A collisions-free WDMA strategy for ring MANs with efficient traffic management: A performance optimization study

In this paper, we focus on the serious problem that many WDM architectures for ring metropolitan area networks introduce: the limited fiber bandwidth utilization and the low values of maximum throughput achieved. We propose an efficient scalable multi-buffer architecture in conjunction with a slotted WDMA protocol that totally avoids both the WDM channels and the receiver collisions providing significant throughput improvement and essential dropping probability and total delay reduction, as compared with other studies. The basic idea of our study includes two combined algorithms: a) the appropriate allocation of the incoming traffic into the multiple buffers according to the destination, and b) the effective buffer selection for transmission that takes into account in a priority base the packet age and the receiver collisions avoidance. In this way, the proposed architecture extends previous studies and not only achieves maximum bandwidth utilization but also it adopts sensitivity to time delays. The study is accomplished by the exhaustive investigation of the required number of buffers per node to maximize throughput, for a fixed network configuration. Simulation results prove the significant performance improvement achieved as compared with studies which use a single buffer per node.