IEEE 802.11 Wireless LAN ▣802.11b ▣802.11a o 2.4-5 GHz unlicensed o 5-6 GHz range radio spectrum o up to 54 Mbps o up to 11 Mbps 口802.11g o direct sequence spread spectrum(DSSS)in o 2.4-5 GHz range physical layer o up to 54 Mbps ·all hosts use same ▣All use CSMA/CA for chipping code multiple access o widely deployed,using All have base-station base stations and ad-hoc network versions 6:Wireless and Mobile Networks 6-166: Wireless and Mobile Networks 6-16 IEEE 802.11 Wireless LAN  802.11b  2.4-5 GHz unlicensed radio spectrum  up to 11 Mbps  direct sequence spread spectrum (DSSS) in physical layer • all hosts use same chipping code  widely deployed, using base stations  802.11a  5-6 GHz range  up to 54 Mbps  802.11g  2.4-5 GHz range  up to 54 Mbps  All use CSMA/CA for multiple access  All have base-station and ad-hoc network versions