Wireless Networking

For grins I decided to add wireless networking to a computer in a different building to keep it on the same network. When I bought the parts I was told yep they will reach 300 feet. Since it was not going that far I thought there should be no problem. After all they said it would pass through walls. Nah did not work at all. By the time it was up and working I had two pole mounted directional exterior antennas that had to be pointed right at each other. With no obstructions the maximum distance is now listed as 1.5 miles.

what kind of equipment were you using for the wireless? they make booster kits for wireless..

I can pick up my neighbor's wireless network (802.11b) which is diagonally across a small intersection from my house.

Heres some good news!


http://www.ekkobsd.org/~rchrys/DA-04-1844A1.pdf

You might be experiencing local interference from another WiFi node. The WiFi channels actually overlap each other, so an adjacent channel that's really busy might be eating bandwidth.

You might have interference from a 2.4ghz cordless phone, wireless baby monitor or even a microwave oven. Generally these operate in the lower channels, so if you have a channel that's 6 or above that's not currently in use by another node, use one of these.

Also, long antennat extension cables chew up a lot of signal. Keep your antenna leads under three feet if at all possible.

And if you're in a lightning-prone area with outdoor antennas, make sure they're grounded properly, lest you experience a "non-passive end-of-life characteristic."
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wow my mom lives 2 minutes walk (averaged both directions)
so maybe I could connect her to my broadband

It's all grounded. I'm sure I must be getting some form of interence from something since I can't get 75 feet away with a high gain antenna.

This might be worth looking at to help find the problem.

802.11b/g WiFi Detector

Unfortunately I can't tell you if it will work for other sources of interference such as microwave ovens or cordless phones but for $ 20.00 it'll at least give an idea of the signal coverage from your units.

The directional antennas work great now that they are up. They do not seem to have any problem with interference.

My mistake...I thought there was still some problem....

There was until I mounted these 1 foot diameter antennas. Nothing else would work.

Convert your old dish:

"Interline links over 110 Kilometres (61 miles) in Poland"

http://www.trevormarshall.com/biquad.htm

"That's all there is to it, folks -- you now have a dish with 27-31 dBi of gain and negligable sidelobe radiation (<40dB). The beamwidth is about 4 degrees.
"

Since every 3dB raises your power by 2x, thats the same as having 51.2 - 102.4 watts on most stock antennas, assuming your wireless was a 100mW unit to start with.

It's also *alot* more secure, since it is very directional.

The new one we put in here is a 14dB with a 30 degree output radius.

Don't have a picnic between the buildings, LOL. Kinda like walking into your microwave ... wait -- it's the same not just like it (2.4 GHz). How'd that get past the FCC?

There is an FCC limit to the power density that you can launch into the airwaves with Wi-Fi in the U.S.
I think that with an average 70-100mw Tx, this limits you to a 14dbi gain antenna.

i love wifi. not that i HAVE it or know anything about it or ever have done anything concerning it. really umm ya. exactly. brilliant.

Brands matter here. The linksys/belkin stuff you buy in the retail chain stores don't work nearly as well as the business gear like Cisco, Cabletron, etc. I can carry my laptop out of my house and down the street with nothing but the little antennas on the end of my Cisco AP, I finally got tired of walking and came back home before I ran out of range.

The stuff in the stores generally runs 70mw output. There are a couple of laptop cards that run 200mw and they work quite well. I've used the high-power SMC EliteConnect card with great results.
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[ QUOTE ]
binky said:
Don't have a picnic between the buildings, LOL. Kinda like walking into your microwave ... wait -- it's the same not just like it (2.4 GHz). How'd that get past the FCC?

[/ QUOTE ]

It didn't - I think one of the reasons that they gave that chunk of spectrum away for unlicensed Part-15 use is that it's already clogged with leaky microwave ovens. If you look at the nameplate sticker on the oven (usually in an inconspicuous place) you'll see that the magic frequency is 2.45 ghz. Yup, right in the Wi-Fi band.

While this may digress a little bit, a leaky microwave oven can cause your eyes to feel "sandy" and tired if you're within a foot or so of one while it's operating. The reason is that the leaking microwave energy is enough to vibrate the molecules in your eyes, causing friction and a teensy amount of drying-out from heating of the tissue.

Over the long run, using a microwave oven that leaks badly can contribute to cataracts. I had a friend who was complaining of some vague "eye trouble" with some familiar-sounding symptoms. I happened to notice that the oven in this individual's kitchen was the really old style with the large mechanical timer knob on the front that goes "ding!" when the cooking cycle has ended. I measured the area for 2.4ghz energy while it was running, and it turned out that this oven was blasting the kitchen with leakage! /ubbthreads/images/graemlins/eek.gif

Needless to say, this would've also knocked out any Wi-Fi in the area. /ubbthreads/images/graemlins/icon15.gif

Check the seals around your oven's door periodically. Also check to make sure that the door is hanging on it's hinges correctly and that it closes completely and that the seal is properly seated when it's closed.

Here is the power output levels of serveral cards:

http://www.cewindows.net/peripherals/pccardwirelesslan.htm


How to hack your WUSB11 to connect an external antenna:

http://www.kcip.com/wireless/wusb11.html


24 dBi gain antenna with the ability to orient horizontal or vertical polarization to screen out terrestrial interference:

http://www.hyperlinktech.com/web/hg2424g.php


A review on the product Photon Wrangler was talking about:
http://www.tomsnetworking.com/Reviews-46-ProdID-SMC2532WB.php

Pay particular attention to the comment about the Linksys on the second page, with 15mW output power, note that it is only a very small fraction of the output power of one that is being reviewed.


Here is another 24dBi gain antenna, with horizontal or vertical polarization choice, for 79.00 ea:

http://www.wirelessnetworkproducts.com/index.asp?PageAction=VIEWPROD&ProdID=523