On Jan 1, 2013 6:50 PM, "Michael Richardson" <mcr@sandelman.ca> wrote:
>
>
> A comment was made a month ago or so about how long it takes wifi APs
> to switch from transmitting (unicast) to one station to another.  That
> there was quite a large latency here, and that this was one reason that
> the AP designers wanted large buffers to accmulate, so that the
> switching time could be amortized over a larger number of packets.
>
> I'm looking for a definitive reference to this problem.
> Will this be in the 802.11 specification, or is this an inherent problem
> in the chipsets, not the physics?
>

I might be way of here, but to me this sounds like a-mpdu which is used to
aggregate frames to get higher throughput. Thats in the specification, its
in 802.11ac and I believe that it go introduced with 802.11n.

It is there to mitigate the overhead of aquiring the channel.