I think the easiest way would be to unload the modules with a script or someting. I do not know which modules it should be and i have no clue about scripting.. but should be looking similar to something like this...

#!/bin/sh

modprobe -r <wifi-module>
modprobe -r <gprs-module>
sleep 36000;
modprobe <wifi-module>
modprobe <gprs-module>
done