Abstract
In this paper, a slot interleaved multiple access (SIMA) scheme for the DQDB metropolitan area networks is proposed. In this scheme, all the active nodes will access the slots in an interleaved fashion. This scheme is very efficient to solve the bandwidth domination problem and the priority domination problem which cannot be solved by the DQDB MAC protocol with bandwidth balancing mechanism. We also propose an Enhanced SIMA (ESIMA) scheme to solve the bandwidth allocation problem which can not be solved by the DQDB MAC protocol. Simulation results show that the SIMA and ESIMA perform much better than the DQDB MAC on throughput as well as the access delay.