RPNoC: A ring-based packet-switched optical network-on-chip

Optical network-on-chip (ONoC) is a promising solution for its high bandwidth and low energy consumption. However, optical circuit switching requires an electrical control network, which leads to network congestion, low network utilization, high latency, and an overhead in energy consumption. In this letter, we propose an architecture called RPNoC based on ring topology using packet switching. A wavelength assignment method and a deadlock-free deterministic routing algorithm are jointly designed, which significantly reduce the maximum number of hops using much fewer optical devices compared with other packet-switched ONoCs. The simulation is carried out for 64-node RPNoC under uniform and realistic traffic pattern. The evaluation results show that it yields higher throughput, lower latency, and lower energy consumption than mesh and ring networks.