The impact of different scheduling policies on traffic class dependent routing in intersatellite link networks

The provision of multimedia applications characterized by the integrated presentation of various data sources requires a network infrastructure providing broadband access, large available bandwidth in the core network, and traffic differentiation which supports efficient utilization of network resources and service level guarantees. In order to distinguish between different traffic classes and to optimize utilization of network resources to their respective requirements, an efficient routing procedure capable of differentiating traffic and adapting to highly dynamic conditions in a non-geostationary ISL network needs to be implemented in combination with advanced fair scheduling policies in the outgoing queues. In this paper we analyze the performance of different scheduling policies in conjunction with adaptive routing procedures in the intersatellite link network of a packet-switched non-geostationary satellite system. In particular, different unfair first come first served and priority and fair weighted round robin, deficit round robin and surplus round robin scheduling policies are considered, in combination with single-service routing and traffic class dependent routing procedures. The performance of different scenarios is assessed, by means of simulation, in terms of average packet delay and average data throughput. The simulation results indicate that differentiated treatment of traffic using traffic class dependent routing and fair scheduling policies provides a significant improvement in overall performance for all traffic classes, regardless of the traffic scenario considered. Copyright © 2004 John Wiley & Sons, Ltd.