I have a DELL Laptop and I installed Ubuntu 14.04 on it but after installation, I wanted to use the WiFi on laptop But the WiFi is not detecting in Ubuntu.The Broadcom hardware is detecting in OS but the drivers was not supporting so here I shared the procedure to install drivers in Ubuntu:
For Broadcom BCM4311,
#sudo apt-get install bcmwl-kernel-source broadcom-sta-common broadcom-sta-source -y
Check now WiFi is working or not.
#sudo apt-get install b43-fwcutter firmware-b43-installer
After following the above procedures your WiFI will work J.
visit here for more info https://help.ubuntu.com/community/BroadcomSTA%28Wireless%29