Fast BSS transition, FT (802.11r)
A roaming method in which a client reuses key material it already holds, so moving to the next access point needs only a short authentication and reassociation exchange instead of a full 802.1X login.
The network analogy
Session resumption: the client presents a ticket the new server can already verify, so it skips the full login.
Why it matters for wireless
FT removes the 802.1X exchange from the roam, which can help keep a moving vehicle's gap inside its connection timeout, but only if the client and every access point on its route support FT for the same key type.
802.11r lets a client carry keys it already holds to the next access point. In the over-the-air method, reassociation uses an authentication request and response with the new access point, and the over-the-DS method uses FT Request and Response action frames. The key hierarchy of PMK-R0 and PMK-R1 is what makes this possible. A full 802.1X exchange is what you get instead, and it is the cost described in slow roam and full reauthentication.
FT is a separate key management type on the network. See fast-roam mismatch for how it presents, and the timing budget for where the roam time has to fit. FT is a property of the whole route, not of one access point.
About this page
Built from 3 sources: 1 vendor document and 2 other sources. Researched and drafted with AI assistance, then reviewed and approved by Ben Rutter on . How pages are made
- First published
- Last updated
Cite this page
Plain
Ben Rutter. "Fast BSS transition, FT (802.11r)." OT Wireless, published October 6, 2026. https://otwireless.com/glossary/fast-transition/
APA 7
Rutter, B. (2026, October 6). Fast BSS transition, FT (802.11r). OT Wireless. https://otwireless.com/glossary/fast-transition/
BibTeX
@misc{rutter2026fasttransition,
author = {Rutter, Ben},
title = {{Fast BSS transition, FT (802.11r)}},
year = {2026},
howpublished = {\url{https://otwireless.com/glossary/fast-transition/}},
organization = {OT Wireless},
}