Large scale WiFi deployment

Setting up large wifi networks for campusses or outdoor is quite a challenge.

hardware

The hardware allows different functionalities. Generally you need AP's (Access Points), maybe repeaters and a management system. AP's have a maximum amount of concurrent / simultaneous users.

Cisco Enterprise Wifi - Enterprise APs have a max of 24 simultaneous users, making this expensive and useless for large deployments

D-Link - has a range of networking products but no meshing and no information on the amount of clients an AP can handle concurrently.

Netgear - has bugs with wireless N. Don't use!

Ruckus - highly recommended

Ubiquiti - new and in heavy development. A bit experimental but promising

management and billing

For management and billing you have several options, which include determining who your users are, printing vouchers, walled gardens, being able to change the default page, filtering by MAC address, etc. Most couple with a radius server.

CoovaChilli Free

HotSpotEngine Cheap

Hotspot Express Hotex billing manager

Patronsoft Firstspot Heavily developed but Windows based

Aradial Linux based and heavily developed

meshing

This is the technology that allows APs to communicate with the controller wirelessly instead of having to run cat-5 cables from a switch to each AP