Interference problem with wifi (I think)

[ugh]

Hi folks,

I've a very odd problem with my wireless connection at home which has been bugging me for a couple of weeks. I'm using a less well known (http://www.prolink2u.com/self/produc...ess/h9300g.php) wifi g router+modem combo which has all the features a normal one would have.

Everything works fine most of the time. But whenever there's another wifi signal that my notebook or desktop can pickup, my connection to my router is intermittent. In fact, I can't even connect to it most of the time.

The strange thing here is that the signal quality is very good (in fact it's 90 when I do a iwlist eth1 scanning on my notebook). However, when I try to connect to the router via DHCP in Ubuntu, it just doesn't get connected. It hangs at "Configuring Device" when viewed through KNetworkManager's status popup. Using WinXP, even though it seems connected, it times out when I ping the router.

I suspect that it could be wireless interference. I've changed my wifi channel to not clash with the rest, but it's still happening. I've tried channels 1, 2, 3, 11 and 13.

Anyone has any idea what's going on?

Any help is greatly appreciated.


Thanks!

 

[Fardringle]

Run NetStumbler on your computer to see what wireless signals are in the area. Pay particular attention to the channels being used. That should give you a better idea of what frequency ranges are not in use. Set your router to an unused channel, preferably as far away from everything else as possible and test to see if the problem persists.

 

[ugh]

A scan using iwlist shows that the other channel used is 6. I've set my channel to those I've mentioned earlier. Still no go.

 

[n0cmonkey]

Connect to the access point with iwconfig and then run dhclient (forget the gui stuff). See where it doesn't work (the connection or the obtaining).

 

[ugh]

Originally posted by: n0cmonkey
Connect to the access point with iwconfig and then run dhclient (forget the gui stuff). See where it doesn't work (the connection or the obtaining).

Thanks for the info. Will try that when I get back.

 

[ugh]

I'm back and I'm looking at iwconfig eth1 display using watch on a 1 second interval. I've managed to connect to the AP and I can see that the Bit Rate reading fluctuates from 2-5.5-11-2-0Mb/s. Same goes for Link Quality. Goes from 80-90-0-61. Signal Level is rather constant at -70 dBm.

Any idea if that's a clear sign of interference or that the signal is way too weak?

 

[nweaver]

that is a pretty weak signal (as shown by the data rates)

Remember, that G bands overlap, it's best to stick with 1, 6, and 11. If you have a channel 13, then I would suspect you have asia based equipment, as 13 isn't available on US based hardware (AP's or client radios).

 

[ugh]

Do you have any reference docs/links where I can read on what's a good signal based on the readings?

 

[spidey07]

Originally posted by: ugh
Do you have any reference docs/links where I can read on what's a good signal based on the readings?

Not really - it all depends on the signal strength, noise (and type of noise) and sensitivity of the radio.

In general - under -70 is getting at the edge of coverage. -80 and under is pretty rough.

Do all troubleshooting with the client and AP in the same room.

 

[n0cmonkey]

Originally posted by: spidey07

Originally posted by: ugh
Do you have any reference docs/links where I can read on what's a good signal based on the readings?

Not really - it all depends on the signal strength, noise (and type of noise) and sensitivity of the radio.

In general - under -70 is getting at the edge of coverage. -80 and under is pretty rough.

Do all troubleshooting with the client and AP in the same room.

But not too close to each other. 😛