An Efficient Scheduling Algorithm for Time-Driven Switching Networks

Abstract

Time-driven Switching (TDS) networks with non-immediate forwarding (NIF) provides scheduling flexibility and consequently, reduces the blocking probability (blocking is defined to take place when transmission capacity is available, but without a feasible schedule). However, it has been shown that with NIF scheduling complexity may grow exponentially. Efficiently finding a schedule from an exponential set of potential schedules is the focus of this paper. The work first presents the mathematical formulation of the NIF scheduling problem, under a wide variety of networking requirements, then introduces an efficient (i.e., having at most polynomial complexity) search algorithm that guarantees to find at least one schedule whenever such a schedule exists. The novel algorithm uses 'trellis' representations and the well-known survivor-based searching principle.