ESPN: A case for energy-star photonic on-chip network

Photonic Network-on-Chips (NoCs) have recently been proposed due to their inherent low latency and high bandwidth. However, the high static power of the photonic components (e.g. laser source, resonators and waveguides) often results in energy-inefficient architectures. In this paper, we advocate the Energy-Star Photonic Network (ESPN) architecture that optimizes energy utilization via a two-pronged approach: (1) by enabling dynamic resource provisioning, ESPN adapts photonic network resources based on runtime traffic characteristics and (2) by utilizing all-optical adaptive routing, ESPN improves energy efficiency by intelligently exploiting existing network resources without introducing high latency and power hungry auxiliary routing mechanisms. Our evaluation results show that compared to the baseline design, ESPN reduces power and energy consumption under synthetic traffic patterns by 50% and 58% respectively.