安装了Ubuntu最新版本 14.04 之后，发现无线网卡不能使用，偿试安装驱动后，问题解决。
首先确定无线网卡类型：
lspci -vnn -d 14e4:
比如我的网卡类型为
06:00.0 Network controller [0280]: Broadcom Corporation BCM4313 802.11bgn Wireless Network Adapter [14e4:4727]
根据网卡类型14e4:4727，对照下面这张表，找到所要安装的驱动，此处我所需要安装的就是wl种类的
请仔细查看设备 ID and 芯片名称 .
| 14e4:0576 | not tested | BCM43224 | a/b/g/n | ? | wl/brcm80211 |
| 14e4:4301 | yes (b43legacy) | BCM4301 | b | B | |
| 14e4:4306 | yes (b43legacy) | BCM4306/2 | b/g | G | |
| 14e4:4307 | yes | BCM4306/3 | b/g | G | |
| 14e4:4311 | yes | BCM4311 | b/g | G | wl |
| 14e4:4312 | yes | BCM4311 | a/b/g | G (r8) | wl |
| 14e4:4313 | not tested | BCM4311 | a | ? | wl |
| no | BCM4313 | b/g/n | LCN (r1) | wl/brcm80211 | |
| 14e4:4315 | yes | BCM4312 | b/g | LP (r1) | wl |
| 14e4:4318 | yes | BCM4318 | b/g | G (r7) | |
| 14e4:4319 | yes | BCM4318 | a/b/g | G | |
| 14e4:4320 | yes (b43legacy) | BCM4306/2 | b/g | G (r1) | |
| yes | BCM4306/3 | ? | G (r2) | ||
| 14e4:4321 | partially | BCM4321 | ? | N (r2) | |
| 14e4:4322 | yes (3.18+) | BCM4322 | b/g/n | N (r4) | wl |
| 14e4:4324 | yes (b43legacy) | BCM4306 | a/b/g | G (r1) | |
| yes | BCM4306/3 | a/b/g | G (r5) | ||
| 14e4:4325 | yes (b43legacy) | BCM4306/2 | b/g | G (r1) | |
| 14e4:4328 | partially | BCM4321 | a/b/g/n | N (r2) | wl |
| 14e4:4329 | partially | BCM4321 | b/g/n | N (r1) | wl |
| 14e4:432a | not tested | BCM4321 | a/n | N | wl |
| 14e4:432b | partially | BCM4322 | a/b/g/n | N (r4) | wl |
| 14e4:432c | yes | BCM4322 | b/g/n | N | wl |
| 14e4:432d | not tested | BCM4322 | a/n | N | wl |
| 14e4:4331 | yes (3.2-rc3+) | BCM4331 | a/b/g/n | HT (r1) | wl |
| 14e4:4350 | yes (3.8+) | BCM43222 | a/b/g/n | N (r6) | |
| 14e4:4353 | yes (3.1+) | BCM43224 | a/b/g/n | N (r6) | wl/brcm80211 |
| 14e4:4357 | yes (3.1+) | BCM43225 | b/g/n | N (r6) | wl/brcm80211 |
| 14e4:4358 | yes (3.17+) | BCM43227 | b/g/n | N (r16) | wl |
| 14e4:4359 | yes (3.17+) | BCM43228 | a/b/g/n | N (r16) | wl |
| 14e4:4360 | no | BCM4360 | ? | AC (r1) | |
| 14e4:4365 | no | BCM43142 | b/g/n | LCN40 (r3) | wl |
| 14e4:43a0 | no | BCM4360 | a/b/g/n/ac | AC? | wl |
| no | BCM4352 | a/b/g/n/ac | ? | wl | |
| 14e4:43a9 | yes (3.17+) | BCM43217 | b/g/n | N (r17) | |
| 14e4:43aa | yes (3.17+) | BCM43131 | b/g/n | N (r17) | |
| 14e4:43b1 | no | BCM4352 | a/b/g/n/ac | AC (r3) | wl |
| 14e4:4727 | no | BCM4313 | b/g/n | LCN (r1) | wl/brcm80211 |
| 14e4:a8d6 | not tested | BCM43222 | ? | N (6) | |
| 14e4:a8d8 | yes (3.6+) | BCM43224 | a/b/g/n | N (r6) | brcm80211 |
| yes (3.6+) | BCM43225 | ? | N (r6) | brcm80211 | |
| 14e4:a8db | partially (3.18+) | BCM43217 | b/g/n | N (r17) | |
| 14e4:a99d | not tested | BCM43421? | ? | ? | wl |
安装步骤：
1、先安装b43-fwcutter工具，如下：
下载b43-fwcutter源码：
http://bues.ch/b43/fwcutter/b43-fwcutter-018.tar.bz2
解压后，进入到目录中，执行
make sudo make install
2、安装驱动
下载驱动文件：
http://www.lwfinger.com/b43-firmware/broadcom-wl-5.100.138.tar.bz2 使用b43-fwcutter工具安装驱动
sudo b43-fwcutter -w /lib/firmware broadcom-wl-5.100./linux/wl_apsta.o
3、加载驱动
modprobe b43
加载驱动可能需要时间比较长，请耐心等待。
对于其他种类的无线网卡，可参考网址：
http://wireless.kernel.org/en/users/Drivers/b43#devicefirmware