After 4 years of hard working, IEEE approved the standard 802.11r, which handles a fast BSS transition.

What this means?

A big wireless network, is built with a lot of access points, this means that if you would like to cover a big city, you might have thousands of access points spreaded around.

This brought a new challenge to 802.11, with the introduction of applications such as voip, the transition between access points needs a very small delay, you would be amazing how annoying is to have a delay bigger then 300ms, can turn your call into something unacceptable if you are roaming into access points too fast.

Of course if you are walking in this city, it will not interfere much because you are slow, but if you are inside a car, you might be changing access points every five seconds, and this is where you’ll find the big problem. We already had the possibility to roam through access points at 100ms (802.11F), but this standard was defunct in 2006 giving space for r, which can roam twice as fast, 50ms, standard for voice transition.

What it basically do is allowing your software client to stabilish a new access point connection before actually switching for it, with this you can do the magic of roaming almost atomic in whatever state the access point is.

If you enjoyed this post, make sure you subscribe to my RSS feed!