802.11

=802.11=

Arthur : Kelvin Han

=IEEE 802.11=

802.11 is a specification for wireless local area network(WLAN). It is also called wi-fi connection. Base station is connected to the internet and send signals to everywhere. Users near by the base station can get the signal and use the internet. There are several specifications such as 802.11, 802.11a, 802.11b, 802.11g, 802.11n. These are developed by IEE (Institute of Electrical and Electronics Engineers). 802.11 is developed for the first time. It is the first wireless LAN standard. The speed of the family of specifications 802.11 > 802.11a > 802.11b > 802.11g > 802.11n

802.11 Developed in 1997. It applies to wireless LANs and provide 1 - 2 Mbps transmission in 2.4GHz band. (*band - the weith

802.11a It is an extension of 802.11. It also applies t wireless LNs and provides 54 Mbps transmission in 5.0GHz band.

802.11b The next level of 802.11a. It provides 54Mbps transmission in 2.4Ghz band.

(Mbps)** || **802.11a Range (40 mW with 6dBi gain diversity patch antenna)** || **802.11g Range (30 mW with 2.2 dBi gain diversity dipole antenna)** || **802.11g Range (100 mW with 2.2 dBi gain diversity dipole antenna)** ||
 * Data Rate
 * Data Rate
 * **54** || 13 m || 27 m || - ||
 * **48** || 15 m || 29 m || - ||
 * **36** || 19 m || 30 m || - ||
 * **24** || 26 m || 42 m || - ||
 * **18** || 33 m || 54 m || - ||
 * **12** || 39 m || 64 m || - ||
 * **11** || - || 48 m || 45 m ||
 * **9** || 45 m || 76 m || - ||
 * **6** || 50 m || 91 m || - ||
 * **5.5** || - || 67 m || 67 m ||
 * **2** || - || 82 m || 82 m ||
 * **1** || - || 124 m || 124 m ||

Range Comparison table for 802.11, 802.11a, 802.11b

(Mbps)** || **Throughput (Mbps)** || **Throughput as a % of 802.11b thoughput** || (with .11b clients in cell)** || 54 || 14 || 233% || (no .11b clients in cell)** || 54 || 22 || 367% ||
 * || **Data Rate
 * **802.11 b** || 11 || 6 || 100% ||
 * **802.11g
 * **802.11g
 * **802.11a** || 54 || 25 || 417% ||

Speed Comparison table 802.11n The latest wi-fi specification. It is recently developed in 2009. It provides up to 300 Mbps transmission in 2.4 GHz band.

Other 802.11 family IEEE 802.11j: Extensions for Japan (2004) IEEE 802.11r: Fast BSS transition IEEE 802.11v: Wireless network management IEEE 802.11d: International roaming extensions. etc...