FMAC: A highly flexible multiple-access protocol for wireless communications systems

Due to the limited bandwidth of wireless networks, an efficient medium-acce ss control protocol is essential to meet the growing demand of wireless acc ess. Most multiple-access protocols require contentions (collisions) in the process of acquiring the transmission medium. While collisions cannot be a voided, successive collisions that consist of the same group of active stat ions are totally unnecessary, Successive collisions not only waste bandwidt h, but also raise the concern of saturation in the channel. In this paper, we solve the problem of repetitive contentions involving the same set of st ations by using the theory of finite projective planes, Due to the property of single-point intersection for an arbitrary pair of sets in the finite p rojective plane, we can minimize the number of unnecessary collisions. Prot ocol finite projective plane-based medium access control (FMAC) is highly f lexible and has many features including adaptation for a mobile environment , support for priority assignment and handoffs in cellular networks, and ex tension of asynchronous transfer mode (ATM) services to mobile users, A per formance evaluation shows that the throughput of the system is higher than that of slotted ALOHA. By dynamically adjusting the retransmission probabil ity and the order of the finite projective plane, protocol FMAC can be stab ilized.