A performance study of photonic local area network topologies

Network topology significantly affects the system performance of local area networks. The bus topology was considered for optical local area networks since the degradation of system performance due to propagation delay could be reduced. Power budget constraints severely limited maximum system size which diminished its appeal. On the other hand, the star topology was shown to have excellent fanout and fault tolerance that led to extensive research interest in star based systems. Recent advances in optical amplifiers which expand the power budget have renewed interest in optical bus based networks. The objective of the authors is to compare the performance of bus and star based systems. They assess the performance improvement of bus based approaches, and show under what conditions it is justified in terms of performance, relative to the increase in component costs