Cell Switching Mechanisms for Access Point Sharing in WLAN over Radio-over- Fiber Systems

Radio-over-fiber (RoF) technology is a promising candidate to provide high data rates and ubiquitous coverage by distributing small cells over the service area. For wireless LAN (WLAN) application in RoF systems, an access points (AP) can be shared among multiple small cells. The medium access mechanisms in the distributed coordination function (DCF) under this context encounter some issues due to the carrier sensing failure between the nodes in different cells. For alleviating this problem and also supporting flexible AP sharing, two switching mechanisms are discussed. One employs a time division scheme for sharing the APs and the other a selective reception of uplink frames among the associated cells. Both approaches are shown to be effective. The proposed mechanisms do not require changes in the existing protocols on both the client side and AP side. And they are complementary to each other due to their different switching principles.