Creating a Free Wi-Fi Hotspot

What I would do is have WPA on the wireless and give the users passwords when they have want wireless. Then change it every day to keep unwanted users off your network. As for the brand well that depends on what you are willing to pay and support if you are going to be the one supporting it.. I've setup several outdoor and indoor wireless and there are a lot of brands out there to chose from..

 

What I think you need is to setup a system that prints out an access code that you can hand out to your customers so they can connect to the wireless network. When the users log in, they are redirected to a web page where they need to enter the code to get access to the internet. The access codes can be valid only for a specific period of time.

You can find router and software solutions by searching for something like "hotspot network access control". There are plenty of solutions out there that meet your needs.

 

My local coffee shop uses WPA, changes the code each morning, and prints it on the till receipt. How simple is that?

That said, the implications of free wifi are that you'll get a lot of campers. These people sit around for hours nursing a cup of coffee and leech your bandwidth. What you need to do is calculate just how much space you can turn over to leechers. If, during busy periods, you have too many leeches stuck to your seats, this impacts your peak capacity and affects income.

Also, you should reduce the transmit power of your access point so you can reliably connect from inside, but not reliably connect when you're 20 feet outside your door. Campers are an unsociable bunch, and tend to sit at 4-seat tables all by themselves. Arranging a long bench with lots of power sockets that just happens to be in a strong signal area out back would be called "prudent" by my coffee-shop-owning friend.

It's very unlikely you'll need to support 200-300 simultaneous users. 5-25 users seems more realistic. Any consumer router can do that.