The live CD/DVD of UBUNTU has the option for installing and activating the wireless broadcom drivers. But if you haven't installed the drivers during the live environment, how can the drivers be installed after UBUNTU has been installed so that the wireless firmware starts working?
Installing Broadcom Drivers
Method1: Using Additional Drivers (jockey-gtk)
If you are using Unity interface, press the super key and search for "Additional Drivers".
Otherwise, in gnome-classic, it can be found at System->Administration->Additional Drivers.
Alternatively, you can press alt+f2 and type "jockey-gtk" for Additional Drivers window.
From here, you can activate the drivers. All you need to do is be connected to internet and hit 'Activate' button. UBUNTU will search for the drivers and install it automatically for you.
Method2: Using Synaptic or apt-get
If the above method does not work, or if you wish to perform the installation yourself, then synaptic can be used to install the drivers.
Go to System->Administration->Synaptic Package Manager
and search for 'b43'.
Install the package b43-fwcutter
fwcutter is a tool which can extract firmware from various source files. It's written for BCM43xx driver files. It grabs firmware for BCM43xx from website and install it.
Depending on your wireless card, you might need to install the following packages:
- BCM4322 (only 14e4:432b)
- BCM4312 (with Low-Power aka LP-PHY)
If you want to use command line, following commands will install the drivers
sudo apt-get install b43-fwcutter firmware-b43-installer
sudo apt-get install b43-fwcutter firmware-b43-lpphy-installer
sudo apt-get install b43-fwcutter firmware-b43legacy-installer