A comparison of scheduling policies for real-time network

This paper deals with non-preemptive and work-conserving M/G/1 queues ordered by Earliest-Deadline-First (EDF) queuing discipline. This discipline is largely used in multimedia communications and in real-time applications. In our study we compare the performances of two scheduling algorithms applied on M/G/1 queuing systems. The first algorithm is a priority scheme and the second is deadline-based. We use multiple real-time traffic streams submitted to a single server and propose an approximate mean value analysis of the waiting time of each stream, assuming that arrivals are Poisson and the server is nonpreemptive. The simulations are made with an event discrete simulator, Opnet tools. Results show that the algorithm implementing a strict deadline is more efficient than a priority scheduling. However, it will be necessary to take into account a ressource allocation mechanism at network level, for future work, to control the loss rate.