[PATCH 1/2] cfg80211: Add support to set tx power for a station associated

[Johannes Berg]

> Sure.. First use case will be to help with the problem of legacy
> client devices that roam across multiple APs. It is a classic
> enterprise Wi-Fi AP problem,  often managed by a "network controller"
> unit that is connected to all the APs. 
> The problem is how to handle seamless handoff of clients between
> multiple  APs while maximizing the client throughput and minimizing
> disruption of IP application services like VoIP calls and video
> streaming. A legacy client will often  hold onto an AP association,
> even down to 1 Mbps as it roams away. Instead,  if the AP can
> recognise that the client RSSI (and therefore throughput) is poor, it
> can "drop" the Tx power significantly (just to that client) such that
> it forcesthe client to look for a better, closer, and therefore
> higher-throughputassociation. It would "give it a kick" without
> blacklisting it. It just needsto hold the power low for the small
> amount of time it takes to convince it to go away.

Not sure that *works* since implementations may just compare beacon
signal strength and hold on to the AP based on that, but it does seem
like a reasonable use case.

How would this interact with automatic adjustment though?

johannes