WPA / 54G WLAN success on A5 here :-D

Neng-Yu Tu (Tony Tu) tony at openmoko.com
Fri Feb 1 12:43:42 CET 2008

> But I am a few metres away from the AP, maybe it helps.
>>> I currently have 2 bugs with our 2.0 firmware:
>>> 1) with my AP, my module doesn't hear the AP's DHCP offer unless I switch
>>> it to full power (no power saving).
> Ah that can be about your AP perhaps?  The powersaving thing relies on a
> rendezvous at beacon times to pick up packets (and the client WLAN
> powers down for ~100ms inbetween), maybe the problem can come from the
> AP side.  Mine is a Belkin F5D7230-4.

Yes, power saving relies on wake up beacon mechanism. And also related 
to the ARP mechanism implement on the access point side. Some AP ARP 
table refresh/update cycle could not in-sync with wi-fi client in 
suspend/low power mode, then AP will think wi-fi client is offline.

The solution in software side is do not rely on power saving function 
that chip default has. But self implement wake up cycle that fits 
certain wi-fi AP network.

This also kinda typical issue for a wi-fi phone. And usually need to a 
lot compatibility test with different AP and network/service provider to 
grantee that wi-fi power saving compatible with existing wi-fi network.

Tony Tu

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