Performance evaluation of CROWNs: WDM multi-ring topologies

It is well known that the maximum node throughput achievable in a single channel ring network is inversely proportional to the number of connected nodes. Furthermore, in an optical medium network, the electronics required to elaborate in-transit data at each node creates a performance bottleneck for the whole communication system. Progress in WDM techniques has opened the possibility to overcome these problems by relying on a multi-channel, optical, solution. The paper presents and analyzes an approach to obtaining a concurrently accessed multi-ring all-optical WDM network (CROWN) with a node architecture in which in-transit packets pass through the node without being converted into the electronic domain. Using a single high speed transmitter and receiver per node, CROWN allows data to be maintained in the optical format while resolving receiver contentions. An original modeling technique, with an effective characterization of the principal aspects of the system behavior, is also provided for performance evaluation, showing that network capacity and network latency are improved under the proposed solution.