outdoor wireless networking

[ws6]

Hi, I need to setup a 802.11b wireless network to bridge 2 building together. They are about 2800 feet apart with good clean LOS between them (it is at a small private ga airport). I am working on a very tight budget and need some help with figuring out how to due this. What will work and what won't?? I have thought about trying to use 1 linksys befw11sf with the wsb24 signal booster to a high gain directional antenna. Tof teh other end I was thinking of using a WAP11 with another wsb24 booster to another directional antenna. Will this work and if so how well? If no what would I need to due to get something that will work? also what effect will rain and ice on the antenna cause?

Thanks,
ws-6

 

[ktwebb]

The elements aren't an issue if your link is clean and solid (read good signal quality or high Signal to Noise ratio). At that distance you certainly do not need any booster if your going to be using decent mid to high gain directional antennas. At a half mile, if you really want to have as little worry as possible over your link, look at some grid dish parabolics. You can use regular yagi's and they will work well but for about the same price your better off with a couple of decent grids. At a half a mile you are still dealing with fresnel zone issues so you'll want to elevate as much as possible. Keep your transmission cable runs as short as possible and use good low loss coax (LMR400 or better for anything from 10 to 60 feet) and you might consider getting your cables premade and crimped. You can try both sites at ground level without using and coax runs but it's a give and take. You want to elevate but if you can't or you just dont want to deal with coax, then you can try at ground level to start, and adjust if your links are not what you need.

 

[ws6]

thanks for your help. where is a good place to buy antenna's?? and is there any special type of grid dish parabolics to look at? what db range?

thanks,
ws-6

 

[Rwalter63]

ktwebb post got pretty much all you will need. One last thing, get your self a couple of lighting arreseters.
Hate to lose your hardware especially since you'll proabably need to eleavate the antenae due to a lighting strike.

 

[ws6]

I had already planned on buying both lightning arrestors and premade low loss cables for both ends.

I found some antenna and was wondering if they where the right ones and also if the price was good. I found them here: http://www.fab-corp.com/pacwireless.htm
I was looking at the 24 dBi Die Cast Directional Antenna that they have. Is this a good antenna or is it over kill? Also since the linksys has 2 antenna mounts on it I was thinking of hooking the other antenna mount to the Indoor 10 dBi Wall Mount Panel Antenna that they list in the panel mount section. Will this work?

Thanks,
ws-6

 

[Ordo1999]

can you use any less expensive cable the what you suggested ktwebb?? If so, could you suggest some? thank you!

also, would both ends need one of these antennas? How do you tell how far these grid dish parabolics boost the signal? all it says is frequency.. Im new to this, and would like to learn.

 

[ktwebb]

Just depends on your cable length. If your just looking for an alternative to Times Microwave LMR400 then Belden 9913 is about the same grade cable but less expensive. About 1 db per 100 foot more loss. A little bit harder to work with. I like the copper core in the LMR400 much better.

Yes, you'll need mid gain directionals on both sides of the link.

The antenna gain will be designated by dBi, a representation of gain for the antenna. 15 dBi, 9 dBi etc.. In laymans terms, the more gain you have the tighter your radiation pattern and more directed the power. It won't give you the distance you can use it for because the manufacturers don't know how much power your pushing to it, how much cable you'll be adding or connector loss.

 

[Ordo1999]

Ok, so a 19 dBi Parabolic Grid Antenna would generally give me how much more of a radius for a wireless lan? My wireless router now, says it has a range of 1,000'

I need another 2,000'

 

[ktwebb]

I've used 24 dBi grid dishes on each side for 18 mile links. The variable will be different than what your going to use but 19 dBi grid is overkill for your needs however if you want to get them they will be plenty. This all assuming you don't have massive signal attenuation due to crappy cable or poorly crimped connectors etc.. All things being adequate, 19 dBi grids are extremely powerful directional antennas.

 

[ws6]

so for a 3000 ft link would you suggest 15 db or 19 db dishes?

ws6

 

[ktwebb]

At 3000 feet you could use 7 dBi yagis, but a grid is always nice and you'd not have to worry much about the link, assuming your cable and connector loss was good starting out. 15 dBi grid dish parabolics are more than enough.