I need to cover a very large area with Wireless LAN, I can run Cable to each Wirless AP, is there special AP's to use, or can I just run 200 ft of cat5 to each one in a sort of "daisy chain"

What do you consider a "Large Area?" Several miles? A few football field lengths? "So won’t you give this man his wings What a shame To have to beg you to see We’re not all the same What a shame" - Shinedown

Up to 20 miles, it is an mining and industrial application

20 miles! With WiFi AP units every 200ft? That would be 528 units. That should get you a nice volume discount! But, each AP unit is designed to support a unique network. How would all this tie together into a coherent communications system?

Up to 20 miles, it is an mining and industrial application I'm thinking you mean the location is 20 miles away (please correct me if I'm wrong) as a 20 X 20 miles = 400 sq miles and that my friend is a LOT of area to cover and would require enormous amounts of $$$. If I'm correct, and you need to get wireless to a location 20 miles away, I'd highly recommend you look into an enterprise level point-to-point wireless solution. Once you have it where you need it, then you can worry about distributing it in a fashion that will allow users to connect. Not sure where you live, but I'm in Canada and we recently had to do some p-to-p wireless shots and used a company called: Glentel You might want to look over their site and products to see what they offer even if you're not in Canada. If you're in North America, I'd wager they have subsidiaries in the US. Other than that, it would at least give you an idea what you're going to need.