The 802.11n standard for Wi-Fi may still be technically a draft specification, but the IEEE has now completed the 802.11r specs, making a new standard for Wi-Fi roaming. Why should you care about this? It’s designed for those moments when a Wi-Fi-connected device moves between hotspots, something the original 802.11 specs didn’t have in mind. Typically a transition between spots involves a drop and re-associate delay of around 0.1 seconds, which is enough to drop a VoIP call: 802.11r allows re-association with the new Wi-Fi source in less than 0.05 seconds, which should keep your call connected. The specs and also cover security associations and reservation of QoS resources for roaming Wi-Fi connections and have been under development for four years.
802.11r2 09 2008