Total Wireless Networking Newb

[hjo3]

Hi. I'm new.

I have to set up 54 mbps wireless networking for three separate buildings with 1 omni antenna and 2 directionals. I know this much. I've worked with regular 100baseT ethernet a lot, but I've never worked with wireless. Mainly, I'm just sketchy on details pertaining to the antennas (amplifiers, brands, types)... could anyone recommend a good how-to, FAQ, or something to help me out?

I have a budget of $300 for the whole setup, but of course they want me to do it for as little as possible.

 

[ktwebb]

A decent antenna will cost you 75 bucks and up. 75 would be a pretty cheap antenna. That is before connectors, transmission cable (Coax) runs, masts, and/or mount brackets. You won't be doing three sites Point to Multipoint for 300 dollars. I suppose if you were able to use just brackets, and could have practically no coax run, but even making your own short pigtails for three sites would be 50 bucks+. If you want to build your own antennas, which would obviously keep costs down, just do a google search for "cantenna" or "pringles can antenna" It won't be something I would rely on but with your budget, it doesn't sound like that is important to you anyway. Several people here that could offer some advice but since you provided only the bare minimum of information it is difficult if not impossible to offer anything more than extremely broad suggestions.

As far as fundamentals. Make sure you have line of sight. Again, you gave no valuable information like this, or distance, mounting height or what kind of structures so its just the basics for advice. Establish your line of sight points. If you already have the bridges, are they POE capable or are you going to have to run power? Too many things to consider with the amount of info you gave really so I'll just leave this as is. People can help here but you must provide some data to go off of.

 

[hjo3]

All I wanted was a decent guide that dealt with wireless networking at ranges greater than inside a single building.

Here are details about my specific situation though, since you've elected to be so helpful: One building (the one where I think I'll need the omni) is 2 stories tall with very clear LOS to one and slightly obscured LOS to the other (trees). Call it building A. An old house.

Building B (the one A has a clear LOS to) is at the bottom of a hill, so it's about 25 feet lower than A. Distance between A and B is about 220 feet. 1 story, a house.

Building C (the one with the trees between it and A) is about 40 feet tall (it's a large warehouse-type structure; an indoor arena). Distance between A and C is around 200 feet.

Distance from C to B is about 230 feet, but with very clear LOS.

I don't have bridges. Running power won't be difficult. For Building C, I only need to run everything into one computer. Building B would need a router or switch I could plug into (2-3 machines). Mounting heights for all buildings would be about the height of their roofs (I'd assume), though the antenna on C could be placed lower than that.

Given your expertise at displaying my ignorance, I'm probably wrong about needing 2 directionals and an omni-directional antenna. What kind of budget do you think this would need?

 

[ktwebb]

I figured you already had the AP/Bridges. If not, then that is your budget right there pretty much, before you begin worrying about antennas, mounting brackets, transmission cable runs, connectors, lightening arrestors and various other things you'll need to be effective.
Parent bridge at your main site with an omni, 5-7 dBi would be fine for that distance but your obstructed LOS is the wildcard here. Might not matter how much gain you have. Yagi's, parabolic, or some kind of sector panel at the remote sites (all directional antennas). A decent patch will make that distance but since you have some trees on one link you'll want the narrowest beamwidth you can find. A good 15 degree yagi might work, but again, trees equal a iffy link at best and very likely a no-go completely.
As far as budget. Impossible to say from a forum post. it wouldn't be an option since money is an issue, but if you really want to know how much it will cost, the network would have to be designed first. Site survey to establish link pheasibility. Mounting points. If you need coax runs to your antennas. If so, how long so you can tell what type of coax you might need. Above roof line would need lightening arrestors. And on and on really. No way to give a ballpark without seeing the site. At least from my perspective. Others may give you some idea based on homebrew WLAN's they've put up. You might could do it right for 250 a site but there's no guarantee of that.
Finally, no need to be pissy chief. You asked a question that couldn't accurately be answered because you provided no background information. Essential for virtually any post in this forum but a must for most wireless questions to be answered adequately. Good luck.