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WAP54G keeps dropping

Discussion in 'Other Linksys Equipment' started by tschus, Feb 9, 2005.

  1. tschus

    tschus Guest

    WAP54PG was running for about six months solid. yesterday the wap54g seem to disappear. I reset the wap54g to factory defaults, rebooted and then reconfigured the wap54g again for my network. All seemed fine and the wap54g worked great for about 4 hours. i left the customer site at 2pm and then my customer called at approx: 6pm and said the wireless network disconnected and when you browse the wireless network, the wap54g is again gone. No wireless networks within range

    items to note
    no power outage
    rebooting the wap54g does not seem to bring back to life
    running in secured mode 128bit on default channel with 8 character ssid
    ssid hardcoded in the pc's driver
    ssid is set to broadcast - i changed it from disable broadcast to enable broadcast to make sure end users can see it
    no new hardware
    no new software
    i can ping the wap54g on the ethernet lan
    firmware is at latest version from the linksys website
    the pc's and the wap54g are about 6 feet from each other
    customer states running the wireless repair wizard does not fix the issue
    all machines are windows xp with latest wmp54g drivers from linksys

    any ideas?
  2. oopsibrokeit

    oopsibrokeit Network Guru Member


    change the channels it's almost certainly interference: microwave oven, welder, cordless phone

    oh, and did i mention the interference?

    our wap has been fine 3 weeks, then it just drops out. it says everything is fine from the lan interface but there is squat wirelessly. every-so-often the AP turns up in the available list, but goes again soon as you connect to it. i've been changing chanels frantically before discovering netstumbler.

    if you use netstumbler and a supported card you will be able to see a signal to noise ratio for the signal (snr). if you change the chanel on the AP and check out the snr on each channel, one at a time, for maybe a half hour each time you will see where the most interference is and be able to set to somewhere the interference isn't so bad.

    it's taken me 6 weeks of earache from my users before i worked this out!!
  3. grape8pe

    grape8pe Network Guru Member

    Re: interference

    Where do you find the signal to noise (snr) in Netstumbler? It looks like I have no noise, but I don't think that's right due to the fact I have a 2.4 GHz phone and my neighbor's do too (I live in a townhome).
  4. littlewhoo

    littlewhoo Network Guru Member

    Re: interference

    Not all cards/drivers are capable of reporting noise values. Some can just report the signal strength.
    From the Netstumbler readme:

    # The Proxim models 8410-WD and 8420-WD are known to work. The 8410-WD has also been sold as the Dell TrueMobile 1150, Compaq WL110, Avaya Wireless 802.11b PC Card, and others.
    # Most cards based on the Intersil Prism/Prism2 chip set also work.
    # Most 802.11b, 802.11a and 802.11g wireless LAN adapters should work on Windows XP. Some may work on Windows 2000 too. Many of them report inaccurate Signal strength, and if using the "NDIS 5.1" card access method then Noise level will not be reported. This includes cards based on Atheros, Atmel, Broadcom, Cisco and Centrino chip sets.


    Another factor is noise. This is "background" radio-frequency junk that your receiver can "hear" but needs to reject. Sources of noise include other wireless networks, cordless phones, microwave ovens, radio hams, medical equipment, Like other radio phenomena, noise may be highly variable. Many wireless network adapters do not report noise, so if you're using NetStumbler with them then you can't even tell how much noise you have in your environment. A typical urban location these days might have an average noise level around -95 dBm. When you switch on the microwave oven or take a call on your 2.4GHz phone, this value will increase. I've seen a 2.4GHz phone produce -50 dBm of noise, which is enough to saturate some Wi-Fi radios and thus kill their connection completely.


    If you happen to have a WRT54G(S) besides the WAP54PG (or perhaps you can get one from a friend), you can also use this device for analysing the radio frequencies in your area. The wl driver of the WRT54G(S) has some extended radio measurement capabilities, which include beacon, cca and rpi measuremants.
    This way you can analyse all wlan and non-wlan (like cell phones, microwave ovens...) activity in the 2,4 GHz band.

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