A comparison of optical time slotted networks

To harness the enormous bandwidth potential of a fiber, Time Division Multiplexing over wavelength channels has been proposed. In one type of time slotted optical network called as Time Wavelength Switched Network (TWSN), the Time Wavelength-Space Routers (TWSRs) are configured to switch time slots within a time frame. Another kind of time slotted network is the Time Domain Wavelength Interleaved Network (TWIN), which eliminates time switching within the network by using passive Wavelength Selective Switches(WSSs) in the core and an intelligent edge utilizing a fast tunable laser to emulate fast switching. In this paper, we provide an integer linear program to solve the scheduling problem for a static traffic matrix (of connections) for the TWIN network, and also present a heuristic algorithm. We then compare the performances of the two networks under dynamic traffic and investigate the benefits of having a fast reconfigurable switch as opposed to WSSs.