Cheap 5km wifi -- hopeless?

Please excuse my ignorance. I have a Draytek Vigor2600We router and a cheap 19dBi antenna off eBay. I have clear line-of-sight to a house with a good ADSL service (which I don't have), about 5km away. Is there any chance, if I give them the router to be sited at a window facing this way and put a wireless card in my PC attached to that antenna and line it up carefully, that I'll be able to connect and get a decent broadband service, or am I dreaming?

Reply to
Robin Faichney
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Hi Robin,

Draytech Vigor 2600WE is an ADSL Router with built-in (indoor) wireless Access Point which is made for indoor usage with limited wireless power!

The issue here is the power of your Access Point not the Antenna size, shortly you might need a signal booster of 200 -500m Watt, which can drive enough power to 19dBi Antenna.

Also you should have the proper anetnna to reach that distance.

Good Luck!

Naim

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Reply to
Panda

Probably won't work. My wild guess(tm) is that you'll also need a high gain antenna at the other end of the link. Quick check... yep, you're about 18dB short on the fade margin.

See the FAQ under "Link Calculations" at: |

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through the exercise. Make your best guess as to the power output and sensitivity of the radios at each end. Come back with your results if you're having problems.

Also, don't assume that line of sight also means that you have Fresnel Zone clearance. See: |

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5km, you need at least 33ft radius clearance about the line of sight line at midpoint.

Reply to
Jeff Liebermann

Hmmm... So you start with a radio that puts out +17dBm and add an amplfier/booster/kicker/loudenbelcher/whatever that increases the power to perhaps +25dBm for a fabulous gain of 8dB. That's kinda marginal for one direction but doesn't do anything for the other direction. Are you perhaps suggesting that he add power amplifiers at BOTH ends of the link? The cheapest 500mw amp that I've seen is about $250 retail. Meanwhile, a pair of 24dBi dish antennas are $60/ea.

It can be done with just 2 antennas and no power amplfiers. Run the numbers first. Then offer solutions.

Reply to
Jeff Liebermann

Sorry, that's rubbish.

As is that.

A pair of high gain directional antennas will do the job.

David.

Reply to
David Taylor

Its possible - but you will need to do a link analysis to be sure. This is a good site for link calculators:

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You'll need to know distances, elevations at both sites, and antenna raitings at both sites.

Reply to
Clark W. Griswold, Jr.

I bet you'd have a terrible time understanding a _passive_ repeater, that consisted of exactly two "large" antennas ("simple" 28 dBi horns) mounted back to back on a tower, and connected with a piece of low loss transmission line (in this case, waveguide). Do the numbers, and you might see how it works - with NO receiver or transmitter at the repeater site. The math is "transmitter power - line loss + antenna gain - pathloss + antenna gain - line loss + antenna gain - path loss + antenna gain - line loss = receiver input level". In this case, the link was just over three kilometers, with the passive repeater sitting on the top of the hill between the sites. We used it for about five months. There was no electrical power on the hilltop, and the local power company refused to bring it up there. Fire regulations prevented having a generator on the hill, and both solar cells and wind powered generators were not practical.

Old guy

Reply to
Moe Trin

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