An efficient scheduling algorithm for real-time traffic on WDM passive star optical networks

One of the major challenges in the design of future-generation high-speed networks is the provision of quality-of-service (QoS) to real-time traffic. In this paper, we propose a novel scheduling scheme, namely differentiated dropping scheduling (DDS), which is designed to handle real-time traffic in passive star-coupled wavelength division multiplexing (WDM) optical networks. By taking channel and destination availability into account, DDS can dramatically improve network performance in terms of message loss rate. Moreover, this scheme has the capacity of preventing channel collision and destination conflict. In order to evaluate the proposed DDS algorithm, extensive discrete-event simulations and mathematical performance comparison are conducted by comparing its performance with Moore and Hodgson´s algorithm and the earliest-due-date (EDD) algorithm. The results show that DDS can achieve the best performance among the three algorithms.