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PostPosted: Sat Oct 11, 2003 4:50 pm
by stevieg
Thanks renderman that was the kind of reply i was looking for but I also kinda mentioned i didnt wanna cover the front side of my house with a wire mesh :-)

But yeah The only reason I've even posted is cause i did talk to the owner and he was like "Thats odd but oh well, live with it" Also to add to this i think as WiFi starts to really become popular this kind of thing is going to become more and more rampant as more and more neighborhoods buy these things and fire em up all on the default channel of 6 kind of thing, then wonder why its not working right.

This whole post wasnt meant as a rant or anything but an actual request for help or ideas on what i can do, Like i said i've been putting up with this for 7 months already and going through a 30minute hoopla everytime i fire up my laptop is geting kind of old REAL quick.


Hrmm nightshade you have got an idea though, I do have a spare AP and a cantenna :-) might just have to go have some fun sometime.

Steve

PostPosted: Sat Oct 11, 2003 5:16 pm
by sparafina
Originally posted by stevieg
Hrmm nightshade you have got an idea though, I do have a spare AP and a cantenna :-) might just have to go have some fun sometime.



Well, there's always FakeAP to get their attention! For educational purposes only of course.

Enemy of State

PostPosted: Sat Oct 11, 2003 7:16 pm
by nashr
Anyone ever see this movie? Anyway, I know you're opposed to the mesh, but I've always wanted to build my own Faraday Cage

Re: Enemy of State

PostPosted: Sat Oct 11, 2003 7:45 pm
by sparafina
Originally posted by nashr
Anyone ever see this movie? Anyway, I know you're opposed to the mesh, but I've always wanted to build my own Faraday Cage


If you want to see one in action, go see the electricty show at the Boston Museum of Science. They have a person in a Faraday cage flanked by 2 two-story Van de Graf generators.

PostPosted: Sun Oct 12, 2003 1:24 am
by Madhadder
Nothing say F-off better than a stun gun attack on the ISP's
Equip. box...

PostPosted: Sun Oct 12, 2003 1:47 am
by ck3k
Originally posted by Chris
Like A Wireless Bridge Over Troubled Water?

Thank you very much ladies and gentlemen...I'll be here all week, make sure to tip your waitresses.


and the fact I am seen in public with you.....:D

What I would do for this 2.4 spamming, is to accidently get an old generation cordless phone, these things suck, my uncle had one, the min i setup the wifi and that bitch went off....spammed the freq. I also would start the wifi wars, I mean it could get bad, get an amped yagi and point it at his ap. I mean at defcon they threw together a huge antenna on a mountain, the guys where afraid to stand in front of it cause of its signal strenght. I want a situation where i can feel packets, probley wouldnt be able to have kids but oh well.

PostPosted: Sun Oct 12, 2003 8:49 am
by Thorn
My question is, have you actually proven that the WISP is is the source of the interference? Have you actually looked at the spectrum on the area? If the WISP is running the maximum legal power, after 5 blocks the signal strength should be low enough not to interfere. Don't jump to conclusions that just because the WISP has the most visible antennae in the area that the interference is orginating there. Get some proof as to the exact source of the interference. A spectrum analaysis of the 802.11b band might show the the interference is much more localized than you think.

For example, if your next-door neighbor ran an X10 video camera at his front door, that would be much more of a problem than the WISP. Telephones, baby monitors, and many other devices all share this band, and some are always transmitting. Furthermore, many do not have channels per se, but take up big chunks of the band.

PostPosted: Sun Oct 12, 2003 11:26 am
by stevieg
Hey Thorn;

Thanks for the insight, I havent done an actual spectrum test of the area but a short drive around the neighborhood with NS running shows no other AP's anywhere in the area with a large enough signal strength.

I am drawing the conclusion that it is the WISP thats causing the problem on quite a few notes,

1.If i look out my front window I have a direct line of sight to the tower (i can actually SEE the tower).

2. I have been monitoring this with NS for about 6 months now and previously when he only had two AP's I could pick whichever channel area he wasnt on and I had no problems, he would randomly change the channel and only then i would have to go and change mine to the blank area.

3. Now that he has 3 AP's all on that tower the only way i can get a connection to my AP is to monitor the signal strength and find whichever channel has the lowest strength and move to that one, then magically I can connect.

Now I do agree with you that any grade of 802.11b equipment that is running "within spec" should not have a high enough signal strength to overpower my AP 5 feet away. I asked him if he was in spec and of course he said he was. I actually dont believe him though, he is providing to an area with a diameter of about 10km from that one tower with 3 aps on it.

Oh yeah I am picking up a signal+ of about ~-45 and a SNR+ of ~50 on my laptop card while sitting in my living room which is about 500-750m away from the tower.

Now this could just be my DLink DWL650+ beign a bit on the sensitive side but I have 3 of them and they all do the same thing.

As for other things in the area providing interference I am also open to that, In my house there are no other 2.4ghz devices that would be causing the interference and there is a decent distance between houses in my neighborhood (at least 100feet on all sides) and with that distance most home devices like that shouldnt interfere too much.

going over that list would you make the same assumption?

Steve

PostPosted: Sun Oct 12, 2003 12:03 pm
by Thorn
Well, that would certainly lead me closer to that assumption. :)

Can you tell what kind of antennae he has running for the APs and the approximate height above ground? Look over the tower with a good pair of binoculars and then if you can tell the antenna brand(s) and if there are any amps near the antennae. It may give you some clues as to what he is running.

10km is a seems like a pretty far distance, even at full (legal) power. (Although it depends on terrain, antenna on the far end, etc. etc.) If he's using directionals, he is allowed up to 48dBm depending on the configuration, so he could be legal.

Document your findings, carefully and completely, and talk to the own of the WISP one last time. If he is complient, you do have to live with the interference. If you think he is not complient, you could call the FCC for an inspection. But it's a hassle for the WISP, and if he is legal, you may make an enemy and still have to live with the problem.

BTW, Mr. White is correct about the Canopy gear. I'd never consider it, for economic reasons alone. Many great WISPs are using COTS 802.11b gear and give great service. This stuff is unlicensed for good reason. The down side is we all have to live with the other users out there.

PostPosted: Sun Oct 12, 2003 12:44 pm
by NightShade737
Silly question, but how much range would an AP gain going from the ground floor of a building to the third floor? Or wouldn't it be noticeable?

I'm guessing you get a sort of water sprey effect where the higher it is, the easier it can cover a bit further away up till a certain distance......

NS

PostPosted: Sun Oct 12, 2003 6:18 pm
by stevieg
As i understand it is depends on the antenna design and gain of the antenna, for example the vertical axis of an Omni antenna looks somewhat like a donut cut in half, then the higher the gain the flatter the donut but is larger in diameter?

Sorry if that is a little hard to understand but i dont have any antenna maps around to show you, its been like almost a year since i did any wireless stuff

Steve

PostPosted: Sun Oct 12, 2003 7:55 pm
by Thorn
Increasing the height above ground doesn't effect the gain. It cannot, since nothing is directly done to the signal. (In case you aren't aware, "gain" is a specific RF term.) Generally there is some improvement in the signal getting out due to raising the antenna above obstructions, but not always. You can actually run into a situation where you lose signal, due to it shooting over your intended reception point, in an umbrella effect. As stevieg says, RF propagation is much more dependant on the antenna design characteristics.

Look in the Antenna FAQ thread. There is an antenna diagram I drew last year; not the best but adequate to give you some idea of how antenna characteristics affect the gain and propagation. There is also some discussion further down about the umbrella effect.

For The Newb's - info with sources.

PostPosted: Sun Oct 12, 2003 8:51 pm
by JimEther
From: http://www.wi-fiplanet.com/tutorials/article.php/972261
An important concept to note regarding channel assignments is that the channel actually represents the center frequency that the transceiver within the radio and access point uses (e.g., 2.412 GHz for channel 1 and 2.417 GHz for channel 2). There is only 5 MHz separation between the center frequencies, and an 802.11b signal occupies approximately 30 MHz of the frequency spectrum. The signal falls within about 15 MHz of each side of the center frequency. As a result, an 802.11b signal overlaps with several adjacent channel frequencies. This leaves you with only three channels (channels 1, 6, and 11 for the U.S.) that you can use without causing interference between access points.


Also...FCC Part 15 - Explained


From: http://www.austinwireless.net/cgi-bin/index.cgi/FreqentlyAskedQuestions#line86

The frequency spectrum under which this operates is not licensed to anyone. There is no limits to how it is used except that the output power can only be 1W. Equipment shall not require a license for legal operation in the United States of America, under the jurisdiction of the FCC. Wireless modems and bridges approved for operation in the ISM bands with a power output of 1 watt or less, when used with an appropriate antenna do not require an FCC license for legal operation in the United States.


In other words... if your wifi card transmits 50mW... your antenna gain shouldn't be much over 13dB gain, if you wanna stay within your 1W limit, even though the FCC allow up to 4Watts in that frequency band.

PostPosted: Mon Oct 13, 2003 8:14 am
by stevieg
thank you very much Jim :-) I wasn't just imagining its been awhile since i read any of that stuff :-)



Steve

PostPosted: Sat Oct 18, 2003 2:11 pm
by michaelp
i think you should take your ap in the basement and see if you can connect, my guess you are just having problems with some of your hardware. 802.11 signal gets killed pretty fast through buildings. On another note the signal can go very far when line of sight. Like the 28mile link into the mountains I've setup.

later,
Michael

http://tv.seattlewireless.net