[maemo-developers] [maemo-developers] WLAN reciever and battery.

[From: Kalle Valo]

"ext George Farris" <farrisg at cc.mala.bc.ca> writes:

> Has anyone information about battery capacity/current draw and WLAN
> connectivity when your presence is set to online?  I would think that
> only the receiver would be active and so battery life would be much
> longer than when browsing.

770 also has to send WLAN and TCP ACKs, at least. I don't know XMPP so
well, but it also might require something to be sent while being
online. So 770 cannot just receive, it also has to send.

> Or is it the case with the 770 that as soon as the WLAN interface is
> enabled, it draws much more current, regardless of transmission?

WLAN Power Saving mode is enabled automatically whenever there's no
traffic. For 770 it's beneficial from power management point of view
if network applications try to keep the network interface as idle as
possible. And whenever there's something to send, application should
send it as fast as possible. Slowly sending few bytes per second for a
long time will drain the battery quite quickly.

As a network administrator you can affect the WLAN idle power
consumption of the client devices. Choose long DTIM values and beacon
intervals in your WLAN AP (but too long values might slow down the
network too much or create other problems, it might need some tuning).
Try to avoid broadcast traffic in the WLAN network as much as
possible. Especially Windows hosts sending netbios broadcasts might
have an effect.

Or if you want even longer use times, use Bluetooth :)

-- 
Kalle Valo