Scheduling high-rate sessions in Fractional Lambda Switching networks: Algorithm and analysis

This work addresses the high-rate session scheduling problem in fractional lambda switching (FlambdaS) networks. With its global phase synchronization and pipeline forwarding (PF) operation, FlambdaS offers promising network performance and scalability over its competitors, e.g., time division multiplexing (such as SONET/SDH) and wavelength division multiplexing (WDM). Yet, Non-Immediate Forwarding (NIF) brings challenging complexity to session scheduling, where other known scheduling methods (e.g. RWTA) are not applicable. A forwarding graph is used to wholly examine the huge schedule space for an end-to-end high-rate NIF session. An efficient scheduling algorithm, eSSM, is proposed to explore all possibilities on the graph and present the optimized non-blocking schedule. Complexity bounds are then devised analytically and experimentally verified under specific circumstances. A low-complexity heuristic is proposed to avoid the complexity of eSSM in low-load networks.