Chapter 6 Deploying Wireless Networks for FortiOS 5.0 : Wireless Mesh : Overview of Wireless Mesh : Wireless mesh deployment modes
  
Wireless mesh deployment modes
There are two common wireless mesh deployment modes:
Wireless Mesh
Access points are wirelessly connected to a FortiGate or FortiWiFi unit WiFi controller. WiFi users connect to wireless SSIDs in the same way as on non-mesh WiFi networks.
Wireless bridging
Two LAN segments are connected together over a wireless link (the backhaul SSID). On the leaf AP, the Ethernet connection can be used to provide a wired network. Both WiFi and wired users on the leaf AP are connected to the LAN segment to which the root AP is connected.