Scheduling Schemes for Delayed Graphs with Applications to Optical Packet Networks

We revisit the problem of scheduling optical rings with tunable transmitters and fixed receivers. When such architectures are applied to metro area rings with long and possibly variable propagation delays, scheduling becomes complex because we need to account for these delays. We devise mechanisms that take into account propagation delays and can achieve 100% throughput for admissible traffic patterns, when traffic demands are known. We also show how the model can be extended to best-effort traffic, without the need for a Medium Access Control protocol, using the idea of Birkhoff-Von Neumann Load Balanced Switching.