Fast scheduling based on iterative parallel wavelength matching for a multi-wavelength ring network-on-chip

Abstract

In synchronous networks-on-chip (NoC), scheduling of packet transmission is required for achieving high throughput, low latency and good fairness, while avoiding packet collisions. Efficient algorithms exist for rearrangeably non-blocking NoC. However, when realized with integrated optical devices, NoC are typically arranged in topologies that are blocking if a single wavelength is used. Mitigation of the blocking behavior is then achieved by exploiting the wavelength domain, which requires however a novel scheduling paradigm. This paper presents an integrated optical NoC based on a ring topology and realized with multiple resonating microrings (MMR). Scheduling in MMR architecture comprises the conventional matching sub-problem along with wavelength assignment sub-problem, which accounts for the additional constraints due to the wavelength domain. A novel scheduling algorithm based on iSLIP algorithm is proposed for jointly addressing both sub-problems. The iterative Parallel Wavelength Matching (iPWM) algorithm achieves performance similar to a two-step scheduler based on sequential iSLIP and first-fit wavelength assignment, but with a computational complexity lower and independent of the number of wavelength

Simulation and FPGA-Based Implementation of Iterative Parallel Schedulers for Optical Interconnection Networks

“…13, the latency is plotted as a function of the load for an optical interconnection network of N 4 and 16 ports. The figure reports the ipLQF performance of both the hardware (HDL error bars) and software implementations (C/C++ lines) achieved using an event-driven simulator [10]. The good matching between the curves and the error bars validates the hardware implementation.…”

Ring Versus Bus: A Theoretical and Experimental Comparison of Photonic Integrated NoC

“…Each microring acts either as an add or drop filter. Add and drop operations occur by properly tuning the microrings at the source and destination ports, enabling the communication between the ports as scheduled [25]. The wavelength of the added (or dropped) signals is fixed by the resonance wavelength of the microrings.…”