I had a really tough time trying to tether my Android-based LG Optimus L5 mobile device, and additionally use it as a portable hotspot. The basic idea was to make it possible to access it via the Ubuntu 12.04.2 installed on my laptop; I run Kubuntu desktop environment on it by the way, and that kind of made it a lot harder… However, since I started using WICD [1] –all my problems are pretty much gone now 🙂
Installing WICD
Installing [1] WICD is easy and straight forward; just ensure the latest version of NetworkManager is installed, then install WICD, and finally uninstall NetworkManager. Incidentally, the instructions for Unity are the same, except for the packages that need to be installed/uninstalled.
sudo apt-get install -d --reinstall network-manager plasma-widget-networkmanagement sudo apt-get install wicd-kde sudo apt-get remove --purge plasma-widget-networkmanagement network-manager
The ‘wicd client’ tool can then be accessed via ‘Applications | Internet | wicd client’. The screenshot below shows the sample output of running WICD.

Tethering
Hook up the mobile to the computer via USB and make sure the mobile device in up. Then confirm the computer can see the device.
phiri@PHRLIG001:~$ sudo ifconfig usb0 up phiri@PHRLIG001:~$ sudo ifconfig : : usb0 Link encap:Ethernet HWaddr 02:51:09:04:39:32 inet6 addr: fe80::51:9ff:fe04:3932/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:7 errors:0 dropped:0 overruns:0 frame:0 TX packets:13 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:600 (600.0 B) TX bytes:2916 (2.9 KB) wlan0 Link encap:Ethernet HWaddr 70:f3:95:e3:a9:a7 inet addr:192.168.43.211 Bcast:192.168.43.255 Mask:255.255.255.0 inet6 addr: fe80::72f3:95ff:fee3:a9a7/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:9195 errors:0 dropped:0 overruns:0 frame:0 TX packets:12302 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:821838 (821.8 KB) TX bytes:1326393 (1.3 MB) : :