Efficient Utilization of Transmitter-Receiver Ports on an Optical Switch

In order to overcome the effects of degradation of the optical signal caused by transmission impairments, regenerators are placed at some intermediate nodes to regenerate the signal to its original level. Regeneration requires the signal to be dropped locally, regenerated and retransmitted back into the network. This process involves provisioning for required number of transceiver pairs at this node to support the additional traffic that is added/dropped locally in addition to the local traffic, which originates or terminates at this node. A common approach is to reserve a specific number of transceiver pairs for regeneration traffic and local add-drop traffic. This approach however leads to under-utilization of the common resource(transceiver pairs). We propose a sharable architecture in which the connections requiring regeneration and local add-drop traffic share a common pool of transceiver pairs. We also show via simulation and mathematical analysis that the sharable architecture achieves a lower blocking probability for add-drop connections without addition of more transceivers. This causes a reduction in the cost of the cross-connect and hence provides savings for the network provider.