A bit of success to report.
I say a bit because there is still a problem to solve with Network Manager which is outside of my programming capabilities at present and the foreseeable future.
After further analysis and trial and error based on the above suggestions by Roky and D.O., I was able to determine that the Modem Manager service could be activated by installing the modem-manager-gui
package and then activating the Modem Manager GUI
applet from the Applications/System Tools sub-menu.
Once the Modem Manager service was activated, the Modem Manager GUI applet could be shut down
(Quit) and the nm-applet could be launched with the Enable Mobile Broadband
option becoming displayed in the right-click context menu from the systray icon.
The Modem was also recognised when creating a Mobile Broadband Network Connection.
However, the password was not being remembered for the Network Connection that I added for the Modem. This was partly solved by installing the gnome-keyring
package but it appears to only work whilst the session is active. After rebooting, when I Edit
the Connection and enter the keyring password, when prompted, the Password field for the Network Connection is vacant again. The same issue exists if attempting to activate the connection is your first interaction with the nm-applet. I haven't been able to find a solution for this. Is it a Live environment problem?
So, it appears that Network Manager has been broken with regards to launching the Modem Manager service. I've since discovered that this may be due to it expecting bloody
systemd to be PID 1 which has probably been cause by some systemd moronic proponent or elitist schmuck. This was noted on the associated Debian bugs page 24/11/2014.
From that bug report, I discovered that executing the command sudo /usr/sbin/ModemManager
from a Terminal will also activate the Modem Manager service. So, there is no need to install the modem-manager-gui
package which can't be used for establishing a connection anyway.
If the Debian Wheezy repository was added to Synaptic and the Network Manager packages etc were downgraded, does anyone think that would provide a more reliable and convenient solution?
Thanks and hasta pronto, Sherlock