Writing anything to /proc/aironet/ethX/Config will restart the radio:
echo > /proc/aironet/ethX/Config
"HoBo" <HoBo@...>@csl.cse.ucsc.edu on 08/06/2000 11:06:43 AM
Sent by: aironet-admin@...
Subject: [Aironet] Hello
I am running a 4500 in a Linux box and I was wondering if there is a way
to restart the radio without rebooting.