Analysis of spectrum channel assignment for IEEE 802.11b wireless LAN

The paper analyzes the channel assignment of IEEE 802.11b wireless LANs operated on the 2.4 GHz ISM band. The tests used to analyze the radio interference between wireless LAN channels are divided into a cable RF test and a radiated RF test. The measurements for the radiated RF test were performed in an office and a hotel conference room. The measurement results show that the performance of a wireless LAN varies greatly with the model. The adjacent channel gain margin between channels 6 and 10 is about 23 dB and that for channels 10 and 11 is about 7 dB. The coupling effect of wireless LANs causes a maximum throughput reduction of 2 Mbps. The interference effect of the conventional 3-channel separated channel and that of the 4-channel separated channel show very different results according to the installation environment. These result are attributed to the fact that the adjacent channel gained a margin of about 7 dB between channels 10 and 11 and cannot cover the impact by the location and observation of wireless LANs and the deviation of the antenna coupling effect. Therefore, the channel separation of either 3 or 4 for APs on a co-site is suitable, but it has been judged to depend on the performance and installation environment of each wireless LAN.