Performance of a multichannel global queue cyclic reservation protocol for laser-switched subcarrier multiplexed passive star networks

Subcarrier multiplexing (SCM) provides a readily-available and cost-effective means for increasing the capacity of local area optical networks. An attractive way of operating such a network is to allow only a maximum number of lasers, Lmax to be on at a particular time. This allows SCM network capacity to be increased significantly. Consequently, no more than Lmax nodes can transmit simultaneously. If Lmax is exceeded, the carrier-to-noise ratio will fall below the designed limit and transmission errors will be introduced. A non-contention based medium access protocol is therefore required to govern the node access to the medium. A multichannel global queue cyclic reservation (MGQCR) protocol is described for use in such an environment. The performance of the protocol is studied both theoretically and through computer simulation with a selection of numerical results being presented. It is found that the performance of this MGQCR protocol can be approximated by a G/M/c queue model with good accuracy, particularly when the number of nodes is large compared to the number of channels