Hardware

i have dell laptop inspiron 1450 having networkcontroller from broadcom commuication
BCM4312 802.11b/g(rev 01).Broadcomm card detail is 4315 (rev01). this i got by lspci command.

The command 'ip link' returned following result:-

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
link/ether 00:25:64:3d:da:7f brd ff:ff:ff:ff:ff:ff
3: pan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN
link/ether de:ea:0d:3e:be:97 brd ff:ff:ff:ff:ff:ff


The command 'lspci -nnk' returned following result:-

# lspci -nnk
00:00.0 Host bridge [0600]: Intel Corporation Mobile 4 Series Chipset Memory Controller Hub [8086:2a40] (rev 07)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: agpgart-intel
00:02.0 VGA compatible controller [0300]: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a42] (rev 07)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: i915
Kernel modules: i915
00:02.1 Display controller [0380]: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller [8086:2a43] (rev 07)
Subsystem: Dell Device [1028:02aa]
00:1a.0 USB Controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #4 [8086:2937] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: uhci_hcd
00:1a.1 USB Controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #5 [8086:293 (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: uhci_hcd
00:1a.2 USB Controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #6 [8086:2939] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: uhci_hcd
00:1a.7 USB Controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #2 [8086:293c] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: ehci_hcd
00:1b.0 Audio device [0403]: Intel Corporation 82801I (ICH9 Family) HD Audio Controller [8086:293e] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: HDA Intel
Kernel modules: snd-hda-intel
00:1c.0 PCI bridge [0604]: Intel Corporation 82801I (ICH9 Family) PCI Express Port 1 [8086:2940] (rev 03)
Kernel driver in use: pcieport-driver
00:1c.1 PCI bridge [0604]: Intel Corporation 82801I (ICH9 Family) PCI Express Port 2 [8086:2942] (rev 03)
Kernel driver in use: pcieport-driver
00:1c.2 PCI bridge [0604]: Intel Corporation 82801I (ICH9 Family) PCI Express Port 3 [8086:2944] (rev 03)
Kernel driver in use: pcieport-driver
00:1c.4 PCI bridge [0604]: Intel Corporation 82801I (ICH9 Family) PCI Express Port 5 [8086:294 (rev 03)
Kernel driver in use: pcieport-driver
00:1d.0 USB Controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 [8086:2934] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: uhci_hcd
00:1d.1 USB Controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #2 [8086:2935] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: uhci_hcd
00:1d.2 USB Controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #3 [8086:2936] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: uhci_hcd
00:1d.7 USB Controller [0c03]: Intel Corporation 82801I (ICH9 Family) USB2 EHCI Controller #1 [8086:293a] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: ehci_hcd
00:1e.0 PCI bridge [0604]: Intel Corporation 82801 Mobile PCI Bridge [8086:244 (rev 93)
00:1f.0 ISA bridge [0601]: Intel Corporation ICH9M LPC Interface Controller [8086:2**9] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel modules: iTCO_wdt
00:1f.2 SATA controller [0106]: Intel Corporation ICH9M/M-E SATA AHCI Controller [8086:2929] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: ahci
00:1f.3 SMBus [0c05]: Intel Corporation 82801I (ICH9 Family) SMBus Controller [8086:2930] (rev 03)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: i801_smbus
Kernel modules: i2c-i801
09:00.0 Ethernet controller [0200]: Marvell Technology Group Ltd. 88E8040 PCI-E Fast Ethernet Controller [11ab:4354] (rev 13)
Subsystem: Dell Device [1028:02aa]
Kernel driver in use: sky2
Kernel modules: sky2
0c:00.0 Network controller [0280]: Broadcom Corporation BCM4312 802.11b/g [14e4:4315] (rev 01)
Subsystem: Dell Wireless 1397 WLAN Mini-Card [1028:000c]
Kernel driver in use: b43-pci-bridge
Kernel modules: ssb

These commands were executed as a super user with command su.

Please tell suitable information and how to proceed with solving the problem.