Verint Wireless Reference

Verint Wireless Reference
Wireless Video System Design
A Comprehensive Reference for the System Integrator
November 2009
Table of Contents
About Verint Video Intelligence Solutions.................................................................................................. 1 About Verint Systems ................................................................................................................................ 1 About This Guide ........................................................................................................................ 2 Fundamentals of Wireless Communication ............................................................................. 3 General Physics of Radio Signals: Frequency and Wavelength ............................................................... 3 How RF Communication Systems Work ................................................................................................... 4 Maintaining Signal Quality ......................................................................................................................... 4 Signal Scatter.......................................................................................................................................................... 4 Orthogonal Frequency Division Multiplexing (OFDM) ............................................................................................. 5 The 802.11 Wireless Standard .................................................................................................................. 6 802.11a ................................................................................................................................................................... 6 802.11b ................................................................................................................................................................... 6 802.11g ................................................................................................................................................................... 6 802.11n ................................................................................................................................................................... 6 Frequency Channels.................................................................................................................................. 7 The 2.4 GHz Band (License Free) .......................................................................................................................... 7 The 5 GHz Bands (License Free) ......................................................................................................................... 10 The 4.9 GHz Public Safety Band (Licensed) ......................................................................................................... 11 Antennae and Transmission Lines .......................................................................................................... 12 Types of Antennae ................................................................................................................................................ 12 Directivity .............................................................................................................................................................. 13 Gain ...................................................................................................................................................................... 13 Radiation Pattern .................................................................................................................................................. 13 Beam Width and the Half-Power Point .................................................................................................................. 15 Side Lobes ............................................................................................................................................................ 15 Nulls ...................................................................................................................................................................... 15 Cables ................................................................................................................................................................... 16 Connectors............................................................................................................................................................ 18 RF Line of Sight (LOS) ............................................................................................................................ 20 The Fresnel Zone.................................................................................................................................................. 20 Foliage Attenuation ............................................................................................................................................... 21 The Effect of Weather on Microwave Systems ..................................................................................................... 21 Unauthorized use, duplication, or modification of this document in whole or in part without the written
consent of Verint Systems Inc. is strictly prohibited.
By providing this document, Verint Systems Inc. is not making any representations regarding the
correctness or completeness of its contents and reserves the right to alter this document at any time
without notice.
Features listed in this document are subject to change. Please contact Verint for current product features
and specifications.
All marks referenced herein with the ® or TM symbol are registered trademarks or trademarks of Verint
Systems Inc. or its subsidiaries. All rights reserved. All other marks are trademarks of their respective
owners.
© 2009 Verint Systems Inc. All rights reserved worldwide.
Since Verint products operate at 2.4, 5.3, 5.4, and 5.8 GHz, such environmental factors
have an insignificant effect on their performance. ................................................................ 22 Designing Wireless Video Systems ........................................................................................ 22 Types of Systems .................................................................................................................................... 22 Point-to-Point Wireless Systems ........................................................................................................................... 22 Point-to-Multipoint Wireless Systems .................................................................................................................... 24 Point-to-Point and Point-to-Multipoint Wireless Systems with Repeaters ............................................................. 25 Bridge Applications ............................................................................................................................................... 26 Bridge Applications with Repeaters ...................................................................................................................... 27 RF Cell Considerations ............................................................................................................................ 28 Non-Adjacent Channels ........................................................................................................................................ 28 Adjacent Channel Interference..............................................................................................................................28 Antenna Separation Requirements ....................................................................................................................... 29 Designing for Maximum Range ............................................................................................................... 30 Determining Range ............................................................................................................................................... 30 Simplifying the Creation of RF Systems with the Verint RF Margin Calculator ..................................................... 31 Creating the Proper Design ..................................................................................................................... 33 Getting Started: What You Need to Know ............................................................................................................. 33 Determining Beam Width ...................................................................................................................................... 35 Completing the Design Using the Verint RF Margin Calculator............................................................................. 37 The Pre-Installation Site Survey .............................................................................................................. 40 Questions to Ask ................................................................................................................................................... 40 Site Survey Equipment ......................................................................................................................................... 41 An RF Site Survey Using the Nextiva S4300 ........................................................................................................ 42 Interpreting the Site Survey Report ....................................................................................................................... 44 Nextiva Wireless Edge Devices ............................................................................................................... 45 Nextiva S1970 Decoders ......................................................................................................................... 46 Antennae.................................................................................................................................................. 47 Third-Party Switches and Power Supplies .............................................................................................. 47 High-Gain Directional Antennae .............................................................................................................. 48 The Proprietary Nextiva SPCF and SDCF Protocol ................................................................................ 48 Sample Ranges with Nextiva Wireless Edge Devices ............................................................................ 48 Appendix D: Maximum S4200 Units per S4300 Bridge.......................................................... 49 Appendix E: Using IP Cameras with the Nextiva S4200 ........................................................ 50 Unauthorized use, duplication, or modification of this document in whole or in part without the written
consent of Verint Systems Inc. is strictly prohibited.
By providing this document, Verint Systems Inc. is not making any representations regarding the
correctness or completeness of its contents and reserves the right to alter this document at any time
without notice.
Features listed in this document are subject to change. Please contact Verint for current product features
and specifications.
All marks referenced herein with the ® or TM symbol are registered trademarks or trademarks of Verint
Systems Inc. or its subsidiaries. All rights reserved. All other marks are trademarks of their respective
owners.
© 2009 Verint Systems Inc. All rights reserved worldwide.
Typical Scenarios for Planning Your Wireless System ........................................................................... 50 Scenario 1 ............................................................................................................................................................. 51 Scenario 2 ............................................................................................................................................................. 52 Other Valid Combinations ..................................................................................................................................... 53 Appendix F: The Verint RF Margin Calculator........................................................................ 54 Advanced RF Calculator Parameter Descriptions and Settings .............................................................. 55 Additional Parameters for the 4.9 GHz Band ........................................................................................................ 57 Appendix G: Video Quality and Default Bit Rates for Nextiva Encoders ..................................... 59 Video Quality Frame Rates for NTSC and PAL....................................................................................... 59 Unauthorized use, duplication, or modification of this document in whole or in part without the written
consent of Verint Systems Inc. is strictly prohibited.
By providing this document, Verint Systems Inc. is not making any representations regarding the
correctness or completeness of its contents and reserves the right to alter this document at any time
without notice.
Features listed in this document are subject to change. Please contact Verint for current product features
and specifications.
All marks referenced herein with the ® or TM symbol are registered trademarks or trademarks of Verint
Systems Inc. or its subsidiaries. All rights reserved. All other marks are trademarks of their respective
owners.
© 2009 Verint Systems Inc. All rights reserved worldwide.
About Verint Video Intelligence Solutions
Verint® Video Intelligence Solutions™ is the leading global provider of networked video solutions that
enhance the security of people, property and assets. Verint’s award-winning Nextiva® portfolio includes
video management software, integrated analytics, encoders and IP cameras, and intelligent DVRs for use
in a variety of vertical market environments. Open, standards based and IT friendly, Verint solutions help
organizations leverage their existing video investments and place IP video within the reach of virtually
every organization.
About Verint Systems
Verint Systems Inc. is a leading provider of Actionable Intelligence® solutions for an optimized enterprise
and a safer world. More than 10,000 organizations in over 150 countries rely on Verint solutions to
perform more effectively, build competitive advantage, and enhance the security of people, facilities, and
infrastructure.
1
About This Guide
When it comes to securing people, property, and essential services, organizations from municipalities and
transit authorities to power plants, airports, and all manner of critical infrastructure increasingly recognize
the value that wireless video provides.
Wireless technology offers more than just the ability to protect hard-to-wire locations. It reduces reliance
on telephone carriers and the expense of telephone charges for significant cost reductions. By decreasing
the need to trench and lay cable, it also pares down infrastructure costs and speeds deployment, making
it especially useful for temporary installations, as well as for long-term deployments. 1
Wireless video is an excellent choice
for historical sites and other settings
where cabling is not permitted. It can
readily secure remote locations
where landline services are not
available. And it is appropriate for
areas that are prone to downed lines
from strong winds, construction, and
other environmental hazards.
However, the complexity of wireless
video technology and the difficulty of
keeping pace with emerging
standards and new vendor solutions
make system design challenging for
both the system integrator and the
customer.2
This reference guide is designed to
provide system integrators and those
organizations that market video
solutions with a more complete
understanding of wireless video
system design and deployment.
Today, over 400 US municipalities and counties have either
deployed wireless networks or are planning to do so.1
Over the next three years, US municipalities are projected to spend
over $3 billion to build and operate public wireless networks. And by
the year 2009, the municipal wireless market will tally $1 billion in
annual sales.2
The guide begins with a thorough
exploration of the fundamentals of
wireless communication, including an examination of how radio signals and RF communications work, a
review of current and pending wireless standards, an in-depth look at available license-free and US public
safety bands, and a detailed description of design factors.
The next section of this guide takes a close look at system design, from the various types of wireless
video systems and the circumstances in which each is most appropriately used, to essential design tools
and the complexities of building systems that meet customer needs.
Several appendices follow, offering detailed information about use of Verint Nextiva solutions in wireless
video systems.
1
muniwireless.com, August 2007.
2
Crossing the Chasm, Mike Perkowski, MuniWireless, March 2007.
2
Finally, a glossary provides an extensive list of pertinent terms and their definitions, and an index helps
readers quickly locate topics of interest.
Fundamentals of Wireless Communication
Before designing a wireless video system, it is important
to understand the fundamental elements of system
design, from such basic concepts as frequency and
wavelength to the wireless standards, equipment, and
operational considerations that must be part of every
design plan. This section of Wireless Video System
Design is devoted to examining these elements and
helping the system integrator gain a more complete
understanding of the fundamentals of wireless
communication.
For More Information
See the Glossary at the end of this
reference guide for a comprehensive list
of pertinent terms and their meanings.
General Physics of Radio Signals: Frequency and Wavelength
RF (radio frequency) communications work by creating electromagnetic waves at a source and then
receiving those electromagnetic waves at a particular destination. The electromagnetic waves travel
through the air at almost the speed of light. The wavelength of an electromagnetic signal is inversely
proportional to the frequency: that is, the higher the frequency, the shorter the wavelength.
Frequency is measured in hertz (cycles per second), and radio frequencies are measured in kilohertz
(KHz or thousands of cycles per second), megahertz (MHz or millions of cycles per second) and gigahertz
(GHz or billions of cycles per second). Since higher frequencies result in shorter wavelengths, the
wavelength of a 900 MHz device is longer than that of a 2.4 GHz device.
In general, signals with longer wavelengths travel a greater distance and go through and around objects
better than signals with shorter wavelengths, as illustrated below.
3
How RF Commu
unication Systems
S
W
Work
Imagine an
a RF transmitter wiggling an electron in
n one
location. This
T
wiggling electron causses a ripple effect,
e
like
dropping a pebble in a pond. The efffect is an electromagneticc
(EM) wave that travels from the initial location an
nd results in
electrons wiggling in re
emote location
ns. An RF recceiver can
detect thiss remote elec
ctron wiggling.
The RF co
ommunication
n system utilizzes this phenomenon by
wiggling electrons
e
in a specific patte
ern to represe
ent
informatio
on. The receiv
ver can make this same infformation
available at a remote lo
ocation, comm
municating wiithout wires.
In designing most wireless systems, designers fa
ace two
significantt consideratio
ons. First, the system mustt operate
over a cerrtain distance
e (range) and transfer a certain amount
of informa
ation within a given time fra
ame (data ratte). Second,
the cost of
o the system must be within budget, the
e system
must be compliant
c
with
h governmentt agency regu
ulations, and
all approvvals and licens
sing must be attained.
Maintaining Sign
nal Qualityy
Signal Sccatter
A significa
ant problem with
w 2.4 GHz and
a 5 GHz wireless system
ms is that radio signals do not go throug
gh
solid objects very well. In order to ge
et around objects and thro
ough doors, th
hese signals must
m
reflect off
o of
the walls and
a ceilings. This is called
d
scattering
g. The better a signal scatte
ers, the
stronger the reception.
Signal sca
attering reduc
ces signal qua
ality
because of
o multi-path fading
f
and inttersymbol
interference (ISI). Multi-path fading can be
compared
d to an echo created
c
when someone
yells in a cavern
c
or a valley. The original
sound com
mes back from
m different dirrections at
different sound
s
levels. Since the ech
hoes take
different paths
p
to return
n to the same
e location,
they arrive
e at different times. If the waves
w
arrive succh that their pe
eaks and valleys are
out of syn
nc (out of phas
se), they canccel each
other out.
When m
multipath fading occurs, sig
gnals arrive ou
ut of phase
and cancel
c
each otther out.
4
The same can be said for a radio signal that is scattered by objects
it encounters on the way to the receiver. The RF reflections
received by the radio from multiple, indirect paths, though
attenuated from the main path, are delayed in time.
The distribution of echoes (reflections) over time (delay spread) can
also create ISI, a condition in which the delayed energy from one
transmission begins to corrupt the symbol arriving next along the
(more) direct path.
Orthogonal Frequency Division Multiplexing (OFDM)
Orthogonal Frequency Division Multiplexing (OFDM) modulation
has been growing in usage because of its ability to overcome the
problems associated with signal scattering and is especially useful
outdoors. OFDM is meant to create a wide-band signal composed
of a number of independent (orthogonal) sub-carriers, each carrying
a low bit rate data stream.
Intersymbol interference occurs
when the information in the signal
cannot be properly read because
of signal pulses that overlap when
they arrive at the receiver.
In 802.11a 5 GHz systems, there are a total of 9 non-overlapping,
20 MHz wide channels, each with 52 sub-carriers that are themselves each approximately 300 KHz wide.
The 2.4 GHz 802.11b/g systems have only 3 non-overlapping channels. The sub-carriers are sent in
parallel, meaning they are sent and received simultaneously.
The receiver processes these
individual signals, each one
representing a fraction of the
total data being sent. With so
many sub-carriers combined in
each channel, an enormous
amount of data can be
transmitted at the same time.
The low bit rate data stream
allows for a sizeable guard
band at the beginning of each
symbol, effectively isolating
the symbols from each other and neutralizing the effect of delay spread. In addition, sub-channelized
operation in conjunction with the proper error correction system proves to be very tolerant of narrowband
multi-path fades.
The error correction used by OFDM is called Forward Error Correction (FEC). FEC sends two copies of
the data to the receiver. If part of the primary data is lost, algorithms are used to recover the data from the
secondary set of data, thus eliminating the need to resend the data again. In most cases, only a limited
number of sub-carriers may be affected by a fade, causing the loss of symbols. With the remainder of the
wideband signal unaffected, the error correction system takes over and is able to reconstruct the small
percentage of missing data bytes.
5
The 802.11 Wireless Standard
Originally released in 1997, the IEEE 802.11 standard today comprises three released standards and one
draft standard.
802.11a
This standard uses the 5 GHz band and provides a physical data rate of 54 Mbps and actual data
throughput up to approximately 24 Mbps. Using standard equipment with omni-directional antennae, the
range is up to 30m/100 feet in outdoor environments at the maximum physical data rate. Greater distance
can be reached by scaling the data rate down from 54 to 36, 24, 18, 12, 9, or 6 Mbps.
802.11b
This standard uses the 2.4 GHz band and provides a physical data rate of 11 Mbps and actual data
throughput up to approximately 6 Mbps. Using standard equipment with omni-directional antennae, the
range is up to 100m/300 feet in outdoor environments at the maximum physical data rate. Greater
distance can be reached by scaling down the data rate from 11 to 5.5, 2, or 1 Mbps.
802.11g
This is the most commonly used standard and provides better performance than the 802.11b standard.
This standard uses the 2.4 GHz band and provides a physical data rate of 54 Mbps and actual data
throughput up to approximately 24 Mbps. Using standard equipment with omni-directional antennae, the
range is up to 100m/300 feet in outdoor environments at the maximum physical data rate. Greater
distance can be reached by scaling down the data rate from 54 to 36, 24, 18, 12, 9, or 6 Mbps. 802.11g is
backwards compliant with 802.11b.
802.11n
This is the next generation of the 802.11 Wireless LAN (WLAN) standard currently being defined by the
IEEE. This standard is expected to be ratified in 2008. 802.11n will operate in the same
frequency band as 802.11b/g, but promises to offer significant
bandwidth increases, with a potential physical
data rate of 540 Mbps and a potential IP payload
For More Information
data rate of 200 Mbps. Note that the measured IP
payload data rate on pre-802.11n products is
See Appendix B: Range and Nextiva
currently 80 Mbps.
Wireless Edge Devices.
802.11n builds upon previous 802.11 standards
by adding Multiple-Input Multiple-Output (MIMO)
technology. MIMO uses multiple transmitter and receiver antennae to allow for increased data throughput
via spatial multiplexing and increased range by exploiting spatial diversity. 802.11n promises greater
range than 802.11b/g.
6
Frequency Channels
The 2.4 GHz Band (License Free)
The 2.4 GHz band has 14 frequency channels, but only 11 are permitted for unlicensed use by the FCC
in the US. Each channel extends 11 MHz on each side of the center frequency. Most importantly, the
channels overlap. See the table below and the diagram on the following page.
Available Frequency Channels – 2.4 GHz Band
Channel
Frequency (MHz)
Location
1
2412
US, Europe, Japan
2
2417
US, Europe, Japan
3
2422
US, Europe, Japan
4
2427
US, Europe, Japan
5
2432
US, Europe, Japan
6
2437
US, Europe, Japan
7
2442
US, Europe, Japan
8
2447
US, Europe, Japan
9
2452
US, Europe, Japan
10
2457
US, Europe, Japan
11
2462
US, Europe, Japan
12
2467
Europe, Japan
13
2472
Europe, Japan
14
2484
Japan Only
7
8
To the extent that channels overlap, they interfere with each other and reduce available bandwidth. For
installations that require multiple access points, three access points using channels 1, 6, and 11 have no
overlap. Larger installations must be properly deployed to minimize interference, or a frequency band with
more available channels must be used.
Consider This
The 2.4 GHz frequency band is limited by the
number of non-interfering channels available,
and most wireless office telephones and
networking equipment use the same frequency
band. This increases the risk of potential
interference and can reduce available throughput
for transmitting video. Consequently, 2.4 GHz
equipment should be used only when there is
little risk of interference from other 2.4 GHz
equipment being used in the area.
9
The 5 GHz Bands (License Free)
The 5 GHz band is actually four frequency bands: 5.1 GHz, 5.3 GHz, 5.4 GHz, and 5.8 GHz. The 5 GHz
band has a total of 24 channels with 20 MHz bandwidth available. Five of these can be used outdoors
without requiring DFS and TPC. Unlike the 2.4 GHz band, the five channels are non-overlapping, so all
five channels have the potential to be used in a single wireless system.
Available Frequency Bands – 5 GHz
Channel
Frequency (GHz)
Location
36
40
44
48
52
56
60
64
100
104
108
112
116
120
124
128
132
136
140
149
153
157
161
165
5.180
5.200
5.220
5.240
5.260
5.280
5.300
5.320
5.500
5.520
5.540
5.560
5.580
5.600
5.620
5.640
5.660
5.680
5.700
5.745
5.765
5.785
5.805
5.825
Indoor Only
Indoor Only
Indoor Only
Indoor Only
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
DFS required
North America
North America
North America
North America
North America
This illustration shows the channel
allotment and center frequencies for
channels in the 5 GHz frequency
band. The two- and three-digit
numbers are the channels, and the
four-digit numbers are the center
frequencies for the channels above
them.
10
The 4.9 GHz Public Safety Band (Licensed)
The US Federal Communications Commission (FCC) allotment of 50 MHz of spectrum in the 4.9 GHz
band permits public safety agencies to implement on-scene wireless networks for streaming video, rapid
Internet, database access, and the transfer of large files, such as maps, building layouts, medical files,
and missing person images. It also allows public safety agencies to establish temporary fixed links to
support surveillance operations. This allocation gives every jurisdiction in the country access to the
spectrum for interoperable broadband communications. Specific FCC rules are covered in Subpart Y in
47CFR part 90 of the FCC regulations.
A 4.9 GHz band license gives the licensee
authority to operate on an authorized channel
in this band within the applicant’s jurisdiction
(city, county, state). A license allows use of
base stations and mobile devices, such as
laptops and PDAs.
The 4.9 GHz band must be shared by all
licensees in an area, with coordinated usage
and channel arrangements. Generally, this is
not an issue since few 4.9 GHz transmitters
exist and few transmit continuously. Licenses
are granted for a period of 10 years.
Increasing the Number of
Channels with Channel
Fragmentation
4.9 GHz Band License Eligibility
Who is eligible to apply for a 4.9 GHz license? All
US state and local government entities, private
companies sponsored by a government entity
(such as private ambulance services), and any
organization with critical infrastructure (power
companies, pipelines, etc.) that provides public
safety services for the protection of life, health,
or property. They may apply on the FCC website
under the ULS section and must pay a $50 filing
fee. Those organizations that do not meet the
eligibility requirements, but support public
safety, may negotiate with the license holder for
sharing agreements.
Since the 4.9 GHz band is limited to 50 MHz,
only 2 standard, independent channels of 20
MHz are available in this band. Channel
fragmentation in the 4.9 GHz band has been
added to allow more than two systems to
For More Information
operate in the same area. With channel
fragmentation, a licensee can select a
See Appendix C: Nextiva Support for 802.11.
channel bandwidth of 20 MHz (standard
channel bandwidth currently supported), 10
MHz, or 5 MHz. The 10 MHz channel bandwidth allows for four independent channels, and 5 MHz allows
10 independent channels. The 5 and 10 MHz channel bandwidths are available only in the 4.9 GHz band.
11
Changing the channel bandwidth has an impact on available
bit rate. If a 10 MHz channel bandwidth is used, the channel
data rate is divided in half; if a 5 MHz channel bandwidth is
used, the channel data rate is divided by four.
The table to the right shows the available bit rate with
respect to the channel bandwidth used.
Antennae and Transmission Lines
20 MHz
10 MHz
5 MHz
6
3
1.5
9
4.5
2.25
12
6
3
18
9
4.5
24
12
6
36
18
9
48
24
12
54
27
13.5
Types of Antennae
There are two broad classifications for antennae, depending
on their directivity:
•
Omni-directional radiates in all directions (360
degrees)
•
Uni-directional radiates best in a particular direction
Channel Bandwidth (MHz) vs.
Channel Data Rate (Mbps)
An omni-directional antenna radiates in all directions with approximately the same power and is nondirectional, so its gain tends to be quite low. Omnis are normally deployed when a number of transmitters
surround a particular area near the receiver.
The following four figures show that as directionality increases, beam width decreases and gain
increases.
12
Directivity
Directivity is the ability of an antenna to focus energy in a particular direction when transmitting or to
receive energy from a particular direction when receiving. If a wireless link uses fixed locations for both
ends, it is possible to use antenna directivity to concentrate the radio beam in the direction required. In
mobile applications where the transceiver is not fixed, it may be impossible to predict where the
transceiver will be, so the antenna should ideally radiate as well as possible in all directions. In addition,
when transmitters surround the receiver and multiple receivers are not a viable option, the ability to
receive from all directions is required. An omni-directional antenna is used in these applications.
Gain
Gain is a “dimensionless ratio,” rather than a quantity that can be defined in terms of a physical quantity,
such as watt (power) or ohm (resistance). Gain is referenced with regard to standard antennae, the two
most common of which are isotropic antennae and resonant half-wave dipole antennae. This section
focuses on isotropic antennae.
Isotropic antennae radiate equally well in all directions. Real isotropic antennae do not exist, but they
provide useful and simple theoretical antenna patterns with which to compare actual antennae. An actual
antenna radiates more energy in some directions than in others. Since antennae cannot create energy,
the total power radiated is the same as an isotropic antenna. Any additional energy radiated in the
directions it favors is offset by equally less energy radiated in all other directions.
The gain of an antenna in a given direction is the amount of energy radiated in that direction compared to
the energy an isotropic antenna would radiate in the same direction when driven with the same input
power. Usually we are interested only in maximum gain, which is the gain in the direction in which the
antenna radiates the most power. Antenna gain of 3 dB compared to an isotropic antenna would be
written as 3 dBi.
Radiation Pattern
The radiation pattern (or antenna pattern)
describes the relative strength of the radiated
field in various directions from the antenna at a
constant distance. The radiation pattern is a
reception pattern, as well, since it also describes
the receiving properties of the antenna. The
radiation pattern is three dimensional, but the
measured radiation patterns are usually a twodimensional slice of the three-dimensional
pattern in the horizontal or vertical planes. These
pattern measurements are presented in either
rectangular or polar format.
This is a rectangular plot presentation of an 18 dBi
antenna typically deployed in projects where a
moderate gain antenna is required.
13
Polar coordinate systems are used almost
universally. In a polar coordinate graph, points
are located by projection along a rotating axis
(radius) to an intersection with one of several
concentric circles.
Polar coordinate systems may be divided
generally in two classes: linear and logarithmic.
Linear Polar Coordinate
Systems
In a linear coordinate system, concentric circles
are equally spaced and graduated. Such a grid
may be used to prepare a linear plot of the
power contained in a signal. For ease of
comparison, the equally spaced concentric
circles may be replaced with appropriately
placed circles representing the decibel
response, referenced to 0 dB at the outer edge
of the plot. In this kind of plot, the minor lobes
are suppressed. This grid enhances plots in
which the antenna has high directivity and
small minor lobes.
A linear polar plot of a 16 dBi, 27 degree beam width
antenna shown just below the plot
Logarithmic Polar Coordinate
Systems
In a logarithmic polar coordinate system, concentric grid lines are
spaced periodically according to the logarithm of the voltage in the
signal. Different values may be used for the logarithmic constant of
periodicity; this choice affects the appearance of the plotted patterns.
Generally the 0 dB reference for the outer edge of the chart is used.
The spacing between points at 0 dB and -3 dB is greater than the
spacing between -20 dB and -23 dB, which is greater than the spacing
between -50 dB and -53 dB. The spacing thus corresponds to the
relative significance of such changes in antenna performance.
A Directional Antenna
14
Beam Width and the Half-Power Point
An antenna's beam width is usually understood to mean the half-power beam width. Peak radiation
intensity is found, and then the points on either side of the peak, which represent half the power of the
peak intensity, are located. The angular distance between the half power points is defined as the beam
width. Half the power expressed
in decibels is -3 dB, so the half
power beam width is sometimes
referred to as the 3 dB beam
width.
Both horizontal and vertical beam
widths are usually considered.
Assuming that most of the
radiated power is not divided into
side lobes, the directive gain is
inversely proportional to the
beam width: As the beam width
decreases, the directive gain
increases.
-3 dB
Side Lobes
No antenna is able to radiate all
energy in one preferred direction. Some energy is inevitably radiated in other directions. These smaller
peaks are referred to as side lobes, commonly specified in dB down from the main lobe.
Nulls
In an antenna radiation pattern, a null is a zone in
which the effective radiated power is at a minimum. A
null often has a narrow directivity angle compared to
that of the main beam. Thus, the null is useful for
several purposes, such as suppressing interfering
signals in a given direction.
For More Information
See the Glossary at the end of this
reference guide for a comprehensive list
of pertinent terms and their meanings.
15
Cables
RF cables are almost exclusively coaxial cables,
or coax for short, derived from the phrase “of
common axis.” Coax cables have a core
conductor wire surrounded by a non-conductive
material called dielectric or insulation. The
dielectric is encompassed by a shielding, which is
often made of braided wires. The dielectric
prevents an electrical connection between the
core and the shielding.
The coax is protected by an outer casing, which is generally made from a PVC material. The inner
conductor carries the RF signal, and the outer shield prevents the RF signal from radiating to the
atmosphere and prevents outside signals from interfering with the signal carried by the core.
Another interesting fact: the electrical signal always travels along the outer layer of the central conductor,
and the larger the central conductor, the better the signal flows. The is the result of the skin effect, a
phenomenon that sees the RF signal energy flowing more at the outer surface of the wire than through
the middle. The higher the frequency, the more the skin effect and the greater the resistance.
Even though the coaxial construction is good at containing the
signal on the core wire, there is some resistance to the
electrical flow: as the signal travels down the core, it fades
away. This fading is known as attenuation, and for
transmission lines, it is measured in decibels per meter
(dB/m). The rate of attenuation is a function of the signal
frequency and the physical construction of the cable itself. As
the signal frequency increases, so does its attenuation.
Cable attenuation should be minimized as much as possible
by keeping the cable very short and using high-quality cables.
16
Selecting Cables for Use with Microwave Devices
•
The shorter the better. The first rule when you install a piece of cable is to try to keep it as
short as possible. Power loss is not linear, so doubling the cable length means that you are
going to lose much more than twice the power. In the same way, reducing the cable length by
half gives you more than twice the power at the antenna. The best solution is to place the
transmitter as close as possible to the antenna, even when this means placing it on a tower.
•
You get what you pay for. Any money you invest in buying good quality cable is a bargain.
Cheap cables are intended to be used at low frequencies, such as VHF. Microwaves require the
highest-quality cables available, and all other choices produce inferior results.
•
Avoid RG-58. It is intended for thin Ethernet networking or CB or VHF radio and not for
microwave.
•
Avoid RG-213. It is intended for CB and HF radio. In this case, cable diameter does not imply a
high quality or low attenuation.
•
Whenever possible, use Heliax (foam) cables for connecting the transmitter to the
antenna. Heliax cables have a solid or tubular center conductor with a corrugated solid outer
conductor to enable them to flex. Heliax can be built in two ways, using either air or foam as a
dielectric. Air dielectric Heliax is the most expensive and guarantees the minimum loss, but is
very difficult to handle. Foam dielectric Heliax is slightly more prone to loss, but is less
expensive and easier to install. A special procedure is required when soldering connectors in
order to keep the foam dielectric dry and uncorrupted. When Heliax is unavailable, use the bestrated LMR cable you can find. LMR is a brand of coax cable available in various diameters that
works well at microwave frequencies. LMR-400 and LMR-600 are a commonly used alternative
to Heliax.
•
Whenever possible, use cables that are pre-crimped and tested in a proper lab. Installing
connectors to cable is tricky business ― difficult to do properly even with the proper tools.
Unless you have access to equipment that can verify a cable you make yourself (such as a
spectrum analyzer and signal generator or time domain reflectometer), troubleshooting a
network that uses homemade cable can be difficult.
•
Do not abuse your transmission line. Never step on a cable, bend it too much, or try to
unplug a connector by pulling the cable directly. All these behaviors may change the mechanical
characteristic of the cable and its impedance, short out the inner conductor to the shield, or even
break the line. These problems are difficult to track and recognize and can lead to unpredictable
behavior on the radio link.
17
Connectors
Connectors allow a cable to be connected to another cable or to a component of the RF chain. There is a
wide variety of fittings and connectors designed to go with various coaxial lines. A few of the more
popular connectors are described below.
Connector
Introduced
Characteristics
Ideal Use
BNC
Late 1940s
Features two bayonet lugs on
the female connector. Mating
is achieved with only a quarter
turn of the coupling nut.
For cable termination for miniature to
subminiature coaxial cable (RG- 58 to RG-179,
RG-316, etc.). These have acceptable
performance up to a few GHz and are most
commonly found on test equipment and
10Base2 coaxial Ethernet cables.
Type N
World War II
Both the plug/cable and
plug/socket joints are
waterproof, providing an
effective cable clamp.
Usable up to 18 GHz and very commonly used
for microwave applications; available for almost
all types of cable.
SMA
1960s
High performance and
compact in size, with
outstanding mechanical
durability.
Precision, subminiature units that provide
excellent electrical performance up to 18 GHz.
18
Selecting Connectors
•
Check gender. Virtually all connectors have a well-defined gender, consisting of either
a pin (the male end) or a socket (the female end). Usually cables have male connectors
on both ends, while RF devices (such as transmitters and antennae) have female
connectors. Devices such as directional couplers and line-through measuring devices
may have both male and female connectors. Be sure that every male connector in your
system is matched to a female connector.
•
Less is best. Try to minimize the number of connectors and adapters in the RF chain.
Each connector introduces some additional loss (up to a few dB for each connection,
depending on the connector).
•
Buy. Do not build. As mentioned earlier, buy cables that are already terminated with
the connectors you need, whenever possible. Soldering connectors is not easy, and to
do this job properly is almost impossible for small connectors, such as U.FL and
MMCX. Even terminating foam cables can be difficult.
•
Do not use BNC for 2.4GHz or higher. Use SMA type connectors (or N, SMB, TNC,
etc.) Microwave connectors are precision-made parts and can be easily damaged by
mistreatment. As a general rule, you should rotate the outer sleeve to tighten the
connector, leaving the rest of the connector (and cable) stationary. If other parts of the
connector are twisted while tightening or loosening, damage can occur.
•
Never step on connectors or drop connectors on the floor when disconnecting
cables. This happens more often than you may think, especially when working on a
mast over a roof.
•
Never use tools such as pliers to tighten connectors. Always use your hands.
•
When working outside, remember that metals expand at high temperatures and
contract at low temperatures. A highly tightened connector in the summer can bind or
even break in winter.
19
RF Line of Sight (LOS)
The least understood of all topics in long-distance, wireless transmission may be RF Line of Sight (LOS).
Most people believe that if you are able to see the other end of the intended link, there is clear RF LOS.
This is not true at times because of the way that radio signals behave. All radio signals will generate a
conical transmission pattern, with the widest point being the midpoint of the signal path. This pattern is
known as the Fresnel Zone and needs to be clear of obstacles to ensure maximum power transfer from
the transmitter to the receiver. As the distance of the wireless link increases, the Fresnel Zone becomes a
larger fraction to consider; since RF signals travel in straight lines, the curvature of the earth can actually
cause the signals to be attenuated.
The Fresnel Zone
The Fresnel Zone is the area around the visual Line of Sight into which radio waves spread after they
leave the antenna. Typically, 20% Fresnel Zone blockage introduces little signal loss to the link. Beyond
40% blockage, signal loss becomes significant. This calculation is based on a flat earth and does not
take the curvature of the earth into consideration. For long links, have a microwave path analysis
performed taking this and the topography of the terrain into account.
20
Foliage Attenuation
Foliage Attenuation is the reduction in signal strength or quality as the result of signal absorption by trees
or foliage obstructions in the signal's LOS path. Trees account for 10 to 20 dB of loss per tree in the direct
path. Loss depends upon the size and type of tree; large trees with dense foliage create greater loss. It is
safe to assume that if light cannot penetrate a stand of trees, microwave losses will be unacceptable.
Frequency (MHz)
Approximate Attenuation (dB/Meter)
432
0.10 - 0.30
1296
0.15 - 0.40
2304
0.25 - 0.50
3300
0.40 - 0.60
5600
0.50 - 1.50
10000
1.00 - 2.00
The Effect of Weather on Microwave Systems
Rain, fog, and snow have negligible impact on system performance for wireless systems operating below
11 GHz.3 Conversely, systems functioning above 11 GHz need to take weather into consideration. One
example is satellite TV systems. The size of the RF signal carrying direct-to-home television is about the
size of the average raindrop. When the weather is clear, the RF signal can reach the satellite TV dish with
a minimum of degradation. However, when it starts to rain, some of the signal gets absorbed by rain, so
less of it reaches the dish on the roof. In fact, very heavy
rain can entirely eliminate the signal.
The effects of weather begin to be felt above 4 GHz, so
2.4 GHz would not be affected by the weather at all.
However, the 2.4 GHz band is quite busy, and the effect
of weather conditions on the 5 GHz band is negligible in
comparison to effect on the 2.4 GHz band over a halfmile link. The number of cameras and the amount of
RF cells needed for the system (and not the weather)
are the determining factors when selecting
equipment and frequency band.
Consider This
To illustrate the different impact of weather on
signal, assume that rain is falling at 30mm (just
over one inch) per hour. The resulting
attenuation at 5 GHz is just 0.07 dB/km, but
nearly 7 dB/km at 30 GHz.
For More Information
For information about Nextiva wireless edge
devices, decoders, and antennae, plus thirdparty
switches
and
power
supplies,
see
Appendix A: An Overview of Verint Nextiva
Wireless Systems.
21
3
Since Verint products operate at 2.4, 5.3, 5.4, and 5.8 GHz, such environmental factors have an insignificant effect on their
performance.
Designing Wireless Video Systems
Now that we have explored the basics of wireless video, we will proceed with more detailed design
considerations, using Nextiva intelligent edge devices to illustrate design constructs.
Types of Systems
Point-to-Point Wireless Systems
Point-to-point is the most straightforward wireless system, usually consisting of a single Nextiva S4100
transmitter/receiver pair, as shown below.
22
When to Use Point-to-Point
The point-to-point system is used when a single, remotely-located
camera must be connected to equipment that requires a coaxial
cable input, such as a DVR, matrix, or analog monitor. Point-to-point
can also be used when two or three remote cameras require
wireless transmission, but the cameras are physically too far apart to
allow for point-to-multipoint implementation.
There are instances when a point-to-point system will incorporate an
S4200 and an S4300 access point. This is when the recording and
viewing are performed using Nextiva Enterprise or Verint nDVR™.
Considerations and Limitations
•
No embedded video analytics
•
No Nextiva or Verint nDVR support
•
MAC modes available: SPCF and SDCF
(Default MAC mode is SDCF)
•
No standard 802.11 support
•
Security: 128-bit AES OCB encryption with key
rotation
•
For configuration, we recommend using
SConfigurator
23
Point-to-Multipoint Wireless Systems
Point-to-multipoint systems incorporate two or more Nextiva S4200 transmitters and one or more Nextiva
S4300 access points, as illustrated below.
When to Use Point-to-Multipoint
Point-to-multipoint systems allow several S4200 transmitters to
share the same RF channel, enabling multiple cameras feeds to be
received by a single S4300 access point, accommodating locations
where there are several remote cameras that require wireless
connections to the receiving end.
Since point-to-multipoint systems support channel sharing, many
more cameras can be deployed in point-to-multipoint systems than
in point-to-point systems, which have a finite number of channels
available.
For point-to-multipoint wireless video over 802.11: This infrastructure
system is used integrate our wireless video encoder with an existing
802.11 WLAN. Data (such as video, audio, meta-data, etc.) can be
sent to Nextiva, nDVR, a Web client, or a standalone video receiver.
Considerations and Limitations
•
MAC protocols available: SPCF and SDCF
(Default MAC mode is SPCF)
•
No standard 802.11 support
•
Security: 128-bit AES OCB encryption with key
rotation
•
No frame bursting available
•
MAC protocol available: 802.11 only
•
Security: WPA1 & 2 PSK and enterprise
•
No site survey available
24
Point-to-Point and Point-to-Multipoint Wireless Systems with Repeaters
These systems are similar to the standard point-to-point and point-to-multipoint systems, respectively,
with the addition of one or more Nextiva S4300-RP repeater units.
When to Use Repeaters
Considerations and Limitations
Point-to-Point
Repeater units are necessary when the
transmission path of the receiver is blocked
by obstacles or when the transmission
distance is too great. Deploying repeaters
will further delay data being sent through
them.
Point-to-Multipoint
•
No embedded video analytics
•
•
No Nextiva or Verint nDVR
support and no SConfigurator
support for the S1100
MAC protocols available:
SPCF and SDCF (Default MAC
mode is SPCF)
•
No standard 802.11 support
•
Security: 128-bit AES OCB
encryption with key rotation
•
No frame bursting
•
MAC modes available: SPCF and
SDCF (Default MAC mode is
SDCF)
•
No standard 802.11 support
•
Security: 128-bit AES OCB
encryption with key rotation
•
No frame bursting
•
For configuration (S4100), we
recommend using SConfigurator
25
Bridge Ap
pplications
The follow
wing is an illus
stration of a bridge
b
applica
ation.
When to Use a Bridge Application
Bridge applications are no
ormally deploye
ed when data in one building
is required
d in another. Tw
wo S4300 bridge
e units would be
e deployed in
this case, with one on eac
ch building. At times,
t
a bridge system
s
is
deployed when a project requires networrk equipment to be deployed
in remote locations that must
m
communica
ate with a netwo
ork in another
location. In some of these
e cases, S4300--RP units are co
onverted into
bridges since they may re
equire 24 VAC power.
p
Consid
derations and
d Limitations
•
MAC proto
ocols available: SPCF and SDC
CF
(Default MAC
M
mode is SD
DCF)
•
No standard 802.11 support
•
Security: 128-bit
1
AES OCB encryption wiith key
rotation
26
Bridge Applications with Repeaters
A bridge application with repeater functions in the same manner as the bridge application alone, with the
same limitations.
27
RF Cell Considerations
Non-Adjacent Channels
All channels in the 5 GHz bands
are non-overlapping, simplifying
system design since there is a
larger number of channels
available for use in a single site.
However, there can still be
interference issues when using
adjacent channels, such as
channels 149 and 153 in the 5.8
GHz band.
Using the Nextiva 5 GHz product
line allows you to deploy three
separate RF cells in one location without interference from RF signals from other Verint wireless devices
installed in the same location. Using non-adjacent channels removes the cross-talk risk between RF cells,
and the antennae do not need to be spaced any given distance apart.
Adjacent Channel Interference
Broadband adjacent channel interference generates considerable side band energy that falls into the
pass band of the adjacent channel. Under these conditions, the amount of link margin, or the size of the
Signal to Interference Ratio (SIR), has a significant effect on the data throughput of the RF channel
affected.
28
Antenna Separation Requirements
For larger sites where more than three RF cells are needed, adjacent channels must be used. This will
not cause interference between channels if the antenna separation rules are correctly applied.
For More Information
See
Appendix
D:
Maximum
S4200 Units per S4300 Bridge
and
Appendix
E:
Using
IP
Cameras with the Nextiva S4200.
Setup
5 GHz (13-dBi Antenna with
Beam Width)
40º
2.4 GHz (6.5-dBI Antenna with 60º Beam
Width)
Side by side
43 feet (13m)
55.8 feet (17m)
On top
13 feet (4m)
6.2 feet (1.9m)
Back to back
7.9 feet (2.4m)
15.7 feet (4.8m)
If antennae with narrower beam widths are used, distances may be reduced.
The installation scenario below uses antenna separation that meets the requirements. This setup uses
only 5 GHz units with the antennae located on the same side of a building. The units using adjacent
channels 52 and 56 are separated by the prescribed 43 feet (13m). You can intersperse other units in
between, as long as they do not use adjacent channels. In this way, you can increase the unit density
without worrying about interference problems.
For more information about antenna separation, see the Nextiva S4300 User Guide.
29
Designing for Maximum Range
Determining Range
In order to accurately calculate system range, it is important to first understand the terms below.
dB-Decibels
Decibels are logarithmic units often used to represent power, gain, and loss in an RF system. The Decibel
dB is actually a dimensionless value found by taking the log of the ratio of two like units, such as power in
watts or milliwatts. For example, dB = 10 log P2/P1, where P1 is the reference value, and P2 is the value
to convert to decibels.
There are two common units of measure that can be used when converting power to decibels: dBW (dB
watts) and dBm (dB milliwatts). dBW is power in decibels relative to 1 watt, and dBm is power in decibels
relative to 1 milliwatt.
•
To convert from watts to dBW, use: Power in dBW = 10* (log x/1) where x is the power in watts.
To convert from milliwatts to dBm, use: Power in dBm = 10* (log x/1) where x is the power in
milliwatts. (Since the reference value is always 1, we do not normally include it in the
calculations.)
Both formulas are identical, except that they yield different results. For example, if 1 watt was used, the
log of 1 is 0, and the log of 1000 (1 watt equals 1000 milliwatts) is 3; the value for dBW in this case would
be 0, and the value for dBm would be 30.
•
Just make certain the same formula is used for all power values, since using dBm for one power value
and dBW for another in the same calculation will yield erroneous results.
Remember: decibels are used in system calculations to allow for simple calculations of gain and loss,
since you only need to add and subtract the db values from each other. If the power information available
is in watts or milliwatts, simply apply one of the above formulas to convert the power to decibel form.
Line of Sight (LOS)
Line of Sight, when speaking of RF, means more than just
being able to see the receiving antenna from the transmitting
antenna. In order to have true RF LOS, no objects (including
trees, houses, or the ground) can be in the Fresnel Zone.
The Fresnel Zone is the area around the visual LOS into
which radio waves spread out after they leave the antenna.
This area must be clear, or else signal strength will weaken.
For More Information
See RF Line of Sight (LOS)
earlier in this guide.
Transmit Power
Transmit power refers to the amount of RF power that comes
out of the antenna port of the radio. Transmit power is usually
measured in watts, milliwatts, or dBm.
Receiver Sensitivity
Receiver (or receive) sensitivity refers to the minimum level
signal the radio can demodulate. In other words, the
An Example
S4200 TX power: 20 dBm
S4300 RX sensitivity: -89 dBm
Total link budget: 109 dBm
30
sensitivity is the lowest level signal from which the receiver can get coherent information. For example,
with sound waves, transmit power is how loud someone is yelling and receiver sensitivity is how soft a
voice someone can hear.
Transmit power and receiver sensitivity together constitute what is known as link budget. The link budget
is the total amount of signal attenuation you can have between the transmitter and receiver and still have
communication occur. For LOS situations, a mathematical formula can be used to figure out the
approximate range for a given link budget. For non-LOS applications, range calculations are more
complex because of the various ways in which the signal can be attenuated.
RF Communications and Data Rate
Data rates are usually dictated by the system: that is, how much data must be transferred and how often
does the transfer need to take place. Lower data rates allow the radio module to have better receive
sensitivity and thus more range. Note that in a point-to-point Nextiva S4100 system using the integrated
12 dBi antennae (5 GHz), radio sensitivity at the maximum possible data rate of 54 Mbps is -72 dBm,
whereas radio sensitivity at the lowest available data rate (6 Mbps) is -90 dBm. This translates to a
maximum distance of 200 meters at 54 Mbps and 2.6 KM for 6 Mbps or about 13 times more distance in
LOS conditions.
Simplifying the Creation of RF Systems with the Verint RF Margin Calculator
The Verint RF Margin Calculator, an MS Excel spreadsheet-based tool, is designed to simplify the
creation of RF systems and can be used without in-depth
knowledge of wireless systems. The Calculator allows you to
select the necessary frequency band for the system, the type
of system (i.e., point-to-point or point-to-multi-point), and
several other parameters to accurately design a system that
For More Information
meets your project requirements. Use of the RF Margin
See Appendix F: The Verint RF
Calculator when designing systems is covered later in this
Margin Calculator.
guide.
Before calculating RF margin, it is important to become
familiar with the terms that follow.
Term
Definition
RF Margin
The amount of extra gain available in the wireless system when the path loss is subtracted
from the total gain of the system.
System Gain
The addition of the power provided by the radio transmitter, the gain of the transmitter’s
antenna, the gain of the receiver’s antenna, and the sensitivity of the radio receiver.
Radio Transmission Power
The amount of energy the radio transmitter is able to produce. The amount of power
produced by the radio is regulated depending on the frequency band being used. This helps
ensure that everyone using the frequency band has equal opportunity to transmit their data
across the air.
Antenna Gain
The amount that the power from the transmitter is increased by the antenna. The higher the
gain of the antenna, the farther the signal travels. The maximum gain used in a system is
also regulated, so that the maximum amount of power produced by the transmitter does not
31
Term
Definition
exceed the level specified in regulations.
Receiver Sensitivity
The minimum acceptable value of received power needed to achieve acceptable
performance. In other words, the sensitivity value of the receiver is the lowest power level at
which the receiver can extract the information from the signal being sent from the
transmitter.
Path Loss
May be the result of many factors, such as free space loss, refraction, reflection, connector
loss, and cable loss. Path loss is usually expressed in dB.
Free Space Loss (FSL)
The transmission loss between two ideal antennae, assumed to be in a vacuum. FSL is the
propagation loss due solely to spreading of the wave front and assumes no blockage of line
of sight or the first Fresnel Zone.
Refraction
The bending of an electromagnetic wave as it passes between materials of different
density. An example of this is a wave going from humid air to drier air.
Reflections
Occur when a wave hits a surface it cannot penetrate. The wave deflects off the surface at
an angle that is the same as the angle at which the original wave hit. Since many objects
that may be in the path of the wave have irregular surfaces (i.e., are not smooth), the wave
can reflect in all directions.
Connector and Cable Loss
Occurs because of the need to connect the antenna to the radio. Since the connection of
these two components requires some type of cable, the cable and the connectors that hold
them together cause a loss of signal strength prior to the signal being sent out into the air.
This is why short cables and a minimum number of connectors should be used in a wireless
system.
32
Creating the Proper Design
At the outset, certain information and tools are essential to creating the proper design. At times, when
some of this information is unavailable or unknown, you must make assumptions that the customer must
qualify. It is important to avoid over-complicating the design during this process.
Getting Started: What You Need to Know
The Number of Cameras
Without information about cameras within the system, there is no way to determine anything else about
the system. You may not get all of this information, but the more you have, the easier it will be. The key
information required is:
•
How many cameras will there be, and what types (analog, IP, fixed, PTZ)?
•
What are the distances from the head end?
•
Do all cameras have RF Line of Sight (LOS) to the head end? (Will repeaters be required?)
•
What video quality and frame rates are expected?
Camera Locations
Another important piece of information is the location
of the cameras. Most customers will have a site
layout that you can obtain. If this information is
unavailable, a verbal description of the site should be
requested. If this is not possible, only a generic
system design can be created, with a disclaimer
stating that no site information was available at the
time of the system design and quote and that design
and associated quote are thus for budgetary
purposes only.
Transmission Distances
A further requirement for a quality design is the
distances of the camera locations to the head end. If
all distances are not available, the camera locations
farthest away from the head end are sufficient.
Head End Location
Finally, the location of the head end (wired network
point of presence) should be determined so that the
system can be laid out.
Basic Tools for Designing a
Wireless System
Site Layout. The site layout needs to have the
camera locations, obstructions (if possible), and
the head end clearly marked. A site layout with
distances marked is desirable.
Video Resolution and Frame Rates. This
provides an estimate of the amount of bandwidth
required per camera in the system.
Head End Equipment. This is the video’s final
destination. Does the implementation require
analog at the head end or will it use nDVR or
Nextiva?
RF Margin Calculator. This Verint calculator
helps you easily determine the maximum length
of RF links and video bandwidth limits and select
antennae.
Protractor and Ruler. These simple, but
invaluable tools of the trade help you determine
the minimum beam width required to capture
multiple cameras.
33
The Preliminary Layout
The example below offers the preliminary information needed to determine how this system can be set
up. Although all distances to the head end are not listed, we know that the maximum distance is less than
1 km.
From this information, we can
create our basic system as
shown below. All camera
locations will require an S4200
unit, and the head end will
require multiple S4300 access
points. As you can see, there
are three S4300 access points
at the head end. The camera
locations naturally divided the
cameras into three distinct
groups, which are referred to
as RF cells. With this all in
place, the system design can
be finalized with the required antennae and a determination of expected throughput for the cameras in the
different cells.
34
Determining Beam Width
Once the RF cells have been determined and distances have been measured, the minimum beam width
for the antennae required for each RF cell can be established. This requires a protractor and a ruler.
To determine the minimum beam width:
1.
Use the ruler to draw a line from the head end location to each of the outer camera positions for each RF cell.
(Refer to the following figure.)
2.
Using the protractor, determine the angle between the two lines previously drawn.
a.
Place the midpoint of the protractor on the point at the head end where the two previously drawn lines
intersect.
b.
Line up the zero degree line with one of the lines so that the second line is under the protractor.
c.
Read the value on the protractor where the second line falls on the graduated dial. This will be the angle
between the two lines that are used to determine the beam width required for the antenna. (See the
figure on the following page.)
35
3.
The example below shows an angle of 17 degrees. This means an antenna with a beam width greater than 17
degrees is required to ensure all cameras are in the antennae beam.
•
4.
Since there is an 18 degree beam width antenna available, one would assume this would be the
logical choice based on the 17 degree angle of separation between the outer camera locations.
However, the choice of antenna is based on more than just this criterion.
Repeat steps 1-3 for all RF cells in the project.
36
Completing the Design Using the Verint RF Margin Calculator
Now that the camera location, distances, minimum beam width requirements, and RF cell creation are
complete, the RF Margin Calculator should be used to bring everything together. There are two ways to
go about completing the system design, depending on the information you have available.
•
Determine the required antennae based on known frame rate and resolution requirements. This
method may require reorganization of RF cells if the available bandwidth based on the distances
involved does not meet the requirements for the project.
•
Determine the maximum amount of bandwidth available per camera based on the throughput
available for the distances, cameras, and antennae needed for a functional system.
Adding System Information to the Calculator
1.
From the Country drop-down box, select the country where the system is to be installed. If the country is not in
the list, select Unregulated.
2.
Select the Frequency Band to be used for the system, as agreed upon by the customer. If this has not been
determined, select one of the 5 GHz bands available in the country selected.
3.
Select the system type: point-to-point or point-to-multipoint.
•
•
Select point-to-point for:
o
S4100 units
o
When S4300 units are used as a bridge
o
When using a repeater; the transmit side of the repeater to a single receiver (S4300 or
S4100-Rx)
Select point-to-multipoint for:
o
Multiple S4200 units transmitting to one S4300
o
The transmit side of an S4300-RP repeater transmitting to multiple S4100-Rx units
37
4.
Enter the longer link distance in the RF cell:
•
For point-to-multipoint systems, this would be the camera location in the RF cell farthest from the
receiving point.
•
Select the Channel Data Rate that will provide the data throughput necessary for the RF link.
5.
Select the Units (both Master and Slave) for the system.
6.
Select the antenna model that satisfies the distance and beam width requirements for the RF link:
7.
•
If the selected antennae do not have the gain needed to satisfy the minimum margin for the
length of the link, the box around the margin value will turn yellow and the margin value will turn
red .
•
Select an antenna that allows the margin to be at least 15 dB.
•
If an antenna is not available with the appropriate gain and bandwidth combination to have all the
cameras within the beam width with sufficient margin, the Channel Data Rate must be reduced to
allow for greater receiver sensitivity and, thus, longer range.
•
If you are unable to find a combination of antenna and data throughput that satisfies the needs of
the customer, either a repeater is required or the number of cameras in the RF cell must be
reduced, or both.
Once the appropriate antennae have been selected, all parts for the system are identified, and a quote can be
created.
38
Tower Height Calculations
The RF Margin Calculator automatically calculates the height at which the antennae must be mounted to
ensure that 60% of the first Fresnel Zone is clear of any obstructions.
Additionally, the Advanced RF Margin Calculator interface calculates the required height of the antennae
in both meters and feet.
The RF Margin Calculator also provides a graphical view of the Fresnel Zone on a separate tab.
Fresnel Zone Calculator Results
For More Information
See Appendix G: Video Quality and Default Bit Rates for Nextiva Encoders.
39
The Pre-Installation Site Survey
This is a basic overview of what should be considered while doing a wireless site survey. A site survey is
simply a map of the site at which your customer wants to install his/her wireless products. It is perhaps
the most important step you must take before implementing any type of wireless devices.
Questions to Ask
•
What type of facility (site) is it? The answer to this
simple question can have a significant impact and
extend the time required to complete the survey.
•
How big is the facility? The size will affect the
power output required, as well as security
considerations.
•
Is it indoor or outdoor (or both)? Different types of
construction affect radio transmissions differently.
─
Consider This
Look at the site from an RF perspective, as well as
a wired perspective. The survey should be well
documented and include the following:
A hospital presents a good example of a site
with indoor hazards. It has radiology
equipment, fire doors, lead-lined walls in the
x-ray department, elevators, and doctors with
PDAs. Be aware of dead zones inside.
•
IP addressing (including all existing
networks)
•
Interference sources
•
Equipment placement
•
Power considerations
•
Wiring requirements
•
If outdoors, does the area experience frequent
tornados or hurricanes? Strong winds can disrupt
a long-distance, wireless connection by moving
one or both of the radio devices. Weatherproof
enclosures may need to be added to your installation list.
•
Are there any existing wireless or wired networks? Ask the facility’s network administrator the
following questions:
─ How many users are on the current network? How many will there be two years from now? (This
has an impact on bandwidth considerations.)
─ Are there any firewalls or routers, and, if so, are any ports blocked?
─ What protocols are allowed/blocked on the LAN?
─ If there is a wireless network in place, what DSSS channels does it use?
─ Where are the wired LAN connections located (wiring closets)?
•
Is a tower required? If installing a system in a PTMP situation, a 20-foot tower may be needed to
clear an obstacle.
─ Do you have access to the roof?
─ Is the roof structurally sound enough to support a tower?
─ Do you need a permit to install a tower?
─ Do you need an engineer?
40
•
Are facility blueprints available? Creating drawings from scratch can take time and are likely not to be
accurate. Existing blueprints can provide you with dimensions, firewall locations, power outlets,
network closets, and other pertinent details.
•
Are there building facilities, such as cafeterias, that have microwave ovens (a major source of
interference)?
Site Survey Equipment
In most cases you will need:
•
At least one access point (S4300)
and/or Spectrum Analyzer (see below)
•
An Ethernet
connectors
•
switch,
cables,
Plenty of paper; be prepared to walk,
sketch, and record your signal
strengths
Site survey software is valuable for properly
planning a wireless deployment. Many site
survey software packages are commercially
available.
A Spectrum Analyzer is also invaluable during
a site survey since it can easily provide you
with the following data:
•
•
•
Things to Record During a Survey
and
•
Trees (Fresnel Zone interference)
•
Buildings (diffraction)
•
Lakes (reflection, major cause of multipath)
•
Visual LOS
•
Link distance (for distances greater than 7
miles, compensate for the curvature of the
earth)
•
Roof accessibility
•
Weather hazards
•
If during the winter, trees that will grow into
the Fresnel Zone during the summer months
Signal strength (in dB)
Noise floor (in dBm)
Signal to Noise Ratio (SNR) (in dB)
Additional equipment to consider when surveying an outdoor installation includes:
•
•
•
•
•
•
Binoculars and two-way radios
Camera for taking pictures
Rain suit
Battery packs
DC to AC converters
Measuring wheel
41
An RF Site Survey Using the Nextiva S4300
A site survey is an evaluation of the observed traffic on all channels that can be used for an RF unit. This
can help with RF planning for a site or troubleshooting installed deployments.
A site survey can be triggered at any time by the user and is also done by the SPCF or SDCF master at
startup when automatic channel selection is used.
A site survey will cause loss of RF connectivity, as the RF unit must passively listen for 1 second on each
channel. In particular, in 5 GHz channels in Europe, performing a site survey will force a new 60-second
period of radar detection, as required by European legislation.
Commands in the CLI
Open a shell on your PC, and connect to the device (telnet <IP_address>: xxx.xxx.xxx.xxx).
Triggering a Site Survey
A site survey can be done as a one-time scan of all channels. This is the recommended way of
proceeding. To do so, select 1) and then ENTER, and enter 1 for the number of Site Survey Iterations.
Use the s) Start/Stop Site Survey command in the menu:
Advanced \ Communication Status and Statistics \ Wireless Status
A site survey can also be done using up to 100 iterations by selecting 1) and entering the number of
iterations required. Then simply use the s) Start/Stop Site Survey command to start the survey; it will
automatically stop after the number of requested iterations has been completed.
***********************************************************
*
Verint Video Solutions S4300 - 172.16.13.16
*
***********************************************************
Advanced \ Communication Status and Statistics \ Wireless Status
----------------------------------------------------------Parameters:
NIC Name
: AT5001 WIS CM6 A,B,G 2.4-5.8 GHz
NIC MAC Address
: 00-0B-6B-30-2A-5B
Current Channel
: 165 (5825 MHz)
Current TX Rate
: Auto rate control
Current RX Rate
: Auto rate control
Average Signal Level
: -55 dBm
Current SCF Connection Status: Auto channel selection in progress
RF Communication Quality : 34 dBm
RF Margin
: 36 dBm
Indoor/Outdoor RF Regulation : Indoor/Outdoor FCCA FCC1
1) Site survey iteration
:5
Commands:
l) Display link(s) Info
s) Start/Stop Site Survey
v) Visualize Last Site Survey Report
r) Reset Site Survey data base
p) Previous Menu
***********************************************************
Command:
42
While the site survey is performed, the following apply:
•
There is no RF connectivity possible.
•
Current SCF Connection Status in CLI will display: Remaining site survey iteration x (where x
could be a value between 1 and 100).
•
The LED flashes as if it were performing auto-channel selection.
Viewing the Site Survey
The last site survey report can be visualized from the CLI:
Advanced \ Communication Status and Statistics \ Wireless Status, command v)
Channel(52) Cost: 1
Channel(56) Cost: 75
Age Interf. Source MAC
Master MAC/
Rx Unit Name/
(s) Type
802.11 BSSID
(dBm) 802.11 SSID
----- --------- ----------------- ----------------- ----- ----------8 SPCF MSTR 00-0B-6B-30-FA-42 00-0B-6B-30-FA-42 -76 Michel's VBrid
8 CRC ERR XX-XX-XX-XX-XX-XX XX-XX-XX-XX-XX-XX -77 UNKNOWN
Channel(60) Cost: 19
Age Interf. Source MAC
Master MAC/
Rx Unit Name/
(s) Type
802.11 BSSID
(dBm) 802.11 SSID
----- --------- ----------------- ----------------- ----- ----------8 CRC ERR XX-XX-XX-XX-XX-XX XX-XX-XX-XX-XX-XX -79 UNKNOWN
Channel(64) Cost: 32
Age Interf. Source MAC
Master MAC/
Rx Unit Name/
(s) Type
802.11 BSSID
(dBm) 802.11 SSID
----- --------- ----------------- ----------------- ----- ----------6 .11 IBSS 00-01-24-70-0D-71 9A-59-24-70-61-6D -82 boeing
7 .11 IBSS 00-01-24-70-0D-6E 9A-59-24-70-61-6D -93 boeing
6 CRC ERR XX-XX-XX-XX-XX-XX XX-XX-XX-XX-XX-XX -83 UNKNOWN
Channel(149) Cost: 72
Age Interf. Source MAC
Master MAC/
Rx Unit Name/
(s) Type
802.11 BSSID
(dBm) 802.11 SSID
----- --------- ----------------- ----------------- ----- ----------5 SPCF MSTR 00-01-24-70-0E-CA 00-01-24-70-0E-CA -79 Michel's VBrid
5 CRC ERR XX-XX-XX-XX-XX-XX XX-XX-XX-XX-XX-XX -80 UNKNOWN
Channel(153) Cost: 67
Age Interf. Source MAC
Master MAC/
Rx Unit Name/
(s) Type
802.11 BSSID
(dBm) 802.11 SSID
----- --------- ----------------- ----------------- ----- ----------4 CRC ERR XX-XX-XX-XX-XX-XX XX-XX-XX-XX-XX-XX -88 UNKNOWN
4 SPCF MSTR 00-01-24-70-29-37 00-01-24-70-29-37 -84 UNKNOWN
Channel(157) Cost: 0
Channel(161) Cost: 26
Age Interf. Source MAC
Master MAC/
Rx Unit Name/
(s) Type
802.11 BSSID
(dBm) 802.11 SSID
----- --------- ----------------- ----------------- ----- ----------2 .11 IBSS 00-01-24-70-28-B5 EA-59-24-70-44-B6 -82 AAA
Channel(165) Cost: 29
Age Interf. Source MAC
Master MAC/
Rx Unit Name/
(s) Type
802.11 BSSID
(dBm) 802.11 SSID
43
----- --------- ----------------- ----------------- ----- ----------1 SPCF MSTR 00-0B-6B-30-2A-5B 00-0B-6B-30-2A-5B -69 HUGOJ VB6
11 CRC ERR XX-XX-XX-XX-XX-XX XX-XX-XX-XX-XX-XX -69 UNKNOWN
******* Cost Spectrum Image *******
Channel: 52 Cost-> 1 |
Channel: 56 Cost-> 75 |>>>>>>>>>>>>>>>
Channel: 60 Cost-> 19 |>>>
Channel: 64 Cost-> 32 |>>>>>>
Channel: 149 Cost-> 72 |>>>>>>>>>>>>>>
Channel: 153 Cost-> 67 |>>>>>>>>>>>>>
Channel: 157 Cost-> 0 |
Channel: 161 Cost-> 26 |>>>>>
Channel: 165 Cost-> 29 |>>>>>
******* Cost Spectrum Image *******
Interpreting the Site Survey Report
The cost of a channel is a number that represents how much interference is present in that channel. The
higher the metric, the worse the channel is. Automatic Channel Selection is performed based on this
metric.
Interferer Types
Type
Description
DCRPT ERR
Decryption error: unknown type of traffic
CRC ERR
CRC error: unknown type of traffic
SPCF MSTR
SPCF Master
SPCF SLAV
SPCF Slave
SPCF CLNT
SPCF Client
SDCF MSTR
SDCF Master
SDCF SLAV
SDCF Slave
SDCF CLNT
SDCF Client
.11 IBSS
802.11 IBSS system (Ad hoc)
.11 BSS
802.11 BSS system (with AP)
Age is the number of seconds elapsed between the last observation of this interferer and the end of the
survey.
Source MAC is the MAC address of the interferer.
Master MAC/802.11 BSSID is the MAC address of the SPCF/SDCF master of the interferer or the 802.11
BSSID of the 802.11 service set of the interferer.
Rx (dBm) is the received signal level in dBm.
Unit Name/802.11 SSID can be unknown for old/unknown interferers, the VSIP unit name for Nextiva
interferers (release 3.20 and higher), or the 802.11 SSID of 802.11 systems.
44
The cost spectrum image is a graphical representation of the cost on the various channels.
Appendix A: An Overview of Verint Nextiva Wireless Systems
Nextiva Wireless Edge Devices
Built for real-world security applications, Nextiva wireless edge devices are
designed to transmit images from anywhere with a combination of features virtually
unmatched in the industry.
Nextiva wireless edge devices support video transmission over license-free 2.4 and
5 GHz wireless bands and the 4.9 GHz US public safety band. Designed for outdoor
use, they feature compact, weatherproof enclosures, SSL-based authentication,
AES encryption with rotating 128-bit key, and a unique protocol to overcome standard wireless limitations.
By combining a multi-band radio, encoder, and antenna in a single compact enclosure, these devices
also speed deployment and reduce power and space requirements.
Nextiva
Device
S4100
Description
•
Video encoder/transmitter and receiver (two units)
•
For point-to-point wireless applications
•
MPEG-4 based video up to 4CIF, 30 fps
•
Ethernet port for configuration or connection of an IP camera or Ethernet-based sensor hardware
•
Dual camera input/output option to provide video and PTZ control for two analog cameras
•
•
•
S4200
•
•
•
•
•
•
Video encoder/transmitter (one unit)
For point-to-point or point-to-multipoint wireless applications
Works in conjunction with Nextiva S4300 access points to allow for multiple camera locations to be
transmitted back to a single receiver, significantly increasing the number of camera feeds that can
be accessed wirelessly in a single location
802.11a/g and WPA2 support
Web-based configuration
Camera tampering detection (with Nextiva Enterprise V5.1 and above)
Dual-stream, MPEG-4 based video up to 4CIF, 30 fps
Optional on-board analytics
Dual camera input/output option to provide video and PTZ control for two analog cameras
45
Nextiva Wireless Edge Devices (continued)
Nextiva
Device
Description
•
Wireless access point for aggregating traffic from multiple S4200 devices in point-to-multipoint
applications
S4300
•
Powered using Power over Ethernet (PoE), using the Ethernet cable to supply both data and
power to the unit
•
Includes 25-meter Ethernet cable
•
Wireless repeater for retransmitting signals from Nextiva wireless devices to a wired LAN in pointto-point or point-to-multipoint applications
S4300-RP
•
Consists of two S4300 units: one to receive wireless data from the camera site(s) and the other to
transmit to the head end or next repeater site
•
Units are connected using a crossover Ethernet cable supplied with the units
•
Powered using a 24 VAC power supply (not supplied with the kit)
•
A wireless bridge for transmitting analog or IP camera images between two LANs in point-to-point
or point-to-multipoint applications
•
Consists of two S4300 units: one to transmit wireless data from a remote building location or IP
camera site and the other to receive the wireless data at the head end or local network site
S4300-BR
•
Units are connected to their local network or IP camera using a 25-meter Ethernet cable supplied
with the units
•
Option to power by either 24 VAC power supply or PoE
Nextiva S1970 Decoders
Verint digital video decoders are designed for use when video received from camera locations must be
converted to analog format for display on analog monitors or recorded using a traditional DVR. The
Nextiva S1970e-R is a highly compact, single-output decoder that lets
users view video from a single camera or view up to four video streams
in quad display or guard tour sequence.
The S1970e-R provides an RS422/485 serial interface to connect to a
PTZ (Pan, Tilt, Zoom) camera control keyboard or any other serial
device that supports the 422/485 protocols.
46
Antenn
nae
Several antennae are available
a
for use
u with Verin
nt wireless so
olutions to add
dress a wide range of wire
eless
applications. Nextiva S4100,
S
S4200
0, and S4300 units are equ
uipped with inttegrated ante
ennae that pro
ovide
8.5 dBi (2.4 GHz) or 12
2 dBi (5.x GHz) of gain. Pu
ublic safety models
m
also off
ffer a 12 dBi
of gain in the 4.9 GHz band. Antenn
nae differ dep
pending on thrree paramete
ers; gain,
directiona
ality and frequ
uency. Be sure
e to use only antennae certified by Veriint to make
sure that the
t combined
d transmission
n power of the
e device and antenna does not
regulations.
exceed th
he maximum value
v
establisshed by your jurisdiction’s
j
Third-P
Party Switches and Power Supplies
Switches
s
When point-to-multipoint systems are required, Nextiva
N
wirele
ess systems need
n
an Etherrnet switch to
allow the components to forward the
eir data to the
e appropriate
destinatio
on. A switch is
s a device tha
at receives da
ata from a hosst on
the netwo
ork; in this cas
se, a Nextiva S4300 or oth
her Nextiva
encoder and
a decoder. The data the switch receivves must go to
oa
certain de
evice also atta
ached to the switch.
s
The sw
witch sends the
data to the
e specific porrt to which the
e receiving de
evice is conne
ected. This is different from
m a hub. A hu
ub
receives data
d
on a portt and sends itt to all ports on
o the hub. Th
his uses a lot more of the available
a
data
a
bandwidth
h, is less effic
cient, and is th
he reason tha
at switches are preferred ovver hubs. Forr small system
ms, a
small swittch is usually required. Sw
witches are rea
adily available
e at consume
er electronics stores.
Power Su
upplies
Unless otherwise spec
cified, Verint products
p
are shipped
s
witho
out power sup
pplies.
Single inp
put devices, such as the Ne
extiva S1950e
e and S1970e
e, come with a power
supply. Ne
extiva S4300 units are pro
ovided with a PoE injector and
a the outdo
oor cable to
connect th
he PoE injector to the S4300 unit. Multi--input devicess do not come
e with a
power sup
pply since the
ey can be dep
ployed individually or as a complete sysstem in a
rack. If ma
any units are deployed in the
t same loca
ation, it is more practical to
o employ a
larger cen
ntral power su
upply to powe
er many units,, than to use many
m
supplie
es to power
each device individually. Both unit power
p
supplie
es (S1260) an
nd central pow
wer supplies
(PS1280) are available
e for purchase
e from Verint. Nextiva S4100 and S4200 wireless
transmitte
ers may be sh
hipped with a power supplyy (24 VAC). However,
H
thesse supplies
are for configuration pu
urposes only. Power supplly units provid
ded by Verint are not
rated for outdoor
o
use. The
T integrato
or is responsib
ble for providing the powerr supplies
for remote
e camera loca
ations. Many camera vendors can proviide the appropriate
power sup
pply that is ra
ated for outdoo
or use with su
ufficient powe
er for both the
e camera
and the S4100
S
transmiitter.
47
Appendix B: Range and Nextiva Wireless Edge Devices
Nextiva wireless edge devices are based on 802.11a and 802.11g Ethernet standards and offer greater
ranges than standard 802.11 equipment for two primary reasons:
•
Use of high-gain directional antennae
•
The proprietary Nextiva SPCF and SDCF protocols
High-Gain Directional Antennae
Directional antennae focus energy in a particular direction when transmitting or receiving energy from a
particular direction. Directivity coupled with a high-gain allows Nextiva wireless edge devices to achieve
greater ranges.
For more information, see Antennae and Transmission Lines earlier in this guide.
The Proprietary Nextiva SPCF and SDCF Protocol
Nextiva wireless video products use software protocol enhancements to eliminate common Wi-Fi
problems and enable greater range. Nextiva wireless products use standard 802.11 PHY and a modified
802.11 MAC, which was optimized for transmitting video surveillance data over greater distances.
Sample Ranges with Nextiva Wireless Edge Devices
Device Type
S4300
S4200
S4100
Frequency
Antenna Type
Range
2.4 GHz
8.5 dBi integrated antenna
Up to 2.1 miles (3.4km)
2.4 GHz
16 dBi directional antenna
Up to 5.8 miles (9.3 km)
5.725-5.825 GHz
12 dBi integrated antenna
Up to 2.1 miles (3.3 km)
5.725-5.825 GHz
19 dBi directional antenna
Up to 6.2 miles (10.0 km)
5.725-5.825 GHz
12 dBi integrated antenna
Up to 2.1 miles (3.3 km)
5.725-5.825 GHz
19 dBi directional antenna
Up to 6.2 miles (10.0 km)
5.725-5.825 GHz
24 dBi directional antenna
Up to 11.1 miles (17.8 km)
2.4 GHz
8.5 dBi directional antenna
Up to 2.1 miles (3.4 km)
2.4 GHz
16 dBi directional antenna
Up to 5.8 miles (9.3 km)
5.725-5.825 GHz
12 dBi integrated antenna
Up to 2.1 miles (3.3 km)
5.725-5.825 GHz
19 dBi directional antenna
Up to 8.8 miles (14.2 km)
48
Appendix C: Nextiva Support for 802.11
Nextiva S4200 devices can be used with commercial 802.11-compliant access points. The S4200 in
802.11 mode supports the following security mechanisms:
•
WPA (Wi-Fi Protected Access) in personal mode (PSK—pre-shared key)
•
WPA2 (also known as 802.11i) in personal mode (PSK)
•
WPA and WPA2 in Enterprise mode, with an 802.1X authentication server
•
WPA and WPA2 are not available with the proprietary SPCF MAC protocol.
The MAC protocol to use is specified in the MAC Mode parameter. The wireless parameters associated
with 802.11 differ from those of the SPCF MAC mode.
The 802.11 MAC mode is available in all frequency bands (2.4 GHz, 4.9 GHz, and 5 GHz).
There are some limitations when using S4200 devices in an 802.11 environment:
•
The S4200 will not be able to connect to an S4300.
•
Inherent problems with 802.11 wireless network products, such as hidden node and quality of
service issues, will be present. Furthermore, equipment range will be lower than with the SPCF
protocol.
Appendix D: Maximum S4200 Units per S4300 Bridge
The maximum number of Nextiva S4200 units that can be associated with a single Nextiva S4300 bridge
depends on several factors. The main factor is the bandwidth required to transmit video at a specific
resolution and bit rate. The higher the resolution and bit rate of the video, the higher the bandwidth
requirement. Overall available bandwidth must be addressed based on the size of the video to be
transmitted. Since site requirements differ, the maximum number of S4200 units to be associated with
each S4300 also differs.
Contact Verint Sales Support for systems that require more than six S4200 units per S4300, so that we
can help you properly calculate RF cell bandwidth and design the system for optimum performance.
49
Appendix E: Using IP Cameras with the Nextiva S4200
With the introduction of an Ethernet port on the Nextiva S4200 and the optional two-camera models,
many new configurations are possible. Video data from more than a single camera can be transmitted
from one S4200 transmitter, but several factors must be considered: the total throughput available from
the S4200, the available bandwidth for the RF cell, and the total amount of bandwidth used by each link in
the RF cell.
When using a single S4200 for multiple camera transmissions, it is important to remember that the onboard processor has a finite amount of available processing power. With a single camera connected to an
S4200 transmitter, it is possible to achieve 4CIF resolution at 30 fps. However, if an IP camera is
connected to the Ethernet port of the S4200, some processing power will be required to transport the IP
data stream from the Ethernet port of the IP camera to the radio for transmission to the S4300 receiver.
The S4200’s processor has the ability to forward an Ethernet stream equal to the maximum available
bandwidth on the wireless link. Obviously, using the maximum available bandwidth for just the Ethernet
port leaves no bandwidth for the video streams from the encoders. Also, to attain good encoding
performance for analog cameras connected to the S4200, the maximum amount of Ethernet traffic from
the Ethernet port cannot exceed 2 Mbps. Exceeding this value can seriously affect encoder performance.
If maximum encoder performance is required (4CIF 30 fps), the total amount of Ethernet traffic being sent
from the S4200 should not exceed 4 Mbps.
For example, consider a wireless cell with four cameras using two S4200 transmitters. If this system is
designed such that the distances dictate a channel data rate of 12 Mbps, the total available video
bandwidth for the entire wireless cell will be 5.6 Mbps at distances of less than 3.1 miles (5 km).
The SPCF MAC protocol divides this video bandwidth equally between the two transmitters, providing 2.8
Mbps for each pair of cameras in the wireless cell.
This equates to a total of 1.4 Mbps per camera, which can accommodate the following resolution and
frame rate (NTSC/PAL) combinations, with either two analog cameras or the combination of one analog
and one IP camera using MPEG-4 encoding:
•
4CIF at 10/8 fps
•
2CIF at 15/12 fps
CIF at 30/25 fps
As the number of multi-camera links increases, the video bandwidth available for each camera
decreases. With the previous example, this time using four transmitters instead of two, the bandwidth
available for each camera becomes 700 Kbps (5.6 Mbps divided by four transmitters divided by two
cameras per transmitter).
•
If an IP camera is used with MJPEG compression, make sure that the combination of frame rates and
resolutions from both the IP and analog cameras do not exceed the maximum video bandwidth available.
As link distances increase, total available video bandwidth decreases because of free space loss and
other factors. If this is not taken into account in the design phase, problems can surface that have a
detrimental effect on total system performance.
Typical Scenarios for Planning Your Wireless System
To help you plan your system, some typical scenarios are provided in the pages that follow. In each
scenario, the maximum number of analog cameras is connected on the device (one for the S4200 and
50
two for the S4200-2V); the compression mode is MPEG-4 or SM4; there is a single stream per camera;
and there is clear RF Line of Sight with an RF margin of 15 dB or better to maintain the data rate
specified. The video performances supplied include a video resolution, a frame rate expressed in frames
per second (fps), and a bit rate expressed in kilobits per second (kbps).
Scenario 1
In this scenario, channel data rate is 6 Mbps, and maximum available video bandwidth is 3.5 Mbps.
Analog Cameras
IP Camera on S4200
IP Camera on S4200-2V
1 camera at 4CIF, 30/25 fps,
3 Mbps
1 IP camera at CIF, 10 fps,
Kbps
2 cameras at 4CIF, 30/25 fps,
6 Mbps
N/A
Available bandwidth is exceeded
1 camera at 4CIF, 15/12 fps,
2 Mbps
1 IP camera at CIF, 30/25 fps, 1
Mbps
N/A
2 cameras at 4CIF, 15/12 fps,
4 Mbps
N/A
Available bandwidth is exceeded
1 camera at 2CIFH, 30/25 fps,
2 Mbps
1 IP camera at CIF, 30/25 fps, 1
Mbps
N/A
N/A
Available bandwidth is exceeded
1 camera at CIF, 30/25 fps,
1 Mbps
1 IP camera at 4CIF,
15/12 fps, 2 Mbps
N/A
2 cameras at CIF, 30/25 fps,
2 Mbps
N/A
1 IP camera at CIF,
30/25 fps, 1 Mbps
None
1 IP camera at 4CIF,
N/A
2 cameras at 2CIFH, 30/25 fps,
Mbps
4
256
N/A
30/25 fps, 4 Mbps
51
Scenario 2
This scenario proposes a channel data rate of 54 Mbps and maximum available video bandwidth of 10.1
Mbps. There are two transmitters in the wireless cell with exactly the same combination of analog and IP
cameras.
Analog Cameras
1 camera at 4CIF, 30/25 fps,
Mbps
IP Camera on S4200
3
N/A
Available bandwidth is exceeded
2 cameras at 4CIF, 30/25 fps,
Mbps
6
N/A
1 camera at 4CIF, 15/12 fps,
Mbps
2
1 IP camera at 4CIF,
fps, 2 Mbps
2 cameras at 4CIF, 15/12 fps,
Mbps
4
N/A
1 camera at 2CIFH, 30/25 fps,
Mbps
1 camera at CIF, 30/25 fps,
Mbps
2 cameras at CIF, 30/25 fps,
Mbps
None
2
1
2
IP Camera on S4200-2V
1 IP camera at CIF, 15 fps, 512
Kbps
1 IP camera at 4CIF,
2 Mbps
15/12
N/A
Not enough processing power
15/12 fps,
N/A
1 IP camera at 4CIF,
30/25 fps, 4 Mbps
N/A
N/A
1 IP camera at 4CIF,
15/12 fps, 2 Mbps
1 IP camera at 4CIF,
30/25 fps, 4 Mbps
N/A
52
Other Valid Combinations
The following tables display additional frame rate and resolution combinations when using IP cameras in
conjunction with analog cameras using the S4200 and S4200-AS. Note that the following values are valid
only if the application has enough wireless bandwidth available for the total amount of data to be
transmitted.
S4200
IP Camera or Ethernet Data Stream
Analog Camera
CIF 30 fps – 1000 Kbps
CIF 30 fps – 1000 Kbps
4CIF 15 fps – 2000 Kbps
4CIF 15 fps – 2000 Kbps
4CIF 30 fps – 6000 Kbps
4CIF 15 fps – 3000 Kbps
S4200-AS
IP Camera or Ethernet Data Stream
CIF 30 fps – 1000 Kbps
4CIF 15 fps – 2000 Kbps
4CIF 30 fps – 6000 Kbps
Analog Camera 1
Analog Camera 2
CIF 30 fps
2CIFH 30 fps
1000 Kbps
2000 Kbps
CIF 30 fps
1000 Kbps
2CIFH 15 fps
1500 Kbps
CIF 30 fps
CIF 30 fps
1000 Kbps
1000 Kbps
53
Appendix F: The Verint RF Margin Calculator
The Verint RF Margin Calculator, an MS Excel spreadsheet-based tool, is designed to simplify the
creation of RF systems and can be used without in-depth knowledge of wireless systems. The Calculator
allows you to select the necessary frequency band for the system, the type of system (point-to-point or
point-to-multi-point), and several other parameters to help you design a system that meets your project
requirements.
The RF Margin Calculator is available in basic and advanced versions, which can be used independently
of each other, if required. The functionality of both calculators is similar, and only the basic version is
addressed here.
To quickly determine the settings and equipment required, the RF Margin Calculator takes all of the
following parameters into account.
54
Advanced RF Calculator Parameter Descriptions and Settings
Parameter
Description
Available Settings
Country
Country in which the system is to be
installed
All countries in which Verint sells products and
which have RF regulations in place
Frequency Band
Frequency band to be used for the system
2.4 GHz
5.1 GHz
System Type
The type of system to be deployed
Point-to-point
Distance
Length of the wireless link; in point-tomultipoint systems, this is based on the
camera location that is farthest from the
receiving point
User modified value
Channel Data Rate
Data rate for the channel; this setting affects
the receiver sensitivity, as well as the
available guaranteed video bandwidth for the
channel
6 Mbps
9 Mbps
12 Mbps
Nb of Connectors
Total number of connectors in the system
between the unit and the antenna; the
default value of connector loss in the
Calculator is 1 dB per connector; realistic
values are .4 dB to.6 dB per connector, but 1
dB is used to add additional margin to the
link budget
User modified value
Total Antenna Cable
Length
Total length of the cable used to connect the
antenna to the unit; default length is 1 meter
based on what is provided from the factory
with the antenna; custom length can be used
by checking the Use Custom Length
checkbox and entering the cable length in
the box provided
Default cable loss is 1 dB; the LRM240 cable
that Verint provides with the antenna has a
loss of 0.67 dB per meter; 1 dB adds extra
margin to the link budget
User modified value
Unit (Slave)
Unit that is remote to the head end
5.3 GHz
5.4 GHz
5.8 GHz
4.9 GHz
Point-to-multipoint
18 Mbps
24 Mbps
36 Mbps
48 Mbps
54 Mbps
S4200
S4100-Tx
S4300/S4300-RP
55
Parameter
Description
Available Settings
With a 5 GHz frequency selected:
• 12 dBi/40 degree integrated
• 19 dBi/18 degree
• 24 dBi/9 degree
• 16 dBi/90 degree
Antenna (Slave)
Antenna to be used on the remote unit
With 2.4 GHz frequency selected:
• 8.5 dBi/65 degree integrated
• 16 dBi/27 degree
With 4.9 GHz frequency selected:
• 12 dBi
• 18 dBi
• 25 dBi
S4100-Rx
Unit (Master)
Unit located at the head end side of the link
Antenna (Master)
Antenna to be used on the remote unit
See Antenna (Slave) above
Data Throughput
Maximum amount of available bandwidth for
video data
Calculated in Mbps (Mega Bits Per Second)
Output Power (Slave)
Output power of the radio based on the
settings applied in the Calculator
Calculated: varies, maximum 20 dBm
Output Power (Master)
Output power of the radio based on the
settings applied in the Calculator
Calculated: varies, maximum 20 dBm
Radio Sensitivity
(Slave & Master)
The radio sensitivity based on the
parameters entered in the Calculator
Calculated: varies, minimum 72 dBm,
maximum 90 dBm
EIRP (Slave)
Equivalent Isotropically Radiated Power
(EIRP) represents total effective transmit
power of the radio, including gains that the
antenna provides and losses from the
antenna cable
Calculated based on the parameters entered in
the Calculator. Maximum values shown on the
right hand side
EIRP (Master)
See above
See above
System Gain (Slave to
Master)
Total gain of the system from the transmitter
to the receiver; derived by adding output
power, antenna gain, and radio sensitivity
Calculated based on parameters selected in
the Calculator
System Gain (Master
to Slave)
Total gain of the system from the receiver to
the transmitter; derived by adding output
power, antenna gain, and radio sensitivity
Calculated based on parameters selected in
the Calculator
Path Loss
A calculated value of the expected loss of
signal strength from the transmitter to the
receiver
Calculated value based on the physics of RF
communications
Margin (Slave to
Master)
The amount of extra system gain available
after the path loss has been subtracted; 15
dB is the minimum for a good RF link
Calculated value based on parameters
selected in the Calculator
Margin (Master to
Slave)
See above
See above
S4300/S4300-RP
56
Parameter
Description
Available Settings
Expected Rx Signal
Level (Master)
The expected level of RF energy in the
Master unit
Calculated based on parameters selected in
the Calculator
Expected Rx Signal
Level (Slave)
The expected level of RF energy in the
Slave unit
Calculated based on parameters selected in
the Calculator
Fresnel Zone
Clearance
The height the antennae need to be above
the highest obstacle in the RF path
Calculated based on frequency and path length
Note concerning Expected Rx Signals:
If obstacle clearances are based on keeping 60% of the first Fresnel Zone clear, the following average loss must be
added to the expected Rx signal values calculated by the RF Margin Calculator:
1. Flat surface adds 2 dB attenuation to free space attenuation
2.
Small houses of similar height / forest adds about 3 dB loss
3.
Urban area adds estimated loss of about 5 dB
Additional Parameters for the 4.9 GHz Band
When the 4.9 GHz band is selected in the Verint RF Margin Calculator, several additional parameters
become available. With the ability to fragment the channels in the 4.9 GHz band, the calculator provides a
combination box for selecting channel bandwidth. The calculator provides data throughput values for the
channel bandwidth selected.
Please note that the Advanced Calculator must be used for channel bandwidths other than 20 MHz.
57
Standard RF
Calculator Display
Standard RF
Calculator Display
a
Advanced RF
Calculator Display
58
Appendix G: Video Quality and Default Bit Rates for Nextiva
Encoders
The following tables contain the default bit rates in Kbps to be expected from Verint Nextiva encoders
with moderate motion in the video. These values can be used as guidelines to determine the amount of
video bandwidth required for the RF links of a wireless system based on frames per second and
resolution required.
Since all camera feeds and locations are different, customers should always be made aware that these
are guidelines only and that the practical application of wireless products may require adjustments based
on actual site performance once the system has been installed.
Video Quality Frame Rates for NTSC and PAL
NTSC
Frames Per Second
Resolution
1
2
4
5-7
6-8
10
15
30
QCIF (176x128)
25
50
64
128
200
256
512
1024
CIF (352x240)
25
50
64
128
200
256
512
1024
2CIFH (704x240)
50
100
128
256
400
512
1024
2048
All lines (352x480)
50
100
128
256
400
512
1024
2048
VGA (640x480)
100
200
256
512
800
1024
2048
4096
4CIF (704x480)
100
200
256
512
800
1024
2048
4096
PAL
Frames Per Second
Resolution
1
2
4
5-7
6-8
10
15
25
QCIF (176x144)
25
50
64
128
200
256
512
1024
CIF (352x288)
25
50
64
128
200
256
512
1024
2CIFH (704x288)
50
100
128
256
400
512
1024
2048
All lines (352x480)
50
100
128
256
400
512
1024
2048
VGA (640x576)
100
200
256
512
800
1024
2048
4096
4CIF (704x576)
100
200
256
512
800
1024
2048
4096
59
Glossary
1000Base–T
See Gigabit Ethernet.
100Base-T
Often referenced in the past as Fast Ethernet. This is the standard Ethernet technology currently in widespread use
with a maximum throughput of 100 Mbps. It is usually deployed in a star topology with segment lengths of up to 100
meters.
10Base-2
Commonly known as ThinNet. This is a very old Ethernet standard that uses thin coaxial cable. This standard is
rarely used today because of the bus topology it requires and the limited bandwidth it provides. The maximum length
of each segment is greater than 100Base-T up to 185 meters, but the available throughput is only 10 Mbps.
10Base-5
Also known as ThickNet. This Ethernet standard uses thick coaxial cables that could have a maximum segment
length of 500 meters. Similar to ThinNet, it uses a bus network topology with a maximum throughput of 10 Mbps. This
standard is also rare today.
10Base-T
The most common Ethernet standard until a few years ago, when 100Base-T took its place. 10Base-T uses
unshielded twisted-pair wiring running at 10 Mbps. Like 100Base-T, it is deployed using the star network topology and
has a maximum segment length of 100 meters.
802.11
The base standard for wireless network specifications. See 802.11a, 802.11b, and 802.11g.
802.11a
One of the more recent standards. 802.11a uses the 5 GHz band and runs at 54 Mbps. It is becoming more popular
because of the availability of five non-overlapping channels.
802.11b
The first prominent wireless networking specification. It is slowly being replaced by 802.11g in the 2.4 GHz frequency
spectrum. It runs at 11 Mbps and has 12 available channels, of which only three do not overlap.
802.11e
The standard that defines Quality of Service enhancements for 802.11 Wi-Fi for delay-sensitive applications, such as
Voice over Wireless IP and streaming multimedia. This new protocol improves the 802.11 Media Access Control
(MAC) layer.
802.11g
The most commonly deployed of the three wireless protocols currently available. 802.11g uses the 2.4 GHz band and
is backward compatible with 802.11b. However, it provides 54 Mbps performance but is still limited to only three nonoverlapping channels. Most wireless equipment installed today uses 802.11g.
802.11h
An ancillary standard to 802.11 that adds the transmission power control and dynamic frequency selection required
by European regulations.
60
802.11i
An additional standard for increasing wireless Wi-Fi security for 802.11a and 802.11b/g wireless networks. 802.11i
provides new data encryption protocols, including the Temporal Key Integrity Protocol (TKIP) and Advanced
Encryption Standard (AES).
802.11n
Currently a draft standard that would double the speeds of the current 802.11a and 802.11b to 108 Mbps or more.
802.11n is expected to become the official standard in 2008. Many wireless companies are offering 802.11n devices
based on the current draft.
802.16 –Fixed
802.16 and 802.16a are the standards for what is being termed WiMax. WiMax is used primarily for long-haul and
back-haul deployments and are normally deployed using licensed frequency bands.
Access Point
A device that acts as a communication switch for connecting wireless units to a wired LAN. Access points are mainly
used with wireless transmitter units to transfer wireless content to the wired IP network.
Ad Hoc Network
A wireless network created without the use of an access point. Bluetooth is an example of an ad hoc network.
AES (Advanced Encryption Standard)
An exceptionally robust encryption standard used to secure wireless connections. 128-bit passkeys are used, which
make it virtually impossible to break. A newer version of AES with 256-bit keys is starting to appear on the market,
although there has not yet been a successful hack of a 128-bit AES system.
Amplifier
A device designed to increase the strength of a weak signal received by the antenna or boost transmission signal
strength to increase the range of a wireless link.
Antenna
An appliance attached to a wireless transceiver that focuses the RF signals to increase their strength and increase
the range of the wireless system.
APIPA (Automatic Private IP Addressing/AutoIP)
A feature of Windows-based operating systems that enables a device to automatically assign itself an IP address
when there is no Dynamic Host Configuration Protocol (DHCP) server available to perform that function. This is also
known as AutoIP.
Band
A synonym for spectrum, used to describe a discrete set of frequencies. For example, 802.11a/b/g wireless network
protocols use both the 2.4 GHz and the 5 GHz frequency bands.
Bandwidth
See Throughput.
Bluetooth
A standard for an omnipresent short-range wireless network. It is often used as a cable replacement, such as in cell
phone headsets.
61
Bridge
A device that passes data between two physically separated networks. Bridge devices do not process the transmitted
data, but just forward the information to the other end. A common use for wireless bridges is to connect remote
buildings in a campus environment to the main building employing a LAN without running leased lines or cables.
Bus Network
A type of network topology where devices are connected to the network via a single line. This is not actually the case,
however, since a “T” connector is used to connect each device to the network media (mostly by way of coaxial cable).
These network configurations are not used in new deployments and are rare.
CAT5
The standard type of cable used for 100Base-T networks. CAT5 consists of unshielded twisted pairs.
CCTV (Closed Circuit Television)
A television system in which signals are not publicly distributed. Cameras are connected to television monitors in a
limited area, such as a store, office building, or college campus. CCTV is commonly used in surveillance systems.
Channel
A particular piece of the radio spectrum used to transmit data. Each wireless protocol has specific channels allocated
based on a center frequency and a bandwidth. For example, the 802.11a protocol has five channels available in the
5.8 GHz band, each with a bandwidth of 20 MHz.
CIF (Common Image Format)
A video format that easily supports both NTSC and PAL signals. Several CIF specifications are available, including
CIF, QCIF, 2CIF, and 4CIF. Each corresponds to a specific number of lines and columns per video frame.
CLI (Command Line Interface)
A text-based user interface in which the user responds to a prompt by typing a command.
Codec (Coder/Decoder)
A device that encodes or decodes a signal.
Configuration Assistant
A proprietary Verint graphical program used to configure and update the firmware of the Nextiva S4100 units.
Crossover Cable
An Ethernet cable that enables a network device to connect directly to another network device. This is possible
because of the transmit and receive pins on a crossover cable being swapped, or crossed over, so that the Tx wire
connects to the Rx wire on one side and vice versa.
Daisy-Chain Network
See Bus Network.
DCE (Data Communication Equipment)
A device that connects to the RS-232 interface in an RS-232 communication channel.
62
Decibels
The unit used for measuring power gain and loss. Decibels are abbreviated as dB, and dBm is often used when
speaking of radio output power (dBm is decibels relative to 1 milliwatt). dBi is also used for antenna gain. The higher
the dBi value, the higher the gain of the antenna. (DBi is decibels relative to an ideal isotropic radiator.)
Decoder
See Receiver.
DHCP (Dynamic Host Configuration Protocol)
A communication protocol that lets network administrators centrally manage and automate the assignment of Internet
Protocol (IP) addresses in a network.
Dipole Antenna
A type of antenna with two elements that provide omni-directional coverage with minimal gain.
DNS (Domain Name Service)
An Internet protocol to simplify what end users need to enter as an address for a site or domain. Instead of needing
the IP address for a website, users simply need to remember the domain name of the site, such as www.verint.com,
or the name of a server to which they need to connect.
DSL (Digital Subscriber Line)
A technology used to transmit Internet information over existing copper telephone lines.
DSSS (Direct Sequence Spread Spectrum)
One of many methods of modulation used for spread-spectrum transmissions. DSSS creates redundant patterns of
each bit, called a chipping code. This allows the signal to be spread over several frequencies with the different parts
being sent at the same time. DSSS is faster than FHSS, but has more issues with interference. 802.11b Wi-Fi
systems use DSSS.
DTE (Data Terminal Equipment)
The device to which the RS-232 interface connects in an RS-232 communication channel. Computers, switches,
multiplexers, cameras, and keyboards are DTE.
DVR (Digital Video Recorder)
A device (usually a computer) that acts like a VCR in that it has the ability to record and play back video images. The
DVR takes the feed from a camera and records it in a digital format on a storage device that is most commonly a hard
drive.
Encapsulating
A method of wrapping data from foreign protocols into Ethernet frames so they can be transmitted over a network.
Once they reach their destination, they are unwrapped and forwarded to the requesting device or service.
Encoder
See Transmitter.
Encryption
The process of encoding data prior to transmission to prevent eavesdroppers from deciphering or altering the data.
AES is a common example of high-quality encryption that requires a passkey to be entered and is known only by the
devices in the system that are communicating with each other. If the key is not used when the information is received,
the information cannot be used.
63
Ethernet
The industry standard for LANs, known also as 802.3. It operates using copper wires or fiber optics at rates of 10,
100, and 1000 Mbps.
Ethernet Backbone
The part of the Ethernet network that carries most of the network traffic. Normally, the backbone will have multiple
smaller access networks connected to it to send information over the network. Wireless access points will also
connect to an Ethernet backbone to give roaming users access to the network without losing network connectivity.
Fast Ethernet
See 100Base-T.
FHSS (Frequency-Hopping Spread Spectrum)
Rapidly switches (or “hops”) between seemingly random frequencies in a predetermined sequence. FHSS is not
affected by reflections or other environmental factors, as is DSSS, but the signal rate is slower. Bluetooth uses this
technology.
Firewall
A device or program that protects the network or computer from potentially hostile traffic by blocking certain access to
ports used by TCP and UDP traffic.
Firmware
The internal software stored in Read Only Memory (ROM) or Programmable ROM (PROM) that runs dedicated
hardware devices. Firmware thus becomes a permanent part of a computing device. Upgrades to firmware are often
necessary to fix problems.
Fresnel Zone
The three-dimensional area around the visual Line of Sight (LOS) that radio waves spread out into after they leave
the antenna. Typically, 20% Fresnel Zone blockage introduces little signal loss to the link. Beyond 40% blockage,
though, signal loss will become significant.
Gain
The total increase in signal strength provided by an antenna or an amplifier on a signal.
Gateway
See Wireless Gateway.
Gigabit Ethernet A
An emerging Ethernet standard providing up to 1000 Mbps or roughly 1 Gbps. Gigabit Ethernet is also known as
1000Base-T.
Gigahertz
The frequency of an electromagnetic wave equal to 1 billion (1,000,000,000) hertz, abbreviated GHz. Most wireless
technologies work in the GHz range, such as 802.11a/b and g, which operate in the 2.4 GHz and 5 GHz bands.
GPS (Global Positioning System)
Uses geo-stationary satellites to give precise location information to receivers on the Earth. This technology allows
receivers to accurately derive any location. Many new cell phones implement this technology to provide public
security agencies with the location of someone who dials 911.
64
Handshake
An exchange of signals used to ensure synchronization between two devices when communications begin. (These
are the different tones heard when a modem connects a user to an ISP.)
High-Gain Antenna
An antenna that significantly increases signal strength to provide for a longer or more robust wireless link.
Hub
A way to connect multiple devices. A precursor to the switch, the hub has no intelligence. It simply receives data from
one port and transmits it to all the others. The switch added intelligence to this scenario, so the hub is now rarely
used.
IEEE (Institute of Electrical and Electronics Engineers)
A professional organization that helps set transmission system standards.
IP (Internet Protocol)
The protocol that manages how packets of data are routed from one computer to another on the Internet.
IP address
A unique number of 32 or 128 bits that identifies a device on a network or on the Internet (192.168.1.123, for
example).
ISDN (Integrated Services Digital Network)
A completely digital communications network providing 64 Kbps bandwidth channels that can be combined to provide
throughput of up to 128 Mbps.
Kbps
Kilobits per second, or thousands of bits per second, a measure of bandwidth or throughput.
LAN (Local Area Network)
A data network that connects devices, usually in the same building.
Latency
The length of time it takes for a unit of data to pass through a particular part of the network.
Long Haul
Long-distance wireless data transmission, which could reach several miles. In the past, cable infrastructure was
necessary for long-haul data transportation, but with newer technologies, such as WiMax, wireless long-haul
transport has become more practical.
LOS (Line of Sight)
A clear visual line between antennae in a wireless system. In RF deployments, RF LOS needs to be taken into
account so as to avoid unnecessary attenuation of the signal.
MAC Address (Media Access Control)
The exclusive hexadecimal address assigned to all Ethernet devices, whether they are an adapter, switch, or wireless
access point. All devices have a unique number. The IP address or domain name used to address the device is
mapped to this unique number to distinguish devices from each other.
Mbps
Megabits (or millions of bits) per second, a measure of bandwidth or throughput.
65
Megahertz
Frequency of an electromagnetic wave equal to 1 million (1,000,000) hertz, abbreviated MHz. FM radio and some
wireless data technologies work in the MHz frequency range.
Mesh Network
A wireless network technology that allows all devices in the network to communicate with each other. This enables a
constant network connection if a device in the network fails. Signals can be rerouted automatically through different
devices to ensure constant data flow.
Modem
Shortened term for modulator/demodulator. A modem is a device that modulates analog signals to encode them
into digital information, so that they can be sent over phone lines. At the receiving end, the modem demodulates the
signal and retrieves the digital data.
MPEG-4
A compression standard for encoding video into a compressed format, reducing the required amount of bandwidth to
transport the video across a network or the Internet.
Multicast
Communication between a single sender and multiple receivers on a network; the devices can be located across
multiple subnets, but not through the Internet. Multicast is a set of protocols using UDP/IP for transport.
Multiplex
Multiplexing provides the means for combining multiple signals into one serial data stream. Ethernet, for example,
provides slots for data from many different sources. The means to put this information into the single Ethernet data
steam is called multiplexing.
NAT (Network Address Translation)
A standard that allows an organization or user to use fewer IP addresses than exist on the internal LAN. NAT is
implemented in a router, firewall, or PC and converts private IP addresses of the machine on the internal private
network to one or more public IP addresses for the Internet. NAT changes the addresses in the packet headers to
new addresses and creates a table to track the changed addresses. When data packets are received from the
Internet, NAT uses these tables to perform the reverse conversion to the IP address of the client machine.
Network
A set of interconnected PCs, servers, and other devices joined together to allow the sharing of information and
access to multiple devices.
Network Adapter
A card or hardware installed in a device that allows it to connect to a network. The device can have several network
adapter cards installed, providing simultaneous access to an Ethernet LAN and WLAN.
Network Diagram
A layout of an existing or proposed network that provides locations and address information for all devices on the
network. These diagrams are vital for IT personnel when expanding or troubleshooting LAN issues.
Network Interface Card (NIC)
See Network Adapter.
66
Network Segments
Sections of a network that are either physically or logically separated from each other. A segmented network enables
more efficient use of available bandwidth, thus reducing the chance of “flooding” the entire network when many users
simultaneously request or send large amounts of data.
Network Topology
Also referred to as network layout.
NTP (Network Time Protocol)
A protocol designed to synchronize the clocks of devices over a network.
NTSC (National Television Standards Committee)
A North American standard (525-line interlaced raster-scanned video) for the generation, transmission, and reception
of television signals. Use of the NTSC standard is not limited to North America; the NTSC standard is also used in
Central America, a number of South American countries, and some Asian countries, including Japan.
OSD (On-Screen Display)
Status information displayed on the video monitor connected to a receiver unit.
Packet
A datagram or segment of data that is routed between the origin and destination device on a network.
Packet-Switched Network
A type of network in which small units of data (packets) are routed through a network based on the address contained
inside each packet. Packets may take different routes to reach the destination device and are subsequently
reassembled so that the first packet of a sequence is decoded first.
PAL (Phase Alternation by Line)
A television signal standard (625 lines, 50 Hz, 220V primary power) used in the United Kingdom, much of western
Europe, several South American countries, some Middle East and Asian countries, several African countries,
Australia, New Zealand, and other Pacific Island countries.
Panel Antenna
An antenna with a flat-panel-type element designed to focus the RF energy in a particular direction. It is mainly used
in point-to-point deployments because of the narrow beam width it provides.
Parabolic Antenna
An antenna that incorporates a parabolic dish to provide a very focused high gain RF signal.
Patch Antenna
See Panel Antenna.
Patch Cable
A short Ethernet cable used to connect devices to a wall panel connector or to connect devices in a rack to a switch.
Pigtail
A short, thin cable that normally connects an antenna to a wireless device, such as a network adapter or access
point.
67
PoE (Power over Ethernet)
A method of providing the electrical power to a device using the Ethernet cable. PoE reduces the number of cables
required, and many switches now provide the power directly from the switch ports. The IEEE designation for PoE is
802.3af.
Point-to-Multipoint
A wireless network setup where one point (usually an access point) receives wireless data from multiple other points.
Standard indoor wireless networks are point-to-multipoint, and many outdoor wireless networks also are set up in this
manner. Video surveillance is a good example of a point-to-multipoint wireless network application.
Point-to-Point
A long-range wireless network connection between two locations. Point-to-point is used as wireless back haul and
makes use of high gain directional antennae.
Port
Can be considered either a physical plug on a network device or wall panel or an identification of data type in a
networking environment. All network services have one or more ports that receive or send information.
Protocol
See Specification.
PTL (Push-to-Listen)
In a two-way system, the communication mode in which the listener must push a button while listening.
PTT (Push-to-Talk)
In a two-way system, the communication mode in which the talker must push a button while talking.
PTZ Camera (Pan-Tilt-Zoom)
An electronic camera that can be rotated left, right, up, or down, as well as zoomed in to get a magnified view of an
object or area. A PTZ camera monitors a larger area than a fixed camera.
Receive Sensitivity
Enables the radio receiver to receive and understand weak signals from the transmitter. Most radios provide variable
sensitivities to reduce the amount of interference that they pick up.
Receiver
A device that converts a digital video signal into analog. Also called a decoder.
Repeater
A range extender for wireless links.
RF (Radio Frequency)
Any frequency within the electromagnetic spectrum associated with radio wave propagation. When a modulated
signal is supplied to an antenna, an electromagnetic field is created that is able to propagate through space. Many
wireless technologies are based on RF field propagation.
RJ-11
The connector used by telephones, not to be confused with the RJ-45 plug type used for Ethernet networks.
68
RJ-45
The connector used for Ethernet networks. The RJ-45 is larger than the RJ-11 used for telephone systems.
Router
An intelligent network device that provides connectivity between networks. Without routers, the Internet could not
exist as it does today. If a device on one network needs to access information on a device in another network, the
information is passed through a router. Essentially, a router translates the IP address of the devices into MAC
addresses and creates lists of these combinations. When one device wants to send data to a different network, the
address of the destination is translated into its MAC address and looked up in a list on the router. If the router has the
address on its list, it sends the data to this device. If it does not have the device on its list, it sends it to other routers
on the network and asks if this address is part of their lists. The router with the proper address then routes the data to
the device.
RS-232
A standard interface approved by the Electronic Industries Alliance (EIA) for connecting serial devices.
RS-422
A standard interface approved by the Electronic Industries Alliance (EIA) for connecting serial devices, designed to
replace the older RS-232 standard because it supports higher data rates and is more immune to electrical
interference.
RS-485
An Electronic Industries Alliance (EIA) standard for multipoint communications.
SConfigurator
A proprietary graphical program used to configure and update the firmware of video servers and outdoor wireless
bridge units.
Sector Antenna
An antenna that provides good gain qualities, while providing a wider beam width. It is used mainly in receiver
locations to accept information from multiple transmitters in point-to-multipoint scenarios. The term sector antenna is
used since many can be deployed to cover a sector. Beam widths are normally 60, 90, or 120 degrees.
Serial Port
An interface that can be used for serial communication, in which only one bit is transmitted at a time. A serial port is a
general purpose interface that can be used for almost any type of device.
Signal Loss
The amount of signal power that is lost between the transmitter and the receiver. This includes free space, cable, and
connector loss, and any other attenuation of the signal between the two devices in the wireless system. This value is
always represented in decibels (dB).
Signal Strength
The strength of a radio signal received in a wireless network system.
Spectrum
A collection of electromagnetic radiation (electromagnetic waves) that includes AM, FM, TV microwave, visible light,
X-rays, and gamma rays. The RF spectrum has been defined to include both licensed and unlicensed frequency
bands up to 300 GHz.
69
Spread Spectrum
A radio technique that continuously alters its transmission pattern by constantly changing either carrier frequencies or
the data pattern. This technique increases bandwidth and reduces the chance of interference or interception of the
transmitted signal.
SSID (Service Set Identifier)
A name given as an identifier to an access point or many access points that make up a WLAN.
SSL (Secure Sockets Layer)
A commonly used protocol developed by Netscape for transmitting private data across the Internet. It uses a
cryptographic system that employs two keys to encrypt data: a public key known to everyone and a private (or secret)
key known only to the recipient of the message. Many websites use SSL to provide a secure link that allows users to
transmit confidential information, such as credit card numbers.
Standard
A specification or protocol that has been agreed upon by enough industry-leading manufacturers or adopted by a
governing body or experts group.
Star Network
A network design in which all traffic is routed through a central point. Most wireless LANs are designed in this
manner.
Subnet Mask
A binary masking value used to identify and describe IP subnets. A subnet mask is a string of 0s and 1s used to filter
or mask out the values of specific bits in a second binary value. A logical operation is performed that uses the bits
from the value to be masked and bits from the mask itself.
The subnet mask lets a network device mask out the host portion of an IP address. This allows a network device
know if the device with which it is communicating is on the same network or on a different one. Masking the host
portion of the address leaves only the network portion of the original IP address. Knowing which network an IP
address is part of is very important in IP communication. Devices on the same subnet can talk to each other directly,
while devices on different subnets need to use a router to communicate with each other.
Switch
A network device that directly connects two communicating devices, thus isolating the communication channel they
are using and increasing throughput. The ports of a switch continuously switch between each other depending on the
devices that are communicating.
T-1, T-3
Telecommunication systems used by phone companies to multiplex several phone calls onto a single copper wire. T1 provides a transmission rate of up to 1.5 Mbps; T-3 provides a transmission rate of 44.7 Mbps. T-1 systems
multiplex 24 64 Kbps groups of phone or data information into a serial stream, which normally gets multiplexed into
the T-3 line for back-haul purposes.
ThickNet
See 10Base-5.
ThinNet
See 10Base-2.
70
Throughput
The amount of data that a transmission system can handle at any given time. Throughput is normally a measure of
bits per second. In certain instances, it is referred to as the speed of a network or is specified in a frequency, such as
25 MHz bandwidth. But, it is the carry capacity of a system, not a speed, since the speed the bits travel is always at
or near the speed of light.
Transceiver (Transmitter/Receiver)
A device that has the ability to transmit and receive analog or digital signals.
Transmit Power
The amount of power available from a radio transceiver to send a signal to the transmission device via either a cable
or antenna. Transmit power is normally stated in milliwatts or as a decibel expression in reference to 1 milliwatt
(dBm).
Transmitter
A device that sends video signals captured by a connected camera or dome to a receiver. The transmitter converts
the analog signal to digital before transmitting it. A transmitter may also be called an encoder.
Twisted Pair
A type of wiring in which each pair of wires is twisted around each other to reduce electromagnetic interference. All
modern network standards specify the use of some twisted-pair technology, such as CAT5 or CAT6 Ethernet cables.
UTP (Unshielded Twisted Pair)
The standard type of twisted-pair wiring, which does not deploy a shield, instead relying on the twisting of the wires to
isolate them from electromagnetic interference.
Video Server
A unit that transmits or receives video signals through an IP network.
VoIP (Voice over IP)
A new standard that provides the means to send digital voice traffic across networks and the Internet. It does not use
standard phone lines, thus eliminating the fees associated with normal phone service.
VPN (Virtual Private Network)
A network protocol that allows for the creation of an encrypted “tunnel” through the Internet to enable secure
connections between a remote user and a corporate server across the public Internet.
VSIP (Video Services over IP)
A proprietary communication protocol for sending messages between a computer and an interferer or between two
units.
WAN (Wide Area Network)
A group of LANs in different locations that are connected by various telecommunication media. The Internet is the
most common example of a WAN, but corporations with multiple sites often use WANs to connect their local offices
with each other and corporate headquarters.
WEP (Wired Equivalent Privacy)
The first wireless encryption system to prevent eavesdropping or unauthorized connections to wireless networks.
Because WEP is easily broken, WPA should be used in its place.
71
Wi-Fi
Wireless Fidelity, used as a generic term when referring of any type of 802.11 network, whether 802.11b, 802.11g,
802.11a, etc. The term is publicized by the Wi-Fi Alliance. Products tested and approved as “Wi-Fi Certified” by the
Wi-Fi Alliance are interoperable with each other, even if from different manufacturers. A user with a “Wi-Fi Certified”
product can use any brand of access point with any other brand of client hardware that also is certified.
WiMax
See 802.16.
Wireless Cell
A group of wireless devices that communicate together on the same radio frequency channel and share the same
wireless passkey.
Wireless Transmission
A technology whereby electronic devices send data to receivers using radio waves, rather than wiring.
WLAN (Wireless Local Access Network)
A LAN that provides connections purely by wireless means.
WPA (Wi-Fi Protected Access)
A more robust encryption method to prevent eavesdropping and unauthorized connections to wireless networks.
72
Index
1000Base–T, 60
100Base-T, 60
10Base-2, 60
10Base-5, 60
10Base-T, 60
2.4 GHz band
antenna separation, 28
channels, 8
Nextiva devices for, 45
4.9 GHz band
channels, 11
license eligibility, 11
Nextiva devices for, 45
5 GHz band
antenna separation, 28
channels, 10
Nextiva devices for, 45
non-overlapping channels, 27
802.11
definition, 60
hidden node - overcoming, 49
Nextiva support for, 49
quality of service issues, 49
802.11a, 7, 60
802.11b, 7, 60
802.11e, 60
802.11g, 7, 60
802.11h, 60
802.11i, 61
802.11n, 7, 61
802.16 –Fixed, 61
Access point, 61
Ad hoc network, 61
Adjacent channels, 27
Advanced Encryption Standard
(AES), 61
AES, 61
Amplifier, 61
Antenna
and gain, 13
beam width, 15
definition, 61
dipole, 63
directivity, 13
for Nextiva wireless devices, 47
gain, 30
half-wave dipole, 13
high gain, 65
high-gain directional, 48
isotropic, 13
master, 56
nulls, 15
omni-directional, 12
panel, 67
parabolic, 67
patch, 67
pattern, 13
reception pattern, 13
sector, 69
sending/receiving energy, 13
separation requirements, 28
side lobes, 15
slave, 56
strength of radiated field, 13
total cable length, 55
types, 12
uni-directional, 12
APIPA, 61
Attenuation
cable, 16
impact of foliage on, 21
impact of signal frequency
increase, 16
AutoIP, 61
Automatic Private IP Addressing
(APIPA), 61
Bands
definition, 61
licensed, 11
unlicensed, 8
Bandwidth, 61
Beam width, 15, 34
Bluetooth, 61
BNC connectors, 18
Bridge
definition, 62
illustration, 25
limitations, 25
when to use, 25
with repeater, 26
Bus Network, 62
Cable
CAT5, 62
crossover, 62
patch, 67
pigtail, 67
Cables
attenuation, 16
carrying the RF signal, 16
conductor, 16
dielectric, 16
foam, 17
Heliax, 17
length, 17
Cameras
connecting to DVR, matrix, or
analog monitor, 22
IP with S4200, 50
PTZ, 68
CAT5, 62
CCTV, 62
Channels
2.4 GHz band, 8
4.9 GHz band, 11
5 GHz band, 10
adjacent, 27
bandwidth impact on bit rate, 12
changing bandwidth, 12
data rate, 55
definition, 62
fragmentation, 11
non-adjacent, 27
overlapping, 6
CIF, 62
CLI, 62
Closed Circuit Television (CCTV), 62
Coaxial cables, 16
Codec, 62
Coder/Decoder, 62
Command Line Interface (CLI), 62
Common Image Format (CIF), 62
Configuration Assistant, 62
Connectors
and cable loss, 32
Ethernet networks, 69
gender, 19
RJ-11, 68
RJ-45, 69
telephone systems, 68
total number of, 55
types, 18
Crossover cable, 62
Daisy Chain Network, 62
Data
encoding, 63
throughput, 56
Data Communication Equipment
(DCE), 62
Data rate, 5
Data Terminal Equipment (DTE), 63
DCE, 62
Decibels, 29, 63
Decoders, 46, 63
Design considerations
basic tools, 32
camera locations, 32
cameras, 32
determining beam width, 34
head end location, 32
integrating all information, 36
Line of Sight (LOS), 29
maximum range, 29
preliminary layout, 33
receiver sensitivity, 30
RF communications and data rate,
30
RF margin, 30
site survey, 39
tower height, 38
transmission distances, 32
transmit power, 30
DHCP, 63
Dielectric, 16
Digital Subscriber Line (DSL), 63
Digital Video Recorder (DVR), 63
Dipole antenna, 63
Direct Sequence Spread Spectrum
(DSSS), 63
Directivity, 13
DNS, 63
Domain Name Service (DNS), 63
DSL, 63
DSSS, 63
DTE, 63
DVR, 63
73
Dynamic Host Configuration Protocol
(DHCP), 63
EIRP, 56
Encapsulating, 63
Encoder, 63
Encryption, 63
Ethernet, 64
Ethernet backbone, 64
Expected Rx Signal, 57
Fast Ethernet, 60, 64
FEC, 6
FHSS, 64
Firewall, 64
Firmware
configuration and update, 62
definition, 64
Foam cables, 17
Foliage attenuation, 21
Forward Error Correction (FEC), 6
Free Space Loss (FSL), 32
Frequency
band, 55
channels, 8
measuring, 4
with regard to wavelength, 4
Frequency-Hopping Spread
Spectrum (FHSS), 64
Fresnel zone, 38
Fresnel Zone, 20, 57, 64
Gain, 64
antenna, 30
definition, 13
system, 30, 56
Gain and loss measurement, 63
Gateway, 64
Gigabit Ethernet A, 64
Gigahertz, 64
Global Positioning System (GPS), 64
GPS, 64
Half-power point, 15
Half-wave dipole antennae, 13
Handshake, 65
Head end location, 32
Heliax cables, 17
High Gain Antennae, 65
Hub, 65
Hub compared to switch, 47
IEEE, 65
Institute of Electrical and Electronics
Engineers (IEEE), 65
Integrated Services Digital Network
(ISDN), 65
Internet Protocol (IP), 65
Intersymbol Interference (ISI), 5
IP
address, 65
definition, 65
ISDN, 65
Isotropic antennae, 13
Kbps, 65
LAN, 65
Latency, 65
Line of Sight (LOS), 20, 29, 65
Linear polar coordinate systems, 14
Link budget, 30
Local Area Network (LAN), 65
Logarithmic polar coordinate
systems, 14
Long haul, 65
LOS, 20, 65
MAC, 49
MAC address, 65
Margin, 57
Mbps, 65
Media Access Control (MAC), 65
Megahertz, 66
Mesh network, 66
Modem, 66
Multicast, 66
Multi-path fading, 5
Multiplex, 66
NAT, 66
National Television Standards
Committee (NTSC), 67
Network
ad hoc, 61
adapter, 66
Address Translation (NAT), 66
bus, 62
connectors, 69
daisy chain, 62
definition, 66
diagram, 66
Interface Card (NIC), 66
layout, 67
mesh, 66
segments, 67
star, 70
Time Protocol (NTP), 67
topology, 67
wireless local access (WLAN), 72
Nextiva
antennae for wireless devices, 47
encoder default bit rates, 59
power supplies for devices, 47
range samples, 48
S1970e decoders, 46
S4100 video encoder/transmitter,
45
S4200 encoder/transmitter, 45
S4300, 46
standards used, 48
switches for edge devices, 47
video quality frame rates, 59
wireless edge devices, 45
NIC, 66
Non-adjacent channels, 27
NTP, 67
NTSC, 67
Nulls, 15
OFDM, 6
Omni-directional antennae, 12
Orthogonal Frequency Division
Multiplexing (OFDM), 6
Output power, 56
Packet, 67
Packet-switched network, 67
PAL, 67
Panel antenna, 67
Parabolic antenna, 67
Patch antenna, 67
Patch cable, 67
Path loss, 32, 56
Phase Alternation by Line (PAL), 67
Pigtail, 67
PoE
definition, 68
in S4300, 46
Point-to-multipoint
definition, 68
illustration, 23
limitations, 23
over 802.11, 23
S4200 encoder/transmitter, 45
when to use, 23
with repeaters, 24
Point-to-point
definition, 68
illustration, 22
limitations, 22
S4100 encoders/transmitter, 45
S4200 encoder/transmitter, 45
when to use, 22
with repeaters, 24
Polar coordinate systems, 14
Port
definition, 68
serial, 69
Power over Ethernet (PoE), 68
Power supplies, 47
Pre-installation site survey, 39
Preliminary layout, 33
Protocol
definition, 68
Nextiva, 48
SPCF/SDCF, 48
PTL, 68
PTT, 68
PTZ camera, 68
Push-to-Listen (PTL), 68
Push-to-Talk (PTT), 68
Radiation pattern, 13
Radio
frequency, 68
sensitivity, 56
transmission power, 30
Range, 5
determining, 29
maximum, 29
Nextiva, 48
Receive Sensitivity, 68
Receiver
definition, 68
sensitivity, 30
Reception pattern, 13
Reflections, 32
Refraction, 32
Repeater
definition, 68
when to use, 24
RF
Calculator parameters, 55
74
Calculator settings, 55
cell considerations, 27
communications, 5
communications and data rate, 30
definition, 68
line of sight (LOS), 20
margin, 30
Margin Calculator, 30, 36
signal interference, 27
simplifying system design, 30
RJ-11, 68
RJ-45, 69
Router, 69
RS-232, 69
RS-232 interface, 62
RS-422, 69
RS-485, 69
S4100
overview, 45
S4200
-2V, 51
-AS, 53
in point-to-multipoint systems, 23
in point-to-point systems, 22
maximum per S4300 bridge, 49
maximum with PTZ and fixed
cameras, 49
overview, 45
performance, 50
sample usage, 51
security mechanisms, 49
using IP cameras with, 50
S4300
in point-to-multipoint systems, 23
in point-to-point systems, 22
S4300 access point
overview, 46
S4300 bridge
system illustration, 25
S4300 repeater
converting into bridge, 24
in bridge applications, 26
in point-to-point and multipoint
systems, 24
overview, 46
S4300 wireless bridge
overview, 46
using S4200 with, 49
SConfigurator, 69
Sector antenna, 69
Serial port, 69
Side lobes, 15
Signal
loss, 69
quality, 5
scatter, 5
strength, 5, 69
Site survey
equipment, 40
pre-installation, 39
questions, 39
report, 43
triggering, 41
using Nextiva S4300, 41
viewing, 42
SMA connectors, 18
Spectrum, 69
Spread spectrum, 70
Standard
802.11, 7
definition, 70
Star network, 70
Subnet mask, 70
Switch, 70
Switches, 47
System gain, 30
T-1, 70
T-3, 70
Temporal Key Integrity Protocol
(TKIP), 61
ThickNet, 60, 70
ThinNet, 60, 70
Throughput, 71
Tower height calculations, 38
Transceiver, 71
Transmission distances, 32
Transmit power, 30, 71
Transmitter, 71
Transmitter/Receiver, 71
Twisted pair, 71
Type N connectors, 18
Uni-directional antennae, 12
Unit
master, 56
slave, 55
Unshielded Twisted Pair (UTP), 71
UTP, 71
Verint RF Margin Calculator
advanced and basic, 58
display screens, 58
overview, 30, 54
parameters, 55
terms, 30
Video
quality and default bit rates, 59
quality frame rates, 59
server, 71
Services over IP (VSIP), 71
Virtual Private Network (VPN), 71
Voice over IP (VoIP), 71
VoIP, 71
VPN, 71
VSIP, 71
WAN, 71
Wavelength
measuring, 4
with regard to frequency, 4
Weather impact on microwave
systems, 21
WEP, 71
Wide Area Network (WAN), 71
Wi-Fi
definition, 72
protected access (WPA), 72
WiMax, 61, 72
Wired Equivalent Privacy (WEP), 71
75
Wireless
access point, 46
bridge, 46
cell, 72
encoders/transmitters, 45
Local Access Network (WLAN),
72
repeater, 46
transmission, 72
WLAN, 72
WPA, 72
76
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