OLPC wireless startup at boot time
bernie at codewiz.org
Wed Oct 20 09:40:23 EDT 2010
On Wed, 2010-10-20 at 08:35 -0500, Mikus Grinbergs wrote:
> > The question is why does it take so long for the connection to be established?
> > A 10-12 second reconnect time is to be expected:
> > 1. A 1 second delay for the device to be probed and initialized on resume
> > 2. NetworkManager has a 7 second delay hardcoded
Really? That sucks!
Finally explained why my simple shell script could connect in just 3
seconds whereas NM took a lot longer.
> [I hope that an XO which is in "I've had my wireless connected for a
> whole hour" mode can nevertheless detect whenever a __new__ AP shows up
> (whose radio signal was not previously noticed). If that is possible,
> then the SAME capability should be applicable even at startup time.]
This is called background scanning. Most wifi firmwares do it because
it's required to hop to another with the same ESSID and better signal
Background scanning may introduce several ms of latency while the radio
is switching channels. Gamers know tricks to disable it.
// Bernie Innocenti - http://codewiz.org/
\X/ Sugar Labs - http://sugarlabs.org/
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