Energy saving through a buffer control approach for hybrid optoelectronic routers

Data center networks are required to have high energy efficiency as well as high communication performance. One approach to achieving these requirements is to use a hybrid optoelectronic router, which has optical packet switching functionality and packet buffering in an electronic domain. These hybrid optoelectronic routers can cut the power of electronic buffers while maintaining optical packet switching functionality. This enables energy consumption to be reduced while maintaining the required communication performance. The routers whose buffers can be shut down depend on the traffic routes; more buffers can be shut down by setting the traffic routes so as to avoid packet collision. However, the routes that avoid packet collision may increase the number of powered-on routers. Therefore, we should select the traffic routes considering the energy consumptions of the routers themselves and their buffers. In this paper, we propose a heuristic route selection method to reduce energy consumption while maintaining the required communication performance. For high energy efficiency, our method efficiently re-uses routers and buffers without degrading the required communication performance. Through simulation, we demonstrate that our method reduces the energy consumption significantly compared to methods that do not consider buffer energy consumption or that calculate the shortest traffic routes through the network.