XO (88W8388) roaming issues

[Dan Williams]

On Fri, 2013-03-22 at 11:43 -0300, Franco Miceli wrote:
> Hi,
> 
> We have a deployment of 400K XOs, which have the marvel
> 88W8388<http://wiki.laptop.org/go/88W8388> chip
> and use Libetas Firmware.
> 
> The issue we are having is when we set the SSID of our schools to the same
> value.
> 
> The laptops (on several tests we have run) jump from AP to AP without
> apparent reason.
> 
> Can something be modified at OS level to try and improve this "bad roaming"
> situation?

They jump from AP to AP because they find a stronger AP and switch over
to that one.  What version of of the wpa_supplicant package is installed
on those machines?  There are some well-known issues with older versions
of wpa_supplicant that are too aggressive and roam to APs when the
signal strength changes only slightly.

Obviously in a wifi environment, signal strength changes quite a bit,
even for the same access point, depending on where you're sitting, how
many walls are between you and the AP, even whether somebody opens a
door or not or turns on a microwave.

So I'd suggest that if the supplicant is an older version (0.7.x
perhaps) it could be updated and/or patched to roam only when the new
APs signal level is significantly better than the old AP.

Dan