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WatchGuard Firebox X Edge
About IEEE 802.11g/b Wireless
In general, RF power and signal bandwidth create a maximum limit
on the rate that data can be sent on a wireless connection. The
equation below calculates the maximum data rate:
This equation shows that the channel capacity (bits/s) is set by:
•
Channel bandwidth: 11 Mbits/s for 802.11b and 54 MBits/s for
802.11g
•
Signal strength: 15 dBm transmitted by the Firebox X Edge
Wireless
•
Noise level: Set by the environmental conditions and the design
of the receiver.
The maximum data rate cannot be more than the channel capacity.
Noise level
Channel capacity is decreased by increasing the noise level in the
frequency range of the system. The noise level is set by many fac-
tors. First, it is affected by background noise caused by the ambient
temperature of the atmosphere at the frequency range of the sys-
tem. Also, the operating temperature of the components of the
802.11 g/b receiver creates noise. The primary cause of interference
is transmitters that use the same frequency range:
•
Cordless phones
•
An 802.11b device set to use adjacent channels. We recommend
that you set three channels between each adjacent wireless
access points (e.g. 1, 5, and 9 or 2, 6, and 10).
•
Microwave ovens
•
Sodium-type lighting systems (fusion lamps)
•
Arc welders (broadband spark-gap transmitters)
•
Blue-Tooth transmitters (A Blue-Tooth transmitter operates at a
lower power level than an 802.11b device. To cause
interference, the Blue-Tooth transmitter must be very near to an
802.11b receiver.)
•
Industrial, scientific, and medical equipment that can also
operate in this frequency range.
ChannelCapacity
ChannelBandwidth
2
1
SignalStrength
+
NoiseLevel
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Summary of Contents for Firebox X15
Page 14: ...xiv WatchGuard Firebox X Edge...
Page 42: ...Installing the Firebox X Edge 28 WatchGuard Firebox X Edge...
Page 72: ...Configuration and Management Basics 58 WatchGuard Firebox X Edge...
Page 146: ...Configuring Logging and System Time 132 WatchGuard Firebox X Edge...
Page 168: ...Managing Users and Groups 154 WatchGuard Firebox X Edge...
Page 204: ...Configuring Virtual Private Networks 190 WatchGuard Firebox X Edge...
Page 242: ...228 WatchGuard Firebox X Edge...
Page 249: ...Certifications and Notices User Guide 235 Taiwanese Notices...
Page 250: ...236 WatchGuard Firebox X Edge Declaration of Conformity...