with packet-monitoring tools such as tcpdump or Wireshark would show that most traffic on the network consists of beacon frames, with a few non-802-11 packets mixed in, such as DHCP packets. If users joined the network, responses to each beacon would begin to appear, along with regular traffic generated by the users. Stations must schedule beacon transmission at the nominal beacon interval. However, the transmission may suffer some delays due to the channel access. Like other frames, beacons must follow the CSMA/CA algorithm. This means that if the channel is busy (e.g., another station is currently sending a frame) when the beacon needs to be sent, it must wait. This means that the actual beacon interval may differ from the nominal beacon interval. However, stations are able to compensate for this difference by inspecting the timestamp in the beacon frame when it is finally sent. Function While beacon frames do cause some non-trivial overhead for a network, they are vital for the proper operation of a network. Radio NICs generally scan all RF channels searching for beacons announcing the presence of a nearby access point. When a radio receives a beacon frame, it receives information about the capabilities and configuration of that network, and is also then able to provide a list of available eligible networks, sorted by signal strength. This allows the device to choose to connect to the optimal network. Even after associating with a network, the radio NIC will continue to scan for beacons. This has several benefits. Firstly, by continuing to scan for other networks, the station has options for alternative networks if the current access point's signal becomes too weak to continue communication. Secondly, as it still receives beacon frames from the currently associated access point, the device is able to use the timestamps in those beacons to update its internal clock. Beacons from the currently associated access point also inform stations of imminent configuration changes, such as data rate changes. Finally, beacons enable devices to have power saving modes. Access points will hold on to packets destined for stations that are currently sleeping. In the traffic indication map of a beacon frame, the access point is able to inform stations that they have frames waiting for delivery. References IEEE 802.11