In Need of Wifi Help? Need to Make a 1.8 Mile Connection HELP? Need some Ideas!
Any help is well appreciated!
'MY GEAR
I'm using a PowerBook G4 laptop, HP Pavilion notebook, and a MacPro Desktop. An Apple Base Station for my in-house network. The Base Station has an external pigtail antenna connector.
'MY PROBLEM'
I live out in the country about 1.8 miles away from Subway (in town) which has a FREE open network with speeds at around 900-1.3mbps. Since I live in the country, an expensive satellite setup just isn't going to happen. I'm only 1.8 miles away from Subway and I'm sure there is a way I can reach the network with a some help, supplies and ingenuity. I read that people are reaching 3, 5, even 10t to 15 or more miles with DIY antennas. Line of sight from my house to Subway isn't the best, there are some obstacles like trees and houses in the way, so there's no direct line of sight at all.
'SEARCHING'
I searched the forum for some ideas. I tried one antenna from the site with a wifi USB-G adapter I had sitting around and was able to reach close to a mile and the signal was really weak. I wasn't using the Base Station, just plugging the adapter into my Mac laptop and using the software it came with. It's a hawkins wifi usb adapter for the Mac.
'IDEAS'
I was thinking of setting up an enclosed solar powered transmitter, using circuitry from one of the two 2.4gzh 5-mile walkie talkies I have, and placing it at a not so visible spot at Subway. The other one would be adapted to my Base Station which I would still have control over the network creating a closed hidden network with WEP encryption, but not sure.
This is where I could use some help and your ideas?
An antenna seems like the best and easiest approach but I'm not sure how to get it to reach 2+ miles and maintain high speeds.
Any helpful advice, links, photos, etc. would be great!
Thanks!'
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http://wscicc.org/DishCantenna.htm
Depending on dish size you could get between 18 and 28 dbi.
24dbi should be a theoretical distance of 3 miles or such.
BUT-
how about the line of sight?
Search for a cantenna or a (double)biquad:
http://www.wlan.org.uk/tincan.gif
http://www.larsen-b.com/Article/201.html
Those are the easiest to build and will have 10-14dbi gain.
A regular router antenna has 3dbi and a range up to something like 300 yards/meter.
+3dbi is about doubled power, and 6dbi is the theoretic doubled distance.
So such an antenna could reach 3-4 times the range of a regular tiny antenna.
Things to note:
A)Antanna-Issues.
-Two directional antennas would be ideal, but even just one at your place will increase the performance, since reception and sending will be boosted.
-The more dbi/Gain, the higher directional the antenna will be. Aiming gets a pain in the rear, especially with antennas above 17dbi...
-Use low loss Cable, H155 or better, and as short as possible, else even a good antenna is useless since cheap cable will have about 1-2dbi loss per yard/meter.
B) Radiowaves
Those numbers will differ very much in the "real" world!
-Line of sight
-Free "fresnel zone" (see pic at http://www.wlanmall.com/wireless_faq.php )
-disturbances of other things (strong radio emitters such as cellphone stations, microwaves) and other wifi stations (which do not have 3-4 channels distance)
-Water! Wifi are microwaves. Microwaves are used to heat water. Rain, Snow, Fishtanks- They will cause problems since the radio waves will not go through!
C) Legal issues
Here in europe 20dbm/100mW EIRP is the maximum power you can emmit before you're breaking the law.
In the US I think its 500mW but I am not sure!
EIRP means your directional antenna may not be stronger at the same distance as a all-arround antenna.
Most wifirouters/laptops/stations have 50-70mW output and a tiny 2-3dbi Antenna. So thats allready as close to 100mW as allowed in most countries (50mW with a 3dbi Antenna equals 100mW EIRP).
So what does a directional Antenna do if you have to reduce the emitted power in order to stay legal? It still has a much better reception, since no one regulates the reception, plus the directional reception will help to "block out" disturbing stations since only transmitters in the focus will be received.
So the relay-station in the middle would be a good idea. Do you know anyone who lives nearby or someone also close or at the same distance that has internet? If both of you use a directional antenna the wifi link will be much better since you can adjust it and point it straight at each others station!
For 1,8 miles I would say its impossible with such a tiny antenna, and if there is no free line of sight or raining then the link will be offline all the time.
A Dish- or Grid-Antenna with 20, 24 dbi or more would be the way to go, but with the EIRP sending limit you will break the law... and even though its usualy not noticed if you are over the max dbm/mW transmittion, a 24dbi grid/dish would make up to a whole Watt (EIRP) out of a boosted WIFI Router which can disturb other stations and therefore arrouse enough attention that you might get in trouble...
Also, if you get someone to relay the signal or share broadband with you, you could buy 5 GHz WLAN Stations. Less disturbance, higher allowed transmittion power (here its 1 or 2 Watts depending on Bands).
-Marcus
By the way: WEP is not secure at all. WPA2+ or such is the way to go.
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