Hi I have a Dell Latitude E6510 computer. I have installed Ubuntu 12.04 LTS. Now I can't access my WiFi network. Cable network is working. I am new one to Ubuntu.

Details of network as follows.

product: BCM43224 802.11a/b/g/n BCM4353

-pc:~$ sudo lshw -C network



PCI (sysfs)  

  *-network               

       description: Ethernet interface

       product: 82577LM Gigabit Network Connection

       vendor: Intel Corporation

       physical id: 19

       bus info: pci@0000:00:19.0

       logical name: eth0

       version: 05

       serial: 00:26:b9:cb:d0:a2

       size: 100Mbit/s

       capacity: 1Gbit/s

       width: 32 bits

       clock: 33MHz

       capabilities: pm msi bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation

       configuration: autonegotiation=on broadcast=yes driver=e1000e driverversion=2.1.4-k duplex=full firmware=0.12-1 ip=139.78.127.227 latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s

       resources: irq:40 memory:f6900000-f691ffff memory:f6980000-f6980fff ioport:7040(size=32)

  *-network

       description: Network controller

       product: BCM43224 802.11a/b/g/n

       vendor: Broadcom Corporation

       physical id: 0

       bus info: pci@0000:02:00.0

       version: 01

       width: 64 bits

       clock: 33MHz

       capabilities: pm msi pciexpress bus_master cap_list

       configuration: driver=bcma-pci-bridge latency=0

       resources: irq:17 memory:f4100000-f4103fff

  *-network DISABLED

       description: Wireless interface

       physical id: 3

       logical name: wlan0

       serial: f0:7b:cb:7f:f7:32

       capabilities: ethernet physical wireless

       configuration: broadcast=yes driver=brcmsmac driverversion=3.8.0-29-generic firmware=N/A link=no multicast=yes wireless=IEEE 802.11abgn

Please help me to resolve this problem