[1] 802.11 is a set of IEEE standards that govern wireless networking transmission methods.
They are commonly used today in their 802.11a, 802.11b, 802.11g and 802.11n versions to provide wireless connectivity in the home, office and some commercial establishments.
The 802.11 working group purposely did not define this element in order to provide flexibility in working with different wired and wireless distribution systems (i.e., wired backbones that interconnect access points).
The protocol is designed for the enforcement of unique association throughout an Extended Service Set and for secure exchange of station's security context between the current Access Point (AP) and the new AP during the handoff period.
Based on security level, communication session keys between Access Points are distributed by a RADIUS server.