Protection of Originating Calls in Handoff Prioritization Schemes

摘要

With the increasing popularity of wireless communication systems, customers are expecting the same quality of service (QoS), availability and performance from the wireless communication networks as the traditional wire-line networks. Currently the research work on radio channel allocation in cellular mobile systems focuses mainly on two aspects, improving the user admission capability and protecting the connection continuity for handoff calls as a QoS constraint. However, given a QoS constraint, a wireless network has to sacrifice its capacity in order to support an increase in handoff rate. In this paper, we propose and analyze a different handoff scheme which not only gives priority to handoff calls, due to importance of them from QoS standpoint, but also protects originating calls to keep system capacity at an acceptable level. In channel reservation schemes, there are some periods that reserved channels are not actively utilized. In this paper, these periods are defined as dead time. Indeed, our scheme mathematically analyzes the mean dead time. We use a system model defined by a two dimensional Markov chain which computes mathematically the performance in terms of the mean dead time, blocking probability of originating calls, forced termination probability and call incompletion probability. Results are compared with conventional predictive channel reservation (PCR) and guard channel (GC) schemes.