Beacons also have to broadcast the DTIM which allows stations to come out of standby if there is data waiting for them. This can be up to 128 bytes. But I agree, beacons are stupidly fat. The basic beacon is quite small except for the additional tags. If you fire up wireshark you'll see the bulk of the bytes in broadcasting all kinds of feature nonsense that IMHO should only be broadcast during a request to join.
e.g the beacon frame is 24B on my Netgear, but the tagged paramters are 300 bytes. Sure, the SSID and DTIM are in there, but then there's a bunch of extended support rates, RSN info, HT info, and vendor specific stuff (Microsoft WMM/WME parameters, 3Com stuff... huh??)
e.g the beacon frame is 24B on my Netgear, but the tagged paramters are 300 bytes. Sure, the SSID and DTIM are in there, but then there's a bunch of extended support rates, RSN info, HT info, and vendor specific stuff (Microsoft WMM/WME parameters, 3Com stuff... huh??)