have not been deployed yet. This type of survey is called “predictive” or “virtual,” because
Wi-Fi characteristics are predicted for the virtual environment model created by the user. The process of
creating and adjusting the virtual environment, selection and placement of simulated APs, and analysis of
the resulting WLAN is commonly referred to as “RF planning.”
To perform a predictive site survey, you need to




Create a new project with the help of the Project Wizard.
Calibrate the floor plan or site map.
Configure the survey options and WLAN requirements.
Create a model of the environment. This includes placing walls and other obstructions on the floor
plan, as well as placing APs and editing their properties.
To create a virtual model of the environment, the user needs to “tell” the application about the position,
size, and type of the physical objects that affect radio wave propagation. Typically, walls and other
obstructions, such elevator shafts, are already shown on floor plans; however, these are merely lines and
dots that are meaningless to the application. The user has to draw such physical objects on top of the
floor plan and define their characteristics.
31
Predictive Surveys | TamoGraph Site Survey
To start creating a virtual model, press the RF Planner button on the tool bar. This will show an additional
tool bar with a few drawing tools. It is recommended to begin by drawing walls. Once the walls have been
drawn, you can place APs on the floor plan, decide how many APs you need to provide adequate coverage,
select the best positions for the APs, and configure their parameters (channel numbers, rates, antennas,
etc.)
Once you have completed this process, you can analyze data as you normally do after a passive survey. If
you are a novice in WLAN design, we also suggest that you read about Best Practices, Tips, and Tricks at
the end of this chapter.
IMPORTANT: You must always verify that your WLAN design works as expected by conducting a
real survey after deploying your WLAN. Predictive surveys cannot take into consideration all the
factors that might affect real-world WLAN performance and therefore cannot fully substitute onsite surveys.
Drawing Walls and Other Obstructions
To draw a wall or other obstructions (e.g., doors or windows) on the floor plan, press the wall drawing
tool button and select one of the pre-defined wall types, for example “Brick wall” or “Interior office
window.” You should select the type that best matches the actual wall you are going to draw. You can
also select one of the two drawing modes: Line or Polygonal path. If you selected the Line mode, left-click
on the floor plan to start a new wall and left-click once again in a new location to finish the wall. A straight
line representing the wall will be drawn. If you selected the Polygonal path mode, left-click on the floor
plan to start a new wall and left-click every time you need to start a new line segment. This will draw a
connected series of line segments. If you hold the CTRL key while drawing walls, the line is drawn in
orthogonal mode (0, 90, 180, or 270 degrees). If you need to cancel the previous move, right-click on the
shape and select Undo Last Segment in the context menu. To finish the wall, click on the last point or
press the ESC key. You can move or resize the walls that you have drawn. To move a wall, select it and
drag it with the left mouse button to a new position. To resize a wall or wall segment, select it, move the
mouse over the vertex (shown as a white circle), click on it, and drag it with the left mouse button to a
new position.
After the wall has been drawn, you can change its properties in the Obstruction Properties dialog. To
display this dialog, double-click on a wall or select the Properties context menu item. In the dialog
window, you can change the obstruction type by selecting one of the existing presets or modify
obstruction characteristics such as attenuation, reflection, or color. Attenuation is a drop in strength
measured in dB that the RF signal experiences when it passes through the obstruction. Because materials
might attenuate differently at different frequencies, there are two separate attenuation values for 2.4
and 5 GHz. You can enter a custom attenuation value. A custom value can be obtained by measuring signal
strength on each side of the obstruction and calculating the difference. Measurements can be performed
using TamoGraph or any WLAN analyzer, e.g., CommView for WiFi. Reflection is a percentage of signal
strength that is reflected by the obstruction at the 90° angle. Color is an arbitrary color used to show the
obstruction on the floor plan. If you prefer obstructions to appear colorless (i.e., grayscale), you can
configure the application to grayscale them in the Visualization Settings panel. When you have edited
obstruction properties, you can save the current configuration for future use by clicking the Save as Preset
button at the bottom of the dialog window.
32
Predictive Surveys | TamoGraph Site Survey
Drawing Attenuation Zones
An attenuation zone is an area where the signal strength drops over distance. This makes it different from
walls and other obstructions, where the drop occurs only one time, when the signal passes through a
specific object, and where the object thickness is negligible. To draw an attenuation zone on the floor
plan, press the attenuation zone drawing tool button and select one of the pre-defined attenuation zone
types; for example “Elevator shaft” (there is also a zone type titled “Floor Area” that is not an attenuation
zone per se; we will talk about this in the Working with Multi-floor Sites chapter). You should select the
type that best matches the actual attenuation zone you are going to draw. You can also select one of the
two drawing modes: Rectangle mode or Polygon mode. A rectangle is defined by its top left and bottom
right corners; it is aligned vertically/horizontally and cannot be rotated. Polygons consist of multiple line
segments, allowing more complex shapes to be created. If you selected Rectangle mode, left-click on the
floor plan to start a new zone, drag the mouse to form a rectangle, and release the left mouse button to
finish. If you selected Polygon mode, left-click on the floor plan to start a new zone and left-click every
time you need to start a new line segment. This will draw a connected series of line segments. If you hold
the CTRL key while drawing, the line is drawn in orthogonal mode (0, 90, 180, or 270 degrees). If you need
to cancel the previous move, right-click on the shape and select Undo Last Segment in the context menu.
To finish the zone, click on the last point, or press the ESC key, or click Done on the info panel below the
floor plan. You can move or resize the zone borders that you have drawn. To move a zone, select it and
drag it with the left mouse button to a new position. To resize a zone or zone segment, select it, move the
mouse over the vertex (shown as a circle), click on it, and drag it with the left mouse button to a new
position.
After the zone has been drawn, you can change its properties in the Attenuation Zone Properties dialog.
To display this dialog, select a zone and double-click on it, or select the Properties context menu item. In
the dialog window, you can change the zone type by selecting one of the existing presets or modify zone
characteristics such as attenuation or color. Attenuation is a drop in strength measured in dB per meter
(or foot, depending on the measurement units of your project) that the RF signal experiences when it
moves across the zone. Because materials might attenuate differently at different frequencies, there are
two separate attenuation values for 2.4 and 5 GHz. You can enter a custom attenuation value. A custom
value can be obtained by measuring signal strength on each side of the zone, calculating the difference,
and dividing it by the distance. Measurements can be performed using TamoGraph or any WLAN analyzer;
e.g., CommView for WiFi. Color is an arbitrary color used to show the zone on the floor plan. If you prefer
zones to appear colorless (i.e., grayscale), you can configure the application to grayscale them in the
Visualization Settings panel. When you have edited zone properties, you can save the current
configuration for future use by clicking the Save as Preset button at the bottom of the dialog window.
Virtual APs Placement Methods
Two AP placement methods are available: manual and automatic. If you use the manual method, you add
virtual APs and select their locations yourself. The number of APs to place, capacity considerations, signal
levels, and all other WLAN requirements are the responsibility of the user. If you use the automatic
method, you let the application decide where to place APs given the requirements (e.g., the number of
APs needed to cover each point, client capacity, etc.). The advantage of the manual method is in its utmost
flexibility: you are in full control of the process. At the same time, this method requires experience in
designing WLANs and may be rather time-consuming. Automatic placement is much simpler and faster,
but the output of even the most advanced algorithm may not be ideal; AP positions may still require
33
Predictive Surveys | TamoGraph Site Survey
manual adjustments. Additionally, when you manually place and configure APs, you can select different
AP models and/or antenna types; with automatic placement, all the APs must be exactly the same.
Manual Placing and Configuring Virtual APs
To place an AP on the floor plan, press the AP drawing tool button and select one of the pre-defined AP
types; for example “Generic 802.11n (2.4 GHz)” or “Generic dual band 802.11n.” Click on the floor plan to
place an AP in a desired location. After that, you can change its properties by double-clicking on the AP or
by selecting the Properties context menu item. The AP Properties dialog can be used for loading AP
characteristics from one the presets, assigning a unique name to the AP, or for customizing AP
characteristics. Virtual AP icons are marked with a small blue “V” in the icon corner so that you could
distinguish between real and virtual APs.
To customize an AP, you can use two tabs: one for Radio #1 (typically 2.4 GHz) and one for Radio #2
(typically 5 GHz). Some newer APs can work in “two 5 GHz radios” mode, in which case you can configure
both radios to use 5 GHz. These tabs allow you to turn on and off these radios independently (using the
Radio enabled check box) and configure the following characteristics for each of the two radios:








Standard. Use this drop-down list to select one of the 802.11 standards. For Radio #1, select
802.11n or one of the 2.4 GHz legacy standards (or even 802.11ac, if your AP works in “two 5 GHz
radios” mode.) For Radio #2, select 802.11ac, 802.11an, or 802.11a.
Channel width. If the selected standard allows channel bonding, then select one of the available
channel widths: up to 40 MHz for 802.11n and up to 160 MHz for 802.11ac.
Channel / Channel set. Select a single channel if the channel width is set to 20 MHz or a set of
channels if the channel width is greater than 20 MHz.
MAC address. You can change the MAC address to your AP. This is typically not necessary because
the application always assigns unique MAC addresses to the APs.
SSID. Use this field to assign an SSID to the AP. The same SSID may be shared by several APs.
Power. Use this drop-down list to select the AP transmit power. Most of APs have a transmit
power of 17 dBm (50 mW). It is always a good idea to refer to the documentation of the specific
AP model you plan to deploy to find this value. Remember that transmit power might depend on
the channel frequency and band.
HT / VHT Parameters. Use this frame to control the advanced 802.11n (HT) or 802.11ac (VHT)
parameters: primary channel number, number of spatial streams, short guard interval, and
supported rates. The Supported Rates dialog can be used to specify the legacy and HT /VHT rates
supported by the AP. It is a common practice to disable some or all of the legacy rates when you
plan a WLAN for performance rather than coverage.
Antenna settings. Use this frame to specify the kind of antenna used by the AP. You can choose
one of the antenna models by major Wi-Fi equipment vendors or one of the generic antenna
types. With the Rotation control, you can specify the angle (in degrees) relating to the horizontal
positioning of the antenna. With the Elevation control, you can specify the angle (in degrees)
above the horizon, i.e., the angle by which the antenna is tilted up or down in relation to the
theoretical horizon. With the Tilt control, you can specify the angle (in degrees) relating to the
vertical axis, i.e., the angle by which the antenna is tilted sideways. The Height control can be
used to specify the height of the AP above the floor level. The Advanced dialog provides top, front,
right, and 3D views of the selected antenna diagram and can be used to adjust the antenna
orientation either by rotating the diagram top, front, or right views or by entering numeric values.
34
Predictive Surveys | TamoGraph Site Survey
When you have edited AP properties, you can save the current configuration for future use by clicking the
Save as Preset button at the bottom of the dialog window.
Automatic Placing and Configuring Virtual APs
Note that currently automatic AP placement functionality is implemented on a per-floor basis
only. If you are working with a multi-floor project, APs from adjacent floors will not be taken into
account when you run the auto-placement wizard. The wizard should be run for each floor.
Before you can auto-place virtual APs on the floor plan, you need to draw one or several areas where you
plan to deploy the APs and where you want to have Wi-Fi coverage; this will determine future AP
positions. You can also optionally define the number and types of WLAN clients for each area, and, finally,
run the auto-placement wizard.
Drawing Deployment and Coverage Areas
To draw a deployment or coverage area on the floor plan, press the deployment or coverage drawing tool
button on the RF Planner toolbar:
Select one of the pre-defined types:

Deployment Area – the area that can be used for deploying APs. Some areas in your office might
not be suitable for AP mounting, in which case you may want to draw one or several deployment
areas that do not cover the areas where AP mounting is undesirable.

Coverage Area – the area where you need to have Wi-Fi coverage. Some areas in your office, for
example bathrooms or staircases, might not need Wi-Fi coverage, in which case you can draw
coverage areas that do not cover bathrooms or staircases.

Deployment and Coverage Area – when deployment and coverage areas fully overlap, you can
draw the combined “deployment + coverage” area.
You can also select one of the two drawing modes: Rectangle mode or Polygon mode. A rectangle is
defined by its top left and bottom right corners; it is aligned vertically/horizontally and cannot be rotated.
Polygons consist of multiple line segments, allowing more complex shapes to be created. If you selected
the Rectangle mode, left-click on the floor plan to start a new area, drag the mouse to form a rectangle,
and release the left mouse button to finish. If you selected the Polygon mode, left-click on the floor plan
to start a new area and left-click every time you need to start a new line segment. This will draw a
connected series of line segments. If you hold the CTRL key while drawing, the line is drawn in orthogonal
mode (0, 90, 180, or 270 degrees). If you need to cancel the previous move, right-click on the shape and
select Undo Last Segment in the context menu. To finish the area, click on the last point, or press the ESC
key, or click Done on the info panel below the floor plan. You can move or resize the area borders that
you have drawn. To move an area, select it and drag it with the left mouse button to a new position. To
35
Predictive Surveys | TamoGraph Site Survey
resize an area or area segment, select it, move the mouse over the vertex (shown as a circle), click on it,
and drag it with the left mouse button to a new position.
Configuring WLAN Clients
After the area(s) have been drawn, you may want to configure the number and types of WLAN client
devices that you plan to service. This step is optional. When you run the auto-placement wizard
(overviewed below), you will be prompted to select one of the three WLAN planning methods: for
Coverage, for Capacity (simple), and for Capacity (advanced). The number and types of WLAN client
devices will be taken into account only if you use the Capacity (advanced) method. To add clients, rightclick on a coverage or deployment + coverage area and select Properties or simply double-click on the
area.
A Coverage Area Properties dialog will be displayed:
On the right side, you can see the list and number of clients that are currently configured for the given
area. When you open this dialog for the first time, this list is empty. To add clients to the area, use the list
on the left side: select one of the available client types and use the arrow button to move it to the right
side or simply drag it to the right side. Once the new client type appears on the right side, select the item
and change the Quantity value to reflect the actual number of clients that you want to service in this area.
Each pre-defined client type is associated with a number of typical applications. For example, Generic
smartphone/tablet may use an e-mail client and VoIP client, but not Web browsing with access to heavy
media content. To edit the applications associated with a client type, double-click on the client type or
click the Edit client template button. To add a new client type, click the New client template button. The
following dialog will be displayed:
36
Predictive Surveys | TamoGraph Site Survey
In this dialog, you can configure the Name for the client type being edited, as well as the 802.11
characteristics of the client adapter, namely Supported standards, Channel width, and the number of
Spatial streams. On the right side of the dialog, you can configure typical associated Applications by
checking or unchecking the corresponding check boxes. Each application has a set of requirements that
you can edit by double-clicking on the application item or by clicking the Edit application template button.
To add a new application type, click the New application template button. The following dialog will be
displayed:
37
Predictive Surveys | TamoGraph Site Survey
Use this dialog to configure the requirements for the selected application, or, if you are creating a new
application, for a new one.
Once you have configured WLAN clients for all of your coverage areas, you can run the auto-placement
wizard to place access points automatically.
Using the Auto-Placement Wizard
The auto-placement wizard is a tool for the automatic placement of access points in the predictive
modeling process. It is an alternative to manual AP placement. The difference between the two is
overviewed in the Virtual AP Placement Methods chapter. To run the wizard, click on the Auto-place APs
button on the RF Planner toolbar. You will be prompted to select one of the three WLAN planning
methods:

Coverage – Use this option to optimize your WLAN for coverage. It is assumed that the APs'
capacity is adequate for the number of clients connected to the WLAN. The wizard will try to make
sure that the entire area is covered by Wi-Fi without considering the number and type of clients
that will be using the WLAN.

Capacity (simple) – Use this option to optimize your WLAN for capacity to provide sufficient
resources for client servicing and load balancing on a site-wide basis. To proceed, you need to
estimate the number of APs that will service your site and enter the estimated value into the Total
number of APs to deploy field.

Capacity (advanced) – Use this option to optimize your WLAN for capacity to provide sufficient
resources for client servicing and load balancing on a per-zone basis. The wizard will try to make
sure that each coverage area is covered by Wi-Fi taking into consideration the number and type
of clients that you have assigned to each area.
After clicking Next, you will be prompted to select the type of APs to be deployed. You can select from
one of the presets by clicking Load Preset or use the configuration options on that page. Be sure to use
the parameters, such as Power, Spatial streams, and Antenna type, that best match the actual APs that
you plan to deploy. If you check Some 2.4 GHz radios can be disabled, the algorithm may turn off 2.4 GHz
radios of some of your dual-band virtual APs to reduce co-channel interference while still meeting the
requirements for coverage and redundancy.
One of the most important parameters to configure is the Channel width. In virtually all high-density
enterprise deployments, you should use 20 MHz channels. There are very few use cases for 40 MHz
channels in the 5 GHz band. Unless the use case is a small branch office or home, with clean spectrum, do
not use channels wider than 20 MHz in the 5 GHz band. In the 2.4 GHz band, the rule of thumb is to never
use 40 MHz channels; there is simply no room left for channel re-use in the 2.4 GHz band if you use 40
MHz channels.
The next page allows you to select specific channel plans for your 2.4 GHz and 5 GHz radios.
38
Predictive Surveys | TamoGraph Site Survey
For 2.4 GHz, we recommend channels 1-6-11 in the regulatory domains where 11 channels are allowed,
or 1-7-13 in the regulatory domains where 13 channels are allowed. As a backup option, you may want to
use 1-4-7-11 and 1-5-9-13, respectively; however, these setups are by no means recommended, because
if you use four 20 MHz channels, a channel overlap is inevitable. For 5 GHz, your choice of channels is
dictated by two key factors: the regulatory domain and the set of channels supported by your APs and
clients. Before you select channels, first verify which of them are allowed in your regulatory domain.
Second, if you want to use DFS channels, verify that hardware supports them; in some APs and clients,
DFS channels are disabled.
On the next page of the wizard, you need to specify two key Coverage requirements (note that this page
is not shown if you have selected Capacity (advanced) as the WLAN planning method). The Minimum
number of APs that must provide coverage in each point value is used to determine the number of APs
used for redundancy and seamless roaming. The With the signal level of at least field is used to determine
the minimum signal level in dBm provided by the APs in each point of the coverage area. It is important
to note that the requirements may or may not be the same for the 2.4 and 5 GHz bands. For example, you
may want to require -67 dBm in the 5 GHz band for your modern VoIP-enabled smartphones and tablets,
but only -75 dBm for legacy 2.4 GHz devices. If you want to have the same requirements for both bands,
use the chain-link button to make the requirements interlocked.
On the final page, you need to select the Computation method to be used: Standard or High precision.
The first method uses a standard mathematical model for a quick AP placement computation. It is
recommended for large WLANs with dozens of APs. The second method uses a much more complex model
for a very detailed and precise AP placement computation. Because of the amount and complexity of
mathematical computations being used in this method, the process might take a long time, especially if
you are not running the program on a high-end, multi-core CPU. That is why this method is recommended
only for small and medium-sized WLANs.
39
Predictive Surveys | TamoGraph Site Survey
Click Done to begin the automatic AP placement computations. If you do not like the result, press Ctrl + Z
to revert to the previous state.
Reconfiguring Virtual APs
In addition to automatic AP placement for new deployments where no virtual APs have been placed
(discussed in the previous chapter), TamoGraph allows you to reconfigure an existing predictive model.
The purpose of such reconfiguration is to optimize the channel allocation of the existing virtual APs and/or
to adjust their output power levels to make sure that your existing virtual APs meet the new requirements.
Unlike automatic AP placement discussed above, reconfiguring virtual APs does not change the APs’
positions on the floor plan.
To run the wizard, click on the Reconfigure APs button on the RF Planner toolbar. You will be prompted
to select one of the following reconfiguration modes:

Coverage requirements – reconfigures an existing predictive model to match new requirements
for signal levels and the number of APs to cover the WLAN.

Channel plan – reconfigures an existing predictive model to optimize channel assignment.

Both – combines the two modes listed above.
The reconfiguration can be applied to all existing APs or to only a subset: use the Bands and AP Selection
frame to select the Bands to reconfigure as well as to indicate whether you want to work with All APs or
only Selected APs.
After clicking Next, you will be prompted to select Coverage requirements (if you have chosen that
reconfiguration mode). The Minimum number of APs that must provide coverage in each point value is
used to determine the number of APs used for redundancy and seamless roaming. The With the signal
level of at least field is used to determine the minimum signal level in dBm provided by the APs in each
point of the coverage area. To reduce co-channel interference, the algorithm may adjust the output power
of the APs to be placed. Use the Minimum AP power and Maximum AP power drop-down lists to set the
constraints of such adjustments. If the Minimum AP power is set to Power off, the algorithm may turn
off the corresponding radio completely. If you prefer to not have the power level adjusted, set Minimum
AP power and Maximum AP power to the same value equal to the AP’s default output power. If you
prefer to avoid any intermediate power level and would rather have the radio either fully turned off or
work at the default power level, check the Don’t allow intermediate power levels box. It is important to
note that the requirements may or may not be the same for the 2.4 and 5 GHz bands. For example, you
may want to require -67 dBm in the 5 GHz band for your modern VoIP-enabled smartphones and tablets,
but only -75 dBm for legacy 2.4 GHz devices. If you want to have the same requirements for both bands,
use the chain-link button to make the requirements interlocked.
On the next page, you will be prompted to select a Channel plan (if you have chosen that reconfiguration
mode). For 2.4 GHz, we recommend channels 1-6-11 in the regulatory domains where 11 channels are
allowed, or 1-7-13 in the regulatory domains where 13 channels are allowed. As a backup option, you may
want to use 1-4-7-11 and 1-5-9-13, respectively. However, these setups are by no means recommended,
because if you use four 20 MHz channels, a channel overlap is inevitable. For 5 GHz, your choice of
channels is dictated by two key factors: the regulatory domain and the set of channels supported by your
APs and clients. Before you select channels, first verify which of them are allowed in your regulatory
40
Predictive Surveys | TamoGraph Site Survey
domain. Second, if you want to use DFS channels, verify that hardware supports them; in some APs and
clients, DFS channels are disabled.
Click Done to begin the AP reconfiguration process. If you do not like the result, press Ctrl + Z to revert to
the previous state.
Working with Presets
Presets are pre-configured sets of values for APs, walls, and attenuation zones (and, additionally, for
floors/ceilings, if you work with multi-floor sites). Presets can be accessed via the Manage Presets menu
item available in the corresponding drop-down menus for each of the three object types. At the top of
the preset management dialog, you can see a drop-down list populated with existing presets. You can
select an existing preset, modify it, and click Save to save it under the same name. To save it under a
different name, change the preset name before clicking Save. You can also click New to create a new
preset from scratch or delete an existing preset by clicking Delete.
Applying Visualizations
Data analysis for predictive surveys is very similar to data analysis for passive surveys; it is described in
detail in the Analyzing Data – Passive and Predictive Surveys chapter. In brief, you simply need to select a
visualization from the drop-down list on the toolbar. However, in case of predictive surveys, you can also
control the Visualization quality by using the corresponding control on the tool bar. Visualization quality
is an important parameter that defines how precise the calculations are. High-precision calculations come
at a cost: the higher the precision, the longer the computation time. The application offers four quality
presets: Low, Medium, Good, and Best. They differ in grid size and in applying advanced RF propagation
effects, such as reflection and Fresnel zones. We suggest that you use low or medium visualization quality
while you design your WLAN and make adjustments to your design. When the design is ready, you can
use good or best visualization quality for the final verification and/or report generation.
IMPORTANT: Calculating RF propagation is a very CPU-intensive task that might take a long time
for large floor plans with many APs. It is recommended that you use a fast multi-core CPU, such
as Intel i7, because in this case the application could take advantage of parallel computations that
are possible on multi-core CPUs. It is also recommended that you split large floor plans into
smaller parts if computing visualizations takes too long.
Working with Multi-floor Sites
When a WLAN for a multi-floor building is being designed, the virtual model must take into consideration
signal “leak” from the adjacent floors. This is important for two reasons. First, it is a common practice to
provide connectivity to the adjacent floor by means of the APs that are deployed one floor below or above
(usually below, because APs are typically placed on the ceiling, and, therefore, are closer to the floor
located above.) Second, if providing connectivity by this method is not planned, it is important to make
sure that the signal that penetrates the floors does not cause interference. With TamoGraph, you can
create and analyze multi-floor models as explained below.
41
Predictive Surveys | TamoGraph Site Survey
Creating a Multi-floor Project
To create a multi-floor project, you should first follow the steps that you follow when you create a
standard project; you must add a floor plan to the project and calibrate it. You can begin with the first
floor. Once the standard project with a single floor plan has been created, you can use the Plans and
Surveys tab on the right panel to manage floors and define their characteristics. Click Add => Floor to
create a new floor level and then drag your first floor plan to the newly created floor item. After that you
can click Add => Floor again to create a new floor level. If the floor plans are identical for all the floors in
your model, you can duplicate floors after drawing walls and other obstructions on the first floor plan and
placing alignment points; this is described in detail below. If the floors are not identical, you should add
individual floor plans images in one of the supported graphic formats for every floor by selecting the
corresponding floor and using the Add => Plan… command. New floor plans must then be calibrated. Note
that for each floor, you can add multiple floor plans that might have different scale and orientation.
Once the floors have been created and the corresponding floor plans have been added and calibrated,
you should specify floor heights and a few other characteristics. New floors are added with default floor
materials and heights; to specify correct values for your building, right-click on any of the floor items and
select Properties or click on the Floor Manager button. You can also use this dialog to rearrange floors.
When the floor properties have been defined, you should take care of floor plan alignment as explained
below.
Aligning Floors
When you work with a multi-floor site model, TamoGraph can analyze Wi-Fi signals that come from the
adjacent floors. To be able to take advantage of this functionality, you need to perform floor alignment.
Floor plan alignment is necessary because floor plans might have different scale, orientation, or offset.
While floor alignment is not mandatory, TamoGraph will use only the data from the current floor unless
you perform floor alignment. To perform it, please do the following:

Right-click on the first floor plan and select Align Floor Plan.

Choose a few locations on the floor plan that will be easily identifiable on the plans of other floors.
This could be elevator shaft corners, building corners, staircase corners, or anything else that you
can easily find on all the floor plans that you use in the project.

Click Add point to place a new marker on the floor plan, and then move the marker to one of
these locations. Create at least two markers. Each marker is assigned a unique number. If you
made a mistake, click Delete point or Clear all.

Once you have placed two or more alignment markers, click Apply.

Repeat this operation for all the floor plans that you would like to have aligned. The markers must
be positioned exactly below or above the corresponding markers on the adjacent floor. For
example, if marker #2 on the 5th floor is placed in the bottom right corner of the building, marker
#2 must be also placed in the bottom right corner of the building on the floor plan of the 6th floor.
To check the current floor alignment status, select Properties or click on the Floor Manager button. The
floors that are properly aligned are marked with a green checkbox. The floors that have not been aligned
yet are marked with a yellow exclamation mark. Just like map calibration, floor alignment must be done
only once.
42
Predictive Surveys | TamoGraph Site Survey
Floor Duplication
If the floor plans are identical for some or all the floors in your model, you can simply right-click on the
first floor and select Duplicate Floor to create a copy of the first floor with exactly the same floor plan. If
the walls and other obstructions, their placement, and materials are identical for all floors, you can
calibrate a single floor plan, draw walls, perform floor alignment as described above, and then use the
Duplicate Floor command; that way, you will not need to recreate the same virtual floor model for every
floor or align the floors, because duplication includes the walls and alignment points.
Dealing with Complex Floor Structures
When you use a floor manager to specify the materials that separate floors, you assume that each floor
is a contiguous piece of material that covers the entire floor plan area. However, there are cases that are
more complex. For example, one can find buildings that have “holes” in the floors that span one or several
stories. To deal with such virtual models, you should use the “Floor Area” drawing tool; it is grouped
together with attenuation zones and can be found in the corresponding drop-down list on the RF Planner
toolbar, next to the “Elevator shaft” or “Filing cabinet” items. Floor areas are drawn just like other
attenuation zones, using Rectangle or Polygon mode. As soon as you have drawn the first floor area on a
given floor, the application will assume that the floor has a non-standard geometry and only those areas
that are covered with “Floor area” contain floor material; areas that are not covered are considered free
from any obstructions.
To avoid unnecessary clutter, floor areas are hidden by default. Their visibility can be turned on and off in
the View => Virtual Objects => Floor Areas menu. We recommend hiding floor areas once you have
completed the design of your virtual model. Additionally, for the sake of clarity, it should be mentioned
that when you edit floor areas, you are editing the floor below your feet, not above your head. It should
also be mentioned that the floor material and its properties are configured on the Floor Manager, as
discussed in the previous chapters.
Analyzing Data
Data analysis for multi-floor sites is similar to data analysis methods for single-floor predictive surveys;
they are described in the Applying Visualizations chapter. However, there are some peculiarities that
should be noted. In addition to the signals from the APs located on the floor being analyzed, TamoGraph
will also analyze the signals that penetrate from the APs located on the adjacent floors, taking into account
their position, height above the floor, and the material of the ceilings. The APs located on the adjacent
floors are displayed on the AP list (the left pane of the main TamoGraph window), but the names of such
APs are shown using a pale blue font color. This allows you to identify the APs that do not belong to the
current floor. Note that you cannot change the properties of such APs or delete them. If you want to
change properties of an AP or delete it, first select the floor to which it belongs using the Plans and Surveys
tab.
Mixing Real and Virtual Data
There are situations when you may want to combine data collected during a passive on-site survey with
the data that you get from predictive surveys. For example, after performing a passive survey, you might
find out that some areas on your floor plan lack good signal coverage. To determine the number and best
placement of additional APs, you can use virtual APs. Simply place them on the floor plan, draw
43
Predictive Surveys | TamoGraph Site Survey
obstructions to get a realistic RF propagation picture for your environment, and select one of the
visualizations to see the results; data from both real and virtual APs will be mixed.
If you no longer need data from virtual APs in your project, you do not have to delete them one by one.
You can simply click RF Planner => Virtual Model to show or hide all virtual APs and other objects used in
predictive surveys. This will also exclude influence from virtual APs on all visualizations.
Best Practices, Tips, and Tricks
Designing WLANs is a complex task that requires a thorough understanding of the underlying technology
and design principles. If you are new to WLAN design and deployment, we strongly recommend that you
read a good book on this topic, such as The Certified Wireless Design Professional Official Study Guide.
Additionally, consider the following tips and tricks.

Just because your AP's maximum output power can be set to 17 or 20 dBm does not mean that it
should be set to this value. You should consider the fact that most Wi-Fi client devices, such as
laptops, tablets, or desktops with Wi-Fi adapters, have a lower output power, typically 13 or 15
dBm. As a result, a client might “hear” a 20 dBm AP from a very long distance, but the AP might
not “hear” the client. Additionally, APs with high output power create unnecessary interference
with other APs in dense WLAN environments. If you design your WLAN for performance rather
than coverage, you will probably want to have a rather dense placement of APs. Here, stronger
does not necessarily mean better. You might consider lowering the power level so that it matches
the power level of client devices.

If you design your WLAN for coverage rather than performance, using high AP output power might
be acceptable. However, be sure to read the AP specifications to find out the actual power level
it can provide. Remember that the maximum allowed power level might be different for different
channels!

Signal level does not tell you the whole story. Consider an 802.11n AP operating in the 2.4 GHz
band with the standard omnidirectional antenna and the default 17 dBm output power placed on
a map with no obstructions. If you select the Signal Level visualization, TamoGraph will draw a
very large (a few hundred meters) circle around your AP. Does this mean that the whole area can
be considered to be covered by the AP? Of course not, because, for example, at the distance of
approximately 300 meters the signal level would be about -90 dBm. Yes, the signal is there; your
client device might even detect the AP and display it on the list of available networks; but there
would be no connectivity. First, because the AP might not “hear” the client, as explained before.
Second, even marginal connectivity requires the signal-to-noise ratio of at least 4 dBm.
Considering that the typical noise level in the 2.4 GHz band in urban areas is about -90 dBm, the
signal level must be at least -86 dBm. At that level, the client might be able to connect, but the
throughput would be extremely poor. That said, the Expected PHY Rate or AP Coverage Areas
visualizations might be much more informative than the Signal Level visualization. TamoGraph
does not draw the signal level if the difference between it and the noise level is below 4 dBm.

It is a common practice nowadays to use the 2.4 GHz band for legacy, low throughput devices and
the 5 GHz band for newer, high throughput 802.11n or 802.11ac devices. When you put a dualband AP on the floor plan, both the 2.4 GHz and 5 GHz radios are enabled by default and both are
selected on the AP list on the left panel of the main application window. This means that the
Signal Level or Expected PHY Rate visualizations will show you cumulative pictures; if more than
44
Predictive Surveys | TamoGraph Site Survey
one radio is included in the visualization, they will show the values for the strongest AP. However,
you will probably want to estimate coverage and expected PHY rates for each band individually,
because the range of 5 GHz radios is shorter and because the attenuation level for 5 GHz signals
is higher. To do that, press the Select APs button on the toolbar and use the checkboxes next to
the APs to select and deselect them individually. You can also group APs by band and then select
or deselect all 5 GHz or 2 GHz APs with a single click. You might notice that while good coverage
is available in the 2.4 GHz band in the entire area, 5 GHz coverage is not available everywhere.

Selecting the right antennas for your AP might considerably increase signal level, decrease
interference, and, therefore, improve performance. If the antennas of your APs are replaceable,
this adds another degree of freedom to your WLAN design. Using TamoGraph, you can select an
antenna from a large collection of generic and vendor-specific antennas. You can also view
antenna patterns in 3D.
45
Predictive Surveys | TamoGraph Site Survey
Analyzing Data – Passive and Predictive Surveys
When TamoGraph has collected the necessary data in the course of one or several passive site surveys,
or when you have created a virtual environment model in the course of a predictive survey, the application
is ready to display a number of Wi-Fi data visualizations that will help you determine important
characteristics of your WLAN, such as signal coverage, and detect potential performance problems. The
information given in this chapter is applicable to passive and predictive surveys; data analysis for active
surveys is described in the Analyzing Data – Active Surveys chapter. You may also want to review
Understanding Survey Types: Passive, Active, and Predictive.
Selecting Data for Analysis
Three key interface elements affect what data will be analyzed and how. These elements are overviewed
below.
The Plans and Surveys tab on the right panel defines what data the application will visualize. This tab is
organized as a hierarchical tree, where for each floor or site plan, you will see one or more site surveys
you have conducted. You need to select the floor plan to be analyzed and mark one or more survey paths
to be included using the corresponding checkboxes (unless you are working on a predictive survey, where
no actual on-site measurements are conducted.) Depending on where and when the surveys were
conducted, you may want to check all or only some of the survey checkboxes. For example, if you have a
large site and you made one break while conducting the site survey, your walkabout path will consist of
two parts, both of which should be included in the analysis. In a different scenario (e.g., if you surveyed
the entire site prior to installing additional wireless hardware and then surveyed it again after the
installation), you will probably want to include only one of the surveys and then compare it with the other
by changing the checkbox selection. The Type column indicates the survey type: Active, Passive, or
Active+Passive. We are reviewing passive surveys in this chapter, so you should select the surveys that
are marked as Passive or Active+Passive in this column. You can use the Comments column to add or
modify comments for surveys or modify the survey names for clarity at any time.
The Visualization drop-down box on the tool bar defines what type of analytical tool will be applied to
the selected site plan. A visualization is a graphical representation of WLAN characteristics displayed as
an overlay on top of the floor plan. The available visualization types will be described below. To select a
visualization, simply select the corresponding item from the drop-down list, under the Passive section. To
clear all visualizations, select None. When no visualization is selected, the floor plan is overlaid with the
walkabout paths and guess range areas (the zones within which TamoGraph can make a good assessment
of the WLAN parameters).
The Selected APs / All APs buttons on the tool bar, along with the AP list, control which subset of observed
APs is used for visualizations. Typically, you should select the All APs mode only if all of the listed APs
belong to your WLAN, as there is no point in visualizing, for example, the wireless coverage areas for the
AP to which your wireless clients cannot connect. The default mode is Selected APs, in which TamoGraph
will analyze only the signals originating from the APs you selected in the AP list on the left panel. In most
corporate WLANs, all APs share the same SSID, so the easiest way to select only your APs is using the
Group by => SSID command button located above the AP list and checking the box next to your SSID.
46
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
Note: It is extremely important that the correct subset of APs be selected for analysis. Selecting
APs that do not belong to your WLAN will result in incorrect coverage maps and prevent
TamoGraph from identifying network issues. It will also slow down the analysis process.
Data visualizations, such as signal level or signal-to-noise ratio, may or may not cover the entire area of
the floor plan. This depends on the Extrapolate data beyond the guess range option, which can be
configured in the new project wizard or at a later time on the Properties tab of the right-side panel. If this
option is enabled, TamoGraph will calculate WLAN characteristics beyond the areas covered by your
walkabout path. While this is convenient, as the time needed to collect data for the entire area is reduced,
data extrapolation cannot produce reliable results. Your walkabout path should normally cover all the
areas for which accurate data is important.
Adjusting AP Locations After Passive Surveys
When you have performed a passive site survey, TamoGraph will automatically place APs on the site map.
The location of APs is estimated based on the collected data. Location estimates may not always be
accurate due to the complex nature of radio wave propagation, but you can correct them by dragging the
AP icon to the correct location with a mouse.
The effect that the AP icon locations have on the calculations of the signal level and other visualizations
depends on the How AP icon locations affect signal setting that you can find on the Visualization Settings
panel (located on the Options tab of the right-side panel.) By default, Estimated AP locations are used to
complement measured signals (new algorithm), which means that correcting the location may improve
the quality of data analysis in the areas located far from the walkabout path. This is recommended for
most surveys. If you select Estimated AP locations do not affect signal levels; they are icons only, the
application displays data based ONLY on the actual measurements; there are no extrapolations. This is
suitable for the surveys where signal levels are low and AP locations cannot be estimated accurately.
Finally, you may want to select Estimated AP locations are used to complement measured signals (old
algorithm, up to version 4.1). This option exists solely for providing compatibility with the TamoGraph
versions prior to 4.2; the result might be overly optimistic.
If you corrected the AP location(s) by moving the corresponding icon(s), you can revert to the original
location by right-clicking on the AP list on the left panel and then clicking Auto-locate Access Points (this
action can be applied to All or Selected APs; here by Selected, we mean the APs that are checked in the
AP list). To remove an AP completely, drag and drop it outside the map area or use the Clear Access Point
Locations command (again, this action can be applied to All or Selected APs; here, by Selected, we mean
the APs that are currently checked in the AP list). Removing an AP from the site map means that the AP
location becomes undetermined, which, in turn, means that, for this AP, no data extrapolation is
performed, and only the actual signal readings are used.
Displaying AP locations is an optional feature. Additionally, by default, TamoGraph does not attempt to
estimate the locations of those APs for which the signal level is low. The AP Detection and Placement
panel (located on the Options tab of the right-side panel) can be used for configuring these features.
When an AP is placed on the site map (either automatically or by the user), this is indicated on the left
panel by a small plus (+) sign in the lower right corner of the AP icon. If an AP was not automatically placed
47
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
on the map and you want to place it there, you can drag the AP icon from the AP list to the site map. To
remove it from the site map, drag the AP icon outside of it.
Splitting an AP into Multiple Unique APs
Sometimes, passive pre-deployment site surveys are performed by moving about a single AP and testing
coverage every time you change the AP location. This method is often referred to as “AP-on-a-stick.” The
purpose of this method is to find good locations for future AP installations and to estimate expected
coverage (or, sometimes, to find the best location for only one AP).
If you perform such surveys using one floor plan, the results will not be ideal because TamoGraph assumes
that your AP location is fixed; it will place only a single AP icon in the estimated location and the coverage
calculations will be based on that estimated location. This is not what you want when you perform AP-ona-stick surveys; you probably want TamoGraph to treat your test AP as a unique physical device in each
of the surveys conducted.
To address this problem, we suggest one of the following solutions (we recommend the second solution):
1. You can add multiple copies of the same floor plan to the project. Every time you move the test AP to
a new location, perform a survey using a new copy of the floor plan. By doing so, you will obtain
completely independent coverage results for each new location. The drawback of this method is that you
will not be able to see cumulative coverage visualization on a single floor plan.
2. You can perform all the surveys using the same floor plan. During a typical “AP-on-a-stick” survey, you
would take the following steps:
a) Choose a location for the future installation of your first AP.
b) Place your “AP-on-a-stick” in that location.
c) Perform a single, full survey of the coverage area. If a single survey is impossible (i.e., if you have
to stop and make several surveys for a single AP placement), be sure to merge such surveys before
moving on.
d) Choose a location for the future installation of your second AP and repeat this cycle for the
second, third, fourth, etc. AP.
When you have completed the testing cycle (new AP location – new survey – new AP location – new
survey…), all of your surveys will contain data for only one AP with a single MAC address. That is not what
you want. What you want is to split a single physical AP into multiple copies, one copy per survey. All AP
copies will be assigned new, unique MAC addresses, and, therefore, TamoGraph will treat them as
independent APs. To do that, select your test AP on the left panel, right-click on it, and then select
Advanced => Split. This will display a dialog window in which you can select two or more surveys that you
performed using the AP-on-a-stick method. Click OK to complete the operation. If you have a dual-band
AP, you will need to perform this split operation twice, once for each band.
After the split, new APs are given new names and new MAC addresses. For example, if the original AP
name is “Cisco 802.11n” and the original MAC address is 00:23:04:88:C6:90, and if your performed three
surveys in three different locations, the new APs would be named “Cisco 802.11n – Copy 1,” “Cisco
802.11n – Copy 2,” and “Cisco 802.11n – Copy 3,” and their MAC addresses would be 00:23:04:88:C6:91,
00:23:04:88:C6:92, 00:23:04:88:C6:93, respectively.
48
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
Once you split the AP into multiple independent, unique APs, you can adjust AP icon locations to reflect
their actual positions, as described in the previous chapter, and apply any visualization to the selected
surveys.
Note that this operation cannot be undone, so you may want to save a backup copy of the project file
prior to performing this operation.
Working with Multi-SSID APs
A multi-SSID (also called “multi-MAC”) access point is a single access point that broadcasts multiple SSIDs
using a single radio. Each SSID uses a separate, distinct MAC address (also known as “BSSID”), which means
that such APs appear as separate, distinct devices for WLAN users. Detection of multi-SSID APs is
important for one of the visualizations, namely Signal-to-Interference Ratio, for an obvious reason:
despite the fact that multiple SSIDs use the same channel, they cause no interference between
themselves.
TamoGraph attempts to detect such multi-SSID APs and mark them accordingly. They appear as a group
of icons on the floor plan, where each SSID/MAC address is represented by one icon. They also share a
single tooltip window that lists the SSIDs and MAC addresses used by the AP’s radio.
Because detection of multi-SSID APs cannot be 100% reliable for a number of technical reasons,
TamoGraph allows you to link several icons to form a multi-SSID AP if automatic detection failed or,
conversely, split an incorrectly detected multi-SSID AP into separate radios. These operations can be
performed using the Multi-MAC/Multi-SSID Access Point context menu of the floor plan (central pane).
Visualization Types
The following chapters describe different visualization types and the configuration settings that affect
them. They will also help you interpret the data and suggest solutions to problems with Wi-Fi coverage
and performance.
Signal Level
This visualization shows the signal strength map (also called the coverage map) measured in dBm. Signal
strength is one of the most important factors that influence WLAN performance, as in the areas with low
signal, establishing a reliable and high-throughput link between the AP and client devices is impossible.
Signal level is shown for the AP that has the strongest signal in the given map area among the APs selected
for analysis. You can deselect one or several of the selected APs to see the signal level of less strong APs.
A signal level above -60 dBm is considered excellent. Levels between -60 and -85 dBm are mediocre, and
levels below -85 dBm provide only marginal connectivity. Signal strength is affected by the distance from
the AP, AP output power, type and direction of antenna, and, most importantly, physical obstructions,
such as walls, doors, windows, and their material.
Double-clicking on the signal level legend on the status bar allows you to configure the color scheme and
change its value range.
49
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
Suggested Solutions
When low signal areas are discovered, the following solutions are suggested:

Change AP locations: You should minimize the number of obstructions between the AP and the
low signal zone. Additionally, the material of the obstructions plays an important role; for
example, the attenuation factor of a brick wall far exceeds that of a cubicle wall or window.

Add more APs: Sometimes repositioning APs does not provide the desired effect, and the option
becomes installing additional APs in the problematic areas.

Use a different antenna: A high-gain antenna (if your AP supports the use of such antennae)
redirects radio signal in the desired direction, thereby increasing the signal level in some zones
and decreasing it in the others.

Increase output power: Some APs allow for the adjustment of the transmission power. However,
for most, the maximum power is already set as the default factory setting.
Signal-to-Noise Ratio
This visualization shows the signal-to-noise ratio (SNR) measured in dB. SNR is a measure to quantify by
how much the signal level exceeds the noise level. Noise is generated by non-802.11 sources of radio
waves (this includes 802.11 frames damaged during propagation). In low SNR zones, client devices may
not be able to communicate with APs. SNR is shown for the AP that has the strongest signal in the given
map area among the APs selected for analysis. You can deselect one or several of the selected APs to see
SNR values for less strong APs.
In a typical environment, the noise level is about -90 dBm. The signal level measured within a few meters
from the AP would be about -50 dBm. This gives an SNR value of 40 dB, which is considered excellent.
Marginal connectivity is possible when the AP signal level is -85 dBm, so an SNR value of 5 dB is considered
poor. A higher noise level and, correspondingly, a lower SNR are usually caused by Bluetooth devices,
cordless phones, and microwave ovens.
Double-clicking on the SNR legend on the status bar allows you to configure the color scheme and change
its value range.
Suggested Solutions
When low SNR areas are discovered, two possible strategies should be considered: increasing the signal
level or decreasing the noise level. The first strategy is discussed in the previous chapter; to decrease the
noise level, the following solutions are suggested:



Check the environment for potential sources of noise and turn them off, if possible, to see how
that affects SNR.
If you experience low SNR values in the 2.4 GHz band, consider switching your APs to the 5 GHz
band, where noise level is typically lower.
If switching to the 5 GHz band is not an option, try to select a different channel in the 2.4 GHz
band.
Note that identifying and removing the source of noise might not be an easy task. In practice, the easiest
solution is usually increasing the signal level rather than decreasing the noise level.
50
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
Signal-to-Interference Ratio
This visualization shows the signal-to-interference ratio (SIR) measured in dB. SIR is a measure to quantify
by how much the signal level of an AP (interfered AP) exceeds the interference level. The interfering signal
is the signal being transmitted by other APs (interfering APs) that may or may not belong to your WLAN
and that use the same or one of the adjacent 802.11 channels. In low SIR zones, client devices may
experience low throughput. SIR is shown for the AP that experiences the worst interference in the given
map area among the APs selected for analysis. You can deselect one or several of the selected APs to see
SIR values for the APs that experience less interference.
Selecting one AP at a time for SIR analysis is recommended because this produces a clearer
picture. You should isolate AP-specific problem zones by selecting your APs one by one. Working
with a cumulative picture, displayed when multiple APs are selected, is more difficult.
SIR is best illustrated with an example. Consider an area where the AP signal strength is -50 dBm, and the
AP works on channel 1. In the same area, a -70 dBm signal from another AP that works on the same
channel can be seen. If WLAN utilization is 100% (i.e., if the APs send radio waves all the time), the SIR
value would be 20 dB. However, real-world WLAN utilization is almost never that high, which decreases
the interference and increases SIR. If the interfered and interfering APs have the same signal strength, the
SIR value would be 0 dB. In classical, non-digital radios, a SIR value of 0 dB makes signal reception
impossible, but 802.11 devices use a technology that allows them to operate despite a zero or even
negative SIR value, which sounds counterintuitive.
Simply put, if an AP is not heavily loaded, it transmits just a few hundred packets per second. If a nearby
AP working on the same channel also transmits a few hundred packets per second, the transmissions
“collide” very infrequently, thus resulting in virtually zero interference. The average network utilization
that is used for SIR computations is a configurable option (see below).
Interference is highest when the interfered and interfering APs work on the same channel. In the 2.4 GHz
band, where channel frequencies overlap, adjacent channel interference is still substantial when the
interfered and interfering APs are one and two channels apart and becomes virtually non-existent when
they are five channels apart. In the 5 GHz band, there is no adjacent channel interference. Many 802.11n
and 802.11ac devices use channel bonding, i.e., two 20 MHz channels for 802.11n and up to eight 20 MHz
channels for 802.11ac at the same time. For example, channel 11 might be used as the primary channel
and channel 6 as the secondary one. In these cases, TamoGraph factors in interference on non-primary
802.11n or 802.11ac channels, if any. It should also be noted that when visualizing SIR, the application
takes into consideration interfering signals from all APs, regardless of whether they are selected in the AP
list. The application also detects multi-SSID APs and does not consider separate different SSIDs with
different MAC addresses of the same AP as sources of interference with each other (see Working with
Multi-SSID APs for more information).
The following options on the Visualization Settings panel (located on the Options tab of the right-side
panel) affect the way SIR is analyzed:

Area is considered covered if signal strength is at least – This setting defines the AP coverage
area based on the minimum signal strength. If the signal strength is below the specified level, the
area is considered to be not covered, and no SIR values will be computed for the area (such areas
will appear as white spots). This improves the SIR visualization clarity: In low signal areas, SIR is
51
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
almost always very low, but such areas should not distract your attention, as they cannot ensure
good connectivity or throughput anyway.

Average network utilization – This setting defines how heavy the interference is from the
interfering APs. If the interfering signal strength is high, but the network utilization is low, the
interfering AP does not create much interference. A typical office WLAN has a network utilization
of between 10% and 25%. Adjust this setting to match the actual value for your WLAN.
Double-clicking on the SIR legend on the status bar allows you to configure the color scheme and change
its value range.
Suggested Solutions
Low SIR areas are not uncommon in WLANs. The presence of such areas does not necessarily mean that
the WLAN will suffer from low throughput. However, if such zones cover most of your site and are located
close to APs, corrective actions should be taken. When low SIR areas are discovered, the following
solutions are suggested:

Change the channel selection. APs working in close proximity should never use overlapping
channels. Consider the classical “honeycomb” AP placement, if possible. Note that in some
802.11n equipment, the position of the secondary channel (below or above the primary one) is a
user-configurable option, which gives you an additional degree of freedom.

If you experience low SIR values in the 2.4 GHz band, consider switching your APs to the 5 GHz
band, where there are more non-overlapping channels from which to choose. If you use an
802.11n AP with 40 MHz bandwidth in the 2.4 GHz band, you have virtually no way of avoiding
interference. For example, if the primary channel is set to 1, the secondary channel is set to 5. In
the United States, where there are eleven channels in the 2.4 GHz band, all you can do is configure
the next AP to work on the primary channel 11, the secondary being 6. As a result, the secondary
channels would be only one channel apart, which may result in high interference. If channel
bonding is not used (i.e., a single 20 MHz channel), you have three non-overlapping channels from
which to choose: 1, 6, and 11. This is illustrated in the image below.
AP Coverage Areas
This visualization shows the areas covered by the APs. An area is considered covered if the signal is strong
enough for the clients to communicate to the AP. You can select and deselect one or several of the APs to
see individual or group coverage areas. Coverage areas are color-coded: For each AP, a small colored
square is shown next to the AP icon. The corresponding color is used to display the coverage area contour
or fill.
The definition of “strong enough” is rather subjective because certain signal strength might be sufficient
for low data rates, but insufficient for the high data rates required for such applications as VoIP.
52
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
Additionally, 802.11 adapters vary in sensitivity, and some adapters might be able to provide good
connectivity in zones where other adapters fail to connect altogether.
The following options on the Visualization Settings panel (located on the Options tab of the right-side
panel) affect the way AP coverage areas are analyzed and visualized:

Area is considered covered if signal strength is at least – This setting defines the AP coverage
area based on the minimum signal strength. If the signal strength is below the specified level, the
area is considered to be not covered.

AP coverage areas – This allows you to change the color coding method used for displaying
coverage areas. In No fill, contours only mode, the application draws contours of the coverage
areas without filling the areas with colors. In Fill and mix colors mode, AP coverage areas are filled
with colors; when areas overlap, the application draws a striped pattern, alternating the colors of
the respective APs. In Fill, strongest AP on top mode, AP coverage areas are filled with colors;
when areas overlap, the application draws the color of the strongest AP. In Fill, weakest AP on
top mode, AP coverage areas are filled with colors; when areas overlap, the application draws the
color of the weakest AP.
Number of APs
This visualization shows how many APs cover the given area. An area is considered covered if the signal
is strong enough for the clients to communicate with the AP. In many WLANs, multiple AP coverage is an
important requirement that ensures uninterrupted connectivity, load balancing, and seamless roaming.
If this requirement exists in your WLAN, you can use this visualization to make sure that AP coverage areas
sufficiently overlap.
As in the AP Coverage Areas visualization, the definition of “strong enough” is rather subjective because
certain signal strength might be sufficient for low data rates, but insufficient for the high data rates
required for such applications as VoIP. Additionally, 802.11 adapters vary in sensitivity, and some adapters
might be able to provide good connectivity in zones where other adapters fail to connect altogether. The
Visualization Settings panel (located on the Options tab of the right-side panel) offers the Area is
considered covered if signal strength is at least setting, which defines the AP coverage area based on the
minimum signal strength. If the signal strength is below the specified level, the area is considered to be
not covered.
Double-clicking on the Number of APs legend on the status bar allows you to configure the color scheme.
Expected PHY Rate
The physical layer (PHY) rate is the speed at which client devices communicate with the AP. When you
move a computer connected to the AP within the WLAN coverage area, the adapter properties dialog on
Windows or the Wi-Fi icon menu on macOS displays the varying connection speed, which may be as high
as 450 or 300 Mbps when you are close to the AP or as low as 1 Mbps when you are 50 meters away from
it. The displayed speed is the PHY rate.
The PHY rate directly affects the throughput rate, which is the average speed at which the client and AP
can exchange application-level data, such as files. The throughput rate is always lower than the PHY rate,
53
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
typically by more than 50%, due to a number of factors, such as protocol overheads and retransmissions.
A low PHY rate always means low data throughput and therefore poor WLAN performance.
When calculating PHY rates, TamoGraph uses the Client Capabilities settings that might or might
not be as good as the AP capabilities. If the adapter's capabilities are inferior (e.g., if an 802.11n
adapter is connected to an 802.11an AP), then the maximum PHY rate that the AP supports will
not be reached. Please refer to the description of Client Capabilities for more information.
The PHY rate is shown for the AP that has the strongest signal in the given map area among the APs
selected for analysis. This mimics the roaming behavior of client adapters that connected to the strongest
AP. While other audible APs may offer higher PHY rates, a typical adapter will connect to the AP with the
strongest signal. You can deselect one or several of the selected APs to see PHY rate values for less strong
APs.
Expected PHY rate calculations are based on signal strength and use a table that maps signal levels to PHY
data rates. The table uses average values for common adapter types. The actual PHY rate that you observe
may be lower or higher than the expected rate, depending on the specific adapter and AP equipment
being used.
Double-clicking on the Expected PHY rate legend on the status bar allows you to configure the color
scheme.
Suggested Solutions
When low expected PHY rate areas are discovered, the following solutions are suggested:

Increase the signal level, as it is directly related to the PHY rate. See the suggested solutions for
increasing signal level in the Signal Level chapter.

Check your AP capabilities. If you are using newer 802.11n equipment, make sure that the
maximum MCS indices, Short GI, and 40 MHz channel bandwidth are allowed in the device
configuration.

Check your Client Capabilities settings. You might have erroneously limited them too much.

If you are using legacy 802.11 a/b/g equipment, consider upgrading to 802.11n or 802.11ac.
Frame Format
This visualization shows what format of 802.11 frames (also called packets) is being used in the given
WLAN area. Wi-Fi networks use three frame formats:

Non-HT: This is a legacy frame format used by 802.11 a/b/g equipment.

HT-mixed: This is a frame format introduced in the 802.11n standard. It uses a protection
mechanism that allows 802.11n devices to coexist with legacy 802.11 a/b/g devices, including
those that do not belong to your WLAN.

HT-Greenfield: This is a frame format introduced in the 802.11n standard, too. Unlike in HT-mixed
mode, devices operating in Greenfield mode assume that there are no legacy 802.11 a/b/g
54
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
stations around using the same or adjacent channels. 802.11 a/b/g devices cannot communicate
with Greenfield devices. Rather, their packets will collide, causing problems for both parties.

VHT: This is the latest frame format introduced in the 802.11ac standard. This format is used in
the 5 GHz band only. It uses a protection mechanism that allows 802.11ac devices to coexist with
legacy 802.11a and 5 GHz 802.11n devices, including those that do not belong to your WLAN.
Frame format is shown for the AP that has the strongest signal in the given map area among the APs
selected for analysis. This mimics the roaming behavior of client adapters that connected to the strongest
AP. While other audible APs may use other frame formats, a typical adapter will connect to the AP with
the strongest signal. You can deselect one or several of the selected APs to see frame formats for less
strong APs.
Among the three pre-802.11ac frame formats, the best throughput is provided by HT-Greenfield. In HTmixed format, protection mechanisms that ensure coexistence with legacy equipment reduce throughput.
However, it should be noted that as per the 802.11n standard, support for HT-Greenfield frame format is
not mandatory, and currently, few APs support it. In the realm of 802.11ac, VHT is the only available
format.
Double-clicking on the Frame Format legend on the status bar allows you to configure the color scheme
and change its value range.
Suggested Solutions
If you do not see the frame formats that you expect to see, the following solutions are suggested:

Check your AP configuration. If you are using 802.11n equipment, see if Greenfield mode is
available, if HT-Greenfield frame format is what you want. Note that some APs have the “802.11n
only” option, but this option does not necessarily mean that HT-Greenfield frame format will be
used. Rather, switching this option on may simply disable legacy data rates.

Your AP's ability to send frames in HT-Greenfield format depends on the wireless environment. A
Greenfield-enabled AP may fall back to HT-mixed format in some situations (e.g., when a non802.11n device connects to the AP or when other non-Greenfield APs are detected nearby).
Because of the changing environment, the site survey results regarding the frame format may
change from time to time. Perform site surveys regularly.

If you are using legacy 802.11 a/b/g equipment, consider upgrading to 802.11n or 802.11ac.

Remember that VHT is not available in the 2.4 GHz band.
Channel Bandwidth
This visualization shows what type of channel bandwidth (also called channel width) is being used in the
given WLAN area. Wi-Fi networks use three types of channel bandwidth:

20 MHz Legacy: This is a legacy type used by 802.11 a/b/g equipment. Each channel occupies 20
MHz of radio spectrum.

20 MHz HT and 40 MHz HT: These are bandwidth types introduced in the 802.11n standard. They
occupy either 20 MHz or 40 MHz of spectrum space and use HT-mixed and HT-Greenfield frame
formats.
55
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey

20 MHz VHT, 40 MHz VHT, 80 MHz VHT, and 160 MHz VHT: These are new types introduced in
the 802.11ac standard. They use 20, 40, 80, or 160 MHz-wide channels. VHT is used only in the 5
GHz band.
Channel bandwidth is shown for the AP that has the strongest signal in the given map area among the APs
selected for analysis. This mimics the roaming behavior of client adapters that connected to the strongest
AP. While other audible APs may offer other types of bandwidth, a typical adapter will connect to the AP
with the strongest signal. You can deselect one or several of the selected APs to see channel bandwidth
types for less strong APs.
Double-clicking on the Channel Bandwidth legend on the status bar allows you to configure the color
scheme and change its value range.
Suggested Solutions
If you see 20 MHz Legacy or 20 MHz HT channel bandwidth in the areas where you expect to see 40 MHz
HT, the following solutions are suggested:

Check your AP configuration. If you are using newer 802.11n equipment, make sure that it is
configured to use 40 MHz or automatic 20/40 MHz channel width.

Your AP's ability to use 40 MHz channels depends on the wireless environment. A 40 MHz-enabled
AP may fall back to 20 MHz mode in some situations (e.g., when an 802.11n client that does not
support 40 MHz bandwidth is connected). Because of the changing environment, the site survey
results regarding the channel bandwidth may change from time to time. Perform site surveys
regularly.

If you are using legacy 802.11 a/b/g equipment, consider upgrading to 802.11n or 802.11ac.
If you see the HT channel bandwidth in the areas where you expect to see VHT, make sure that your AP is
configured to use the 802.11ac mode and that you have correctly configured its channel width. Also, keep
in mind that VHT is available only in the 5 GHz band.
Channel Map
These visualizations (there are two separate visualizations for the 2.4 GHz and 5 GHz bands) show perchannel coverage for the selected band. The predominant channel is determined by the AP that has the
strongest signal in the given area. Each channel is marked with the corresponding legend color.
These visualizations are intended to assist the surveyor in detecting problems with channel reuse patterns
in existing high-density WLANs that do not use dynamic frequency selection. They are also instrumental
in predictive surveys, when you design new Wi-Fi deployments.
Requirements
This visualization shows what requirements set by the user are met. The Requirements panel (located on
the Properties tab of the right-side panel) allows the user to set thresholds for key WLAN parameters,
namely (under the Passive section):


Minimum signal level (shown as SL on the legend)
Minimum signal-to-noise ratio (shown as SNR on the legend)
56
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey





Minimum signal-to-interference ratio (shown as SIR on the legend)
Minimum APs required (shown as AP on the legend)
Minimum PHY rate (shown as PHY on the legend)
Minimum allowed frame format (shown as FF on the legend)
Minimum channel bandwidth (shown as CB on the legend)
The zones where the requirement is not met are marked with the corresponding legend color. If more
than one requirement is not met, only one color will be used (priority is given to the requirements closer
to the top of the list). If multiple APs are required, the strongest AP will be checked against the
requirement list. If all the requirements are met, no color overlays will be displayed.
The meaning of the requirements listed above is explained in detail in the preceding sections of the
Analyzing Data – Passive and Predictive Surveys chapter.
Double-clicking on the Requirements legend on the status bar allows you to configure the color scheme
and change its value range.
57
Analyzing Data – Passive and Predictive Surveys | TamoGraph Site Survey
Analyzing Data – Active Surveys
Once TamoGraph has collected the necessary data in the course of one or several active site surveys, the
application is ready to display a number of Wi-Fi data visualizations that will help you to determine
important characteristics of your WLAN, such as actual PHY rate or throughput rates, and detect potential
performance problems. The information given in this chapter is applicable to active surveys; data analysis
for passive surveys is described in the Analyzing Data – Passive and Predictive Surveys chapter. You may
also want to review Understanding Survey Types: Passive, Active, and Predictive.
Selecting Data for Analysis
Three key interface elements affect what data will be analyzed and how. These elements are overviewed
below.
The Plans and Surveys tab on the right panel defines what data the application will visualize. This tab is
organized as a hierarchical tree, where for each floor or site plan, you will see one or more site surveys
you have conducted. You need to select the floor plan to be analyzed and mark one or more survey paths
to be included using the corresponding checkboxes. Depending on where and when the surveys were
conducted, you may want to check all or only some of the survey checkboxes. For example, if you have a
large site and you made one break while conducting the site survey, your walkabout path will consist of
two parts, both of which should be included in the analysis. In a different scenario (e.g., if you surveyed
the entire site prior to installing additional wireless hardware and then surveyed it again after the
installation), you will probably want to include only one of the surveys and then compare it with the other
by changing the checkbox selection. The Type column indicates the survey type: Active, Passive, or
Active+Passive. We are reviewing active surveys in this chapter, so you should select the surveys that are
marked as Active or Active+Passive in this column. You can use the Comments column to add or modify
comments for surveys or modify the survey names for clarity at any time.
The Visualization drop-down box on the tool bar defines what type of analytical tool will be applied to
the selected site plan. A visualization is a graphical representation of WLAN characteristics displayed as
an overlay on top of the floor plan. The available visualization types will be described below. To select a
visualization, simply select the corresponding item from the drop-down list, under the Active section. To
clear all visualizations, select None. When no visualization is selected, the floor plan is overlaid with the
walkabout paths and guess range areas (the zones within which TamoGraph can make a good assessment
of the WLAN parameters).
Unlike passive surveys, active surveys do not include information on the APs in the survey area; they are
focused on the specific WLAN or AP to which you connected during the active survey. For this reason, the
Selected APs / All APs buttons on the tool bar are disabled when you select a visualization for an active
survey. The AP list might still be available if you also performed a passive survey or if APs can be currently
“heard” by the application, but checking or unchecking the boxes next to the listed APs has no effect in
this case.
Visualization Types
The following chapters describe different visualization types and the configuration settings that affect
them. They will also help you interpret the data and suggest solutions to problems with Wi-Fi coverage
and performance.
58
Analyzing Data – Active Surveys | TamoGraph Site Survey
Actual PHY Rate
The physical layer (PHY) rate is the speed at which client devices communicate with the AP. When you
move a computer connected to the AP within the WLAN coverage area, the adapter properties dialog on
Windows or the Wi-Fi icon menu on macOS displays the varying connection speed, which may be as high
as 450 or 300 Mbps when you are close to the AP or as low as 1 Mbps when you are 50 meters away from
it. The displayed speed is the actual PHY rate at which the client was connected to the AP during an active
survey. This is unlike the Expected PHY Rate available for passive surveys, where the PHY rate is not
measured, but rather estimated based on the signal level. The actual PHY rate that you observe may be
lower or higher than the expected rate, depending on the specific adapter and AP equipment being used.
To be able to determine the maximum possible PHY rate, the set of supported rates and standards
of the adapter you use for active surveys must be at least as good as that of the AP. If the adapter's
capabilities are inferior (e.g., if an 802.11b adapter is connected to an 802.11n AP), the maximum
PHY rate will not be reached.
The PHY rate that is measured is the rate at which the adapter is connected to the AP at any given spot
along the survey path. As you move along the path, the adapter typically roams to the AP that provides
the strongest signal within your WLAN.
It is important to remember that some adapters let you adjust roaming thresholds; these roaming settings
might affect the roaming behavior and, therefore, the measured PHY rate. For example, consider two APs
located 20 meters away from each other with the signal level ranging from -30 dBm next to the APs to 70 dBm in the middle of the distance between the APs. As you walk from the first to the second AP, some
clients will roam as soon they pass the middle point, while others will not roam until they are only a few
meters away from the second AP. For this reason, the PHY rate visualization is heavily dependent upon
one's walkabout path and its direction. Walking from the first to the second AP might produce a picture
that would be different from the one produced by walking in the opposite direction.
Double-clicking on the Actual PHY rate legend on the status bar allows you to configure the color scheme
and change its value range.
Suggested Solutions
When low actual PHY rate areas are discovered, the following solutions are suggested:

Verify that the set of supported rates and standards of the adapter being used for active surveys
is at least as good as that of the AP.

Low PHY rates might be caused by non-aggressive roaming. Check the adapter roaming settings
and repeat the survey in the questionable zones. Try to walk very slowly to give the adapter time
to roam and establish a good quality link to the AP.

Increase the signal level, as it is directly related to the PHY rate. See the suggested solutions for
increasing signal level in the Signal Level chapter.

Check your AP capabilities. If you are using newer 802.11n equipment, make sure that the
maximum MCS indices, Short GI, and 40 MHz channel bandwidth are allowed in the device
configuration.

If you are using legacy 802.11 a/b/g equipment, consider upgrading to 802.11n or 802.11ac.
59
Analyzing Data – Active Surveys | TamoGraph Site Survey
TCP Upstream and Downstream Rate
The TCP Upstream Rate and TCP Downstream Rate visualizations show TCP throughput rates measured in
Mbps (megabits per second.) Throughput (also often referred to as “goodput”) is the amount of
application-layer data delivered from the client to the server (upstream) or from the server to the client
(downstream) per second. The protocol overhead is not included, so when we talk, for example, about
the TCP throughput rate of 1 Mbps, we mean that 125 Kbytes of actual data payload were sent between
two network nodes during one second, not including TCP, IP, and Ethernet or 802.11 headers.
Throughput rates are one of the most important real-world metrics of a WLAN, because they determine
the end user experience and network-related application performance.
Double-clicking on the TCP Upstream and Downstream Rate legend on the status bar allows you to
configure the color scheme and change its value range.
Suggested Solutions
When low throughput areas are discovered, the following solutions are suggested:

Verify that the actual PHY rate is sufficient. Throughput rates cannot exceed PHY rates; in practice,
they are about 50% lower than PHY rates. For example, if the PHY rate in the given area is only 2
Mbps, you should not expect the throughput rate to exceed 1 Mbps. In practice, it might be as
low as 0.1 or 0.2 Mbps, depending on other conditions.

Other common reasons for low throughput rates are interference and excessive network traffic.
The Signal-to-Interference Ratio visualization available for passive surveys might provide insight
into interference issues. Excessive network traffic might be caused either by oversubscription (too
many clients per AP) or by excessive network load by some clients. The former can be addressed
by increasing the number of APs, while the latter should be verified and handled by network traffic
monitoring software.

The client-AP part of the link might not be the bottleneck. Even if the wireless link quality is
excellent and provides high throughput rates, the wired side of the network might be the
problem. For example, if the throughput test server utility is running on a computer equipped
with a 100 Mbps adapter, your throughput rates in this test will never exceed 80 or 90 Mbps,
despite the fact that the wireless side of the link might provide 150 or 200 Mbps throughput.
Make sure that the bandwidth of the wired side exceeds the bandwidth of the wireless side; check
Ethernet adapter speeds, switch port speeds, cabling, etc. All the hardware between the client
and server should support the speed of at least 1 Gbps.
UDP Upstream and Downstream Rate
The UDP Upstream Rate and UDP Downstream Rate visualizations show UDP throughput rates measured
in Mbps (megabits per second.) Throughput (also often referred to as “goodput”) is the amount of
application-layer data delivered from the client to the server (upstream) or from the server to the client
(downstream) per second. The protocol overhead is not included, so when we talk, for example, about
the UDP throughput rate of 1 Mbps, we mean that 125 Kbytes of actual data payload were sent between
two network nodes during one second, not including UDP, IP, and Ethernet or 802.11 headers.
60
Analyzing Data – Active Surveys | TamoGraph Site Survey
Just like TCP throughput rates, UDP throughput rates are one of the most important real-world metrics of
a WLAN, because they determine the end user experience and network-related application performance.
Unlike TCP, UDP is typically used in audio and video streaming applications, such as VoIP, so UDP
throughput metrics might give you an insight into expected VoIP quality.
Double-clicking on the UDP Upstream and Downstream Rate legend on the status bar allows you to
configure the color scheme and change its value range.
Suggested Solutions
When low throughput areas are discovered, the following solutions are suggested:

Verify that the actual PHY rate is sufficient. Throughput rates cannot exceed PHY rates; in practice,
they are about 50% lower than PHY rates. For example, if the PHY rate in the given area is only 2
Mbps, you should not expect the throughput rate to exceed 1 Mbps. In practice, it might be as
low as 0.1 or 0.2 Mbps, depending on other conditions.

Other common reasons for low throughput rates are interference and excessive network traffic.
The Signal-to-Interference Ratio visualization available for passive surveys might provide insight
into interference issues. Excessive network traffic might be caused either by oversubscription (too
many clients per AP) or by excessive network load by some clients. The former can be addressed
by increasing the number of APs, while the latter should be verified and handled by network traffic
monitoring software.

The client-AP part of the link might not be the bottleneck. Even if the wireless link quality is
excellent and provides high throughput rates, the wired side of the network might be the
problem. For example, if the throughput test server utility is running on a computer equipped
with a 100 Mbps adapter, your throughput rates in this test will never exceed 80 or 90 Mbps,
despite the fact that the wireless side of the link might provide 150 or 200 Mbps throughput.
Make sure that the bandwidth of the wired side exceeds the bandwidth of the wireless side; check
Ethernet adapter speeds, switch port speeds, cabling, etc. All the hardware between the client
and server should support the speed of at least 1 Gbps.
UDP Upstream and Downstream Loss
This visualization shows loss of UDP packets from the client to the server (upstream) or from the server
to the client (downstream) measured in percentages. Packet loss is applicable to UDP tests only, because
in TCP, all packets must be acknowledged and no data loss may occur. UDP loss is calculated as the
percentage of data that was lost during transmission. For example, if the server sent 1 megabit of data in
10 milliseconds and the client received 0.6 megabits in 10 milliseconds, while 0.4 megabits were lost en
route, a 40% downstream loss has occurred.
UDP loss determines end user experience in audio and video streaming applications, such as VoIP. High
loss percentage might cause high jitter and delays in audio and video.
When viewing this visualization, it is very important to understand that high downstream loss is normal.
UDP traffic is not acknowledged. This means that the party that sends traffic can send as much traffic as
the networking system can handle without “caring” about how much of it will be lost. A typical computer
on the wired side of the network (server) equipped with a gigabit adapter can send hundreds of megabits
per second. This data will first reach a switch, which might be the first bottleneck, and then the AP, which
61
Analyzing Data – Active Surveys | TamoGraph Site Survey
is almost always a bottleneck, because a typical 802.11n access point cannot send more than 100 or 150
Mbps of data downstream, i.e., to the client. As a result, over 50% of UDP packets might be lost en route,
but this is the only way to figure out the maximum downstream UDP throughput value.
Suggested Solutions
When high UDP loss areas are discovered, the following solutions are suggested:

Verify that the actual PHY rate is sufficient. Throughput rates cannot exceed PHY rates; in practice,
they are about 50% lower than PHY rates. For example, if the PHY rate in the given area is only 2
Mbps, you should not expect the throughput rate to exceed 1 Mbps. In practice, it might be as
low as 0.1 or 0.2 Mbps, depending on other conditions.

Other common reasons for low throughput rates are interference and excessive network traffic.
The Signal-to-Interference Ratio visualization available for passive surveys might provide insight
into interference issues. Excessive network traffic might be caused either by oversubscription (too
many clients per AP) or by excessive network load by some clients. The former can be addressed
by increasing the number of APs, while the latter should be verified and handled by network traffic
monitoring software.
Round-trip Time
This visualization shows Round-trip time (RTT) measured in milliseconds. RTT is the length of time it takes
for a data packet to be sent from the client to the server and back.
RTT affects application responsiveness: A high RTT value means that an application server's response to a
client request is slow. RTT also affects end user experience in audio and video streaming applications,
because a high RTT value will inevitably cause a VoIP lag. Varying RTT might also cause VoIP jitter.
When the surveyor walks the facility during an active survey, the adapter periodically renegotiates the
PHY rate and roams to new APs. During these periods of time, RTT values might peak, which is normal.
Suggested Solutions
When areas with consistently high RTT are discovered, the following solutions are suggested:

Common reasons for high RTT values are interference and excessive network traffic. The Signalto-Interference Ratio visualization available for passive surveys might provide insight into
interference issues. Excessive network traffic might be caused either by oversubscription (too
many clients per AP) or by excessive network load by some clients. The former can be addressed
by increasing the number of APs, while the latter should be verified and handled by network traffic
monitoring software.
Associated AP
This visualization shows to which APs the client was associated during an active survey. As you move along
the path, the client adapter typically roams to the AP that provides the strongest signal within your WLAN.
It is important to remember that some adapters allow for adjustment of roaming thresholds; these
roaming settings might affect the roaming behavior and, therefore, this visualization. For example,
62
Analyzing Data – Active Surveys | TamoGraph Site Survey
consider two APs located 20 meters away from each other with the signal level ranging from -30 dBm next
to the APs to -70 dBm in the middle of the distance between the APs. As you walk from the first to the
second AP, some clients will roam as soon as they pass the middle point, while others will not roam until
they are only a few meters away from the second AP. For the same reason, the Associated AP visualization
is heavily dependent upon the walkabout path and its direction. Walking from the first to the second AP
might produce a picture that would be different from the one produced by walking in the opposite
direction.
Requirements
This visualization shows what requirements set by the user are met. The Requirements panel (located on
the Properties tab of the right-side panel) allows the user to set thresholds for key WLAN parameters,
namely (under the Active section):






Minimum TCP upstream rate (shown as ↑TCP on the legend)
Minimum TCP downstream rate (shown as ↓TCP on the legend)
Minimum UDP upstream rate (shown as ↑UDP on the legend)
Minimum UDP downstream rate (shown as ↓UDP on the legend)
Minimum actual PHY rate (shown as APHY on the legend)
Maximum round-trip time (shown as RTT on the legend)
The zones where the requirement is not met are marked with the corresponding legend color. If more
than one requirement is not met, only one color will be used (priority is given to the requirements closer
to the top of the list). If all the requirements are met, no color overlays will be displayed.
The meaning of the requirements listed above is explained in detail in the preceding sections of the
Analyzing Data – Active Surveys chapter.
63
Analyzing Data – Active Surveys | TamoGraph Site Survey
Spectrum Analysis
Spectrum analysis involves the use of special RF equipment designed to listen to and analyze the
frequency bands utilized by Wi-Fi devices. Because these bands are unlicensed, they are often shared with
non-Wi-Fi sources of RF signals, such as wireless video cameras, microwave ovens, or cordless phones,
which cause interference. The purpose of spectrum analysis is to detect and identify such sources of
interference, eliminate them, and/or identify the WLAN channels with minimal interference. While
spectrum analysis is not a mandatory part of a site survey, it might be very beneficial, especially in noisy
RF environments.
Hardware Requirements
TamoGraph can perform spectrum analysis simultaneously with passive surveys by interfacing with WiSpy, a USB-based spectrum analyzer. Wi-Spy can be purchased directly from MetaGeek.
TamoGraph supports the following Wi-Spy models:



Wi-Spy DBx (dual-band, 2.4 GHz and 5 GHz)
Wi-Spy 2.4x (single-band, 2.4 GHz)
Wi-Spy 2.4i (single-band, 2.4 GHz)
Note that TamoGraph DOES NOT support the oldest Wi-Spy model (“Wi-Spy original” with a green logo)
or 900x models.
When a dual-band model, Wi-Spy DBx, is used, it continuously sweeps both bands, one after the other.
Using two Wi-Spy DBx units simultaneously might improve data quality, as TamoGraph would dedicate
each of the units to one band only.
64
Spectrum Analysis | TamoGraph Site Survey
Spectrum Data Graphs
When Wi-Spy is plugged in, a live spectrum picture is displayed on the central pane of the main
TamoGraph window, as shown below.
The spectrum pane is similar to the one you can see in Chanalyzer, a spectrum analysis application by
MetaGeek that comes with Wi-Spy. By default, the spectrum pane displays one or two planar spectrum
graphs for single- and dual-band Wi-Spy models, respectively.
The appearance of the graphs can be controlled via the context menu. Select 2.4 GHz, 5.0 GHz, or Dual to
have the spectrum pane display one of the single frequency bands or two bands simultaneously (5.0 GHz
and Dual are available only if you have a dual-band Wi-Spy model.) Select Current Level to display a line
that shows the current signal amplitude; select Max Level to display a line that shows the maximum signal
amplitude. The X-axis item allows you to select the measurement units of the horizontal axis; you can
choose between Frequency in MHz and Channel numbers. By enabling the Waterfall view, you can have
the application graph amplitude over time. Select 1/3, 1/2, or 2/3 of the window size to adjust the area
of the window occupied by the waterfall graph. The spectrum pane can be detached from the main
application window and displayed as a separate floating window. Use the Detach Window and Attach
Window to perform the respective operations. You can also hide the spectrum pane by checking or
unchecking the View => Spectrum item in the main application menu.
Note that in order to view spectrum data in TamoGraph, you must close Chanalyzer if it is running; WiSpy cannot be accessed and controlled by multiple applications simultaneously.
65
Spectrum Analysis | TamoGraph Site Survey
Performing Spectrum Analysis Surveys
Spectrum data can be collected either simultaneously with passive surveys or in spectrum-only mode (you
will be prompted to select one of these two options in the survey type selection dialog.) The survey
procedure is very similar to the one that you follow when you perform standard passive surveys. It is
described in detail in the Data Collection chapter. To collect spectrum data during a passive survey, simply
plug Wi-Spy into a USB port of your computer before you begin the survey. However, there are a few
peculiarities that you should keep in mind:

Spectrum data collection cannot be performed simultaneously with active surveys. During active
surveys, spectrum data might be distorted due to the proximity of the Wi-Fi adapter that sends
and receives large amounts of data. Therefore, spectrum data collection is disabled when active
or simultaneous passive + active surveys are performed.

The data collection style for a spectrum survey is typically different from the style used for
standard Wi-Fi surveys. Specifically, when performing spectrum surveys, the surveyor should
spend more time in each survey point before moving to the next one. However, simultaneous WiFi and spectrum data collection might give the surveyor valuable information. We recommend
using the point-by-point mode, as described in the Data Collection chapter, because in that mode,
the spectrum analyzer has more time to collect data than it has in continuous mode. If you prefer
to collect spectrum data in a traditional way, i.e., spend 30 seconds or a minute in a given location
or zoom into a specific frequency range, you can do that using Chanalyzer.
Viewing Collected Spectrum Data
After you have performed a survey, the spectrum data collected can be viewed in two ways. The first
option is viewing data in the main application window. When you hover the mouse over any point of the
walkabout path, the spectrum pane displays the graph for the given survey point. Because a meaningful
chart must contain data collected over a certain period of time (typically one minute), the chart displays
data collected during the time period starting -30 seconds prior to the selected walkabout path point and
ending +30 seconds following the selected walkabout path point, or a total time span of one minute. If
you analyze the points at the very beginning of the walkabout path, the time span shifts accordingly. For
example, for the first point, the time span would start with the first second and end with the 60th second.
The same principle works for the points at the very end of the walkabout path. When you move the mouse
away from the walkabout path, the spectrum pane begins displaying live data again (if Wi-Spy is plugged
in.)
The second option is viewing data in PDF or HTML reports. When a report with spectrum data is
generated, location markers are overlaid on the floor plan and walkabout path, and a sequence of
spectrum charts corresponding to each location marker is added to the report.
Exporting Spectrum Data
The spectrum data collected during site surveys can be exported into the WSX format for subsequent
viewing in Chanalyzer by MetaGeek (version 4.2.1.28 or higher required). To export spectrum data, open
a project that contains a spectrum analyzer survey, select a survey on the Plans and Surveys tab, and click
Project => Export Spectrum Data.
66
Spectrum Analysis | TamoGraph Site Survey
Reporting and Printing
After performing a site survey and viewing its results in the main application window, you can create a
report that contains all the information and visualizations related to your survey. To configure the report
options and generate a report, click Project => Generate Report in the main application menu.
The report generation dialog allows you to configure the following report options:

Plans and Surveys. This frame lists the available floor plans and survey paths to be included in the
report. Depending on where and when the surveys were conducted, you may want to check all or
only some of the survey checkboxes. By default, the selection is the same as in the main
application window. If you are working with a predictive survey, data from this survey is shown as
a “Virtual Data” item. If you are working with a survey that contains spectrum analysis data, that
data is shown as a “Spectrum Data” item. At the bottom of this frame, you can also see the
indication of the Current AP selection mode, which tells you if the report will be generated for all
or for only the selected APs. Again, the selection is the same as in the main application window.
If you want to change the AP selection mode, close the report dialog and change the mode, using
the corresponding buttons on the tool bar of the main window. By default, TamoGraph merges
the data collected during all the selected surveys. Check Don't merge surveys if you want to get
a separate report for each of the survey paths. This might be useful if you want to generate a
report illustrating the changes in WLAN characteristics depending on varying conditions, e.g.
multiple surveys of the same office when you test different AP placements at the deployment
stage. Normally, Don't merge surveys should not be checked.

Project information. Use the Surveyor, Location, and Description fields to specify additional
information about your project.

Visualizations. This list allows you to select which visualizations you would like to see in the report
by checking or unchecking the corresponding boxes. Check Map with no visualizations if you
would like to have the original site map / floor plan included. Add per-AP visualizations is an
important option that allows you to add additional visualizations for each of the selected APs. For
example, if you want to create a report for five APs and include the Signal Level visualization with
the Add per-AP visualizations option, the report will contain one cumulative signal level
visualization for all of the five APs and, additionally, five separate visualizations for each of the
APs. Without the Add per-AP visualizations option, the report will contain only one cumulative
signal level visualization that includes data on all of the five APs. The Add per-AP visualizations
option is available only when the Don't merge surveys option is turned off.

Additional items to include. Check the corresponding boxes to include additional information
pertaining to your site survey. Checking Walkabout paths will add survey paths to the site map(s)
(not available if you do not include the Map with no visualizations item); checking AP list will add
the table that lists all of the APs observed during the survey; checking Map descriptions will add
the descriptions (if any) of the floor plan(s) entered by the user; checking Survey comments will
add the comments (if any) for specific surveys entered by the user; checking Virtual Obstructions
will display virtual obstructions, such as walls or attenuation areas, on the floor plan. This option
is applicable to predictive surveys only. Checking Media Objects will add photographs taken
during the surveys.

Output settings. Use the Format drop-down list to select the report format. You can choose
between PDF, HTML, HTML (single file), and KMZ (Google Earth™) formats. The difference
67
Reporting and Printing | TamoGraph Site Survey
between the HTML and HTML (single file) is that in the former, images are stored in a separate
subfolder, whereas in the latter, images are embedded into a single .MHT file, which can be
natively viewed only in Microsoft Internet Explorer. KMZ files can be used for viewing results of
GPS surveys in Google Earth; see the Google Earth Integration chapter for details. The Paper size
drop-down list can be used to specify the size of the report pages: A4 or Letter. If you generate
reports in PDF format, you can control the JPEG quality (the higher the quality is, the larger the
file size will be) and the Embed fonts option. Embedding fonts increases the output file size
considerably, but ensures that the file looks correct on any system, even if the fonts used in that
file are not installed.
Once you have configured all the options, you may want to customize its look (fonts, colors, logos, etc.)
by clicking Customize and then clicking Save to select the file name and have TamoGraph generate the
report. Check the Open report after generation box to have the file opened by the associated viewer
upon generation. If you would like to print the report without saving it to a file, click Print. Alternatively,
you can first save the report and then print it from the associated viewer (Adobe Acrobat in the case of
PDF files or your favorite browser in the case of HTML files).
Customizing Reports
IMPORTANT: Report customization is available to Pro License users only.
The report customization dialog can be accessed by clicking the Customize button and checking the
Enabled report customization box. By using the customization functionality, you can change text colors,
fonts, logos, or add additional text to PDF or HTML reports.
The following customization elements are available:

Heading #1 and Heading #2 – use these fields to modify the default report heading and
subheading on the first report page.

Footer – use this field to modify the default footer text that is placed at the bottom of every report
page except the first one.

Additional summary row and Additional summary text – use these fields to add a row to the
report summary located on the first page.

Logo – this element allows you to replace the default logo on the first page. You can select an
image in any common graphic format.

Colors – use this frame to set custom colors. #1 is for the heading on the first page; #2 is for other
headings; #3 is for the background of the tables; #4 is for the table heading text color; #5 is for
the main text color.

Fonts – use this frame to modify the default fonts. #1 is for the heading font; #2 is for the main
text font.
Additionally, you may want to Add a page before the report and/or Add a page after the report by
checking the corresponding boxes. Clicking Edit opens an editor window where you can enter and format
any text and specify the headings for the additional pages. To apply the new settings, click OK. To restore
the default settings, click Default.
68
Reporting and Printing | TamoGraph Site Survey
Google Earth Integration
You can export survey results to a popular geographical information program, Google Earth™. This
functionality is intended for large outdoor GPS-assisted surveys that you conduct using TamoGraph. By
exporting data to Google Earth, you get an additional analysis option that integrates TamoGraph
visualizations with rich geographical data provided by Google Earth. Data is exported in to a single Google
Earth file (KMZ format) and can be viewed on any computer where Google Earth is installed.
To be able to export data to Google Earth, your survey project must be GPS-calibrated; see the GPS
Calibration chapter for more details. When you open the KMZ file in Google Earth, your visualizations are
overlaid on top of the satellite images or street maps. You can control which layers/visualizations are
shown using the Places interface element in Google Earth. You can also rearrange the report according to
your requirements by dragging the tree nodes in the Places interface element; such rearranged reports
can be saved into a new file. You can learn more about working with Google Earth by visiting
http://earth.google.com/support/.
There are two methods of data export from TamoGraph to Google Earth.
Current Visualization Export
This is the simplest method that lets you export a single visualization that is currently selected. Select a
visualization on the toolbar, use the Project => Save current visualization menu command, select Google
Earth (*.kmz) as the file output format, enter a file name, and then click Save to save the visualization.
The resulting KMZ file can then be opened in Google Earth by double-clicking on it.
Export from the Report Dialog
For more advanced options, you can use the Project => Generate Report menu command. In the report
configuration dialog, check the visualization(s) and survey(s) you would like to export and then select KMZ
(Google Earth) from the Format drop-down list. Note that not all the surveys can be exported to Google
Earth; only those surveys that were GPS-calibrated can be exported because the application must know
the exact coordinates of your map to be able to export data; see the GPS Calibration chapter for more
details. Click Save to generate a KMZ file. Unlike the first method that includes a single visualization, this
method allows TamoGraph to generate a complex report file that contains a tree-like structure of layers
that can be navigated and displayed in Google Earth. Visualizations and auxiliary elements can be accessed
in the Places interface element in Google Earth. You will be able to select layers, view locations of APs,
turn on and off visualizations, and further customize the view.
69
Google Earth Integration | TamoGraph Site Survey
Configuring TamoGraph
Virtually all of the application and project settings can be configured using the right-side panel (if the panel
is hidden, click View => Right Panel or click on the central part of the right splitter to have it displayed).
This panel includes three tabs whose functionality is described below in detail.
Plans and Surveys
This tab displays a hierarchical list of the project floor plans or site maps and performed surveys, as shown
below.
This list is an important tool that offers the following functionality:

Add, rename, or delete floors (for multi-floor projects) and floor plans / site maps: The project
hierarchy consists of floors, floor plans, and surveys. The top hierarchy level is a floor, which
contains one or several floor plans. A floor plan contains one or several surveys (i.e., walkabout
paths with associated data collected by TamoGraph). Adding a floor is optional. Your project does
not necessarily have to have the top-level floor node; when you create a new project, a floor level
is not automatically created, and your floor plan becomes the top-level node. To add a new floor,
click Add => Floor. To add a new plan, select the floor you want to add the plan to and click Add
=> Plan or Add => Street map, if you want to import a map from one of the online map services
or Microsoft MapPoint (MapPoint Europe or MapPoint North America are required to use
MapPoint maps). To move a plan and related surveys to a newly created floor, simply select the
plan with the mouse and drag it to the corresponding floor node. You can also use the context
menu commands to Rename or Delete floors and floor plans.

Include, exclude, or delete surveys: Every survey that you performed shows up as a separate
check-boxed item under the floor plan where the survey took place. Checking the box makes the
application include the data collected in the course of the selected survey in data analysis and
visualizations. Depending on where and when the surveys were conducted, you may want to
check all or only some of the survey check boxes. For example, if you have a large site and you
made one break while conducting the site survey, your walkabout path will consist of two parts,
both of which should be included in the analysis. In a different scenario (e.g., when you surveyed
the entire site prior to installing additional wireless hardware and then surveyed it again after the
installation), you will probably want to include only one of the surveys and then compare it with
the other one by changing the check box selection. You can also use the context menu commands
to Rename or Delete surveys.
70
Configuring TamoGraph | TamoGraph Site Survey

Merge surveys: Sometimes, you may want to merge several surveys into a single one for clarity
and/or convenience. Typically, this might be desirable when you made a break and then resumed
the survey from where you previously stopped. In such a situation, it is quite logical to merge two
surveys into a single one, as they represent a single logical walkabout path. To do that, check the
surveys you want to merge and use the Merge Surveys context menu command. Please note that
that the types of the surveys to be merged, their data collection methods, and all other
parameters must be exactly the same. For example, you can merge two active surveys conducted
in continuous mode in which you collected TCP and UDP throughput data, but you cannot merge
an active and a passive survey, or two active surveys if in one of them you collected TCP data and
in the other you collected TCP and UDP data. Similarly, you cannot merge two surveys if one of
them was conducted in continuous mode while the other was conducted in point-to-point mode.
The Type column displays the type of survey that was conducted: Passive, Active, or Passive + Active. You
can use the Comments column to add or modify comments for surveys. The Floor Manager is a tool that
may be used in multi-floor predictive surveys; more information can be found in the Working with MultiFloor Sites chapter.
Properties
Using this tab, you can configure the project properties. It includes four panels: Plan / Map, Environment,
Requirements, and Scanner. You can collapse or expand panels by clicking on the arrow button on the
right-hand side of the panel.
Plan / Map
The Plan / Map panel can be used for editing the floor plan Map name, adding Description/Comments to
the plan, and adjusting the image brightness and contrast, if the floor plan is too bright, too dark, or lacks
contrast. If the floor plan image is colored, you may want to check the Discard color information box to
convert it to grayscale, as grayscale images give you a clearer picture when overlaid with data
visualizations.
Environment
The Environment panel allows you to configure some of the very important project parameters that affect
the way data visualizations are computed.
Because different environments have different characteristics in terms of signal attenuation, diffraction,
reflection, etc., you are asked to Select an environment from the list. You should select the environment
that best describes the site being surveyed.
For each environment, the application recommends a Guess range. A guess range is the diameter of the
circle for which the application predicts WLAN characteristics with a high degree of certainty. The lower
the range, the more accurate the measurements, but the longer your walkabout path is. The higher the
range, the less accurate the measurements, but the less time you spend performing a survey. When you
conduct a site survey and click on the map to mark your location, TamoGraph displays your path and
draws the guess range around the route points and your path, thus giving you a visual indication of the
zone that you covered with your survey. The image below illustrates the walkabout path and guess range
zone drawn along the path.
71
Configuring TamoGraph | TamoGraph Site Survey
It is quite all right to decrease the suggested guess range, but increasing it is not recommended for the
reasons explained above.
For passive surveys, TamoGraph can also compute WLAN characteristics outside the guess range zone,
although such computations will have a lower degree of accuracy. Check the Extrapolate data beyond
the guess range box to enable such computations. Enabling this option will mean that data visualizations
will cover the entire map rather than the areas that you actually surveyed. Enabling this option is not
recommended.
For predictive surveys, you can specify the expected noise level for your virtual environment. There are
two separate controls for the 2.4 GHz and 5 GHz bands. The default level is -90 dBm for 2.4 GHz and -95
dBm for 5 GHz.
Finally, the Measurement units control can be used to choose the preferred units (feet or meters) for
displaying distances and coordinates throughout the application.
Client Capabilities
The PHY rate used in the AP-client connection is determined by the capabilities of the AP and the
capabilities of the client. For example, an 802.11ac AP that supports three spatial streams and 80 MHz
channels can provide data rates up to 1,300 Mbps. However, if the client is limited to 802.11n, two spatial
streams, and 40 MHz channels, the PHY rate will not exceed 300 Mbps.
Using the Client Capabilities panel, you can simulate different types of clients, and this affects the
Expected PHY Rate and Requirements visualizations. You can selected the Supported standards (802.11
a/b/g/n/ac, 802.11 a/b/g/n, or 802.11 a/b/g), Channel width (20, 40, 80, or 160 MHz), and Spatial streams
(between 1 and 4). By default, client capabilities are set to the best real-world values: 802.11 a/b/g/n/ac,
80 MHz channel width, and three spatial streams. While the 802.11ac standard allows up to eight spatial
streams and up to 160 MHz channel width, such clients currently do not exist. If you want to visualize the
Expected PHY Rate constrained by the client capabilities, you can do so by adjusting them. Note that the
client capabilities configured in this pane affect only passive and predictive surveys; they do not affect
active surveys, because in an active survey, PHY rates depend on the actual client adapter that you use.
Requirements
Using the Requirements panel, you can configure the requirements that your WLAN should meet. The
configuration that you create will be used for displaying the Requirement (passive surveys) and
Requirements (active surveys) visualizations. These visualizations are helpful for a quick and easy
72
Configuring TamoGraph | TamoGraph Site Survey
evaluation of the overall health of your WLAN and detection of potential issues. You can set thresholds
for the following WLAN parameters (click on the links for the detailed description of the corresponding
items):

Passive and Predictive Surveys
o
o
o
o
o
o
o

Minimum signal level
Minimum signal-to-noise ratio
Minimum signal-to-interference ratio
Minimum APs required
Minimum PHY rate
Minimum allowed frame format
Minimum channel bandwidth
Active Surveys
o
o
o
o
o
o
Minimum TCP upstream rate
Minimum TCP downstream rate
Minimum UDP upstream rate
Minimum UDP downstream rate
Minimum actual PHY rate
Maximum round-trip time
To facilitate requirements configuration, three presets are available: Basic (for basic, low throughput
connectivity), Medium, and Advanced (for high throughput, redundant connectivity, e.g., for VoIP). You
can select a preset from the drop-down list, adjust the values, or create your own by clicking on the New
button, typing a preset name, and then clicking the Save button. You can also delete presets by clicking
on the Delete button.
Scanner
The Scanner panel gives you access to the Wi-Fi scanner configuration. The application scanner sweeps
through the channels supported by the wireless adapter to collect and analyze packets being sent on the
selected channels. It is not recommended that you modify the default 250 ms per channel scan interval.
As for the list of channels to be scanned, you may want to modify it if you know that some of the channels
supported by the wireless adapter are not used in your WLAN. For example, if your WLAN does not use
the 5 GHz band, you may want to turn off all 5 GHz channels; this will shorten the scanning cycle and,
therefore, increase the data accuracy. However, please keep in mind that skipping some of the channels
may result in the application's inability to detect sources of interference, such as neighboring APs that
work on the channels that were skipped. If you uncheck the Use the same interval for all channels box,
you will be able to specify individual per-channel intervals. It is recommended that you leave this box
checked. You can use the Select channels button for selecting or deselecting all channels, as well as for
selecting channels based on the country- or region-specific allowed channel lists (e.g., choosing United
States will select channels 1-11 and deselect channels 12-14 in the 2.4 GHz frequency band). The Scanner
panel can be used only if you have a compatible adapter for passive surveys.
73
Configuring TamoGraph | TamoGraph Site Survey
Options
This tab allows you to configure the application options. It includes four panels: Colors and Value Ranges,
AP Detection and Placement, Visualization Settings, and Miscellaneous. You can collapse or expand panels
by clicking on the arrow button on the right-hand side of the panel.
Colors and Value Ranges
Using this tab, you can configure color schemes, drawing styles, and value ranges used in visualizations
overlaid on top of the floor plan or site map. Use the Survey path color selection boxes to choose the
colors to be used for drawing active and inactive paths. An active path is the path along which you are
currently walking, marking your location on the map. Inactive paths are the paths from previously
performed surveys.
You can also choose between several Visualization schemes that will be used for visualizations, such as
signal level or expected PHY rate. Checking the Smooth colors box makes the transition between colors
smooth. Checking the Invert colors box inverts the colors in the selected visualization scheme. If you
would like to see the contours between areas of different color, check the Contour box.
Using the Value Ranges section, you can configure the range of values represented by the selected color
scheme for the Signal Level, Signal-to-Noise Ratio, Signal-to-Interference Ratio, Expected PHY Rate, Actual
PHY Rate, TCP Upstream and Downstream Rate, UDP Upstream and Downstream Rate, and Round-trip
Time visualizations. For example, if you selected the color scheme that ranges from red to blue and a
signal level value range from -80 dBm to -30 dBm, any area where the signal level is equal to or below -80
dBm will be shown in red, and any area where the signal level is equal to or above -30 dBm will be shown
in blue. Additionally, you can adjust the Steps value (i.e., the number of distinct colors to be used). Using
the same example, the entire value range from -80 to -30 dBm would be 50 dBm; setting the Steps value
to 10 would mean that every 5 dBm, a new color would be used to display the signal level and the total
number of distinct colors zones would be 10. Setting the Steps value to 20 would double the number of
distinct colors, making the color overlay much smoother.
AP Detection and Placement
This tab allows you to configure some of the options that control how TamoGraph detects APs and shows
them on the map.
Ignore APs if max. signal is below – Checking this box prevents the application from detecting and
processing signals from very weak APs. Typically, such APs do not affect your WLAN and cannot provide
connectivity due to weak signal. The default cut-off level is -90 dBm; if the signal from an AP never exceeds
the specified level, TamoGraph will completely ignore it.
Mark estimated AP locations – Checking this box makes the application automatically place APs on the
map once the survey has been performed. If the estimated AP location is not accurate, you can correct it
by moving the AP icon on the map with the mouse. If you corrected the AP location(s) by moving the
corresponding icon(s), you can revert to the original location by right-clicking on the AP list on the left
panel and then clicking Auto-locate Access Points (this action can be applied to All or Selected APs; here
by Selected we mean the AP that is currently highlighted in the AP list).
Don't auto-place APs if max. signal is below – Checking this box prevents the application from trying to
determine the location of those APs for which a strong signal was not detected. TamoGraph automatically
74
Configuring TamoGraph | TamoGraph Site Survey
determines the position of APs with strong signals and marks them on the map (if the previous option is
enabled). If the signal is not strong enough, such AP placement may not be accurate: The AP might be
located outside of the site map and might not belong to your WLAN. The default cut-off level is -75 dBm;
if the signal from an AP never exceeds the specified level, TamoGraph will not try to mark its position on
the map. If the AP was not placed on the map, you can do it yourself by dragging the corresponding AP
icon from the left-side AP list and dropping it on the map.
Maximum number of APs in tooltips – When a mouse hovers over survey path turning points, a tooltip is
displayed. The tooltip contains the list of the strongest APs audible in the selected point. Use this control
to limit the number of APs shown on the list.
Visualization Settings
The following settings affect the way TamoGraph displays some of the visualizations:
Area is considered covered if signal strength is at least – This setting defines the AP coverage area based
on the minimum signal strength. If the signal strength is below the specified level, the area is considered
to be not covered, which means that some data values will not be computed for the area (such areas will
appear as white spots). The definition of “strong enough” is rather subjective because certain signal
strength might be sufficient for low data rates, but insufficient for the high data rates required for such
applications as VoIP. Additionally, 802.11 adapters vary in sensitivity, and some adapters might be able to
provide good connectivity in zones where other adapters fail to connect altogether. The default value is 70 dBm. This setting is applicable to the following visualizations: Signal-to-Interference Ratio, AP Coverage
Areas, and Number of APs.
Average network utilization – This setting defines how heavy the interference is from the interfering APs.
If the interfering signal strength is high, but the network utilization is low, the interfering AP does not
create much interference. A typical office WLAN has a network utilization of between 10% and 25%. Adjust
this setting to match the actual value for your WLAN. This setting is applicable to the following
visualization: Signal-to-Interference Ratio.
AP coverage areas – This setting allows you to change the color coding method used for displaying
coverage areas. In No fill, contours only mode, the application draws contours of the coverage areas
without filling the areas with colors. In Fill and mix colors mode, the AP coverage areas are filled with
colors; when areas overlap, the application draws a striped pattern, alternating the colors of the
respective APs. In Fill, strongest AP on top mode, AP coverage areas are filled with colors; when areas
overlap, the application draws the color of the strongest AP. In Fill, weakest AP on top mode, AP coverage
areas are filled with colors; when areas overlap, the application draws the color of the weakest AP. This
setting is applicable to the following visualization: AP Coverage Areas.
Grayscale obstructions – This setting controls whether virtual objects (used in predictive surveys) are
displayed in color or grayscale mode. Available options are Always, When applying visualizations, and
Never.
How AP icon locations affect signal – This setting controls the effect that the AP icons have on the
calculations of the signal level and other visualizations. The following three options are available:

Estimated AP locations do not affect signal levels; they are icons only – Suitable for the surveys
where signal levels are low and AP locations cannot be estimated accurately. In this mode, the
application displays data based ONLY on the actual measurements; there are no extrapolations.
75
Configuring TamoGraph | TamoGraph Site Survey


Estimated AP locations are used to complement measured signals (new algorithm) –
Recommended for most surveys. It uses a new, more realistic algorithm for computing signal
propagation. This is the default option.
Estimated AP locations are used to complement measured signals (old algorithm, up to version
4.1) – The old-style algorithm used in versions prior to 4.2. The result is typically overly optimistic.
Miscellaneous
The following miscellaneous options are available:
Use voice assistance during survey – Check this box if you want TamoGraph to use the operating system’s
text-to-speech engine to pronounce hints and warnings while you perform a survey. This option is
available only if the current program interface is set to English. The drop-down list below this box allows
you to select one of the available voices.
Load last opened project at startup – Check this box if you want TamoGraph to automatically load the
last project you worked on (if any) when the application starts.
Display scanner progress on the taskbar – Check this box if you want TamoGraph to animate the Windows
taskbar button while you perform a survey. Not available in macOS.
Use AP names from Cisco Aironet extensions – Check this box if you want TamoGraph to use Cisco CCX
to assign names to Cisco APs. This box also enables similar functionality when displaying Aruba APs.
Custom AP names are used globally – Check this box if you want TamoGraph to use custom AP names
throughout all the projects that you work with on a given computer. When this box is not checked, custom
AP names are project-specific.
Show AP labels on the map – Check this box if you want TamoGraph to display a small label with the AP
name next to each AP on the floor plan.
Ignore multi-touch features – Check this box if you want TamoGraph to ignore the fact that you are
running it on a computer with a multi-touch display. When TamoGraph detects a multi-touch display, it
makes certain changes to the interface elements to make them more convenient to use. For example,
pane splitters become wider, the circles that represent walkabout points become larger, and so on. If you
do not need these changes, you can use this option to force TamoGraph to use a standard user interface.
Enabling or disabling this option requires a restart. Not available in macOS.
Smart map scrolling – Select when you want TamoGraph to use smart map scrolling: Always, During
Survey, or never, if you uncheck this box. Smart map scrolling scrolls the map automatically whenever
you click or tap next to the map edge, eliminating the need to scroll the map as you move along your path.
Enable automatic updates – Check this box if you want TamoGraph to connect to the TamoSoft Web site
and see whether a new TamoGraph version is available. When this option is enabled, TamoGraph checks
for updates once a week.
76
Configuring TamoGraph | TamoGraph Site Survey
Configuring GPS Receiver
IMPORTANT: GPS functionality is available to Pro License users only.
To perform GPS surveys using TamoGraph, you need a source of Global Navigation Satellite System (GNSS)
data. TamoGraph supports two types of such data sources:

A GPS receiver. TamoGraph supports any GPS receiver as long as it is NMEA-compliant. This
includes almost all Bluetooth and USB GPS receivers; such receivers communicate with the
computer over a virtual COM port (also referred to as a “serial port”). Unlike GPS receivers, GPS
navigators (which typically have displays) are usually not NMEA-compliant and therefore cannot
be used with TamoGraph unless special software is used. You can use Garmin devices; however,
you will have to use either Spanner, a freeware utility by Garmin, or GPSGate Client, a commercial
utility, to make your Garmin navigator NMEA-compliant.

On Windows only: a Windows GNSS sensor. Such sensors are integrated into many new Windows
laptops and tablets. Note that there are location sensors that do not use satellite navigation.
TamoGraph supports only satellite-based (GPS or GLONASS) sensors; other types of location
sensors are not supported.
Using GPS Configuration Dialog
If you use an integrated Windows GNSS sensor, you do not need to perform any additional configuration
steps or driver installations. Simply click Settings => GPS Settings to verify that your sensor is working and
providing data on your current coordinates.
If you use an external GPS receiver, connect it to your laptop and configure it as per the manual provided
by the device manufacturer. For Bluetooth devices, this typically involves “Bluetooth pairing”; and for USB
devices, a driver installation is usually needed. Once your device has been connected to your laptop and
turned on, click Settings => GPS Settings.
To configure TamoGraph to use your GPS receiver, all you need to know is the COM port number (on
Windows) or Port name (on macOS) through which your device is connected to your computer and the
Bits per second rate. The Port Settings frame allows you to select these values. Finding out the port
number is discussed below in this chapter. The Bits per second rate is typically 4800 or 9600; please refer
to the GPS receiver manual to find out this value. You can also click Detect to have TamoGraph scan your
ports and detect the correct values. However, this might take several minutes.
Once you have selected or detected the port number/name and data rate values, click Connect to test
your GPS receiver. The dialog will display the connection Status and the availability of GPS data (also
referred to as a “GPS fix”). If GPS data is available, which typically requires that you be outdoors, you will
see your current Coordinates (you can select the format you prefer in the corresponding frame), as well
as the data accuracy information. Click Save Configuration to save the data. You are now ready to perform
GPS-assisted site surveys.
77
Configuring GPS Receiver | TamoGraph Site Survey
The GPS settings dialog on Windows is illustrated below:
78
Configuring GPS Receiver | TamoGraph Site Survey
The GPS settings dialog on macOS is illustrated below:
Finding the GPS Receiver Port Number
As was explained earlier in the chapter, GPS receiver configuration requires that you enter the correct
COM port number or name for your receiver. This information can be either automatically detected in
the GPS configuration dialog or easily found by the user.
Windows
For Bluetooth devices, open Devices and Printers in Windows, find your Bluetooth device, and doubleclick on it. The Hardware tab will display the port number, as shown below.
79
Configuring GPS Receiver | TamoGraph Site Survey
For USB devices, open Device Manager and find your device under Ports (COM & LPT). The device name
will be followed by the port number, as shown below.
80
Configuring GPS Receiver | TamoGraph Site Survey
macOS
For Bluetooth devices, the port name typically contains the name of the GPS receiver that you have
connected. An example of the port name would be “/dev/cu.BT-GPS-38B134-BT-GPSCOM” for the GPS
receiver illustrated below:
For USB devices, the port name typically looks like “usbserial-xxxx”.
81
Configuring GPS Receiver | TamoGraph Site Survey
Taking Photographs
If you would like to add photos to your survey: e.g., images of APs, cabling, or other objects of interest,
you can do so by using a video camera integrated into your laptop or tablet. To configure your video
camera, click Settings => Camera and Voice Settings in TamoGraph and select the Video Camera tab. You
can select the camera you want to use if there is more than one camera, as well as select the resolution
of the photos that will be taken. Remember that while higher resolutions provide better image quality,
such photos are much larger in size, which means that your project file might become much larger.
Once you have configured your camera, you can add photos to a floor plan. To take a photo, click on the
webcam button on the toolbar or press Ctrl + P. A preview window will appear. When you are ready to
take a shot, press Enter or click on the preview window. To cancel, press Esc or click outside the preview
window. The photo that you have taken appears as a small camera icon on the floor plan. The position of
the icon depends on when you took the photo:

While you were surveying: You may want to take photos while you are conducting a survey. The
best method is to pause the survey, take a photo, and resume the survey. In this scenario, the
photo icon is placed at your current location on the floor plan.

While you were not surveying: You can take photos while you are inspecting the facility without
conducting a survey at the same time. In this scenario, the photo icon is placed in the center of
the floor plan image, as the application is not aware of your current location, unless you have
configured a GPS receiver and your current map has been GPS-calibrated, in which case the photo
icon is placed at your current GPS location on the map.
Regardless of the initial photo icon position, you can move the icon to any location on the floor plan by
dragging it with the mouse. When you hover the mouse over the photo icon, you can see a small preview
window. To see the full size photo, click on the preview window. If you do not want to see photo icons on
the floor plan, use the View => Media Objects menu command to turn them on or off. To delete a photo,
drag it off the floor plan image or press Del while viewing the full-size photo.
Photos can also be included in the reports. If the Media Objects checkbox in the report configuration
window is checked, your photos will be appended to the report. For each photo, its location on the floor
plan will be indicated.
82
Taking Photographs | TamoGraph Site Survey
Voice Control
IMPORTANT: Voice control can be performed in English only. An English voice recognition engine
may not be available in non-English operating system editions.
When you conduct site surveys, it is often convenient to control the application without using your hands.
With TamoGraph, this can be achieved by using the operating system’s voice recognition engine. You can
actually “tell” the application what to do using simple voice commands; for example, “TamoGraph, pause”
or “TamoGraph, pan left”. To configure voice control, click Settings => Camera and Voice Settings in
TamoGraph and select the Voice Commands tab. Check the Enable voice recognition box to turn on this
functionality and select a Voice input device, which might be a microphone integrated into your
laptop/tablet; or, better yet, headphones with a microphone; an external microphone typically provides
a much higher voice recognition quality. On Windows, the Voice recognition engine control allows you to
select a language to be used, e.g. “English – US” or “English – UK”. On macOS, you may need to enable
enhanced (offline) dictation. To enable it, open the system preferences dialog, select “Keyboard”, then
“Dictation”, turn on “Dictation”, enable the “Use Enhanced Dictation” feature, and restart TamoGraph.
After configuring the voice recognition parameters, use the Voice command test frame to test it. Press
Start and say one of the pre-set commands:








Zoom in, Zoom out – zooms a floor plan in and out.
Start – starts a survey.
Stop – stops a survey.
Pause – pauses a started survey.
Resume – resumes a paused survey.
Pan up, Pan down, Pan left, Pan right – pans a floor plan.
Take photo – takes a photo.
Don’t listen – turns off voice recognition.
Each command must be prefixed with the specified Command prefix. By default, the prefix is
“TamoGraph”, but you can change it to any other word. The reason why you need to use a prefix is the
following: When voice recognition is enabled, the application is constantly listening for speech in the
microphone. If you talk to someone while you are surveying and say, for example, “I need to take a photo”,
the voice recognition engine hears the “take a photo” part and performs the action associated with this
command, although you never wanted it to. To prevent the actions from being triggered by such phrases,
actual commands intended for execution should be prefixed by a special word (by default, “TamoGraph”).
To test voice recognition, say “TamoGraph, zoom in” or “TamoGraph, take photo”. If the pronounced
command is recognized, you will see and hear the confirmation message; e.g., “Zoom in ok”. For some of
the commands, you can customize the associated action. Zoom step and Pan step control the percentage
of zoom and pan, respectively. Take photo after (sec.) controls the time interval after which the photo is
automatically taken.
Once you have configured and tested voice recognition, you can close the configuration dialog and use
voice commands to control TamoGraph. If a command is not applicable now; e.g., pausing a survey that
was never started, you will be notified accordingly. Voice recognition can be turned on and off using the
microphone icon on the right side of the status bar of the main TamoGraph window.
83
Voice Control | TamoGraph Site Survey
Using TamoGraph in a Virtual Machine
You can install and use TamoGraph Site Survey inside a virtualized Windows OS running as a guest
operating system on a Mac (or PC, if you prefer a virtual environment for whatever reason). In order to
do that, you will need virtualization software, such as VMWare, Parallels Desktop for Mac, or Virtual Box.
Guest Operating System
As a guest Windows version, you can use Windows 10, Windows 8.1, Windows 8, or Windows 7, although
we recommend Windows 10 or 8.1 for the reasons explained below.
Hardware
To use TamoGraph for passive surveys, you need a compatible adapter. When you run our software on a
Windows laptop, you can use any of the compatible adapters in different form factors. The list of
compatible adapters can be found here. When you run TamoGraph inside a virtual Windows machine,
you can use USB adapters only. Please refer to the adapter list to find the USB adapter you are going to
use. We strongly recommend that you choose an adapter marked "Recommended." They are also always
available from us directly when you buy the boxed version.
Virtualization Software Configuration
If your virtualization software supports USB 3.0 emulation (which is the case if you are using VMWare or
Parallels Desktop for Mac), be sure to use USB 3.0 emulation rather than USB 2.0 emulation, even if the
USB port and the Wi-Fi adapter you are going to use are USB 2.0. Support for USB 3.0 requires Windows
8 or higher as the guest OS. USB configuration in VMWare is illustrated below.
84
Using TamoGraph in a Virtual Machine | TamoGraph Site Survey
USB 3.0 emulation is preferable because it dramatically increases the communication speed between the
Wi-Fi adapter and guest OS. For example, in some adapters, switching the Wi-Fi channel might take 500
or even 1,000 milliseconds if you use USB 2.0 emulation and only 100 milliseconds if you use USB 3.0
emulation. Considering the fact that TamoGraph typically switches channels every 250 milliseconds, this
difference is dramatic. Using USB 2.0 emulation might slow down the application considerably.
For this reason, we recommend that you do not use VirtualBox as virtualization software. At the time of
writing, VirtualBox has no USB 3.0 support. If you still want to use VirtualBox, at least use the Enable USB
2.0 (EHCI) Controller option; otherwise, your USB Wi-Fi adapter might not work.
Adapter Installation
Plug in the USB adapter into your computer. Once the adapter is plugged in, you will need to configure
your virtualization software to use the detected USB device, i.e. disconnect it from the host OS and
connect it to the guest OS. The configuration method depends on the specific virtualization software that
you use; please refer to the related documentation. After the virtual machine takes control of the adapter,
Windows will notify you that a new USB device has been found and will try to find the driver for the device.
Click Help => Driver Installation Guide in TamoGraph to find the instructions for installing our special
packet capture driver. Once that driver has been installed, you can restart the application and use it.
85
Using TamoGraph in a Virtual Machine | TamoGraph Site Survey
Frequently Asked Questions
Q. Why is TamoGraph much more affordable than the competing site survey products?
A. Surprisingly, this non-technical question is probably the most frequently asked one. TamoGraph is more
affordable for a number of reasons. We don't spend money on an impressive office in Silicon Valley. We
don't fly first class looking for more venture capital. We've been in the software business for 15 years and
we know how to work efficiently, to maintain a high brain-to-fat ratio. We also believe that all WLAN
professionals should be able to afford a professional tool to do their job.
Q. Do I need a compatible Wi-Fi card to perform active surveys?
A. No, you can use pretty much any modern Wi-Fi adapter. However, active surveys give you only a small
part of the WLAN picture. To get comprehensive information, passive surveys are mandatory. A
compatible adapter is required for passive surveys.
Q. My card is not on your list of supported hardware. What are my options?
A. On Windows: Our hardware compatibility list includes only those cards that we've tested ourselves in
our test lab. There are other cards that may be compatible with TamoGraph. The best way to find out if
your card is compatible is downloading our Adapter Test Utility and running it on your computer. If a
compatible adapter is installed, the utility will display its name. Before running our test utility, make sure
that you use the latest driver supplied by your computer or adapter vendor. Visit their Web site to
download and install the latest driver version. This is important, because the results of the test depend
on the driver that is used. The newer the driver, the better the chances that it will work with TamoGraph.
Finally, you may want to buy a compatible card, as they are not terribly expensive these days. Or simply
order a boxed version from us; it comes with a compatible USB adapter. On macOS: TamoGraph works
with the integrated Wi-Fi adapter built into your MacBook. It neither requires nor supports external USB
adapters.
Q. Why is the left panel that is supposed to display the list of access points empty?
A. This might be the case for a number of reasons:

You do not have a compatible adapter for passive surveys. The access point list is populated only
if you have a compatible adapter or if you opened a project that already contains previously
collected survey data.

You did not install the driver for your compatible adapter. Please refer to the Driver Installation
chapter for instructions. To verify that your compatible adapter is present and functioning
correctly, look at the lower left corner of the application window. Your compatible adapter name
should be displayed there. If the adapter name is displayed, but the list is still empty, contact our
technical support.
Q. Does TamoGraph support 802.11ac WLANs?
A. Yes, it does.
86
Frequently Asked Questions | TamoGraph Site Survey
Q. Do I need an 802.11ac adapter to survey 802.11ac WLANs?
A. This depends on the type of survey. For passive surveys, a supported 802.11n adapter is sufficient, as
long as it is a dual-band adapter, i.e., if it can work in the 5 GHz band. Such adapters can capture 802.11ac
management frames, which is needed for passive surveys. For active surveys, when your adapter is
associated to the WLAN to measure throughput and actual PHY rate, you may want to use an 802.11ac
adapter if you need to know the WLAN metrics for 802.11ac clients. However, this is not mandatory,
because you may want to estimate throughput for 802.11n clients, which are far more widely used than
802.11ac clients are at the time of this writing. In this case, an 802.11n adapter for active surveys will
suffice.
Q. I have a Wi-Spy USB spectrum analyzer. Do I still need a separate Wi-Fi adapter for passive or active
surveys?
A. Yes, you do. Wi-Spy can be used for spectrum analysis only. It cannot replace a Wi-Fi adapter because
it cannot capture packets or connect to networks.
Q. If I select a small Guess Range, then the predicted coverage at the end of the survey does not cover
the whole office area that I am testing. Yet, if I increase the Guess Range, the coverage shadows seem
to be bigger and cover the whole office. So I am confused how the results can have any accuracy when
the Guess range can easily be manipulated to change the outcome of the coverage visualization.
A. Survey results may have an accuracy close to 100% only if you survey every square centimeter of the
floor plan. Of course, this is impossible in practice (and not necessary), so the application has to do some
extrapolation work to calculate the results for areas that have not been surveyed but that are near the
walkabout path. There is a dependency between the guess range and the environment. If you are in the
middle of a stadium field with no obstacles, Wi-Fi signal propagates freely and can be easily predicted
dozens of meters around; therefore, you can use a greater guess range. If you are in a crowded office,
signal propagation is very complex, so using the guess range that you used on the stadium field would be
wrong. TamoGraph recommends a guess range for each environment type; this recommended value
should be taken into account when you plan your walkabout paths. For example, if the recommended
guess range is 5 meters and you survey the area by walking parallel paths, the distance between the
parallel lines should not exceed 5 meters. To sum this up, if you conduct a quality survey by walking the
entire area and leaving no “blank spots,” and if your walkabout paths are not far apart, then increasing
the guess range would have almost no negative effect. That’s because, in such a scenario, you leave no
room for the guesswork.
Q. I noticed that the AP icon location affects the visualizations. When I move the icon, the visualizations
change. How can I avoid that?
A. Moving the AP icon may or may not affect visualizations; this depends on the TamoGraph settings. A
very detailed explanation of this functionality can be found in the Visualization Settings chapter of this
help file; see the How AP icon locations affect signal option description.
Q. Do I need to link the Multi-SSID APs manually to get valid results in the SIR visualization?
87
Frequently Asked Questions | TamoGraph Site Survey
A. Usually, TamoGraph tries to group multiple SSIDs together automatically during the survey. However,
depending on specific WLAN implementations, it might not be an error-free process. If you noticed that
TamoGraph had not detected some SSID groups correctly, it is recommended that you link the SSIDs
belonging to the same physical AP manually to get proper SIR results. It is preferable to do manual SSID
linking after the entire passive survey is completed.
Q. Does TamoGraph support multi-floor projects?
A. Yes, you can create projects with multiple floors in TamoGraph. If you are doing a predictive survey,
simply add new floors in Floor Manager, add floor plans for each floor, define floor height and material,
and then align the floors.
Q. Do I need to use the Floor Manager in passive surveys? Does the program take into account the floor
materials and floor order in passive surveys?
A. No. The Floor Manager should be used for predictive surveys only. In passive surveys, the application
collects actual signal data regardless of the floors and AP locations; in other words, it doesn’t “care” about
floors, their order or materials.
Q. I conducted a passive survey in a multi-floor building, and some of the APs were auto-placed on
adjacent floors rather than on the floor where they are actually located. How do I correct that?
A. If you know the actual locations of the APs on the their respective floors, then for each floor: (a)
manually correct the locations of the APs that are physically located on that floor and (b) drag the icons
of all APs that belong to other floors off the floor plan. If you don’t know the actual locations of any APs
and wish to view the signal coverage map only, then clear all AP locations; this will make the application
use only the actual data, without any extrapolations.
Q. I have one physical AP that I want to move around to simulate multiple APs before deploying my
WLAN. Can TamoGraph treat this single AP as multiple APs so that I can estimate the characteristics of
the future WLAN?
A. Yes, this widely used method is called “AP-on-a-stick”. TamoGraph provides the functionality necessary
to handle such scenarios. Please see Splitting an AP into Multiple Unique APs for detailed instructions.
Q. It appears that there are very few virtual AP templates and all of them are for generic APs. How do I
create a virtual AP that simulates a specific model by a major Wi-Fi equipment vendor?
A. Virtual APs can be constructed like Legos. For example, if you want to simulate a Cisco Aironet 2700
series AP, you should begin with the Generic dual 802.11ac template. Place the AP on the floor map,
double-click on it, configure its properties to match the properties of the physical AP you plan to deploy
(e.g., channel width or output power), and then select the antenna type, which in your case should be
Cisco Aironet 2700 series 4 dBi. Be sure to do this for both radios of this dual-band AP. In other words, you
use Lego bricks to build a model that matches the actual AP. You can then save this configuration as a new
template and use it in your projects. Why don’t we provide you with a ready-to-use model? Because we
cannot know how you plan to configure your physical Cisco Aironet 2700 series APs. For example, we
cannot know whether you plan to use 20 or 40 MHz channels in your APs. This is why you have the utmost
flexibility in creating your own template.
88
Frequently Asked Questions | TamoGraph Site Survey
Q. Is there a way to tell the software to ignore all APs except the one with which I am are surveying? I
want to collect data for our survey AP only and generate a report for this AP only.
A. You can have visualizations for any set of AP, even a single AP. There are two buttons on the toolbar
that switch between the “All APs” and “Selected APs” modes, so you can press the latter and select only
one AP on the left pane. Please note that in case of the Signal-to-Interference Ratio visualization, the
signal of the selected AP is analyzed against all APs in the projects.
Q. Can I use multiple adapters with TamoGraph to make the scanning process faster?
A. On macOS - no. On Windows - yes, TamoGraph can capture data from multiple channels simultaneously
if you use multiple compatible USB adapters. This shortens the time needed to collect data from the
channels being scanned as you move along the survey path, and, therefore, improves the data quality.
For example, with the default 250 ms per channel interval, it takes five seconds to sweep through 20
channels if you use only one adapter. If you use three adapters, the same amount of data will be collected
in less than two seconds. The following 802.11n USB adapters can be used for multi-channel capturing: DLink DWA-160 v.A1, v.A2, v.B2, and v.C1, Edimax EW-7733UnD, Linksys AE3000, NETGEAR WN111 v2,
NETGEAR WNDA3100 v1, Proxim ORiNOCO 8494, SMC Networks SMCWUSB-N2, Sony UWA-BR100, TPLink TL-WDN3200, TP-Link TL-WN721N, TP-Link TL- WN722N, TP-Link TL-WN821N v1, v2, and v3, TP-Link
TL-WN822N v1 and v2, Ubiquiti SR71-USB, and CACE Technologies AirPcap Ex or NX. The following
802.11ac USB adapters can be used for multi-channel capturing: Belkin F9L1109 v1, D-Link DWA-180 rev
A1, D-Link DWA-182 rev C1, Edimax EW-7822UAC, EnGenius EUB1200AC, Linksys WUSB6300, NETGEAR
A6210, Proxim ORiNOCO 9100, TP-LINK Archer T4U, TRENDnet TEW-805UB, and ZyXEL AC240. Note that
different types of adapters cannot be mixed; all of the adapters should be of the same model. You should
also install the same driver for all of the adapters.
Q. Some of the channels in the scanner options window are not listed. Is this normal? What if I want to
monitor these channels?
A. The answer depends on the adapter type and operating system. For Windows:

Atheros-based miniPCI and miniPCIe adapters: Depending on your country, your wireless adapter
may not support all the channels shown in that window. The channels that are available for use
in a particular country differ according to the regulations of that country. In the United States, for
example, FCC regulations only allow channels 1 to 11 to be used in the 802.11b/g/n band. The
firmware of the wireless adapters being sold in the US is typically configured to disallow channels
12 and 13.

Atheros-based USB adapters, Intel 7xxx and 8xxx miniPCIe adapters, and recommended Ralink-,
MediaTek-, and Realtek-based USB adapters: All channels are always available when using them
in TamoGraph.

Other adapters (e.g. Intel 6xxx, Dell, or Broadcom): enabling channels 12 and 13 may be possible.
Open the TamoGraph application folder (usually C:\Program Files\TamoGraph or C:\Program Files
(x86)\TamoGraph). You will see the file named ch1213.exe there. Double-click on that file to
execute it. Restart TamoGraph and enable channel 12 and 13 in the scanner options; these
channels will become available for selection. Note that the adapter's ability to capture packets on
channels 12 and 13 depends on the regulatory domain set by the laptop vendor. If the vendor
89
Frequently Asked Questions | TamoGraph Site Survey
enabled them in your case, there won't be a problem. However, we've heard of many examples
when laptop vendors did not enable channels 12 and 13 even in the laptops that were sold in a
country where these channels were legal.
For macOS, depending on the region where it was sold, your MacBook’s Wi-Fi adapter comes with a preset
country code, e.g. “US” (for USA), “AU” (for Australia), or “X2” for Europe. This normally defines the set
of available channels. However, the set of available channels might change dynamically. On macOS
versions prior to Sierra, the Wi-Fi adapter “listens” to the country codes that some routers broadcasted
using the 802.11d standard. Once the adapter “decided” that it had been relocated to a new regulatory
domain, it changed its country code, effectively changing the list of available channels and a few other
parameters, such as maximum output power. On macOS Sierra and newer, the system uses Location
Services to figure out where your MacBook is located. If, for whatever reason, you want to prevent macOS
from switching to a new country code, go to System Preferences => Security and Privacy => Privacy =>
Location Services => System Services => Details and uncheck the “Wi-Fi Networking” box.
Q. Why is the UDP downstream throughput value always zero?
A. This is a firewall issue. This means that the UDP data being sent from the server cannot reach the client.
When performing UDP testing, the client sends upstream UDP traffic to the server from a random UDP
port to the server port (27100 by default.) The return downstream traffic goes from port 27101 to the
client source port. Use this information to configure your firewall.
Q. Why do I see very high (over 50%) UDP downstream loss?
A. This question is answered in the UDP Upstream and Downstream Loss chapter.
90
Frequently Asked Questions | TamoGraph Site Survey
Sales and Support
At TamoSoft, we want you to be happy with your purchase. That is why we encourage you to try our
products and technical support free of charge for 30 days before you make a decision regarding your
purchase. By making the most of these free evaluations, you can fully test the software and make sure
that it does everything you need. When you are ready to buy, we welcome you to
http://www.tamos.com/order/ to order directly from us or through our partners and resellers.
As a registered user, you will receive:




A fully functional, unrestricted copy of the software
Free updates that will be released within one year from the date of purchase
Information on updates and new products
Free technical support
Prices, terms, and conditions are subject to change without notice. Please check our Web site for the
latest product offerings and prices.
For technical support, please visit http://www.tamos.com/support/.
91
Sales and Support | TamoGraph Site Survey