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What is Wi-Fi (802.11)?
Wi-Fi (802.11) is a suite of specifications for wireless Ethernet.
802.11 security is a significant concern because 802.11 (Wi-Fi) networks can allow almost untraceable entry into networks.
The 802.11 (Wi-Fi) Standards
The 802.11 standards are defined by the IEEE (Institute of Electrical and Electronic Engineers) at http://grouper.ieee.org/groups/802/11/.
| Standard | Speed | Frequency | Modulation |
|---|---|---|---|
| 802.11 | 2Mb | 2.4GHz | Phase-Shift Keying |
| 802.11a | 54Mb | 5GHz | Orthogonal Frequency Division Multiplexing |
| 802.11b | 11Mb | 2.4GHz | Complementary Code Keying |
| 802.11g | 54Mb | 2.4GHz | Orthogonal Frequency Division Multiplexing |
The 802.11 (Wi-Fi) Channels
The most common 802.11 specification, 802.11b, defines twelve channels. These channels utilize overlapping frequencies. Channels one, six, and eleven do not overlap.
| Channel | US Frequency | European Frequency | Japanese Frequency |
|---|---|---|---|
| 1 | 2412 | ||
| 2 | 2417 | ||
| 3 | 2422 | 2422 | |
| 4 | 2427 | 2427 | |
| 5 | 2432 | 2432 | |
| 6 | 2437 | 2437 | |
| 7 | 2442 | 2442 | |
| 8 | 2447 | 2447 | |
| 9 | 2452 | 2452 | |
| 10 | 2457 | 2457 | |
| 11 | 2462 | 2462 | |
| 12 | 2484 |
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