802.11i's AP authenticate itself with keys and client stations in order to encrypt the network traffic that is derived. Pairwise Master Key (PMK) will be provided shared key to last entire session. Pairwise Transient Key (PTK) provide attribute like STA nonce, STA MAC address and AP MAC.
802.11r
IEEE 802.11r-2008 or fast BSS transition (FT) is an amendment to the IEEE 802.11 standard to permit continuous connectivity aboard wireless devices in motion, with fast and secure handoffs from one base station to another managed in a seamless manner.
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.
802.11k
802.11k is a proposed standard for how a wireless local area network (WLAN) should perform channel selection, roaming, and transmit power control (TPC) in order to optimize network performance. It is part of the 802.11 family of specifications.
802.11w
IEEE 802.11w-2009 is an approved amendment to the IEEE 802.11 standard to increase the security of its management frames.
IEEE 802.11w is the Protected Management Frames standard for the IEEE 802.11 family of standards. TGw is working on improving the IEEE 802.11 Medium Access Control layer. The objective of this is to increase the security by providing data confidentiality of management frames, mechanisms that enable data integrity, data origin authenticity, and replay protection. These extensions will have interactions with IEEE 802.11r and IEEE 802.11u.
Reference:
http://www.iis.sinica.edu.tw/page/jise/2010/201007_12.pdf
http://www.cwnp.com/cwnp_wifi_blog/wireless-lan-security-and-ieee-802-11w
