NETGEAR 2.4 GHz MA111 - Manual (Page 12)

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.
Note: The available channels supported by the wireless products in various countries are
different. For example, Channels 1 to 11 are supported in the U.S. and Canada, and Channels
1 to 13 are supported in Europe and Australia.
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Channel Center Frequency Frequency Spread
1 2412 MHz 2399.5 MHz – 2424.5 MHz
2 2417 MHz 2404.5 MHz –2429.5 MHz
3 2422 MHz 2409.5 MHz –2434.5 MHz
4 2427 MHz 2414.5 MHz –2439.5 MHz
5 2432 MHz 2419.5 MHz – 2444.5 MHz
6 2437 MHz 2424.5 MHz –2449.5 MHz
7 2442 MHz 2429.5 MHz –2454.5 MHz
8 2447 MHz 2434.5 MHz – 2459.5 MHz
9 2452 MHz 2439.5 MHz –2464.5 MHz
10 2457 MHz 2444.5 MHz –2469.5 MHz
11 2462 MHz 2449.5 MHz – 2474.5 MHz
12 2467 MHz 2454.5 MHz – 2479.5 MHz
13 2472 MHz 2459.5 MHz – 2484.5 MHz
Authentication and WEP Encryption
The absence of a physical connection between nodes makes the wireless links vulnerable to
information theft. To provide a certain level of security, IEEE 802.11 standard has defined two
types of authentication methods, Open System and Shared Key. Open System authentication is
a null algorithm. Shared Key authentication is an algorithm where both the transmitting node
and the receiving node share an authentication key to perform a checksum on the original
message. By default, IEEE 802.11 wireless devices operate in an open system network.
Wired Equivalent Privacy (WEP) data encryption is utilized when the wireless nodes or access
points are configured to operate in Shared Key authentication mode. There are three shared key
methods implemented in NETGEAR 802.11b solutions: the standard based 64-bit WEP data
encryption and 128-bit WEP data encryption.
The 64-bit WEP data encryption method allows for a five-character (40 bits) input.
Additionally, 24 factory-set bits are added to the 40-bit input to generate a 64-bit encryption
key. (The 24 factory-set bits are not user configurable.) This encryption key will be used to
encrypt/decrypt all data transmitted via the wireless interface. Some vendors may refer to the
64-bit WEP data encryption as 40-bit WEP data encryption since the user configurable key
used in the encryption process is only 40 bits wide.
The 128-bit WEP data encryption method consists of 104 configurable bits. Similar to the 64-bit
WEP data encryption method, the remaining 24 bits are factory set and not user configurable.
Wireless Channel Selection
802.11b
IEEE 802.11b 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.
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Encryption
Key Size
# of Hexadecimal
Digits
Example of Hexadecimal
Key Content
64-bits (24+40) 10 4C72F08AE1
128-bit (24+104) 26 4C72F08AE19D57A3FF6B260037