Wireless Network Interference

[Morfiend]

Ok, heres the deal.

My old Linksys Wireless-G router finally went belly up yesterday after about 4 years, which I would consider a pretty good run. I went out and bought a new one HERE. I was having major connection issues with my laptop. Running a ping to the router would give me a ping between 1000 and 4600, and I was 2 ft from the router. After much searching, I have found that it seems to be my desktop PC under my desk that is putting out interference. I have my PC under my desk, and my laptop sits on top of the desk above the PC. As long as I move the laptop away from the PC by more than 2 feet, the ping to the router drops to between 1 and 3.

My laptop was always fine sitting on the desk with my old router.

I don't now enough about wireless to really trouble shoot this. I dont have another spot on my desk to put my laptop, and its a major pain in my ass. Does any one have any ideas on what I could do?

[Lantyssa]

Have you tried relocating the router?

[Trippy]

Is the side door off your case or do you have a window on the side? Does your desktop computer use any wireless devices?

[Viin]

Do you use a wireless headset on your PC? Normal culprits are usually your phone or microwave, so your PC must be doing something weird (trying to establish an ad hoc network?).

Might also try connecting with G only, B only, etc and see if one works better than the other .. might help narrow it down at least.

[Murgos]

If you just want to be a nerd you could build a Faraday cage around your PC.  It would probably cost less than 10 bucks.

[Signe]

Faraday cage, Farabloc clothes and a tin foil hat - I always forget if that makes you a nerd or a libertarian. 

[Murgos]

Faraday cage, Farabloc clothes and a tin foil hat - I always forget if that makes you a nerd or a libertarian. 

The tin foil hat is what marks the line.  Everyone knows that nerds wear propeller beanies.

[Morfiend]

Have you tried relocating the router?

Yes, no difference.

Is the side door off your case or do you have a window on the side? Does your desktop computer use any wireless devices?

Side door is on. Yeah it has a window. No wireless device.

Do you use a wireless headset on your PC? Normal culprits are usually your phone or microwave, so your PC must be doing something weird (trying to establish an ad hoc network?).

Might also try connecting with G only, B only, etc and see if one works better than the other .. might help narrow it down at least.

No wireless headset. I already tried unplugging the microwave, no difference.

What do you mean ad hoc network. I will try turning it to G only when I get home and see if that helps.

BTW. I forgot to mention my laptop is a MacBook Pro. My PC is a self built.

[Murgos]

So, uh, just out of curiosity whats the case of your home-built computer made of?  And is ground on your wall socket actually connected to ground?

[Viin]

No wireless headset. I already tried unplugging the microwave, no difference.

Microwaves typically cause problems while on, and usually not to G networks, but you never know.

What do you mean ad hoc network.

Does your PC have a wireless card? Disable it if it does (should be hard wired into the router, right?). You can do this through the device manager to be certain.

More info: You can put a wireless card into ad hoc mode vs join a router network mode. In ad hoc mode it tries to connect directly to another computer rather than going through a router, this may be mixing the signals up.

I will try turning it to G only when I get home and see if that helps.

I don't know about your specific router, but you can usually configure the router to only accept A, B, or G connections. Instead of "all" (which is usually default) try setting it to B or G alone and see if your laptop has an easier time connecting. Since MBPs have G wireless cards, it should be able to connect as either B or G.. B should be easier for it to connect to and maintain a good connection. I think.

[Morfiend]

So, uh, just out of curiosity whats the case of your home-built computer made of?  And is ground on your wall socket actually connected to ground?

Plastic and metal. Antec-900.



Viin, as far as I know my computer doesn't have wireless.

I'll try the ad-hoc thing also when I get home.

[Morfiend]

Something else I wanted to mention.

The reason we changed routers is my roommate started dropping packets like crazy to the router over wireless, and putting the router to default seemed to help. Well, its started happening again last night. So now I am thinking there is some new tech on of the nearby apartments that is interfering with our wireless.

I am convinced this is two separate problems though. Cause all the testing I did on my laptop confirms that it is my computer interfering with my laptop, and yet not with his signal.

[Murgos]

Plastic and metal. Antec-900.

Well, the plastic side could be an issue for EM radiation, if you have a piece of conductive material, like a metal screen or a cookie sheet or even (maybe) a couple of layers of tin/aluminum foil you could place it over the plastic portions making sure it stays in contact with a metal part of the case and test your wireless to see if that helps.

Wireless g is at 2.4 ghz and there could be EM sources inside the case that would be around that frequency (which would explain the within a few feet of the case part).

[Morfiend]

Plastic and metal. Antec-900.

Well, the plastic side could be an issue for EM radiation, if you have a piece of conductive material, like a metal screen or a cookie sheet or even (maybe) a couple of layers of tin/aluminum foil you could place it over the plastic portions making sure it stays in contact with a metal part of the case and test your wireless to see if that helps.

Wireless g is at 2.4 ghz and there could be EM sources inside the case that would be around that frequency (which would explain the within a few feet of the case part).

I can give that a try. Whats odd, is that this has only started happening since I got the new Linksys-N router. It was fine with my old Linksys-G.

[bhodi]

I highly recommend downloading and playing with Net Stumbler while you are testing out all this stuff. Just having it running and walking around with your laptop or moving things around while watching your signal strength will give you a good idea of what is/isn't interfering.

It'll also tell you if you've got multiple networks sharing the same frequency, which can also be causing issues. You should also be able to pinpoint passive rather than active interference as well. It's easy to see a consistent drop in signal strength, for example, when stuff in the wall gets between my wireless router and my laptop, and when I turn on my microwave downstairs, the signal strength gets jagged.

[Morfiend]

I highly recommend downloading and playing with Net Stumbler while you are testing out all this stuff. Just having it running and walking around with your laptop or moving things around while watching your signal strength will give you a good idea of what is/isn't interfering.

It'll also tell you if you've got multiple networks sharing the same frequency, which can also be causing issues. You should also be able to pinpoint passive rather than active interference as well. It's easy to see a consistent drop in signal strength, for example, when stuff in the wall gets between my wireless router and my laptop, and when I turn on my microwave downstairs, the signal strength gets jagged.

Know of any OS X version of something like that? My laptop is a MacBook Pro.

[bhodi]

http://kismac.macpirate.ch/  or  http://istumbler.net/  should work for you. iStumbler is a bit more user friendly, but kismac has some additional nerdy bits.

[Morfiend]

http://kismac.macpirate.ch/  or  http://istumbler.net/  should work for you. iStumbler is a bit more user friendly, but kismac has some additional nerdy bits.

Humm, the first one was giving me page not found for the download page, and the second one sucks. What about this:

http://www.chimoosoft.com/products/apgrapher/

[bhodi]

That should work. You're just concerned with signal strength and SSID listings.

[Morfiend]

So, I changed my router from "20mhz/40mhz Auto" to "20mhz Manual" and then set it to channel 11.

All my problems went away. Very very odd.

[Lantyssa]

There might have been another router or device using that frequency which was causing interference.

[vex]

Interesting.  I thought the current draft confined 40 Mhz channels to the 5 Ghz band.

[Morfiend]

Interesting.  I thought the current draft confined 40 Mhz channels to the 5 Ghz band.

I had to change it off of the 40mhz channels, because the only option I had for channels was "auto". If I set it to 20mhz then it opened up the channels options, and I could choose different ones.