Will u use ad-hoc wireless networks or wireless networks based on access points to ofer a publicly open net?

Answer 1

You would want to use access points. An ad-hoc network only allows two (or more) computers to talk to each other, not to the Internet. It is used for file sharing.

Answer 2

ad-hoc is for computer to computer access only, meaning 2 laptops talking to each other, provided they are configured to talk to each other. In any public hot spot, there is an access point which provides the connectivity to the net.