[Bug 64405] low transmit power on Broadcom BCM4318 wifi adapter - very low range

Boleslaw Dawidowicz bdaw at o2.pl
Thu Oct 12 09:58:36 UTC 2006

Public bug reported:


I have Acer Aspire 5024 which has:

bdaw at bdaw-laptop:~$ lspci |grep Network
0000:06:05.0 Network controller: Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller (rev 02)

wireless controler. Using it on linux needs some extra kernel module
(http://www.archernar.co.uk/acer_acpi/acer_acpi_main.html) just to power
it on - BTW. this is quite a stopper for unexperienced users and maybe
should be revised....

Anyway I have it working ok. Using Ubuntu 6.06 it's even quite ok as
ndirswrapper is built in kernel so not much is needed to configure.

The only problem is that it runs on very low trasnmit power:

IEEE 802.11b/g  ESSID:off/any  Nickname:"Broadcom 4318"
          Mode:Managed  Frequency=2.484 GHz  Access Point: xx:xx:xx:xx:xx:xx
          Bit Rate=11 Mb/s   Tx-Power=19 dBm
          RTS thr:off   Fragment thr: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

As you see it's "TX-Power=19 dBm" and I guess it should be 24 dBm.

Tweeking it using commands like:

sudo iwconfig eth1 txpower 24dBm

seems to not take any effect (value 24dBm sets it to 14dBm and value
100dBm sets it back to 19dBm)

In the effect I'm losing connection at around 5m distance while on Windows it's ok. I tested it quite tought so I tried:
- disabling network manager to manage my connection manually
- set up not secured hot spot (no WEP or anything) and connect to it manually  (iwconfig/ifconfig)
- I run ping to my router and was watching packages stop going to it while I'm away from my wireless router more than around 5m and start back when I'm closer.

My kurrent kernel:
bdaw at bdaw-laptop:~$ uname -a
Linux bdaw-laptop 2.6.15-27-386 #1 PREEMPT Sat Sep 16 01:51:59 UTC 2006 i686 GNU/Linux

Besides that most things work ok. On this laptop Ubuntu is currently the
best running distro (the higher Out Of Box functionality) so this is
quite important for me.

** Affects: ndiswrapper (Ubuntu)
     Importance: Undecided
         Status: Unconfirmed

low transmit power on Broadcom BCM4318 wifi adapter - very low range

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