mysterious wireless problem

I have a d-link 802.11g wireless access point. It has two big antenaes. Across the room is a linksys 54g wireless pci board. It also has a big antennae. Throughout the house are scattered other wireless things like a tivo downstairs and a couple other computers. Most times, things work, although I only get 83% signal strength from

15 feet away. Sometimes though, the wireless network goes down. When this happens, my network disappears from the list when I browse for networks, and sometimes reappears breifly, but does not allow connections. This is exceptionally annoying.

There are a lot of wireless networks in the list, like a dozen or so.

I'm using 128 bit wep as is everyone else.

I've tried three different access points. All showed identical behavior.

All the machines go down at once.

Changing the channel has no affect.

Can anyone suggest what might be happening and how to fix it? My gut is telling me that there are so many networks that we're stepping on each other, or that someone has a cordless phone or something that happens to occupy the same frequency band.

brian

Reply to
brianlanning
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snipped-for-privacy@gmail.com hath wroth:

Model number? Hardware version? Firmware version?

How many inches or cm do you consider big?

Model number? Hardware version? Driver version? Windoze version?

Is the 15ft line of sight or is there furniture in the way? Can you see the "big" antenna sticking out of the Wireless PCI board or is it buried behind a steel box amid a mess of wires and cables? 83% seems only a little bit too low. It should be about 90% especially with "big" antennas. However, the detector that outputs RSSI is not terribly accurate and rarely gets to 100%. It saturates at perhaps

90% on most devices I've tinkered with.

How often does it disappear and for how long? This is not a trivial question. If it follows a pattern, it will help identify a possible source of interference such as 2.4GHz cordless phones, microwave ovens, and other wireless networks. Do you have any other 2.4GHz wireless devices in the area?

What happens when you wiggle the "big" antennas? Could be a loose or broken antenna.

What list? Windoze Wireless Zero config or the Linksys PCI card driver utility? Are they currently available networks or just leftovers from previous connections? If you're not sure, flush the list of anything you don't need and see if the re-appear.

I'm using WPA. It's much more secure than WEP.

Did you use the same "big" antennas? What else didn't change? If the access point is NOT the problem, that leaves your wireless PCI card. Check the web pile for driver updates. The relatively low signal strength makes me wonder if the card or antenna connector isn't broken. However, this is unlikely.

Bingo. Interference, probably at the access point. Do you have it located in a window where it can see the crud from the rest of the neighborhood? If so, move it behind a wall. Try a different RF channel (1, 6, or 11). Look around for interference sources.

If it is inteference, then it's not coming from another wireless network. That leaves cordless phones, microwave ovens, industrial dryers, video links, and frequeny hopping devices.

Dunno. Spectrum analyzer?

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Do you have any control over the other Wi-Fi devices? If so, unplug or disarm and run a test to see if there's one particular device that's causing problems. Definately try moving the access point to a more "protected" location.

Reply to
Jeff Liebermann

It's this one:

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But I've tried another d-link and a linksys router and all behaved exactly the same way.

The card is a linksys wmp54g. I'm using xp, but I can't remember the service pack level off hand. All of the machines in the house are xp. They have different boards (mostly netgear), all go down including the tivo.

Line of sight.

It goes down maybe twice a week. When it happens during the day, my wife gives up on it. Then when I get home, I disable/enable and it comes right back up. Other times when it happens, there's nothing to connect to since it doesn't show up in the list. I just keep hitting refresh. Sometimes it comes back, sometimes not.

It's probably not the microwave since we use that a lot more than it goes down. We have a cordless phone, but iirc, it's not 2.4ghz. And using or not using the phone doesn't seem to have an affect. There's no other wireless devices in our house. If there is interference, it's not from us.

Moving the antenae has no affect, nor does changing the channel.

No, it's accross the room on a book case. Although it still manages to pick up *a lot* of other networks when it's working. Like 10-12 other networks. When it goes down, I can see 2 or 3, none of them mine.

Would the neighbor's phone be close enough for this? it's a tract neighborhood with maybe 20 feet between the houses.

same thing. it's not ours.

like in a laudromat? we don't have any. And our dryer is gas-powered and runs constantly.

like a wireless security camera? I don't have anything like that. maybe the neighbors do.

I'm not sure what this would be. Car transmitters or garage door openers? Those work in bursts. I would think they could knock me off, then I could get back on. Sometimes, I'm kept off for 20 minutes or more.

I'm not sure where I would put it.

The guy at besy buy (yuk) suggested switching to a different "country" that has channels other than 1-11. My card supports this, but it looks like the access point doesn't.

It's been behaving lately, but now comcast is flaky. I'll see if I can gather more intel next time it goes down.

brian

Reply to
brianlanning

Dlink DI-634M MIMO wireless router. The one my customer bought had version 2.00 firmware. I had to update it to 2.01 to get it to stay connected for more than 10 minutes.

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'm not sure if this has anything to do with your problem. Probably not but worth checking the firmware version.

If that's true, and it is interference, then it's happening at the DI-634M end. Do something to protect the router from interference. Instead of the bookshelf, move it down to the floor temporarily.

Reading between the lines, when it does down, it stays down for 10-20 minutes. Is this correct?

So, it does NOT come back by itself. If the connection is dropped for less than about 60 seconds (or so), then the client should reconnect automagically. However, interruptions of longer than about a minute will initiate a disconnect and the client will need to manually reconnect. There should be a setting in XP Wireless Zero Config that allows for additional persistance and automatic reconnect. Same with the Linksys WMP54G driver program. I don't have either running in front of me and therefore can't supply the exact location of the setting. Something like "preferred network SSID" and "connect automatically".

Are you beaconing your SSID? I presume so since you're trying to refresh the list of SSID's. However, if you installed the SSID in the clients connection profile, it might not find it. I don't think this is the problem but if you happen to have SSID broadcast disabled, try turning it on and see if it recovers more gracefully.

Also, the Super-G and Turbo-G products have problems making connection to ordinary clients. If you're not using Super-G or "dynamic turbo", try turning them both off:

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Think of the pattern. Once or twice a week for periods lasting a few minutes with fairly high power levels. That's not something that's very common. Frankly, I don't have a clue. Instead of trying to identify the source, methinks the best strategy would be to protect the router and to do whatever is necessary to help the client recover more quickly.

Checklist of possible interference sources: Microwave oven 2.4Ghz video or security camera link (X10). Municipal wireless networks. Bluetooth devices (mouse, phone, PDA, headset, cell phone, etc) Portable wireless TV camera used at sports events. Frequency hopping cordless phones (Panasonic Gigarange) 802.11b/g wireless keyboards, PDA's, and cell phones. 2.4GHz game pads and controllers. RF Excited Lighting (Fusion Lighting). 2.4GHz baby monitors. 2.4GHz ham radio operation. WISP (wireless internet service providers) which may be using non-802.11 type of modulation (i.e. WiMax). Breezecom/Alvarion/Symbol/Raylink frequency hopping networks. Western Multiplex or Proxim non-802.11 wireless links. (e.g Lynx). HomeRF frequency hopping network. Zigbee 802.15.4 sensor wireless network. Microwave fruit drying oven, plastic mold preheater. Unstable high power wi-fi power amplifier spraying garbage.

If it takes a week for it to happen, how many changes have you made or tried? I didn't say move the antenna. I said move the entire access point with the antenna to some place that is less susceptable to outside interference.

So, when the alleged interference is present, you can only see 2-3 networks. That's possible if the interference is very strong. The only thing that can cause literally everything to go deaf simultaneously is a very strong source of RF interference.

No. Too low power, too far away, wrong interference pattern.

No. Any manufactory that needs to remove water from something might have a microwave drier. Fruit driers, plastic injection molding pre-heaters, flash pasturizers, etc. Got any industry nearby?

That's a possible. Some video links are rather high power and are run by motion detectors or alarms. The only way you're going to see one is with a spectrum analyzer. Also, TV stations use 2.4GHz on some of their wireless cameras. These run rather high power (up to 10 watts). Any nearby TV studios?

No. FHSS are some cordless phones, Alvarion/Breezecom radios, Bluetooth, Proxim radios, HomeRF networks, and other devices. None of these fit the interference pattern.

At the end of a CAT5 extension cord. Use your imagination.

Tell him I'll be happy to turn him in to the FCC (if they offer a suitable bounty or reward) for illegal modifications to wireless equipment. The frequencies above CH11 are used by satellite mobile downlinks. I'm sure they'll be thrilled.

Get the signal strength and noise level numbers from the WMP54G for normal and when interference is present.

Reply to
Jeff Liebermann

have you tried a different connection to your computer? For example, in a relatively low signal area of my house, my Thinkpad drops it's signal very frequently. But, in the same area, if I use a good Linksys PC card, the connection is held and signals don't drop.

Louise

Reply to
louise

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