Transmitter Vs. Receiver SDL Solutions for Contention Resolution in WDM Ring Networks

Abstract

In a single channel ring network the maximum achievable node throughput is inversely proportional to the number of nodes. Recent progress in WDM has opened the possibility to overcome this limitation by utilizing the multiple channels for parallel transmissions. Here we present an approach to obtaining a Concurrently accessed multi-Ring all-Optical WDM Network (CROWN) in which in-transit packets pass through the node (are switched) without being convened into the electronic domain. This avoids the well-known electronic bottleneck which further reduces the throughput of conventional WDM networks. The proposed architecture is also economical by using only a single high speed transmittcr and receiver per node. To allow data to be maintained in the optical format and still benefit from the multiplicity of channcls this low-cost node configuration introduces the use of Switched Dclay Lines (SDL) as part of either the receiver or the transmitter hardware. It is shown that in the WDM multi-channel system the (per node) capacity is at least 50% of the capacity of a single channel optical system with equivalent total bandwidth. However, the cost of the proposcd WDM solution is greatly reduced as it does not require that nodes access the network at the network aggregate bandwidth rate.