Performance comparison of media access protocols for Gbit/s networks in the local area

Abstract

The evolution towards future communication systems is strongly influenced by increasing transmission capacities, changing service requirements and the emerging ATM technology. The next generation of high-performance local and metropolitan area networks has to be designed including control schemes which provide high throughput while simultaneously supporting real-time services. The slotted ring architecture enhanced by spatial slot reuse is one potential approach for data transmission and admission control in distributed Gbit/s networks. Various concepts have been proposed for an efficient medium access control which maintains fairness and bounded access delays. By using simulation results, this paper compares the performance of several protocols: ATMRing (ATMR), CRMA-II (Cyclic Reservation Multiple Access) and MetaRing. First, the differences in their basic mechanisms are generally analysed applying saturated traffic scenarios. Then the behaviour in a multi-service environment is discussed, with particular regard to the requirements of universal broadband services. It is shown that all approaches offer efficient bandwidth sharing mechanisms. They overcome the well-known trade-off between high throughput and strong real-time requirements by providing extended bandwidth for user data and suitable end-to-end delays. Their performance, however, is quite sensitive to the actual network conditions and chosen protocol parameters.