This answer is based on an extensive research done by various Ubuntu users that worked together in almost all issues related to Broadcom. Special users like chili555 who have helped in the Ubuntu forums and on this site with many questions related to Wireless devices to others who have contributed through E-Mail, chats, IRC and more in testing various drivers with several of the most popular Broadcom Wireless cards (Huge Thanks to Chili555 really. This guy knows his stuff).
In total we wanted to offer an answer that could be easy to follow and covered most Broadcom Cards / Drivers. After you follow this guide, you will NEED to test your wireless connection for at least 2 hours (I actually recommend 8 hours) with another device in either Ad-Hoc Mode, Infrastructure Mode or Both. Common problems that will be solved (Apart from drivers not installing) are:
Connections timeout after several minutes or hours
Stops searching for other devices (Does not see any other device)
Keeps asking for password even on cases where AP does not have any
Stops any receiving/transmitting traffic (Needs reboot to temporarily fix)
Crashes system with dmesg errors in log (Link 1 Below)
System freezes completely (You can only press Reboot/Power button) (Link 1 Below)
Creates huge log reports trying to correctly configure or connect
Fails when installed via Additional Drivers / Additional Hardware (Link 3 Below)
Connects and disconnects continuously every X amount of seconds
Appears connected on Network Manager but does not receive Internet
Tries to connect many times without correctly finishing connection
Takes too long to connect
After upgrading from a previous version (eg: 12.04 to 12.10) it stops working
Wireless card does not turn on, enable or disable (Link 2 Below)
Wireless card blocked by hardware
More problems found in Launchpad, Ubuntu Forum and Askubuntu
Link 1 -
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1060268Link 2 -
https://bugs.launchpad.net/ubuntu/+source/bcmwl/+bug/732677Link 3 - Gives an error similar to "Sorry, installation of this driver failed."
So with that in mind, the following is what we have right now which is simplified in just 3 steps:
1. Knowing what Broadcom Wireless Card you have
There are dozens of Broadcom wireless cards and more seem to appear every day. The key to finding the correct driver for any network card is what is known as the PCI ID (PCI.ID). To find out which PCI.ID you have, we proceed to opening the terminal by pressing CTRL+ALT+T (It should open a window with a blank background) and inside this terminal we run the following command:
lspci -nn -d 14e4:
You will get something like the following if you have a Broadcom Wireless Adapter (The ID 14e4 used in the example above in most cases is a Broadcom Wireless Card):
Broadcom Corporation BCM4306 802.11bgn Wireless Network Adapter [14e4:4320] (rev 03)
The PCI.ID in this example is 14e4:4320 as seen inside the Brackets [...]. In some cases you will also need the revision version (if it appears) for some special cases. In this case, the revision version is rev 03 as shown inside the Parentheses (...) at the end. So what you will need after this search is:
[14e4:4320] (rev 03)
With this new information you can look in the table below and select the appropriate method to install your driver. For example, In this case, since you have the 14e4:4320 rev 03, if we go down the list to the one that shows the exact same PCI.ID you will see that in the columns for Ubuntu 12.04, 13.10 or 14.04 it shows the linux-firmware-nonfree package driver. This means that you will only have to install this particular package since it appears in all Ubuntu version columns.
NOTE - Before proceeding, if you have previously installed any drivers, have blacklisted or uncommented any driver files or configuration files or have done any changes whatsoever to the system to make the drivers work in previous attempts, you will need to undo them in order to follow this guide. We assume you are doing this from scratch and have not changed any configuration files, modules or drivers in the system in any way (apart from updating the system). This includes any installations using apt-get, aptitude, synaptic, dpkg, software center or manual compilation and installation of the packages. The system has to start from scratch in order for this to work and to avoid any conflicts that may appear if earlier work was done.
For example, if you have previously installed the bcmwl-kernel-source package, you will need to remove it by using the purge method:
sudo apt-get purge bcmwl-kernel-source
2. Preparing the System
If you have just installed Ubuntu, you will need to build an index of available packages before we can install your driver if you have not done so already:
sudo apt-get update
I would even go so further as to update the Ubuntu list of PCI.IDs:
sudo update-pciids
Just in case the ID of a particular new Broadcom Device you are using has just appeared.
Now using the PCI.ID you found in the steps above, we then search in the list below to find the matching PCI.ID and the method to install the driver associated with it in a simple and correct way. The terminal will be used to avoid any GUI related issues. This applies with all cases, except as noted. The installation procedure is done only via terminal and also while connected to the internet with a temporary wired ethernet connection or USB modem or any means possible that can give your PC, for the time, Internet access. After you find in the list below the correct package we then proceed with the installation.
3. Installing the Package
Assuming you used the PCI.ID 14e4:4320 rev 03 as found in your search above, and then looked at the table below and found that the correct package to install is the linux-firmware-nonfree, we then proceed to simply install this package in the terminal:
sudo apt-get install linux-firmware-nonfree
and then reboot
sudo reboot
The format to install is pretty simple, it's just:
sudo apt-get install <PACKAGE_NAME>
and then reboot. In the example above, the PACKAGE_NAME is linux-firmware-nonfree.
BROADCOM WIRELESS TABLE (Updated 31 March 2014)
PCI.ID 12.04 LTS 13.10 / 14.04 LTS
------------------------------------------------------------------------------------
14e4:0576 Special Case #1 Special Case #1
14e4:4301 firmware-b43legacy-installer firmware-b43legacy-installer
14e4:4306 firmware-b43legacy-installer firmware-b43legacy-installer
14e4:4306 rev 2 firmware-b43legacy-installer firmware-b43legacy-installer
14e4:4306 rev 3 linux-firmware-nonfree linux-firmware-nonfree
14e4:4307 linux-firmware-nonfree linux-firmware-nonfree
14e4:4311 linux-firmware-nonfree linux-firmware-nonfree
14e4:4312 linux-firmware-nonfree linux-firmware-nonfree
14e4:4313 linux-firmware-nonfree linux-firmware-nonfree
14e4:4315 firmware-b43-lpphy-installer linux-firmware-nonfree
14e4:4318 linux-firmware-nonfree linux-firmware-nonfree
14e4:4319 linux-firmware-nonfree linux-firmware-nonfree
14e4:4320 rev 02 firmware-b43legacy-installer linux-firmware-nonfree
14e4:4320 rev 03 linux-firmware-nonfree linux-firmware-nonfree
14e4:4324 linux-firmware-nonfree linux-firmware-nonfree
14e4:4325 firmware-b43legacy-installer linux-firmware-nonfree
14e4:4328 bcmwl-kernel-source linux-firmware-nonfree
14e4:4329 bcmwl-kernel-source bcmwl-kernel-source
14e4:432a bcmwl-kernel-source bcmwl-kernel-source
14e4:432b bcmwl-kernel-source bcmwl-kernel-source
14e4:432c bcmwl-kernel-source bcmwl-kernel-source
14e4:432d bcmwl-kernel-source bcmwl-kernel-source
14e4:4331 linux-firmware-nonfree linux-firmware-nonfree
14e4:4335 UNKNOWN linux-firmware-nonfree
14e4:4353 Special Case #1 Special Case #1
14e4:4357 Special Case #1 Special Case #1
14e4:4358 bcmwl-kernel-source bcmwl-kernel-source
14e4:4359 bcmwl-kernel-source bcmwl-kernel-source
14e4:4365 Special Case #2 bcmwl-kernel-source
14e4:43a0 UNKNOWN bcmwl-kernel-source
14e4:4727 Special Case #3 Special Case #1
14e4:a962 UNKNOWN linux-firmware-nonfree
------------------------------------------------------------------------------------
Special Case #1 - This device uses the driver combination bcma and brcmsmac. It shouldn't be necessary to install anything at all. Required firmware is installed by default in the package linux-firmware.
Special Case #2 - Probably only working in 64-bit only. See: How do I install BCM43142 wireless drivers for Dell Vostro 3460/3560?
Special Case #3 - Use brcmwl-kernel-source for kernel versions less than 3.8. To check for Kernel version open the terminal and type: uname -r. For kernel versions 3.8 and later, use brcmsmac.
If you have a Broadcom card that has a different pci.id, please ask a new question. Once solved, the solution will be added to this howto.
DEBUGGING
The following is additional material to read about solving various issues related to Wireless Management and conflicts with other Network areas. Know that it some cases you need to have an updated Kernel version, since each new version of the Kernel introduces either new Network drivers, improvements over existing drivers or solves bugs regarding them.
To configure your wireless devices through the terminal I recommend How to connect and disconnect to a network manually in terminal?
If your connection drops every so often some users have suggested to set IPv6 to Ignore. Just go to Network Manager (The network icon on the top panel). Click on it then select Edit Settings. Then go to the Wireless connection you are using, select it. Now go to the last Tab in there that mentions IPv6 Settings. In the Method field select Ignore.
If your laptop does not detect your wireless card some users have mentioned that using rfkill unblock all will solve the problem. Others simply turned the WiFi switch on their laptops off and then on again (Physical switch available on this laptops). For more information about rfkill please read rf kill unblock all DOES NOT WORK!
If you are getting b43-phy0 ERROR: Fatal DMA error / b43-phy0 warning: Forced PIO do the following:
sudo rmmod b43
sudo modprobe b43 pio=0 qos=0
If it works then add it to you RC files so it is executed every time you boot. You can change PIO to 1 if you need to it.