I used the solution of #67614 (https://answers.launchpad.net/ubuntu/+source/network-manager/+question/67614), providing command line arguments to enable/disable the wireless network interface:

dbus-send --system --type=method_call --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.DBus.Properties.Set string:org.freedesktop.NetworkManager string:WirelessEnabled variant:boolean:false

false --> disable wireless
true --> enable wireless

In "Preferences>>Sessions>>Add" I added a new startup program:

Name: Wireless_Down

Command:
dbus-send --system --type=method_call --dest=org.freedesktop.NetworkManager /org/freedesktop/NetworkManager org.freedesktop.DBus.Properties.Set string:org.freedesktop.NetworkManager string:WirelessEnabled variant:boolean:false

VIA

Last modified on 2011-02-09