A media access control protocol architecture for wireless local area networks

A wireless LAN is modeled as a cascaded system architecture which consists of an up-link channel, a switching network, and a down-link channel. This architecture inherently avoids the problems of hidden terminals and up-down collision. Based on this architecture, a media access control (MAC) protocol stack is proposed which consists of a slotted-ALOHA protocol, a token-passing ring protocol, and a time-token protocol. Their operations are consistent and interaction among them is harmonic. This protocol stack properly treats the effect of various interferences, handover problem, and power consumption. The combination of contention and polling revealed in the stack turns out to fit the characteristics of wireless LANs and gives a very flexible and easy access to a wireless communication resource. Key features and effects of important design parameters on the performance of the architecture are demonstrated and evaluated using simulation results, which also show excellent response performance