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Tracking Down Wi-Fi Interference?

Posted by kdawson on from the hello-fcc-i'd-like-to-report-hello?-hello? dept.

Nicros writes "Almost every evening, between 8:30 and 10:00, my Wi-Fi just dies. This, in itself, could be explained by a crappy Wi-Fi source or some hardware failure, except that I know both of my neighbors are experiencing the same loss of signal at the same time. While the Wi-Fi is down, the LAN is OK, and anything plugged into Cat5 can access the Internet just fine. One possibility comes to mind — perhaps some other neighbor arrives home and turns on their router from 8:30 to 10:00? And something in their signal is hosing our Wi-Fi? I have tried looking around for software to help identify the source of interference, but either the programs are ridiculously expensive for a home user, or else my card (Intel Link 1000 BGN) isn't supported. (Netstumbler is an example of the latter.) Any suggestions on how I can track this down?"

9 of 499 comments (clear)

  1. Change channel / Try Kismet by originalhack · · Score: 4, Insightful


    First thing to try is setting your AP to a different channel.

    If that doesn't set you right, get a USB Wifi device that is supported under Linux and fire up Kismet and identify any strong signals nearby.

    1. Re:Change channel / Try Kismet by Z00L00K · · Score: 4, Insightful

      That is assuming that the interfering signal is something other than noise.

      Do you someone around that does a lot of welding? That's a lot of sparks flying around and it causes interference. Bad microwaves does too, but considering the time it's unlikely.

      Radar is also a factor. Commercial and military communication as well.

      Of course - it may also be someone's TV that's radiating interference. Especially old TV:s can be suspect. And other older equipment since RF filters may degrade by time - or the fact that they weren't tested for interference at the high frequencies that WiFi are using. 2.4GHz was something very exotic during the 70's.

      --
      If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
  2. Try it the low tech way... by javaguy · · Score: 5, Insightful

    ...put a sign in your front window or building lobby asking if anyone else is having the same problem, or uses electrical equipment only between those times. Make it a friendly note, with smiles, rainbows, and unicorns, so you don't offend anyone or make it look like a witch. As a bonus you get to know your neighbours.

  3. Buy a cheap supported wifi card? by millisa · · Score: 5, Insightful

    If you are finding your fancy wifi card isn't supported by stumbler and other free channel overlap type tools . . . why not buy a cheap wifi card to use with those apps? You could always drop it back on craigslist/ebay (or even return it to the store claiming it doesn't match your curtains).

  4. Use your local ham radio club by crath · · Score: 5, Insightful

    Talk to someone in your local ham radio club and see if they have a member with a spectrum analyzer and a directional antenna. Have them come out to the house and do some direction finding to determine who is transmittin on the WiFi freqeuncies in your neighbourhood.

    Be polite. Ask nicely. Buy them pizza and beer to say thank you.

    Hams are nice guys and gals and they will probably be happy to help out.

    The ARRL website can probably provide a contact for your local ham radio club.

  5. Re:report it to the fcc by Bing+Tsher+E · · Score: 5, Insightful

    It's an unlicensed service, provided you use licensed hardware to operate on it. That means, there's FCC certification behind all the commercial wifi gear you use. If you modify it or add on power boosting transmitters, you're using unlicensed hardware and the FCC will come after you.

  6. Re:Agree - Old wireless house phones! by shawb · · Score: 5, Insightful

    8:30 - 10:00 could also be a baby monitor.

    --
    I'll never make that mistake again, reading the experts' opinions. - Feynman
  7. Voodoo? by Demena · · Score: 4, Insightful

    Not at all. Changing channels is a low work method to solve the problem which will take little time. Since it may very well fix it, it is an efficient first thing to do. Who needs to know about interference on an unused channel? Additionally they may provide information. For example, If all channels are blocked then it is not likely to be another Wi-FI issue unless something is majorly broken (to the point of not functioning). If the quick, cheap and easy fail then you assign resources to the problem.

  8. Re:Try it the low tech way... by BarryJacobsen · · Score: 4, Insightful

    As a bonus you get to know your neighbours

    You do realise you're posting on slashdot?

    Not everyone knows their mom as well as they should.

    --
    Track your TV Shows with your iPhone - FREE