Overlaying rings onto a mesh network

Optical packet switching (OPS), a promising technology for small, high-capacity networks such as metro or regional networks, leverages optical transparency to decrease the number of interfaces to be deployed and the energy consumption of a network when compared with an opaque technology. Based on those principles, ring-based OPS techniques such as POADM (Packet Optical Add-Drop Multiplexers) were proposed in the past. However, many networks that are already deployed are physical meshes. In this paper, we tackle the problem of mapping OPS rings onto physical meshes. We propose meta-heuristic algorithms based on simulated annealing (SA) and a genetic algorithm (GA). The algorithms also determine where backbone/core nodes should be located. The algorithms minimize the cost of the network expressed for instance in terms of optoelectronic conversions. The impact of various physical constraints (maximum ring length, maximum number of wavelengths in a ring) are included and characterized. We show that, for standard physical constraints, a fully opaque Ethernet network requires 50% more optoelectronic devices than the proposed optical packet switching network.