Chapter 6 Deploying Wireless Networks for FortiOS 5.0 : Introduction to wireless networking : Deployment considerations : Multiple access point networks
  
Multiple access point networks
To cover a larger area, such as multiple floors of a building, or multiple buildings, multiple access points are required.
In the WiFi controller, you configure a single virtual access point, but the controller manages multiple physical access points that share the same configuration. A feature known as “fast roaming” enables users to move from one physical access point coverage area to another while retaining their authentication.