What roaming technology uses stored keys at the APs for roam back if a client...

PMK caching(Pairwise Master Key caching) is a roaming technology where the access point (AP) stores the PMK derived during the initial authentication of a client station (STA).If the client roams away and then returns to the same AP, the stored PMK allows for a quicker re-association without the need for a full authentication process.

This mechanism enhances roaming efficiency by reducing latency during re-association, which is particularly beneficial for applications sensitive to delays, such as VoIP.