When my tablet was sitting idle at home, with WiFi enabled on my home network, the battery ran down at about 1% per hour ("battery-status" app)
When I took it to work, still idle with WiFi enabled, the battery ran down at about 12% per hour. Our work LAN is much noisier with more broadcast traffic. I wondered if that was causing the CPU to run, and if filtering it out might help.
Of course, iptables is running the CPU too; what's needed it to filter it in the
ethernet chip but that lets broadcasts through on purpose.
I'm not sure if I'm seeing a repeatable effect, or just got confused about what was running.

This is a very interesting thought. In normal situations the tablet sets a CAM timeout of 100ms (ie, it puts the wifi gear to sleep really quickly) but I assume if it receives traffic it increases that timeout. Also, the CPU doesn't need to be doing anything to be sucking power, it just has to be woken up to deal with something like receiving network traffic then discarding it. Maybe it could be set to ignore broadcasts in some situations?

-John

I just found a post on mamo-users mentioning power management issues on some wireless APs. Not sure of the details.
I tried running a broadcast ping for a few hours at home but it didn't make much difference.

Excellent explanation of power-saving mode by Kalle:
http://www.gossamer-threads.com/list...rs/38954#38954

Network noise should not be a problem compared to PSM failure