B
Roaming at base stations and access points
Roaming in Wi-Fi networks is done through two protocols. The 802.11k protocol is responsible for reporting link signal measurements between station and AP and helps the station in its objective to change AP within the Wi-Fi network while avoiding packet loss in the move. The 802.11v protocol forces the station to switch to another access point decided by the AP that is currently serving the station.
https://www.teldat.com/blog/roaming-802-11-k-v-r-wi-fi/