stevech0
join:2006-09-17
San Diego, CA
edit:
May 3rd, @02:25AM
| reply to huf67
Re: Long Distance WiFi
I doubt it'll work, for 6 miles. Especially at 2.4GHz due to interference. Long links in unlicensed band are more often done at 5.8GHz with 802.11a or a proprietary method such as TDD.
with the 50 ft tower, do you have line of sight to the far end? If not, unlikely it'll work.
What's the elevation at the far end? IF it's not well above the treetops and buildings in the line of sight path, unlikely the link will work.
Both ends need to clear the so-called Fresnel zone. Imagine a football-shaped thing touching each of the two antennas. The fatness of the football depends of path length (and frequency). If too much of that football is blocked by trees/buildings, you'll get a too-weak signal. This can be calculated if you know what the line of sight conditions are.
Amplifiers: Do very little good unless BOTH ends have the same transmitted power. I hear you but you don't hear me. And the bi-directional amplifiers raise the noise floor of the receiver excessively.
Again, this is done every day with a bit of planning and math, and some software tools. But rarely in 2.4GHz, esp. in suburban areas.
Best way to do this is with a pair of wireless bridges from Demarc Tech, Deliberent, or equivalent. These are about $150 each.
The 24dBi mesh parabolic antenna you have is nice, but you must put the wifi device atop the tower, else the coax to the bottom will attenuate the signal too much. The outdoor bridges I mentioned above have no coax; integral antennas, for this reason. And their radios are designed for the temperature extremes outdoors.
and keeping the 24dBi dish aimed correctly over a long time can be difficult as it has a very narrow beamwidth. Gotta have really good mechanicals and tower stability. The wireless bridges have 14dBi or so and are less critical, but get the same radiated power via special radios for the purpose. |
