Wireless Channel Selection - NETGEAR FVM318 Reference Manual

Reference Manual for the Model FVM318 Cable/DSL ProSafe Wireless VPN Security Firewall
Note: The AP and the client adapters can have different default WEP Keys as long as the keys are
in the same order. In other words, the AP can use WEP key 2 as its default key to transmit while a
client adapter can use WEP key 3 as its default key to transmit. The two devices will communicate
as long as the AP's WEP key 2 is the same as the client's WEP key 2 and the AP's WEP key 3 is
the same as the client's WEP key 3.

Wireless Channel Selection

IEEE 802.11 wireless nodes communicate with each other using radio frequency signals in the
ISM (Industrial, Scientific, and Medical) band between 2.4 GHz and 2.5 GHz. Neighboring
channels are 5 MHz apart. However, due to spread spectrum effect of the signals, a node sending
signals using a particular channel will utilize frequency spectrum 12.5 MHz above and below the
center channel frequency. As a result, two separate wireless networks using neighboring channels
(for example, channel 1 and channel 2) in the same general vicinity will interfere with each other.
Applying two channels that allow the maximum channel separation will decrease the amount of
channel cross-talk, and provide a noticeable performance increase over networks with minimal
channel separation.
The radio frequency channels used are listed in Table 8-1:
Table 8-1. 802.11 Radio Frequency Channels
Channel Center Frequency
1 2412 MHz
2 2417 MHz
3 2422 MHz
4 2427 MHz
5 2432 MHz
6 2437 MHz
7 2442 MHz
8 2447 MHz
9 2452 MHz
10 2457 MHz
11 2462 MHz
12 2467 MHz
13 2472 MHz
B-18
Frequency Spread
2399.5 MHz - 2424.5 MHz
2404.5 MHz - 2429.5 MHz
2409.5 MHz - 2434.5 MHz
2414.5 MHz - 2439.5 MHz
2419.5 MHz - 2444.5 MHz
2424.5 MHz - 2449.5 MHz
2429.5 MHz - 2454.5 MHz
2434.5 MHz - 2459.5 MHz
2439.5 MHz - 2464.5 MHz
2444.5 MHz - 2469.5 MHz
2449.5 MHz - 2474.5 MHz
2454.5 MHz - 2479.5 MHz
2459.5 MHz - 2484.5 MHz
Network, Routing, Firewall, and Wireless Basics