An adaptive scheduling algorithm for differentiated services on WDM optical networks

One of the important issues in the design of next generation high-speed networks is to provide Differentiated Services to different types of applications with various time constraints. In this paper, we study the problem of providing real-time service to either hard or soft real-time messages in conjunction with a normal transmission service to variable-length messages without time constraints in wavelength division multiplexing (WDM) optical networks. We propose an adaptive scheduling algorithm to schedule and manage message transmissions in single-hop passive-star coupler based WDM optical networks. In particular, we develop an adaptive scheme for scheduling message transmissions in order to improve the network performance when both real-time and non real-time messages are transmitted in one single topology. In addition, we have conducted extensive discrete-event simulations to evaluate the performance of the proposed algorithm. This study suggests that when scheduling message transmission in WDM networks, a differentiated service should be considered to benefit the transmission of both real-time and non real-time messages so that the overall performance of the network could be improved