NM scanning policy

[Bill Moss <bmoss clemson edu>]

Proposed change to NM scanning policy.

Context menu scan item: three states -- On, Auto, Off

On: NM's current policy which is to always scan but adjust the time 
between scans.

Auto (default): When a wired connection has been established, stop 
scanning (also consider powering down radio). As soon as a wired 
connection is not available, begin scanning. After a wireless connection 
has been made, stop scanning but start again if the signal strength 
falls below a threshold.

Off: Do not scan or stop all wireless devices and power down radios.

Justification: Scanning powers up the radio.  When operationg on battery 
and connected by wire, scanning wastes power. Scans that take a long 
time can be disruptive.

--
Bill Moss
Professor, Mathematical Sciences
Clemson University