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Question about Beacon Interval

Discussion in 'Cisco/Linksys Wireless Routers' started by DixonHill, Jan 2, 2006.

  1. DixonHill

    DixonHill Network Guru Member

    Immediately after setting up my new WRT54G I noticed a background noise on my desk phone. The phone is not wireless, for the record. The noise is a fast series of muffled "ticks" which sounds like a cat purring and while that's cute and loveable coming from a cat, it's rather annoying while trying to carry on a phone conversation.

    After tweaking a few things in the setup, I've discovered that the purring is directly related to the Beacon Interval and setting the Beacon Interval higher makes the individual "ticks" spread out. At about 5,000 milliseconds it's at a point where the ticks are barely noticeable, or at least less of an annoyance.

    Now, my question is... how will this affect my wireless connectivity, if at all. My understanding of the Beacon Interval is that it serves to maintain the connection between the router and my laptop, like a ping, making sure the connection still exists between the devices every 50 milliseconds. Will upping this to 5,000 make disconnects more of a possibility?

    Thanks,
    Dix
     
  2. cgondo

    cgondo Network Guru Member

    my suggestion is to search on some information regarding the use of beacon in WLAN. I can write a long explanation on it but i guess you better research it yourself so that you can understand the purpose of beacon and the implication of changing it.
     
  3. DixonHill

    DixonHill Network Guru Member

    While I can appreciate your "teach a man to fish" philosophy... really not a warm and fuzzy resonse to a first post on this site. Suggestions for further reading are always appreciated, but at least provide some semblance of an answer to the posted question. Otherwise you just come off elitist. Not zesty. :thumbdown:

    That said, thanks for pointing me in a good direction to learn everything I needed to know about beacons. :thumb: I've reset the interval to 50.

    Now I have a new question. Any suggestions on how to get rid of the "purring" sound?

    I've tried searching the web, but "noise" and "interference" all relate to valid terms used elsewhere in networking so I end up getting a lot of bad hits. Further, most decent hits seemed to deal with Vonage VOIP phones and data noise on the line, not handset speaker interference from the beacon.

    Would a different antenna help? Or is it just a matter of moving the router farther from the phone?

    Thanks,
    Dix
     
  4. cgondo

    cgondo Network Guru Member

    you can do trial and error. If you suspect that the hissing sound is the effect of the wireless part of the router then turn the wireless off and see what happens. Once you can deduce that it is in fact related to the WLAN then try putting it further apart
     
  5. Couledouce

    Couledouce Network Guru Member

    Try changing channels?
     
  6. DixonHill

    DixonHill Network Guru Member

    It's definitely the router. Specifically the Beacon. Whenever the router sends its Beacon signal, there's a muffled click on the earpiece of my phone. Put a muffled click every 50 milliseconds and you get a purring sound.

    Also as a trial, I loaded yahoo.com while my Laptop was upstairs and I was listening on the phone and there was some mild disturbance in the earpiece that correlated with the page load so I'm almost 100% sure that the wireless is creating electronic interference that's messing with the speaker in my phone.

    As for channels, I changed from 11 to 2 and it seemed to go away, but then was right back again later that evening.

    I've even moved the antennas around to try and see if that would have any beneficial effect, but no luck. Though it seemed that the noise did go away while I was touching the antennas.

    We're also now having difficulty with our 2.4 GHz cordless downstairs. My fiancee says it's breaking up periodically like a cell phone. I haven't run into this myself, but I rarely use that phone.

    On a lark, I've picked up a Netgear router and plan to try it out later this week and see if I run into the same problem. My hypothesis is "yes", but we'll see.

    Any other suggestions? I've discovered I've got a v5, so maybe that's got something to do with it?

    Thanks,
    Dix
     
  7. anotherlab

    anotherlab Network Guru Member

    Have you considered replacing your cordless phone with a 900 mhz or 5.8 ghz model? Your 2.4 ghz phone is sharing bandwidth with your router (and your microwave, but lets leave the kitchen appliances out of this) and they are stepping on each others signal.

    If you can hear your router's beacon over the phone, just image what that phone signal is doing to your wireless bandwidth.
     
  8. Couledouce

    Couledouce Network Guru Member

  9. DixonHill

    DixonHill Network Guru Member

    Considering what my fiancee spent on that phone, I think she'd be remiss to replace it. Believe me, I've considered it and might take action if it becomes a bigger problem. More likely though, I'll switch to 802.11a instead to avoid interference with any neighbor's phones and the 6 other wireless networks overlapping my house at any given time. (Including the McDonald's down the street)

    Who was the genius that decided to heap so many different devices on 2.4 GHz?

    Sheesh,
    Dix
     
  10. DixonHill

    DixonHill Network Guru Member

    Looks like an interesting app, I'll check it out.

    Point of clarification: I'm not experiencing trouble with transmission or interference, I'm getting a physical noise in my "corded" handset's speaker when using the phone. Those of you with cell phones that cause speakers to go nuts periodically know what I'm talking about. The electromagnetic signal the router is emitting is manipulating the speaker remotely, causing it to emit a noise or a series of noises.

    Has anyone else experienced this?

    Dix
     
  11. swinn

    swinn Network Guru Member

    The 2.4GHz range is open for amateur usage.. anything can use it without regulation from the FCC.

    http://www.ntia.doc.gov/osmhome/allochrt.pdf
     

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