Ekahau Positioning Engine™ User Guide

Ekahau Positioning Engine™ User Guide
User Guide
Welcome to Ekahau Positioning Engine™ (EPE),
the most accurate positioning platform for the
Wi-Fi. EPE is a powerful software solution that
enables a variety of new location-based
applications for Wi-Fi tags, PDAs, laptops, and
any 802.11a/b/g-enabled devices. The
Positioning Engine includes a standalone
Manager application and two ways (a Java SDK
and a language-independent YAX™ TCPprotocol) for reading client location (x, y, floor),
speed, heading, and logical area information,
such as "Conference Room".
This User Guide takes you through software
installation and setup, and helps you fully utilize
the performance and features of EPE 3.0.
GETTING STARTED ......................................................................... 3
AWARD-WINNING POSITIONING CONCEPT ....................................... 3
POSITIONING ENGINE COMPONENTS .............................................. 3
EVALUATION SETUP REQUIREMENTS .............................................. 4
PRODUCTION SETUP REQUIREMENTS .............................................. 5
INSTALLING EKAHAU POSITIONING ENGINE™.................................... 6
INSTALLING EKAHAU CLIENT....................................................... 6
ACCESSING EKAHAU TECHNICAL SUPPORT ....................................... 7
CHAPTER 1: WI-FI HARDWARE SETUP ............................................ 8
SUPPORTED WI-FI ADAPTERS ..................................................... 8
ACCESS POINT PLACEMENT AND CONFIGURATION................................ 9
CHAPTER 2: EKAHAU CLIENT™...................................................... 11
USING EKAHAU CLIENT ...........................................................11
LIMITING POSITIONING ENGINES.................................................13
CHAPTER 3: EKAHAU MANAGER™.................................................. 14
HOW TO START USING EKAHAU MANAGER ......................................14
LOADING AND CONFIGURING YOUR MAP .........................................16
RESTRICTING NETWORKS AND ACCESS POINTS .................................19
RESTRICTING NETWORKS AND ACCESS POINTS .................................19
DRAWING AND EDITING TRACKING RAILS™ ....................................20
PERFORMING SITE CALIBRATION™...............................................22
DRAWING AND EDITING LOGICAL AREAS ........................................27
SAVING AND LOADING POSITIONING MODELS...................................28
ANALYZING POSITIONING ACCURACY ............................................29
CHAPTER 4: EKAHAU MANAGER VISUALIZATIONS......................... 30
SIGNAL STRENGTHS ...............................................................30
LOCATION PROBABILITY ...........................................................32
EXPECTED POSITIONING ERROR ..................................................33
ACCURACY ANALYSIS ..............................................................34
CHAPTER 5: MAINTENANCE .......................................................... 35
PERIODIC ACCURACY TEST........................................................35
POSITIONING MODEL MAINTENANCE METHODS .................................36
WORKING WITH CONFIGURATION FILES .........................................38
WORKING WITH POSITIONING ENGINE LOG FILES ..............................47
CHAPTER 8: LICENSE UPGRADE .................................................... 49
HOW TO UPGRADE THE LICENSE ..................................................49
Award-Winning Positioning Concept
The award-winning concept of Ekahau Positioning Engine™ is to
create a unique positioning model for each positioning site (such as a
hospital, warehouse, or office), by recording Wi-Fi network data from
various network locations. This patented process is called Ekahau
Site Calibration™ and it allows significantly higher positioning
accuracy than any other method, such as signal propagation or
triangulation that does not take the actual radio environment
characteristics into account.
Positioning Engine Components
Ekahau Positioning
Java-based application server that
Ekahau supports
provides the Ekahau T101 tag, PC,
Windows® XP and
and PDA locations, areas, speed,
and heading via Ekahau Java SDK,
YAX protocol, or visually in sample
applications or Ekahau Manager.
Ekahau SDK™ and
Ekahau Software Development Kit
Ekahau supports
contains the SDK Java package,
Windows® XP and
Javadoc, and code examples for
quickly connecting to the
Positioning Engine and reading
location information. Programmers
using other than Java language
can alternatively use the Ekahau
YAX™ protocol to read the location
information via TCP socket.
Ekahau Manager™
Application for creating positioning
Windows® XP, 2000
models, saving them in the
(requires a laptop)
Positioning Engine, drawing logical
areas, testing live positioning, and
analyzing positioning accuracy.
Ekahau Client™
Network reader component, which
Windows® XP, 2000
must be installed and running on
Pocket PC 2002 and
each PC or PDA device that is to
be tracked. Also required by
Ekahau Manager laptop.
Evaluation Setup Requirements
For quick evaluation, install EPE completely on a light laptop PC.
You will need the following items for the evaluation setup:
Light laptop PC with at least Windows® XP or 2000 Professional,
1 GHz processor, 256 MB RAM, and 500 MB HD space
Ekahau Positioning Engine™ (full installation)
A supported Wi-Fi adapter and driver (see
http://www.ekahau.com/devices for supported versions)
At least 3 standard Wi-Fi access points (all 802.11a/b/g models
supported) – the test area should provide at least 3, preferably 5
or more access point signals at each location
Map or floor plan of the area (in PNG, JPG, or BMP format)
Measuring tape
Production Setup Requirements
For production use, install the Positioning Engine on a dedicated
server and use a separate laptop PC for the Manager application.
Install Ekahau Manager and Ekahau Client on a light laptop PC
with at least Windows® 2000 or XP Professional, Pentium III, 256
Install Positioning Engine on a server with at least Windows® XP
or 2000, 1 GHz processor, 256 MB RAM, and 500 MB HD space
Install Ekahau Client on all tracked PC or PDA devices with at
least Windows® Pocket PC 2002 or 2003
Supported Wi-Fi adapters for the Ekahau Manager laptop PC and
each client device to be tracked
At least 3 Wi-Fi access points (all 802.11a/b/g models
Map or floor plan of the area (in PNG, JPG, or BMP format)
Measuring tape
Example: EPE
is running on a
server. Ekahau
Client must be
installed and
running on
each PC or PDA
device that is
to be tracked
Installing Ekahau Positioning Engine™
Double-click Install_Engine_win32.exe. In case of CD
installation, place the CD in the drive.
If the installation does not start automatically, browse the CD’s
root folder and double-click Install_Engine_win32.exe.
3. Follow the on-screen instructions and select the components you
wish to install on the target computer (typically Full Install).
Installing Ekahau Client
To locate a wireless PC or PDA, you need to install the Ekahau Client
software on the device, and keep the Client running.
Fully install a supported Wi-Fi adapter on the device. See
http://www.ekahau.com/devices for supported adapters.
In case of Windows XP or 2000 computer, use the Positioning
Engine installer or CD as described above, but only install
Ekahau Client and the included Wi-Fi drivers.
In case of PDA installation (Pocket PC), first install Ekahau
Client completely on a PC, then synchronize your PDA with
ActiveSync® to install the Pocket PC version of Ekahau Client.
Accessing Ekahau Technical Support
If you encounter problems while evaluating Ekahau software, or if
you have improvement ideas, contact support@ekahau.com. The
Ekahau technical support will respond within 24 hours on business
days (Monday through Friday). Please include the following
information in your e-mail:
Detailed description of the problem
Operating system in use
Wi-Fi adapter manufacturer, model, and driver version
Access point manufacturer and models
Ekahau technical support is free during the evaluation and for 30
days after purchasing a commercial license. After this initial period, a
support package is required for further support and software
updates. Ekahau support packages can be purchased at
CHAPTER 1: Wi-Fi Hardware Setup
An old driver version of a Wi-Fi adapter is the most common reason
for not receiving network data from Ekahau Client. Please update
your Wi-Fi adapter driver after installing the adapter:
Insert your Wi-Fi adapter to the PC card slot and refer to its user
manual to properly install the included drivers and utilities.
After installing the Wi-Fi adapter driver, open any adapter utility
or diagnostics tool to display the driver version.
If the driver version number is lower than the one supported, you
need to update the driver. For update instructions, see
After installation, open any adapter utility or diagnostics tool to
confirm that the driver was updated properly. If you have trouble
updating the driver, please refer to the adapter and driver
documentation before contacting Ekahau support.
Supported Wi-Fi Adapters
Ekahau Client and Positioning Engine have been tested on Windows®
XP and 2000 with more than 40 leading Wi-Fi adapters, drivers, and
PDA devices from Agere, Avaya, Buffalo, Cisco, D-Link, Enterasys,
IBM, Nortel Networks, Proxim, and other manufacturers.
Click Start > Programs > Ekahau > Client > Release Notes or visit
http://www.ekahau.com/devices for the latest list of supported Wi-Fi
adapters, drivers, and devices.
If you find out that an untested adapter works, please send its model
and driver version to support@ekahau.com.
Access Point Placement and Configuration
Ekahau Positioning Engine supports all 802.11a/b/g Wi-Fi Access
Points. Follow these steps for good positioning results:
Provide at least 3 access point signals at each location
EPE can locate a device with only one AP signal, but a
minimum of 3 signals must be detected by the client device in
each location for better than 5 meter (15 ft) average accuracy
Increasing the number of AP signals increases accuracy. The
preferred number of signals per location is 5-10
Install “dummy” access points for additional signals
To increase the number of AP signals per location, you may
install additional “dummy” access points without network
connection. Just power up the dummies. Channel
configuration is not very important as the dummies are not
sending data and will not interference with data networks.
Disable automatic power management features
Disable optional power management and self-healing features
for reliable positioning results
Enable ESSID broadcasting / probe responses to locate Wi-Fi
adapters that do not support passive scanning
Access point placement tips
Start from the corners of the intended coverage area.
With 3 access points the test area size can be, for example,
20x20 m (obstructed) – 40x40 m (open).
If the area has low-height obstructions, such as office
cubicles, attach the access points (using indoor antennas) to
ceilings or walls above the height of the obstructions.
Do not place the access points (or antennas) in straight lines
or near one another (less than 5 meters). Use adhesive tape to
secure the antennas for a site survey and testing before
installing them permanently.
Minimized interference (noise)
High interference may decrease data throughput and
positioning accuracy. Noise can be minimized by proper
channel configuration, for example using 802.11b channels 1,
3, 6, 9, and 11 (for 5 adjacent access points), to keep the
channels as separated as possible. Also try to minimize radio
interference from other Wi-Fi networks and radio sources
Strong but diversified AP signals
Strong access point signals typically vary less than weaker
signals. This is why the best positioning accuracy is usually
achieved closer to access points, whereas areas with fewer and
weaker signals provide lower accuracy.
Stronger is better, but moving APs or using directional
antennas to provide different RSSI for areas in close proximity
will help differentiating the areas and improving accuracy.
Site survey
Depending on the desired coverage area, refer to your access
point manual to adjust the output power levels.
To ensure that your access point placement provides the
maximum coverage, perform a site survey with Ekahau
Manager or Site Survey. Refer to Chapter 3 of this guide
Quick positioning demos with Ekahau Manager laptop
To quickly test positioning accuracy, use “dummy” access
points only. Record a positioning model with Ekahau Manager
and click the Ekahau icon in the upper right corner to display
your laptop’s location. Walk around to test the accuracy
If you need to move an access point after recording positioning
model, refer to Chapter 3 to disable the moved access points
from the positioning model, or re-calibrate the affected area.
CHAPTER 2: Ekahau Client™
Using Ekahau Client
Ekahau Client allows Ekahau Manager to retrieve network data for
site calibration (typically from a Wi-Fi adapter installed on a local
computer), and allows the Positioning Engine to retrieve network data
from client devices for positioning. This is why Ekahau Client must be
installed and running on the Ekahau Manager laptop and on each
client device that is to be tracked.
The Windows XP/2000 version of Ekahau Client provides Ekahau
Client Controller / Properties dialog that can be used for:
Viewing the Client status
Starting and stopping the Ekahau Client service
Configuring the allowed or restricted Positioning Engines
Enabling or disabling the writing of an Ekahau Client log file
To access Ekahau Client Properties dialog, click the Ekahau icon
in Windows system tray. If the icon is not displayed, start the
Client Controller by selecting Start > Programs > Ekahau > Client >
Ekahau Client Controller.
If you need to view, start, or stop Windows services manually, rightclick My Computer on the desktop, and select Manage > Services and
Applications > Services.
Red Client icon (
) on system tray means the Client service
is not running. A yellow exclamation mark (
) means an
error. Click the icon to view error status.
Ekahau Client
dialog’s Status
tab in Windows
Do not install more Ekahau Clients on PC or PDA devices than
your EPE license permits (after Ekahau T101 tags). While
installing is OK, you might run into tracking problems if the
“wrong” client devices happen to register themselves into
Positioning Engine before the preferred “right” ones.
Ekahau Client’s GPS settings are for Ekahau Site Survey only,
and are not supported by Ekahau Manager or Engine 3.0.
Limiting Positioning Engines
Ekahau Client users can limit the Positioning Engines that are
allowed to locate them. When using the default Positioning Engine
settings (set automatically during the installation), all available
Positioning Engines typically appear in the Recently Discovered
Positioning Engines listbox. You can then uncheck the Accept
checkbox to deny positioning requests from that specific Positioning
Engine. To allow requests from known Positioning Engines only,
uncheck the Accept by default checkbox.
If you want to save the Positioning Engine settings, click the Add…
button, select the name of the Positioning Engine from the drop-down
listbox, modify the settings as appropriate, and click OK.
If you have manually modified Positioning Engine communication
settings (see Chapter 6 to see why and how to do this), you may need
to manually configure the Positioning Engine by clicking the Add…
button. Select <custom settings> from the drop-down listbox, fill in
or modify the Positioning Engine details, and click OK.
Ekahau Client
dialog in
XP/2000 with
the Positioning
Engines Tab
CHAPTER 3: Ekahau Manager™
How to Start Using Ekahau Manager
1. Double-click the Ekahau Manager shortcut.
2. When Ekahau Manager starts you are asked to provide the
location and password of the Positioning Engine. If you installed
the Positioning Engine on the same computer, click OK.
Otherwise, enter the correct name or IP address of the computer
that runs the Positioning Engine, and click OK. Use empty value
for password unless you have manually configured Positioning
Engine to use special password.
Engine Login in
3. After Ekahau Manager has started, you can create a new
positioning model or open an existing positioning model either
from a file or the Positioning Engine database. Select New
Positioning Model and click OK.
Startup options
When opening a saved positioning model from the Positioning
Engine, make sure that the Positioning Engine is running.
4. Select View > Signal Strengths. You should see blue and gray
bars indicating access point signal strength (RSSI) values.
5. If you do not see the blue / gray RSSI bars, ensure that your WiFi adapter and driver version are supported (see Chapter 1 for
details). Update the driver if necessary and restart the computer.
If you still experience problems, contact support@ekahau.com.
6. If you want to change the unit system between Metric and
Imperial, select File > Preferences…
Loading and Configuring Your Map
You need a map image for creating the positioning model. Supported
map formats are PNG, JPG, and BMP.
To import a map, select New Map… from the File menu.
Alternatively, you can right-click the Maps folder in the left
window, and select New Map… from the context menu.
Click Browse to select a suitable map image.
To ensure that Ekahau Positioning Engine functions accurately,
you must define the correct map scale for each map image. If you
already know how many map pixels equal the map’s selected
distance unit (meter/foot), you can type the value in the Map
Scale field and click OK.
If you do not know the pixels/map unit ratio of the map, leave
the field as zero and click OK. The map should shortly appear.
Click the blinking Measure tool (
) and click a point on the
map – for example the corner of a wall or another measurable
object. Then click another point on the map, at least 3 meters
(10 feet) apart from the starting point. Next, walk to the marked
location on site and measure the real-world distance between the
two points with a measuring tape. Type the real-world distance
in the lower text field, and click Set Map Scale.
Use Measure tool for
setting map scale. After
setting the scale, you
can use the Measure
tool for measuring
on the map
Performing Site Survey with Ekahau Manager
When setting up a Wi-Fi network, the best access point or antenna
locations are typically searched for maximum coverage and data
throughput before installing the access points or antennas
permanently. This process is often called site survey, and it is also
recommended before recording data for a positioning model.
When performing site survey for positioning, you should observe the
most important positioning attributes:
Number of detected access point signals at each location.
Accurate positioning requires at least 3, preferably 5-10
Signal strength (RSSI) of each AP signal. Stronger is better in
general, however, adjusting APs or using directional antennas to
provide different RSSI for different areas may help differentiating
the areas and improving accuracy
Noise level (available separately in Ekahau Site Survey).
Significant radio noise will decrease positioning accuracy. Avoid
noise with standard channel planning (see Chapter 1)
Performing site survey for positioning use with Ekahau Manager:
Display signal strength information in the bottom view by
selecting View > Signal Strengths.
Take your laptop with you and walk around the area while
observing the number of detected signals and their signal
strengths (RSSI) in Ekahau Manager. If necessary, move or add
“dummy” access points to have at least 3, preferably 5-10 access
point signals (blue bars) available in each location.
Once you have at least 3 access point signals everywhere, open a
map and draw Tracking Rails as described later in this chapter.
Take your laptop with you and walk again around the area,
stopping on the nearest tracking rail every 5-10m (15-30 ft), and
clicking the rail with calibration tool (
) selected. This will
associate processed network data to your location.
After covering most of the important areas, click Ekahau
Manager’s Visualization Tab and select Signal Strength view.
This allows you to observe the 5 strongest access point signals at
each location, typically helping network planning. At least the 3
strongest signals should provide average or strong signal
strength for good accuracy.
For complete visualization instructions, see Chapter 4.
Manager with
Signal Strength
(RSSI) display
Restricting Networks and Access Points
All detected access points do not necessarily belong to the network
under your control. For example, another company nearby may begin
to use Wi-Fi access points that can be observed with Ekahau
Manager. This causes problems if you use all detected access points
for calibration, and your neighbors change their AP locations.
Prevent unwanted or unreliable access points from being used for
positioning by de-selecting them in Access Point View below the
Browser View, and clicking Apply. Clicking Reset will undo any
changes that were made before clicking Apply.
When changing your Wi-Fi network, de-select from your
positioning model any access points that have been physically
moved or uninstalled, and save it back to Positioning Engine.
The restrictions apply for each map separately. To define
restrictions for other maps, open each map image individually.
Access Point
View below the
Browser View.
Data from all access points is processed and saved in the
positioning model, but only the selected access points are used
for positioning and accuracy analyses. This makes it possible to
quickly test positioning and accuracy analyses with different
access point combinations without a need for re-calibration.
Drawing and Editing Tracking Rails™
Before recording data for the positioning model, Tracking Rails must
be placed on the map to indicate possible travel paths between
rooms, corridors, floors, and other locations. The rails are quick to
draw and provide improved positioning accuracy.
Activate Rail tool by clicking its icon (
Place the mouse pointer in the center of a walking path, room, or
corridor, and click the map once to create a starting point.
Move the pointer as far as you can on the path without crossing
any wall or other obstruction. Click the map again to create a
curve point, and continue drawing all essential paths in the area.
To end the current rail, click the right mouse button. To
continue, click the left mouse button.
You do not need to work on-site while drawing the rails, unless
you want to observe the area when placing the rails.
To select a rail or a curve point, activate the Edit tool
click the desired rail or curve point. You can select several
objects by holding down the left mouse button. To move a rail,
press down the left mouse button and drag the rail to another
location. To delete a rail, select it and select Edit > Delete, or
right-click the rail and select Delete from the context menu.
To continue on an existing rail, or to create junctions, place the
pointer on an existing rail or curve point, and left-click once.
To draw rectangular rails that are always in a 45° angle, hold
down the Shift key and left-click once.
To connect two adjacent maps or floors, draw a rail curve point
for example in front of an elevator door or staircase, but do not
end the rail. Select another map by clicking it in the Browser
View. When you move the mouse pointer back on the other map,
you will notice a round map link icon with a thumbnail map of
the starting point. Move the cursor in front of the other floor’s
elevator doors and click the map to create a two-way tracking rail
between the two floors or adjacent maps.
1. Starting point of a map link in front
of an elevator. Do not end the tracking
rail but select another map
2. Select another map (another floor or
adjacent map) by clicking it in the
Browser View. Move the mouse pointer
back on map to see a thumbnail of the
first map
3. Click the correct location to place the
map link’s end point. Continue the rail
normally from the end point
The location estimates depend much on the rails that you place
on maps. Be careful in marking only the correct paths that are
accessible and used by the tracked devices.
Example of
how to place
Rails™ in
Performing Site Calibration™
By placing Tracking Rails™ on the map, you have successfully
created a positioning model. However, before you can use the
positioning model for locating devices, it needs to be calibrated, i.e.
you need to record network data from various map locations.
For the best tracking accuracy use only supported adapters
for site calibration and tracking. Ekahau also recommends
using similar devices for creating the positioning model and
tracking. Please see the next headings for details.
Take the Manager laptop with you and walk to a nearby Tracking
Rail, making sure that you are standing on it.
Activate the Calibration tool by clicking its icon (
Move the mouse pointer to your current location on the rail and
click the map to record a sample point (SP). Do not move away
from your current location until the record dialog disappears (in
10–20 s). While you remain in your current location, turn around
slowly a full 360° to record the signals from all directions.
Walk about 3–5 meters along the rail and repeat Step 3 until you
have calibrated the entire area. Please follow the recommended
sample point recording principles for maximum positioning
Record a SP at least every 3–5 meters
Record a SP in all Tracking Rail intersections
Record a SP in all Tracking Rail ends
Record a SP in all locations where the radio environment
suddenly changes. For example, record one SP from both sides
of a door (typically from a room and corridor).
In case of open areas, draw a grid of Tracking Rails and record
a SP in the corners of each square. To reach high accuracy,
draw and calibrate at least 5x5 – 3x3 meter grid.
To remove sample points, select Edit > Undo, or alternatively
select the Edit tool (
), right-click the unwanted sample point
and select Delete Sample Point from the context or Edit menu.
To save the calibrated positioning model in the Positioning
Engine, select File > Save to Positioning Engine. Type a filename
and click OK. If the Positioning Engine is not running or cannot
be connected, you will receive an error message.
Using Remote Calibration Client for Higher Accuracy
For the best tracking accuracy, Ekahau recommends using similar
devices for creating positioning model and tracking.
For example, to locate Ekahau T101 Wi-Fi tags or certain PDA devices
only, you should also record the data for your positioning model
using a T101 tag or the PDA, not just any Wi-Fi adapter. Ekahau Card
Models will automatically minimize the differences between any
supported Wi-Fi adapters and devices, but using similar adapter or
device for calibration and tracking phases is always the best option.
Make sure the tag, PDA, or other device can communicate with
Wi-Fi network.
In case of PDA, make sure you are using a supported Wi-Fi
adapter and driver (see www.ekahau.com/devices for the list).
In case of PDA, install Ekahau Client software and make sure it is
running properly.
In case of T101 tag, open a terminal program and connect to the
T101 tag via your laptop’s terminal program (see T101 user guide
for instructions), then type in command calibrate<Enter>.
This makes the T101 send data as fast as possible for site
calibration use. If you hit ESC or the tag drops off from the
calibration mode for some reason (you will see this if the status
LED is not blinking every few seconds anymore), just repeat the
calibrate command and continue.
Open Ekahau Manager, select File > Preferences > Calibration
Client, and choose the IP address or friendly name of the device.
This allows Ekahau Manager to retrieve network data from the
selected remote device for creating the positioning model.
Attach or hold the tag or PDA similarly to the most typical user,
for example using the tag’s belt clip.
Take your laptop and perform the site calibration (record data for
your positioning model) as described in the previous sections.
Mitigating Adapter Differences with Adapter Models
Wi-Fi adapter manufacturers use different radio hardware and
software in Wi-Fi adapters. Even individual adapters from same
manufacturer typically have slightly incompatible scales for observing
the RSSI values. This can cause positioning inaccuracy if the
calibration and tracking steps are preformed using different Wi-Fi
adapters. The positioning inaccuracy caused by different adapter
scales is typically 1-5 meters (3-15 ft) depending on the adapter,
without using any mitigation technology.
Ekahau’s patented technology minimizes the positioning inaccuracy
caused by RSSI measurement differences. Ekahau Client and
Manager use method called Ekahau Adapter Models to automatically
apply the correct adapter model to mitigate the differences.
The card models can be found from functions.cfg under Ekahau
Manager’s conf directory.
In case of low accuracy for a specific device, open the Devices
tab, right-click on the problematic device, and select
Properties… from its context menu. Make sure the device’s
Wi-Fi adapter and driver are supported. The conversion
function for the specific technology should display OK.
Displaying Device Locations and Properties
After drawing Tracking Rails and calibrating the positioning model,
you can easily locate client devices by using Ekahau Manager’s
internal positioning test feature.
To locate the Ekahau Manager laptop, click the Ekahau icon
in the upper right corner.
To locate any other device, select Devices tab in the bottom view.
Click the Tracking checkbox for each device on the list to test
tracking in Ekahau Manager. Make sure Ekahau Client software
is installed and running on each PC or PDA to be located. Only
devices running Ekahau Client will appear on the device list.
Right-click on a device and select from context menu:
Properties… to display many device properties such as MAC
Show RSSI… to display the device-specific signal strengths
Follow to automatically keep the device in map display
dialog for a
Windows® XP
The device list is retrieved from the Engine. This is why the
Engine must be running to let Ekahau Manager display the
device list. Ekahau Manager however uses its local model
and location test feature for locating the devices.
Drawing and Editing Logical Areas
Logical areas are user-drawn areas (polygons) that can have a name
and other location-based properties. Logical areas are used to
determine whether a client device is within a given area.
1. Activate the Logical Area tool by clicking the icon (
2. Click the map, move the mouse, and click again until you have
drawn the desired area. Use the left mouse button to connect
the polygon ends and quit drawing.
3. Right-click the area in Browser View to name the area or to
define custom properties for the area, available for application
developers via Ekahau Java SDK or YAX protocol.
4. The most probable logical area is displayed for each client device
in the Devices Tab when the Tracking checkbox is selected for
the device. Logical area information can also be read from the
Positioning Engine by using Ekahau SDK or YAX.
Make sure that you place at least one Tracking Rail and record
at least one sample point inside each logical area –
otherwise the logical area will not function correctly.
Saving and Loading Positioning Models
Ekahau Manager can save models either as Ekahau Database files
(.edb), or directly in the Positioning Engine’s internal database.
Typically, the best positioning model is always saved in the Engine,
while test calibrations and exercises are saved as files.
After saving a positioning model in the Positioning Engine, it takes a
few seconds before the Engine reads the new model into memory, and
starts using it for tracking. As the tracking history queue is emptied,
positioning accuracy can slightly decrease for the next 5–20 seconds.
Sharing Work by Merging Positioning Models
Ekahau Positioning Engine supports merging models to share
calibration work between multiple users. For example, to calibrate a
10-map building, you can first agree that 3 people will record the data
and merge their changes directly in the Positioning Engine.
Create and calibrate a positioning model for the floors you agreed
to take care of.
When done, select File > Merge from Positioning Engine to read
and merge any existing positioning model (saved by your
colleagues) from the Engine to your model in Ekahau Manager.
Nothing is changed in the Engine at this point.
10. The merge function will basically add any new maps, rails,
sample points, and logical areas into your local positioning
model in Ekahau Manager. However, merge will not update items
that you have changed in your model if the same item(s) exist in
the Engine and Manager models during the merge operation.
11. After inspecting that the merging was successful, you can save
the latest positioning model (now including your changes) in the
Positioning Engine, overwriting the existing version.
12. Before using the model, remember to add map links between the
adjacent maps or floors.
Analyzing Positioning Accuracy
To statistically analyze positioning accuracy, select the Analysis
tool by clicking its icon (
Open the map where you are located (inside the calibrated area).
Start walking at a constant restful speed across the areas that
you wish to include in the accuracy analysis. Stay inside the
calibrated area and always click the map in your current location
when changing your direction or speed.
Right-click the map to end the analysis and display the error
vectors in the Map View and statistical analysis on Accuracy
Analysis Tab. Each “arrow” on the map describes the difference
between the actual (clicked) location and a calculated estimate
(constructed from the network data in the open positioning
model, recorded for the same clicked location).
Right-click the accuracy analysis to access its context menu. You
can rename or delete the analysis, update the analysis (to
visualize it after opening an existing model), display error charts,
or export the analysis data as a text file.
Should the average error be worse than 5m in any area, the
likely reason is an insufficient number of available access point
signals in the area, suboptimal placement of access points (or
antennas), or too high radio interference. The placement issues
can be resolved by modifying access point (or antenna) locations
so that at least 3 access point signals can be detected
throughout the area. However, this requires a new calibration.
Contact support@ekahau.com in case of consistent low accuracy.
When opening a previously saved model file (.edb) that
includes Accuracy Analyses, right-click on the analysis name
and select Update Analysis to visualize the analysis results.
CHAPTER 4: Ekahau Manager Visualizations
To display the visualizations, you first need to draw Tracking Rails on
a map and record some sample points. The selected/de-selected
access points for each map affect the visualizations.
Signal Strengths
Select the Visualization tab from the bottom view.
Select the Signal Strength view.
Optionally, select Viewed Signal.
Viewed Signal
Displays the RSSI of the strongest access point (of all
recorded) at each map location. This can be any
(selected) access point that has the strongest signal at
that map location
2nd Strongest
Displays the 2nd strongest RSSI at each map location.
Useful to see what happened if the strongest access
point would crash: Is there a backup and how would it
cover the area?
3rd Strongest
Displays the 3rd strongest RSSI at each map location.
Useful to see what happened if the 2nd strongest
(typically a backup) would crash: Is there another
backup access point and how would it cover the area?
4th Strongest
See above
5th Strongest
See above
Optionally, select the preferred color scale from the drop-down
color listbox.
Optionally, configure the visualization’s granularity. Granularity
affects to the edge length of the visualization. Use coarser setting
when you do not have much sample points, but want to display
as wide coverage as possible. Use finer level when you have more
sample points and need more accurate visualization.
The visualization settings such as Granularity do not affect
positioning in any way.
displays the
coverage area
of all
access points
in the
By switching the view between different access points, areas with
poor network coverage can be spotted.
Displaying the accuracy analysis error vectors on the coverage areas
provides insight to network planning problems that might cause
decreased accuracy. For example, poor network coverage typically
correlates with decreased positioning accuracy in the area. To solve
the problem, change access point locations or antenna directions, or
add more access points in the problematic area.
Location Probability
Select the Visualization tab from the bottom view.
Select the Location Probability view.
Optionally select Positioning Mode.
displays the
probability for
any device to
be located
inside the grid
Positioning Mode
Displays the probability for any device to be located
inside the grid square, using device history of around 5
seconds (location update interval x 2.5 s)
Real Time
Same as above with 1 s device location history.
No History
Same as above without device location history. This
view is similar to the Expected Error.
Expected Positioning Error
Select the Visualization tab from the bottom view.
Select the Expected Positioning Error view.
The Expected Error view is not using devices’ history information,
meaning that the accuracy is typically lower than in reality. The
Engine utilizes location history by default for higher accuracy.
Error displays
the estimated
location error
at each
without using
Accuracy Analysis
Select the Visualization tab from the bottom view.
Select the Accuracy Analysis view.
Accuracy Analysis view displays the recorded statistical average
positioning error in colors for each location.
You must have at least one analysis case visible and calculated to
display the visualization. Click the Accuracy Analysis tab, right-click
the analysis case, and select Update from the context menu, after
opening an existing model from a file or Positioning Engine.
displays the
error in
colors for
CHAPTER 5: Maintenance
Periodic Accuracy Test
Positioning model inconsistency – the difference between recorded
calibration data and actual radio environment – increases with
changes in the environment, such as new walls, cubicle changes,
large containers or furniture, and so on.
Extensive tests in various dynamically changing environments have
proved that during a continuous 30-day field testing the average
positioning accuracy may decrease up to:
Ÿ 5-10% in areas with dynamic changes (manufacturing area)
Ÿ 10-20% in areas with significant dynamic changes
(shipping & receiving area)
Despite of the good robustness, Ekahau recommends testing active
positioning models 3 times a year. Periodic testing can be performed
quickly by opening the positioning model from the Positioning Engine,
activating the tracking feature, and walking around while comparing
the actual location to location estimate.
A more accurate and recommended method is to record new sample
points (5–10 % of the number of points in the positioning model) to be
analyzed against the original positioning model in Ekahau Manager.
For detailed instructions on how to use Ekahau Manager for
positioning accuracy analysis, see Chapter 4.
Positioning Model Maintenance Methods
In case of decreased average positioning accuracy, there are three
correction methods. Before starting, back up the existing positioning
model by saving it in a file under a different filename.
1. Record more sample points
Record more sample points in the areas with decreased accuracy and
save the positioning model in the Positioning Engine. This is typically
the fastest and easiest solution, if the average accuracy has decreased
by less than 20%.
2. Recalibrate problematic areas
If adding new sample points did not help, or the average accuracy has
decreased by less than 30%, delete the existing sample points by
selecting the Edit tool and “dragging a rectangle” over the problem
area with the mouse, then right-clicking a sample point, and selecting
Delete Sample Point(s). Record new sample points in the deleted
areas and save the positioning model in the Positioning Engine. This
method is very helpful if the area has changed only partially and
neighboring areas do not need to be recalibrated.
3. Recalibrate the entire positioning site
If adding new sample points did not help, or the average positioning
accuracy has decreased by more than 50%, create a new positioning
model, recalibrate the entire site, and save the positioning model to
the Positioning Engine. This method is required if positioning
accuracy has decreased due to structural or other major changes in
the environment.
CHAPTER 6: Configuring Positioning Engine™
Ekahau Positioning Engine runs as a Windows XP/2000 service. All
you need to do is keep the service running, thus allowing Ekahau
Manager to save positioning models in the Positioning Engine, and
location-based applications to query client location coordinates and
other information from the Positioning Engine.
Ekahau Positioning Engine service starts automatically during
the Windows startup.
If you need to manually start or stop the Positioning Engine
service in Windows XP/2000, right-click My Computer on the
desktop, and select Manage > Services and Applications >
To save a positioning model in the Positioning Engine, select
File > Save to Positioning Engine in Ekahau Manager. It takes
about 10 seconds after saving to initialize and start using the
new positioning model.
After saving a Positioning Model to the Positioning Engine, refer
to Chapter 3 to see how to locate devices on map using Ekahau
Manager. Refer to the Developer Guide to find out how to use
Ekahau SDK or YAX™ protocol to retrieve the location
information to your application.
When to Configure Positioning Engine,
Manager, and SDK
In most cases, the Positioning Engine default installation works well
out-of-the-box. There are times however when you may need to
configure some of the Positioning Engine properties. For example, you
may need to configure Positioning Engine to use another TCP/UDP
port in case another application has already reserved the default port.
Working with Configuration Files
Positioning Engine service and Manager Application can be
configured by modifying the engine.conf and manager.conf files with
any text editor. The configuration files are located in the conf
directories under the Ekahau Positioning Engine / Ekahau Manager
/ SDK installation folders. Save a backup copy of the original file
before making changes, and remember to restart Positioning Engine,
Ekahau Manager, or SDK application to apply the new settings.
The Positioning Engine and Manager Configuration files are in
hierarchical XML format. For example, Ekahau Client’s UDP port
setting is under the hierarchy conf > deviceConnector >
clientUdpPort. You can see what the hierarchy looks like in the
engine.conf example below.
If a configuration file does not exist, or contains incorrect values, the
system default values are automatically applied.
If you modify the UDP communication settings between Ekahau
Manager, Positioning Engine and Ekahau Client in the configuration
files, you will also have to change those accordingly in Ekahau Client.
engine.conf and manager.conf files can be found under the conf
folders in the Positioning Engine installation directory.
Contents of engine.conf configuration file:
<?xml version="1.0" encoding="UTF-8"?>
<technology name="802.11 a/b/g">
<band format="X"/>
<netid format="{0x13:0x05}"/>
<bsid format="{uppercase(0x13:0x06)}"/>
<channel term="0x04" voc="0x13"/>
<field term="0x41" voc="0x15"/>
<field term="0x42" voc="0x15"/>
<technology name="802.11b">
<band format="802.11b"/>
<!-- Assume 802.11b by default -->
<netid format="{0x13:0x05}"/>
<bsid format="{uppercase(0x13:0x06)}"/>
<channel term="0x04" voc="0x13"/>
<field term="0x41" voc="0x15"/>
<field term="0x42" voc="0x15"/>
<identifier format="{uppercase(0x13:0x06)}"/>
<identifier format="{0x13:0x02}"/>
<identifier format="{0x13:0x03}"/>
<identifier format="(0x11:0x01)"/>
<!-- defaults to productionparameters -->
<!--1 = realtime, 2=accurate -->
<entry from="-310" to="0"/>
<entry from="-309" to="7"/>
<entry from="-300" to="6"/>
<entry from="-301" to="6"/>
<entry from="-302" to="6"/>
<entry from="-303" to="6"/>
<entry from="-304" to="6"/>
<entry from="-305" to="1"/>
<entry from="-306" to="5"/>
<entry from="-307" to="1"/>
<entry from="-308" to="1"/>
<entry from="-1" to="0"/>
<entry from="-2" to="7"/>
<entry from="-3" to="5"/>
<entry from="-4" to="1"/>
<entry from="-5" to="0"/>
<entry from="-6" to="1"/>
<default remove-after="2m"/>
<group name="YAX" remove-after="10m"/>
<group name="ECLIENT" remove-after="10s"/>
<sweeper run-interval="10s"/>
<group name="administrator">
<attr name="app-id" value="manager*"/>
<privilege name="db" value="rw"/>
<group name="guest">
<privilege name="db" value="r"/>
The following attributes can be changed or added in the Positioning
Engine configuration file. The XML hierarchy is described by dots:
The password used to
authenticate with the
Positioning Engine
Positioning Engine listens
to this TCP port for Ekahau
Manager, SDK, and YAX
10000 (ms)
Timeout for the server
socket to wait for
authentication TALK and
HELLO-messages before
disconnecting the client
socket. You may have to
adjust this if you test YAX
with a telnet for example
devices.default remove-after
2 (min)
Device is removed from
the device list after 2
minutes. These devices do
not belong to either YAX or
devices.groups.group name
These are the default
groups of devices. YAX
means Ekahau tags and
Palm client, while ECLIENT
means PC/PDA with
Ekahau Client software
devices.groups.group remove-
10s for Ekahau
Devices which belong to
Clients, 10min
this group are removed
for YAX devices
from the device list after a
certain timeout. Use s, m
or h postfix. For example
20h means 20 hours
Ekahau Clients (PC, PDA)
have a small timeout
because their own
timeouts are checked
before they end up here.
YAX devices (Tags, Palm)
are not removed before
their socket connection is
closed. These parameters
only affect devices without
a new socket connection
during the timeout period.
devices.sweeper run-interval
10 (s)
The former remove-afterparameters are checked /
devices removed between
intervals configured here
DNS name (leave
You can set a custom
in comments)
Positioning Engine name
here. Maximum length is
128 characters
Positioning Engine UDP
port used for receiving
data from client devices
Positioning Engine UDP
port used for sending data
to client devices
10000 (ms)
Client query interval in
milliseconds. Positioning
Engine sends
“AreYouAlive” UDP queries
to queryAddress every n
Engine sends
“AreYouAlive” UDP queries
to this address
10000 (ms)
Positioning Engine’s device
list gets cleaned up from
old/not responding clients
every n milliseconds
30000 (ms)
If the device has been idle
n milliseconds, the next
device list cleanup will
mark Ekahau Client device
for removal
The engine database path
technologies.XX and
Used to format and
identify data, for example
BSIDs. Usually there is no
need to edit these
Internal parameters, no
need to edit
By default, all Ekahau
Managers with correct
password can update the
model database. Here you
can create read-only
managers which can only
browse the model and
track devices. Take app-id
from your manager’s
license.xml, for example
“manager-42”, and
<attr name="app-id"
<attr name="app-id"
After this modification (and
restarting Engine) only
Ekahau Manager with appid “manager-42” can save
a model in the Engine
The production parameters
are described in the
Developer Guide. These
production parameters in
engine.conf override the
system defaults, but any
YAX protocol or Ekahau
SDK user can override
these with their own
values (check the
developer guide to see
Contents of manager.conf configuration file:
<?xml version="1.0" encoding="UTF-8"?>
<technology name="802.11 a/b/g">
<!-- Ignoring the band in EPE
<band format="{0x13:0x01}"/>
<band format="X"/>
<netid format="{0x13:0x05}"/>
<bsid format="{uppercase(0x13:0x06)}"/>
<channel term="0x04" voc="0x13"/>
<field term="0x41" voc="0x15"/>
<field term="0x42" voc="0x15"/>
<technology name="802.11b">
<band format="802.11b"/>
<!-- Assume 802.11b by default -->
<netid format="{0x13:0x05}"/>
<bsid format="{uppercase(0x13:0x06)}"/>
<channel term="0x04" voc="0x13"/>
<field term="0x41" voc="0x15"/>
<field term="0x42" voc="0x15"/>
<identifier format="{uppercase(0x13:0x06)}"/>
<identifier format="{0x13:0x02}"/>
<identifier format="{0x13:0x03}"/>
<identifier format="(0x11:0x01)"/>
<!-- defaults to productionparameters -->
<!--1 = realtime, 2=accurate -->
<!-- milliseconds -->
<!-- These translate the "internal" errorcodes from
FlowProblems and DeviceProblems
to "external" errorcodes in DeviceStatusConstants.
These should be in severity-order meaning that if the
first-one is found
from the list of errors for the order, then that one
is the error sent to
client no matter what the other errors are.
<entry from="-310" to="0"/>
<entry from="-309" to="7"/>
<entry from="-300" to="6"/>
<entry from="-301" to="6"/>
<entry from="-302" to="6"/>
<entry from="-303" to="6"/>
<entry from="-304" to="6"/>
<entry from="-305" to="1"/>
<entry from="-306" to="5"/>
<entry from="-307" to="1"/>
<entry from="-308" to="1"/>
<entry from="-1" to="0"/>
<entry from="-2" to="7"/>
<entry from="-3" to="5"/>
<entry from="-4" to="1"/>
<entry from="-5" to="0"/>
<entry from="-6" to="1"/>
Here are explanations for only the attributes which differ from
Positioning Engine’s address
Positioning Engine’s port. This must be same
as engine.conf file’s gatekeeper.port
Working with Positioning Engine Log Files
Positioning Engine logging can be configured by modifying
log.properties file in conf folder under the Positioning Engine
installation folder.
The log files are by default stored in the log folder under the
installation folder. To change the default folder, edit this line:
log4j.appender.file.File = log/Ekahau${logfilesuffix}.log
For example, if you want the log files to be stored under c:\logdirectory, the line should look like this:
log4j.appender.file.File = c:/log/Ekahau${logfilesuffix}.log
Other important logging parameters are the maximum file size and
maximum backup index:
The maximum file size means that when the log file has reached
a certain size, it will be backed up to another file and a new log
file is created.
The maximum backup index is the maximum amount of the
backup log files. When this number is reached, the oldest file is
deleted and replaced with the second oldest.
In the example below, we have changed the maximum file size to 2
MB and backup index to 7:
log4j.appender.file.MaxFileSize = 2048KB
log4j.appender.file.MaxBackupIndex = 7
If you decide not to include general INFO level messages in your logs
at all, change the level to WARN, ERROR or FATAL as follows:
log4j.rootLogger=FATAL, file
CHAPTER 7: Introduction to Ekahau SDK™ and YAX™
Ekahau Positioning Engine (EPE) 3.0 offers two ways for serving
location information to local or remote applications:
Ekahau SDK™ Java API for Java developers
Character-based TCP protocol Ekahau YAX™ for any
programming language that supports TCP sockets
Both options utilize TCP sockets to connect to the Positioning Engine.
The SDK is just an easy-to-use Java front end for the YAX protocol.
After recording a positioning model and saving it in the Positioning
Engine with Ekahau Manager, use Ekahau SDK or YAX Protocol to
read client coordinates, logical areas, speed, heading, and other
information from Positioning Engine into your application.
For instructions on how to create location-based applications with
Ekahau SDK and YAX, see the Developer Guide.
CHAPTER 8: License Upgrade
How to Upgrade the License
The limited Evaluation version of EPE expires after 30 days.
To track up to hundreds of devices without restrictions, visit Ekahau
homepage at www.ekahau.com to purchase your full license.
After purchasing your license, you need to upgrade each Manager,
Positioning Engine, and SDK installation separately:
To upgrade Ekahau Manager, click Start > Programs >
Ekahau > Manager 3.0 > License Upgrade. You may
alternatively click Help > About > Upgrade license, if you are
already running Ekahau Manager. Type the license key
exactly as given, browse for the license file, and click OK. The
About window should now display full license information.
To upgrade the Positioning Engine, select Start > Programs >
Ekahau > Engine 3.0 > License upgrade. Type the license
information exactly as given, browse for the license file, and
press Enter. The Positioning Engine license is now upgraded.
To upgrade Ekahau SDK, select Start > Programs > SDK 3.0
> License upgrade. Type the license information exactly as
given, browse for the license file, and press Enter. The SDK
license is now upgraded.
Legal Notice
Ekahau, the Ekahau logo, Ekahau Site Survey,
Ekahau Positioning Engine, Ekahau Manager,
Ekahau T101 and Ekahau Client are trademarks
or registered trademarks of Ekahau.
Other product and company names may be
trademarks or trade names of their respective
The enclosed software contains implementations of
Ekahau’s patent pending inventions.
Under no circumstances shall Ekahau or Ekahau
be responsible for any loss of data, income, or any
direct, special, incidental, consequential or indirect
damages howsoever caused.
Copyright © Ekahau, Inc. 2000–2004. All rights
Ekahau, Inc.
12930 Saratoga Avenue, Suite B-9
Saratoga, CA 95070
Phone 1-866-4EKAHAU
Fax 1-408-725 8405
Ekahau Oy
Tammasaarenlaituri 3
00180 Helsinki, Finland
Phone +358 20 743 5910
Fax +358 20 743 5919
email: sales@ekahau.com
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