Unfortunately as of today June 19, the repository drivers of Wireless Broadcom BCM4313(wl.ko) don’t work well at all in Linux Mint 11. After making some research on Google I found out that there are new Linux drivers provided by the manufacturer Broadcom that simply need to be downloaded and installed. I did it and it worked … with a small adjustment. Here is what to do:
Note: I used the following references for this HOWTO:
http://www.broadcom.com/docs/linux_sta/README.txt
http://www.linuxquestions.org/questions/blog/frandalla-68463/patching-802-11-linux-sta-driver-for-kernel-2-6-37-3558/
1) Although the driver doesn’t work well, install the driver anyway for Broadcom STA wireless BCM4313 from:
Mint Menu ==>> ‘Control Center’ ==>> ‘Additional drivers’
and make sure you activate it after download and installation.

2) Download the latest driver from:
http://www.broadcom.com/support/802.11/linux_sta.php

3) Uncompress the tar.gz file into a new directory.
mkdir -p /usr/src/bcmwl-5.100.82.38+bdcom
tar fvxz hybrid-portsrc_*.tar.gz -C /usr/src/bcmwl-5.100.82.38+bdcom
cd /usr/src/bcmwl-5.100.82.38+bdcom

4) To prepare your system for compiling the driver, execute the following commands:
apt-get install build-essential linux-headers-generic
apt-get build-dep linux

5) To avoid a small problem when compiling, modify the source code of the following file:
/usr/src/bcmwl-5.100.82.38+bdcom/src/wl/sys/wl_linux.cat around line 485
FROM:
init_MUTEX(&wl->sem);TO:
#ifndef init_MUTEX
sema_init(&wl->sem,1);
#else
init_MUTEX(&wl->sem);
#endif

6) Compile the driver with the commands:
cd /usr/src/bcmwl-5.100.82.38+bdcom
make clean
make

6) Replace the Mint Broadcom driver with the newly compiled one using these commands. (Replace the {kernelversion} with your actual kernel version)
rmmod wl
mv /lib/modules/{kernelversion}/updates/wl.ko /lib/modules/{kernelversion}/updates/wl.ko.original
cp /usr/src/bcmwl-5.100.82.38+bdcom/wl.ko /lib/modules/{kernelversion}/updates/
depmod
modprobe wl

That’s it.
Enjoy your new WLAN connections.