Question about wireless networking

I want to network my computer to another about 3 miles away is there a way to do this wireless? If so could someone recommend some products for this. Thanx in advance

3 miles?, no way..., your only alternative would be a microwave dish, very expensive.

You could run a vpn over the internet though, but each pc must have a local isp connection... like cable or dsl.

Yeah, see the internet thing is the problem, I have dsl on my comp and not on the other and I live in the country where dsl is hard to get and expensive. That's why I wanted to network them togther so the dsl would be on the other comp too. I see 3com makes some building to building wireless stuff. I have't checked into it very much but I suppose it won't go as far as I need it to go anyways. Thanx for the reply

Yes wireless can work.

No, a "microwave" dish isn't required. Nice, yes. Required, no.

1) you need to be able to see one site from the other
2) you need to have about 25 feet of clearance around this line of sight midway between the two points
3) you need an access point/wireless bridge that can pump out about 100mw
4) you need a pair of antennas that have about 13+ dBi gain - higher end Yagis would work here

(No I ain't that great at wireless surveys, but I do have Cisco's "Radio Antenna Calculation" spreadsheet which is very handy for questions like this)

huck, what..?, are you talking about bridging several APs together?, i guess that could work, but packet-loss would probably kill the bandwidth. Over 3-miles, you would probably have to have like 10 Access Points! Plus, 3 miles is a long way for clear site distance...

hmmm, no "cheap" way for this... lol, you could string some coffee cans together... ;o)

There are trees in the way I cannot see the other place. It's probably only 2 miles. But oh well, it was a good idea at least...

Motley said:

huck, what..?, are you talking about bridging several APs together?, i guess that could work, but packet-loss would probably kill the bandwidth. Over 3-miles, you would probably have to have like 10 Access Points! Plus, 3 miles is a long way for clear site distance...

Click to expand...

Naw, works quite well, at least between two APs. You do have to have decent equipment, though ("Ronco" APs need not apply). The distance (assuming necessary clearance between point A and point B) is more dependant on the types of antennae being used, and your transmit power. There are some folks in these forums who have used similar equipment over much longer distances. The best I've done is about 40 miles (but I cheated and used 10ft dishes) between two Carribean islands - and with higher-end 5.8Ghz equipment.

Will it work between an AP and a client station? Yes - however you will probably need to use higher gain antennae as the client may not be able to push as much power as you need. In this case you may indeed need to find a higher gain (read more directed) antenna or two.

The silver antenna is the one shooting about 40 miles to St. Croix(64 km).





One of the hills above Red Hook, St. Thomas, USVI.

[Edit: Hmmm, the hosting service I'm using doesn't seem that great. Here's the URL: Wireless relay ]
[Edit: Anyone willing to host some piccies?]

Interesting..

Here are some pics of one of my backhaul links (5.8, redline, 36mb/s)

Closeup of redline, thisone is on a tower ontop of a building:


View from building towards otherend of the link:


Opposite end of the link (we are renting space on this tower, and it is as scary as it looks):


In the above picture you can also see another redline positioned below the one pointed out, that link is 27mi. The satelite looking dish is a motorola canopy (10mb/s up + down) at just over 13mi.

Motley said:

huck, what..?, are you talking about bridging several APs together?, i guess that could work, but packet-loss would probably kill the bandwidth. Over 3-miles, you would probably have to have like 10 Access Points! Plus, 3 miles is a long way for clear site distance...

hmmm, no "cheap" way for this... lol, you could string some coffee cans together... ;o)

Click to expand...

I do 5-7mi links almost daily via 802.11b standard equipment. My primary AP's (full 36db eirp) have about a 10mi radius of coverage. The smaller WiPoP's range anywhere from 2 to 5mi radius. We also do 900mhz, which can use an indoor antenna at .5-1mi and do 3-5mi NLOS (Non Line of Sight) and 8mi LOS with an outdoor antenna.

For the 802.11b protocol, about 12mi is the theoretical *reliable* distance. There is a timing issue with the protocol that begins to become a factor at ranges above 12mi and reliablility and throughput begin to suffer. In my experience I have ran into it at 10mi and also tested a 14mi link that worked fine (the 14mi link required the full fcc limit of 48db)

So... I am a newbie for this stuff. How much would the equipment cost to do this?

aronmartin said:

So... I am a newbie for this stuff. How much would the equipment cost to do this?

Click to expand...

Just a quick generalization for a 2-3mi ptp link:

2 - 19db antennas. 14db's are too borderline depending on the tx power of the radio, you can getaway with a 14 on one end and a 19 on the other.. There are too many variables to consider since you claim not to have LOS. $30-$50/ea

2 - Radios.. Lots O choices here, do you want to bridge the networks? Route? Ap-Client setup? expect to pay $60-$200 for consumer based radios.

LMR 400 - $.50-$1.50 per foot
N-Male Connectors - $2.50 - $5 ea
2 - Pigtails to go to the radios from the lmr $19-$30 ea


If you do not have clear LOS there is really no need to try.. You can build a tower, at about $80 per 10ft section. We charge $100 per 10ft section to stand a tower upto 60'..

Here is a couple links to a discussion we had over at 2cpu, the first is the link I created from one of our towers to our new office, the other is a question much like this one..

Office link
General info

Since this type of question has come up alot lately I am going to try to do a writeup on creating a simple ptp link using some of the equipment I have on hand..