Reduce Channel Scanning Time in wpa_supplicant

[Dan Williams]

On Thu, 2012-02-23 at 00:48 -0500, Nithyananthan Poosamani wrote:
> Hi,
> 
> 
> I am working with wpa_supplicant 0.6.x provided along with the Android
> source git. I am working on supplicant for NexusOne phone.
> 
> 
> In driver_wext.c file and in the method
> "wpa_driver_wext_set_cscan_params", there is the code to do passive
> channel scanning.
> So by default of 250 ms dwell time, if my understanding is right,
> Android takes close to 3.5 sec to do one full-channel scan and return
> the results.
> 
> 
> My question is, how can I do scanning for only one specified channel ?
> So basically I would do scanning for 250 ms only and then return
> results.

That depends largely on the wifi driver, and how much control that
driver exposes to userspace for the scanning process.  Most drivers
don't expose much control at all, though nl80211-based drivers are
starting to get there.

Dan

> 
> Also the previous scan results are cached somewhere, so whenever the
> phone screen is turned on, we check the cached results first to
> speed-up association else do new scanning.
> How are the cache results changed, how periodically ?
> 
> 
> I would be happy if any of you can help me understand these
> phenomenon's.
> 
> 
> Thanks for your time !
> 
> 
> Sincerely,
> Nithy
> _______________________________________________
> HostAP mailing list
> HostAP at lists.shmoo.com
> http://lists.shmoo.com/mailman/listinfo/hostap