Performance evaluation of multirate time division multiplexed wavelength routed optical networks

We consider a wavelength routed all-optical mesh network, where the wavelengths are divided into individually routed timeslots to improve utilization and to allow for a higher degree of optical transparency. The multirate scheduling problem is defined mathematically by integer linear programming formulations. The equivalence of this problem to traditional wavelength routed optical networks is shown. An approximative analytical expression for the gain of using timeslots is derived and verified by simulation. We find that this type of network improves scalability and utilization of all-optical networks significantly when the typical size of a traffic demand corresponds to a couple of wavelengths or less.