Long range Wi-Fi is another one of my hobbies. I have successfully installed over 20 projects that range from 600ft to 5 miles. I thought I would post a little bit about how I do this. The 5+ mile links are by far the most fun and they are really quite amazing when they work correctly. I do this for fun and do not really have a business or anything (so far). The main purpose of this is to share a single internet connection between multiple houses however it is a full network that supports file & printer sharing or anything else you would like to do.
Here is a typical 12 dB omni directional antenna on one of my installations. The white box houses the access point. I will use these for the base station if multiple clients are used. This particular antenna links 9 houses that range from 2000ft to 1 mile in range. The antenna is mounted on a roof.
The diagram above shows how the system works. Its just like setting up a wireless router in your house except all the antennas go outside. One house will have the router and internet connection and the "other" houses will connect as clients just like a laptop connects to your home wireless router.
Line of sight is very important. I live out in the country and can see for miles in every direction. A few trees will not interfere much but a forest or huge buildings will severely cripple the signal. The farm in the distance is 1 mile away and has WiFi. I have a perfect signal from where I am standing. Roof top height is more than ample for this technology as long as you have line of sight.
Houses that are clients get a panel antenna. It's about 12dBi gain and is directional. I just aim it at the base station antenna and it works perfect. The AP mounts inside this particular panel antenna.
Inside the panel antenna is the Access Point (AP). Signal loss is huge in the antenna wire so you want to keep your antenna wire as short as possible. Mounting the AP inside the antenna is a great way to minimize signal loss. All I do now is run cheap Cat5e cable from the inside computer to the antenna on the roof. This antenna is a "Rootenna" and cost about $30. I have bought about 15 of these and they are excellent.
Here is another panel type antenna on a house. This one does not have an inside spot for the AP so I had to mount the AP in a separate box under the antenna. It still works perfect.
Getting power to the AP is easy. What you need to buy is a Power Over Ethernet (POE) injector. The one on the right is $5 and works excellent. What this does is injects 12 volts from a power adaptor and sends it over the unused CAT5e pairs. The Access Point is "smart" and can be powered right from the CAT5e cable. This injector will sit under your desk by the PC and plug into a wall outlet.
The access point is made by En Genius and is the most expensive part of the setup. They are roughly $130 but there are other options available today that are cheaper. I have bought about 20 of these and will gladly vouch for their quality. I have some that have been in service for 4 years outside without a single reset.
There is more to this than just the hardware setup. The networking, TCP/IP setup, and DHCP control is another subject on its own which will not get explained here. You will have to do some reading on that subject on your own.
There was a time when I had no money but still liked to play with wireless stuff. You can make your own equipment fairly easy if you want to. I made many antennas and they all worked well.
Here is a very simple 1/4 wave omni antenna called a "spider" and is made from a female N type connector. It has one vertical radial and 4 ground radials. This antenna works very well for what it is and is very small. It works very well for war driving.
This antenna has no gain.
This is my favorite homemade antenna. It is called a bi quad and is directional. I use this exclusively for war driving to identify where the signal is coming from. You can also use these to feed an old dish network dish for increased range.
I have connected up to a mile with this antenna and the PCMCIA card below.
It has 11dBi gain and can have 24dB if used to feed a old dish network or direct TV dish.
Here is my old laptop PCMCIA card and homemade pigtail. I use this for war driving and site surveys for new clients. It's a 200mW card and I have connected miles away with this card.
More to come......page under construction.
Copyright © 2008-2010 Mike Freeman