Scheduling optical packets in wavelength, time, and space domains for all-optical packet switching routers

This paper describes a novel sequential wavelength-time-space (sWTS) scheduling algorithm to solve the arbitration problem in an all-optical packet switch router and shows the simulation as well as the hardware implementation results. The simulation results with self-similar traffic input demonstrate that the sWTS arbitration algorithm effectively improves the packet blocking rate, forwarding latency and jitter as the number of wavelength channels per port and the number of recirculation buffer ports in the switch fabric increase. The proposed algorithm further facilitates a very fast and hardware-efficient mixed-tree output port arbiter design. The hardware implementation is evaluated in terms of area and delay for various switch sizes with both the Xilinx XCV1000E FPGA and a 0.25-micron commercial ASIC library.