Summary: <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> Multiple BSSID sets out to aggregate individual beacon frames from an access point to a single beacon frame.<br> <br> <br> <br> It helps solve the issue of beacon overhead. As it is today, each SSID broadcasts a beacon. The more SSIDs you’re broadcasting, the more the beacons eat up airtime.<br> <br> <br> <br> Airtime is a precious resource for Wi-Fi devices. Sometimes beacon overhead can take up a large amount of airtime.<br> <br> <br> <br> Multiple BSSID aims to reduce the airtime by broadcasting less beacon frames for better efficiency and less wasted airtime capacity.<br> <br> <br> <br> While Multiple BSSID can be found in 802.11-2020, it was first introduced in 802.11v-2011. In the episode, Rowell mentions that it is mandatory in Wi-Fi 6. But we have not seen documented to be mandatory, or maybe we just missed it.<br> <br> <br> <br> Within Multiple BSSID, you will find a new information element that contains all the active BSSIDs within the Multiple BSSID set. There will be one transmitted BSSID and the others SSIDs will be listed with non-transmitted BSSID profiles.<br> <br> <br> <br> Be sure to check out the video and the pcap file!<br> <br> <br> <br> Sections in the 802.11-2020 standards talking about Multiple-BSSID:<br> <br> <br> <br> <br> * 4.3.19.12 Multiple BSSID capability<br> <br> <br> <br> * 9.4.2.45 Multiple BSSID element<br> <br> <br> <br> * 9.4.2.73 Multiple BSSID-Index element<br> <br> <br> <br> * 10.6.9 Multiple BSSID Rate Selection<br> <br> <br> <br> * 11.1.3.8 Multiple BSSID procedure<br> <br> <br> <br> <br> Resources<br> <br> <br> <br> <br> <br> <br> <br> Frame capture: <a href="https://drive.google.com/file/d/17G2yB2rTXKiAiJxTXXG2QgkpeyW-ZLSi/view"></a><a href="https://drive.google.com/file/d/17G2yB2rTXKiAiJxTXXG2QgkpeyW-ZLSi/view">https://drive.google.com/file/d/17G2yB2rTXKiAiJxTXXG2QgkpeyW-ZLSi/view</a><br>
