The standard promises to improve the quality and security of VoIP services, as with existing protocols, swapping from one access point to another takes considerable time.
With the 802.11r standard, which is also known as Fast Basic Service Set Transition, it takes less than 50 milliseconds to enable the security authentication of the service, during the course of switching over.
This is less than half the time taken by existing standards.
Development of the 802.11r standard began in 2004 and approval for publishing the final draft of the standard was given by the 802.11r task group in January.
Read more about it here.