Performance analysis of a prioritization scheduling scheme for asynchronous optical packet switching networks

All-optical packet switching is a promising scheme to meet high-capacity data transmission and avoid the bottleneck of optical-electrical-optical conversion. However, optical buffers implemented by Fiber Delay Lines (FDLs) suffer a signal quality issue that noise and crosstalk from optical components of FDL buffers induce signal loss and noise accumulation. Optical packets will be dropped, if signal loss and noise accumulation result in poor signal quality. Because of this, packet scheduling becomes more difficult in the FDL buffer than in the RAM buffer, and requires additional design considerations to reduce packet loss. In this paper, we propose a prioritization scheduling scheme for asynchronous all-optical packet switching networks with FDL buffers. The prioritization scheduling scheme is intended to minimize the packet loss probability and the average latency of the networks by ranking packets in the optimal balance between latency and residual distance. We demonstrate quantitatively how to achieve the fitting balance between latency and residual distance so that the network performance can be improved significantly.