Wifi sur ubuntu

Bonjour,
je n'arrive pas a me connecter en wifi sur ubuntu voila ma config
ali@ali-marv:~$ cat/etc/lsb-release
bash: cat/etc/lsb-release: No such file or directory
ali@ali-marv:~$ lsusb
Bus 007 Device 002: ID 05a9:2640 OmniVision Technologies, Inc.
Bus 007 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
ali@ali-marv:~$ lspci
00:00.0 Host bridge: Intel Corporation Mobile PM965/GM965/GL960 Memory Controller Hub (rev 0c)
00:01.0 PCI bridge: Intel Corporation Mobile PM965/GM965/GL960 PCI Express Root Port (rev 0c)
00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #4 (rev 02)
00:1a.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #5 (rev 02)
00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 02)
00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 02)
00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 02)
00:1c.3 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 4 (rev 02)
00:1d.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #3 (rev 02)
00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f2)
00:1f.0 ISA bridge: Intel Corporation 82801HEM (ICH8M) LPC Interface Controller (rev 02)
00:1f.1 IDE interface: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) IDE Controller (rev 02)
00:1f.2 SATA controller: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) SATA AHCI Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801H (ICH8 Family) SMBus Controller (rev 02)
01:00.0 VGA compatible controller: nVidia Corporation GeForce 8600M GT (rev a1)
03:00.0 Ethernet controller: Broadcom Corporation BCM4401-B0 100Base-TX (rev 02)
03:01.0 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 05)
03:01.1 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 22)
03:01.2 System peripheral: Ricoh Co Ltd R5C843 MMC Host Controller (rev 12)
03:01.3 System peripheral: Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter (rev 12)
03:01.4 System peripheral: Ricoh Co Ltd xD-Picture Card Controller (rev ff)
0c:00.0 Network controller: Broadcom Corporation BCM4311 802.11b/g WLAN (rev 01)
ali@ali-marv:~$ sudo lshw -c network
[sudo] password for ali:
*-network
description: Network controller
product: BCM4311 802.11b/g WLAN
vendor: Broadcom Corporation
physical id: 0
bus info: pci@0000:0c:00.0
version: 01
width: 32 bits
clock: 33MHz
capabilities: pm msi pciexpress bus_master cap_list
configuration: driver=b43-pci-bridge latency=0 module=ssb
*-network
description: Ethernet interface
product: BCM4401-B0 100Base-TX
vendor: Broadcom Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: eth0
version: 02
serial: 00:1c:23:b4:fc:6d
size: 100MB/s
capacity: 100MB/s
width: 32 bits
clock: 33MHz
capabilities: pm bus_master cap_list ethernet physical mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=b44 driverversion=2.0 duplex=full ip=192.168.1.165 latency=64 link=yes module=ssb multicast=yes port=twisted pair speed=100MB/s
*-network:0 DISABLED
description: Wireless interface
physical id: 2
logical name: wlan0
serial: 00:1e:4c:68:05:58
capabilities: ethernet physical wireless
configuration: broadcast=yes multicast=yes wireless=IEEE 802.11bg
*-network:1 DISABLED
description: Ethernet interface
physical id: 3
logical name: pan0
serial: fa:2f:1c:cf:18:0c
capabilities: ethernet physical
configuration: broadcast=yes driver=bridge driverversion=2.3 firmware=N/A link=yes multicast=yes
ali@ali-marv:~$ iwconfig
lo no wireless extensions.

eth0 no wireless extensions.

wmaster0 no wireless extensions.

wlan0 IEEE 802.11bg ESSID:""
Mode:Managed Frequency:2.412 GHz Access Point: Not-Associated
Tx-Power=0 dBm
Retry min limit:7 RTS thr:off Fragment thr=2352 B
Power Management:off
Link Quality:0 Signal level:0 Noise level:0
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

pan0 no wireless extensions.

ali@ali-marv:~$ ifconfig
eth0 Link encap:Ethernet HWaddr 00:1c:23:b4:fc:6d
inet addr:192.168.1.165 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::21c:23ff:feb4:fc6d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3263 errors:0 dropped:0 overruns:0 frame:0
TX packets:2985 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2841392 (2.8 MB) TX bytes:579221 (579.2 KB)
Interrupt:17

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:526 errors:0 dropped:0 overruns:0 frame:0
TX packets:526 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:37604 (37.6 KB) TX bytes:37604 (37.6 KB)

ali@ali-marv:~$ sudo iwlist scan
lo Interface doesn't support scanning.

eth0 Interface doesn't support scanning.

wmaster0 Interface doesn't support scanning.

wlan0 Interface doesn't support scanning : Network is down

pan0 Interface doesn't support scanning.

ali@ali-marv:~$ uname -r -m
2.6.27-7-generic i686
ali@ali-marv:~$ cat /etc/network/interfaces
auto lo
iface lo inet loopback

ali@ali-marv:~$ nm-tool

NetworkManager Tool

State: connected

- Device: eth0 ----------------------------------------------------------------
Type: Wired
Driver: NULL(info.linux.driver)
State: connected
Default: yes
HW Address: 00:1C:23:B4:FC:6D

Capabilities:
Supported: yes
Carrier Detect: yes
Speed: 100 Mb/s

Wired Settings

IPv4 Settings:
Address: 192.168.1.165
Prefix: 24 (255.255.255.0)
Gateway: 192.168.1.1

DNS: 192.168.1.1


- Device: wlan0 ----------------------------------------------------------------
Type: 802.11 WiFi
Driver: NULL(info.linux.driver)
State: unavailable
Default: no
HW Address: 00:00:00:00:00:00

Capabilities:
Supported: yes

Wireless Settings
WEP Encryption: yes
WPA Encryption: yes
WPA2 Encryption: yes

Wireless Access Points