All-Optical Wavelength-Routed Architecture for a Power-Efficient Network on Chip

In this paper, we propose a new architecture for nanophotonic Networks on Chip (NoC), named 2D-HERT, which consists of optical data and control planes. The proposed data plane is built upon a new topology and all-optical switches that passively route optical data streams based on their wavelengths. Utilizing wavelength routing method, the proposed deterministic routing algorithm, and Wavelength Division Multiplexing (WDM) technique, the proposed data plane eliminates the need for optical resource reservation at the intermediate nodes. For resolving end-point contention, we propose an all-optical request-grant arbitration architecture which reduces optical losses compared to the alternative arbitration schemes. By performing a series of simulations, we study the efficiency of the proposed architecture, its power and energy consumption, and the data transmission delay. Moreover, we compare the proposed architecture with electrical NoCs and alternative optical NoCs under various synthetic traffic patterns. Averaged across different traffic patterns, 2D-HERT reduces data transmission delay by 24, 15, 18, 4, and 70 percent and achieves average per-packet power reduction of 58, 47, 52, 45, and 95 percent over Phastlane, Firefly, Corona architecture, $(\lambda)$-router, and electrical Torus, respectively.