Roaming and steering

802.11v - BSS Transition Management

Wireless Network Management (WNM) allows STAs to exchange information, in order to improve the overall performance of the wireless network. STAs use WNM protocol to exchange operational data, which has network conditions of them.

BSS transition management has three messages, include BTM query, BTM request, BTM response.

BTM query message is transmitted by a STA requesting or providing information on BSS transition candidate AP.

BTM request message is transmitted by an AP in response to a BTM query frame.

BTM response message is transmitted by a STA in response to a BTM request frame. In this message, there is status code of STA.

Status code	Meaning
0	Accept
1	Reject - Unspecified reject reason
2	Reject - Insufficient Beacon or Probe Response frames received from all candidates
3	Reject - Insufficient available capacity from all candidates
4	Reject - BSS Termination undesired
5	Reject - BSS Termination delay requested
6	Reject - STA BSS Transition Candidate List provided
7	Reject - No suitable BSS transition candidates
8	Reject - Leaving ESS
9-255	Reserved