DESIGN OF WAVELENGTH-ROUTED OPTICAL NETWORKS FOR PACKET-SWITCHED TRAFFIC

We consider problem of designing a logical optical network topology fo r a given physical topology (or fiber layout) and a given traffic dema nd matrix between the end-users. Traffic between the end-users is carr ied in a packet-switched form and the objective of our logical topolog y design is to minimize the maximum congestion on the logical connecti ons in the logical topology, The logical connections are realized by w avelength continuous paths or lightpaths between end-users and they ar e routed via wavelength-selective routers. Note that a topology with l ower maximum link congestion will allow its traffic demand matrix to b e scaled up by a larger factor, In the logical topology each node is e quipped with a limited number of optical transceivers, hence logical c onnections cannot be set up between every pair of nodes. In this paper we present an improved lower bound for maximum congestion on any link in the logical topology, The bound is shown to be up to 50% higher th an the existing ones, An analytical model for obtaining the maximum an d average logical connection loads for a given logical network and tra ffic demand matrix is also formulated, and it has been confirmed via s imulation, Finally, two heuristic algorithms for constructing a logica l topology that reduces maximum logical connection congestion are pres ented.