Design of an Optical Packet Switch for Real-Time Applications

Network switches are typically designed for best- effort Internet traffic. Most of existing studies have been focused on improving throughput and delay performance in an average sense rather than providing guaranteed delay bound that is critical for real-time applications. It has not been fully investigated how to design an efficient packet switching algorithm for real-time applications. In this paper, we propose a design framework for a real-time optical switch that is intended for use as an optical switch fabric. Our contributions are two folds: First, by introducing a clearance-time optimal switching together with clock-based scheduling, our switching design guarantees any feasible real-time traffic to be switched in two- clock periods. Second, we investigate key implementation issues of an optical packet switch such as packet size and buffering for real-time applications, and take account of these issues in design and performance evaluation of a switching algorithm. Our numerical study shows that the proposed switching algorithm provides a larger schedulability region with significantly reduced delay compared to the well-known iSLIP scheme.