restart the wireless on acer 5745

root@cb-DOC:~# modprobe -r brcmsmac ; modprobe brcmsmac

root@cb-DOC:~# ifconfig wlan0
wlan0     Link encap:Ethernet  HWaddr 5c:ac:4c:b0:3f:4d
          inet addr:192.168.1.2  Bcast:192.168.1.15  Mask:255.255.255.240
          inet6 addr: fe80::5eac:4cff:feb0:3f4d/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:242082 errors:0 dropped:0 overruns:0 frame:0
          TX packets:210420 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:272178906 (259.5 MiB)  TX bytes:36995927 (35.2 MiB)

mine is a subnetted network /28

root@cb-DOC:~# iwconfig
lo        no wireless extensions.

vmnet8    no wireless extensions.

wlan0     IEEE 802.11bgn  ESSID:"Wiz@dmin"
          Mode:Managed  Frequency:2.417 GHz  Access Point: 4C:60:DE:D5:68:63
          Bit Rate=57.8 Mb/s   Tx-Power=19 dBm
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:off
          Link Quality=44/70  Signal level=-66 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:748  Invalid misc:333   Missed beacon:0

eth0      no wireless extensions.

vmnet1    no wireless extensions.

For more information view the doc

root@cb-DOC:~# view /usr/share/doc/wireless-tools/README.Debian