Is having too many WAPs in one area a bad thing?

I ran NetStumbler and noticed 21 different WAPs (houses and apartments) in one area. Wow. Does having this many cause problems like inter- ferences even with good/decent signals? I noticed most of them use channel 6.

Thank you in advance. :)

Reply to
ANTant
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It'll definitely cause problems on channel 6! I'd pick another channel as far from those as I could get... Of course, the best thing to do would be put together an ad-hoc frequency managment council, map spacial coverage of each unit, and determine which units should be set to which channels (and which units can be set to a lower output power where applicable), but I imagine that'll never happen.

Wonder how many others are there with SSID broadcast turned off?

Reply to
William P. N. Smith

It will definitely won't happen with that many WAPs and how many people live here. No way. I don't even know my neighbors. ;)

I will try channel 1. Isn't NetStubmler supposed to pick up both off and on?

Reply to
ANTant

apartments)

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Reply to
frankdowling1

Most wireless routers are delivered on channel 6. The alternative non-overlapping channel options are 1, 6, and 11. You can get away with channels in between, but you run the risk of getting interference from both 1/6 and 6/11.

Netstumbler only shows the wireless access points and peer to peer networks. There are also client radios that are not being shown. Assuming at least 1 client per access point, you now have about 40 radios in the nighborhood. Probably more. Incidentally, best is from the roof of a downtown San Jose office building showing about 200 visible access points.

The odd part is that you could easily have 100 access points in the area, and not have any problems with interference, if they are not active. Most of the access points you're seeing are only active when the residents are home and operational. When traffic is minimal, so is interference. The ocassional beacons do little damage.

What you'll see is that one or two active access points will slow you down noticeably when running at maximum speed. The access point uses the signal to noise ratio (not the signal strength) to determine the maximum connection speed. If the noise level increases, as it would if there were other users on the channel, the access point will slow down. Some firmware takes a full minute to recover. However, these slowdowns will only happen when the neighbors are using their systems and moving traffic.

The exceptions are the wireless TIVO and music systems. Also, some (not all) point to point wireless transparent bridges. These are belching traffic almost continuously. You won't see the bridges with Netstumbler.

If it's any consolation, your system will generate as much interference as it receives. If you can see 21 neighbors, they can also see your transmissions. Therefore, you too can be part of the problem. (The surest sign of success is pollution, and Wi-Fi is certainly successful).

The easiest solution is to locate your in-house network away from windows and areas with lots of neighborhood exposure. Directional antennas and reflectors also help. Try to select a least used channel. Beyond that, you can probably expect some interference if you see that many access points.

Reply to
Jeff Liebermann

Reply to
Bob Willard

I will try that. There are five existing WAPs using channel 11. Only one was using channel 1. I tried channel 1 for the last two days as the second AP, but it doesn't seem to make much differences. Will channel

11 be that much better?
Reply to
ANTant

Interesting, Yeah, wireless is pretty frustrating. Even my own hearing aid can hear interference if I am close enough to a WAP! It's like being close to a digital cellular phone. Analog cellphondes didn't have this problem.

Directional antennaes and reflectors will be hard to set up in this home since it is not mine and lack of space due to tiny room size. Isn't Hi-Gain USB Wireless-G Adapter (Model: HWU54D)'s Hi-Gain Antenna ( photographs on

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) sufficient enough? It doesn't seem to help during bad times.

I am currently trying channel 1, but it didn't seem to help much last night when I had connection problems. :( I don't think switching to channel 11 that someone suggested will improve. Beside it already has five existing WAPs on it. Channel 1 had one before I joined it. Do you think channel 11 will help?

Reply to
ANTant

If it were easy, it would be no fun.

Analog cell phones do not pulse on and off like TDMA and GSM phones. You're "hearing" the pulses. Same with 802.11 that pulses on and off. However, CDMA (Verizon and Sprint) is spread spectrum and does not pulse. You should not hear CDMA on your hearing aid.

I'm not thinking of a dish or yagi antenna. Something small and simple. Just a piece of aluminium sheet metal located between the access point and the window should be sufficient to block anything in that direction.

Yes, that should be sufficient to aim most of the signal away from the windows. However, its effectiveness depends upon from what and where the intereference originates. With 21 possible sources of local interefence, methinks simply aiming the antenna for minimal interference will be a major challenge.

It doesn't take very long to try channel 11. I suggest you do so. If the interference is coming from other 802.11b/g devices, then channel juggling will help. However, if it's a broadband source of junk, or a radio that continuously hogs half or all the spectrum (i.e. Proxim Lynx), then it won't help.

It's difficult to guess from here and MUCH easier to just try it.

Reply to
Jeff Liebermann

Unpredictable. Just try it.

Reply to
Bob Willard

Alright. I will have to try that when the connection gets really bad. I thought it was bad to use other channels like 2, 3, 4, 5, 7, 8, 9, etc.

Reply to
ANTant

You don't have to use 1, 6, or 11. Try to pick a channel that's at least five away from the strongest signal and as far as you can get from other strong signals. You'll have to monitor for a while and experiment with different channels.

Reply to
Neill Massello

Ahh... I know my father uses Cingular cellphones that I can hear interferences.

Oh. Aluminum sheet metal like tin foils?

Yeah, it is a major challenge when I try to figure out the sweet spot in my room.

OK.

Alright, I will try that when unstable connections come back. They come and go. No specific patterns on weather, hours, temperatures, etc.

Reply to
ANTant

Too much of anything is bad.

Barry

Reply to
Barry OGrady

~ Neill Massello wrote: ~ > wrote: ~ ~ > > Bob Willard wrote: ~ > > > snipped-for-privacy@yahoo.com wrote: ~ > > > > I agree. ~ > > > > Would never of thought that congestion would be an issue. ~ > > > > Maybe there is a need for the new aband frequencies after all. ~ > > > > What channels would the experts suggest trying after channel 1 ? ~ > > > > snipped-for-privacy@zimage.com wrote: ~ > > ~ > > > 11. There is no band overlap between 1 and 6, or 6 and 11. ~ > > ~ > > I will try that. There are five existing WAPs using channel 11. Only one ~ > > was using channel 1. I tried channel 1 for the last two days as the ~ > > second AP, but it doesn't seem to make much differences. Will channel ~ > > 11 be that much better? ~ ~ > You don't have to use 1, 6, or 11. Try to pick a channel that's at least ~ > five away from the strongest signal and as far as you can get from other ~ > strong signals. You'll have to monitor for a while and experiment with ~ > different channels. ~ ~ Alright. I will have to try that when the connection gets really bad. I ~ thought it was bad to use other channels like 2, 3, 4, 5, 7, 8, 9, etc.

You're really better off having multiple APs on the same nonoverlapping channel (i.e. one of 1, 6, 11) than having them on overlapping channels. See

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Aaron

Reply to
Aaron Leonard

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So far, 1 and 6 do not help much. I will try 11 but I doubt that will help either. Someone told me to try increasing the intervals by 25. I will try that too (on the router).

Reply to
ANTant

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