IEEE 802.11r specifies fast
Basic Service Set (BSS) transitions between access points by redefining the security key negotiation protocol, allowing both the negotiation and requests for wireless resources (similar to
RSVP but defined in
802.11e) to occur in parallel.
The key negotiation protocol in
802.11i specifies that, for
802.1X-based authentication, the client is required to renegotiate its key with the
RADIUS or other authentication server supporting
Extensible Authentication Protocol (EAP) on every handoff, a time consuming process. The solution is to allow for the part of the key derived from the server to be cached in the wireless network, so that a reasonable number of future connections can be based on the cached key, avoiding the 802.1X process. A feature known as
Opportunistic Key Caching exists today, based on 802.11i, to perform the same task. 802.11r differs from OKC by fully specifying the key hierarchy.
