OLPC wireless startup at boot time

Hal Murray hmurray at megapathdsl.net
Wed Oct 20 04:14:33 EDT 2010

>  - Preserving "last scan results" may improve user experience. 

I think that depends on the reason for powering off or closing the lid.

If you moved to a new building, you probably need a new AP.

If you moved from one tree to another, they are either using the same mesh 
channel to cooperate (or simplify things), or they are using a different one 
to avoid interference.

If you shut down to save power but didn't move, you probably want to 
re-connect to the same AP/mesh.

>  - Waking up the WLAN & scanning ASAP is key -- I think we are reasonably
> good there already 

It doesn't feel that way to me.

On lid open, the WiFi LED blinks a few times, finds a few APs, but doesn't 
find my AP.  After a long pause (10+ seconds), it blinks again, finds my AP, 
turns the LED on, and connects to my AP.

I just measured the pause at 20 seconds.  Is there a reason for that delay?  
Why doesn't the WiFi LED turn on sooner?

>  - Trying to pick quickly which AP to connect to is problematic. The
> preferred AP may only appear on the 2nd or 3rd scan. See earlier discussions
> about asking NM to wait _longer_ on that task to work on a more complete
> list of available networks. 

What is a "scan"?  Does it check one channel or all 3?  Assuming that a 
"scan" checks all 3, I'd expect most people to be using nearby APs with good 
signal strength so they should be easy to find and not require extra scans.

I'm guessing the first set of blinks is only checking one channel.  My AP is 
on channel 6, so that fits if it scans them in the order: 1, 6, 11.

Perhaps it should try the last active channel first, or even give the last AP 
a quick try.  (assuming there was a last AP)

These are my opinions, not necessarily my employer's.  I hate spam.

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