The IEEE has approved the 802.11r standard that allows Wi-Fi devices to roam between Wi-Fi access points with a delay of less than 50 milliseconds during the handoff.
Handoffs are already supported by the 802.11 a, b and g standards but only for data, not for voice or video. So if you are walking down the street talking on your Wi-Fi enabled device (e.g. a Nokia phone with Wi-Fi) and the access points to which your device is connecting while you are walking take too long to hand off your call (i.e. to re-associate your device to the next access point down the street), you will notice a loss of connectivity. To support handoffs for voice and video using 802.11 a, b and g devices (i.e. most access points on the market today), individual vendors of Wi-Fi equipment added the capability to hand-off voice and video at less than 50 milliseconds of delay. Now, having this feature baked into the 802.11 standard allows manufacturers to mass produce Wi-Fi equipment with this capability.
Although most news reports hail the approval of the 802.11r standard as a major step in improving VOIP service, hardly anyone mentioned video.
The approval of the 802.11r standard has significant repercussions on municipal wireless broadband. Many municipal wireless networks are used by city government employees such as police officers while they are on the go: they make calls and look at video while they are in a moving vehicle, or walking down the street (e.g. inspectors). Indeed, for the rest of us, being able to make calls and view video, while walking or driving in a city that has a municipal Wi-Fi network, on a iPhone or other Wi-Fi enabled mobile phone has come a step closer. For people who don’t want to suffer roaming charges on their cellular devices or who can’t bear the slow GRPS (EDGE) networks, this is great news. Although the new iPhone now works on 3G networks, in many parts of the world, there are no 3G cellular networks, making data and other multimedia applications horribly slow.
The IEEE is working on other enhancements to the 802.11 standard, notably, 802.11y which would allow high-powered Wi-Fi equipment to operate in the 3650 – 3700 MHz frequency band. Among the applications for this type of equipment are backhaul for municipal wireless networks, last mile broadband access, and fixed point to point links.
All this good news depends on the Access Points that implement this standard being connected to the same network that then connects to the internet, so that the upper layer protocol, i.e. SIP still sees the same IP address from the device as it moves from AP to AP. It won’t help if one AP is connected to comcast, and the other to Quest DSL.
It all depends from the vendors and the big players that will follow the implementation of the standard.If there will be key players’ products in the market that will be 11r enabled then the amendment to the IEEE 802.11 standard will make an impact.