Beacon frame is one of the management frames in IEEE 802.11 based WLANs. It contains all the information about the network. Beacon frames are transmitted periodically, they serve to announce the presence of a wireless LAN and to synchronise the members of the service set. Beacon frames are transmitted by the access point (AP) in an infrastructure basic service set (BSS). In IBSS network beacon generation is distributed among the stations. For the 2.4 GHz spectrum, having more than 15 SSIDs on overlapping channels (or more than 45 in total) and beacon frames start to consume significant amount of air time and degrade performance even when most of the networks are idle. Beacon frame is one of the management frames in IEEE 802.11 based WLANs. It contains all the information about the network. Beacon frames are transmitted periodically, they serve to announce the presence of a wireless LAN and to synchronise the members of the service set. Beacon frames are transmitted by the access point (AP) in an infrastructure basic service set (BSS). In IBSS network beacon generation is distributed among the stations. For the 2.4 GHz spectrum, having more than 15 SSIDs on overlapping channels (or more than 45 in total) and beacon frames start to consume significant amount of air time and degrade performance even when most of the networks are idle. Beacon frames consist of an 802.11 MAC header, body and FCS. Some of the fields in the body are listed below.