The IEEE standards body quietly published the 802.11r roaming specification last month, allowing handoffs between Wi-Fi access points in the same way cellular phones shift between basestations.
The IEEE 802.11r-2008 standard was ratified on July 15.
While most cellular phones need to shift between basestations with ranges measured in the hundreds or thousands of yards, a Wi-Fi connection can typically be measured in feet. VOIP phones that are on the go may need to shift between different access points, hence the reason for the 802.11r standard. Handoffs between Wi-Fi APs also need to maintain persistent security features if possible, which the new standard allows.
The handoffs take place in less than 50 milliseconds, rather than the several seconds needed to negotiate a secured connection.
Consistent handoffs are also a required feature of a Microsoft initiative, Vi-Fi, a joint project between the University of Massachusetts, Microsoft and the University of Washington.
The Wi-Fi Alliance, meanwhile, has tried to implement a complementary standard, called "Voice Personal," for routing VOIP calls over Wi-Fi signals. In late June, the Alliance developed a certification program, which has approved devices like the Intel 4965AGN Wi-Fi link and the Intel 3945ABG network connection that have been tested for interoperability.
El Fon Blog: "New WiFi Roaming Protocol Established"
Extremetech.com: "IEEE 802.11r Roaming Standard Quietly Approved"
Wikipedia.com: "IEEE 802.11r-2008"