Adaptive high-speed and ultra-low power optical interconnect for data center communications

In this paper, two basic methods for a performance and power adaptivity on system and component level in optical interconnects for data center communications are introduced and explained. The approaches are investigated in the EC FP7 project ADDAPT (Adaptive Data and Power Aware Transceivers for Optical Communications) which targets significant power savings in optical interconnects. First, a rapid link on/off switching is investigated when idle symbols are present in the data stream. For active data, a rapid on-switching in less than 20 ns at data rate of 56 Gb/s is achieved, which is almost one order of magnitude faster than in current systems. To evaluate power savings potential in links with multiple lanes, network analyses were performed and several packet statistics were investigated. As a result, up to 80% power savings can be achieved at 10% link utilization. Second, dynamic speed adaptation allows scaling down the performance of individual link system according to varying network traffic load. By this adaptive tuning, a reduction of the nominal power consumption by up to 80% is estimated when tuning down the link data rate from 56 Gb/s to 7 Gb/s.