All,

According to the bug FAQ at
http://openwrt.org/Bugs#head-328f778d05 … db65fa3716

Setting the TX power w/ OpenWRT versions up to at least 2004/05/08 has no effect.  I'm curious if this is still the case?  I love OpenWRT, but I'd like to bump-up the TX power a little.

Thanks,
-Dustin

This is exactly the thing I was wondering... 

Anybody have an answer to this one?

Yes, it works, I'm using wl tool to do that - simply 'wl txpwr 60' will set TX power to 60mW.

According to the bug you can set it, but it has no effect.  Can you verify that it does indeed work?  Setting it to "1" and seeing what happens might be a good test .

Thanks,
-Dustin

I wouldn't say it works if it didn't :

For example: two routers - router8 is an AP and router2 is it's client:

root@router8:~# wl txpwr 20
root@router2:~# wl rssi
rssi is -81

root@router8:~# wl txpwr 84
root@router2:~# wl rssi
rssi is -73

And if you set txpwr to 250, what happens?

WRT burns... But first it finds ESSID NASA-Cassini-Mission-HotSpot :-).

Ok, to be serious, you can't set it to more than 84mW.

OK, this is done on a wtr54g v2.0 ;-)

root@wrt15:~# wl txpwr
txpwr is 251
root@wrt15:~# wl rssi
rssi is -91
root@wrt15:~#

You should give it a try, it's running for 2 months on 3 wrt54g...

In fact, I wonder if
1 -> 1 mW
255 -> 84 mW
127 -> 42 mW

What do you think about it?

Cool, thanks, I apprecate it.  Just wanted to make sure before I reloaded OpenWRT .

-Dustin

> root@wrt15:~# wl txpwr
> txpwr is 251
> root@wrt15:~# wl rssi
> rssi is -91
> root@wrt15:~#

From wl help:

txpwr   Set tx power in milliwatts.  Range [1, 84].

Strange - never trust Broadcom .

> In fact, I wonder if
> 1 -> 1 mW
> 255 -> 84 mW
> 127 -> 42 mW

root@router2:~# wl txpwr 100
root@router2:~# wl curpower
User Target:              20.00 dB (= 100mW)
Regulatory Max:           63.00 dB
Regulatory Constraint:     0.00 dB
Current Limit:            21.00 dB

Seems 1 -> 1mW, 100 -> 100mW, ..., 10000 -> 10W ?? .

>root@router2:~# wl txpwr 100
>root@router2:~# wl curpower
>User Target:              20.00 dB (= 100mW)
>Regulatory Max:           63.00 dB
>Regulatory Constraint:     0.00 dB
>Current Limit:            21.00 dB
>
> Seems 1 -> 1mW, 100 -> 100mW, ..., 10000 -> 10W ??

You can't set it to 10000 because the value is a byte and if you try 256, you get 1 from the next wl txpwr.

root@wrt14:~# wl txpwr 250
root@wrt14:~# wl curpower
User Target:              24.00 dB
Regulatory Max:           63.00 dB
Regulatory Constraint:     0.00 dB
Current Limit:            21.00 dB
root@wrt14:~#

So, we can set it to more than 84 mW...

I'm wondering about the exact problem myself. Does the changing of txpwr do anything at all?

Like:

root@spildra:/# wl rssi 00:0C:41:3A:7B:16
rssi is -77
root@spildra:/# wl txpwr
txpwr is 40
root@spildra:/# wl txpwr 1
root@spildra:/# wl rssi 00:0C:41:3A:7B:16
rssi is -77

It also seems to me that output from 'wl rssi' is just bogus information. And, what about 'iwconfig'. Can I trust that on anything?

I'm running some WRTs in WDS mode, and the other day I had to change one of the WRTs, and now I can't seem to get a decent throughput on the link no more. So, I'm wondering what settings I should be looking at to tweak the connection. Currently both is set up like this:

root@spildra:/# wl rate
rate is 5.5 Mbps
root@spildra:/# wl band
b

The ping is fine (around 2-3 ms), but I have the occasional packet loss and ping times goes alarmingly high once I try pushing something over the link.

What can I do?

playing with wl txpwr values on one end and wl rssi queries on the other between my 54g and 54gs it appears that using txpwr >84 has no effect on the 54g while it does work on the 54gs.

anyone else agree?

I have graphed the relation between "wl txpwr" and receive signal strength.

http://krypton.mnsu.edu/~workmj/Power-v … -Noise.pdf

That's some priceless data there! May I ask what firmware version and which hardware (WRT54G 1.1, 2.0, WRT54GS, etc)?

Thanks!!

Hi,
The firmware I used for the graph was OpenWRT (not sure exactly which version) on a Linksys WRT54G v1.1

A couple of things to note:

I did not use wl curpower to find the _actual_ curpower after setting it with txpwr, so the values in the txpwr axis _might_ be wrong.

Also, there are locale related settings that enforce various regulatory paramaters as limits on the card. I have not tested if these settings affect output power or just what channels it can use.

As you can see, the power actually seems to level off around 80mW. This could be due to the regulatory parameters, but I am not sure. I need to do some more tests, which I do not have time to do at the moment.

same for me, wl txpwr has no effect ...