Simulation analysis of a collisionless multiple access protocol for a wavelength division multiplexed star-coupled configuration

A collisionless wavelength division multiple access protocol is introduced for a passive star-coupled photonic network that possesses significant performance and flexibility advantages over alternative approaches. A detailed simulation analysis is developed to study the behavior of the protocol with varying system characteristics. The protocol is control channel based: one of the WDM channels is used to reserve access for data packet transmission on the remaining data channels. Control channel access arbitration is achieved through time-division multiplexing, enabling all active nodes the opportunity to transmit once every control cycle. This approach significantly reduces the long synchronization delays typical of time-division multiplexing systems: the control cycle length is proportional to the control packet size rather than the data packet size. The proposed approach has the advantage that variable sized data packets in a collisionless environment are supported without utilization degradation. Furthermore, a mechanism is introduced that relaxes the constraints on the switching times of the optical components by decreasing the performance sensitivity. The performance is evaluated in terms of network throughput, packet delay, and control and data channel utilization. In particular, this paper examines the performance impact with variations in the number of nodes and data channels, packet generation rate, data packet length, and the optical device switching latencies.