software to limite my wifi access

Hi.

I assume you have a F5 BigIP appliance (with LTM + APM) , and are looking for a creative solution to limit connections for 1 hour ?

If you don't have a F5 appliance, then this is the wrong forum to ask.

There are a number of solutions that offer wifi portal / usage metering for SME businesses.

eg:

http://dev.wifidog.org/

http://www.chillispot.org/

There will be commercial vendors in that space also.