Home > Published Issues > 2014 > Volume 9, No. 6, June 2014 >

Performance Modeling in Multi-Service Communications Systems with Preemptive Scheduling

Shuna Yang and Norvald Stol
Department of Telematics, Norwegian University of Science and Technology, Trondheim 7030, Norway

Abstract—This paper presents two separate Markov models to investigate blocking probabilities in multi-service communications systems, when preemptive scheduling is adopted to implement service differentiation. One is the generalized model, which is built as a multi-dimensional Markov chain, based on a variant of the multi-dimensional Erlang loss model. The other is the hierarchical model, which is constructed as a multi-level Markov chain, based on a combination of one-dimensional Erlang loss models. A detailed comparison when applying these two models to a general R-service communications system is presented. This validates the major advantages of the proposed hierarchical model: the closed form expressions of blocking probabilities; the dramatically reduced computational complexity; and the excellent scalability for analyzing larger systems. Furthermore, the analytical values are compared with simulation results for two- and three-service systems. Results show that the proposed hierarchical model provides a high degree of accuracy in the blocking probabilities under different scenarios, especially when the relative arrival rates of the lower priority classes are high.

Index Terms—Markov chain, preemptive scheduling, multi-service system, service differentiation, blocking probability

Cite: Shuna Yang and Norvald Stol, "Performance Modeling in Multi-Service Communications Systems with Preemptive Scheduling," Journal of Communications, vol. 9, no. 6, pp. 448-460, 2014. Doi: 10.12720/jcm.9.6.448-460