Call admission control and QoS criteria in wireless networks

Abstract

Wireless communication systems have developed rapidly as there have been many advances in the related technology. Wireless communication systems of today permit a user to communicate from any where at any time with on-demand quality of service (QoS) for different applications. The available resource is limited in wireless communication system all the time although technological development in that area. Service operators have been faced with a problem how they can provide satisfying service to their subscribers with limited resource. One of the major topics of optimization in the wireless systems is call admission control (CAC). CAC is a decision process to admit a new or handoff call according to the amount of available resource versus user’s QoS requirements and the effect upon the QoS of the existing calls imposed by the new admission. In this thesis we approach CAC in two different aspects. Both of them we try to maximize overall throughput of system. First we propose a CAC scheme with considering that the available physical resource is limited. The physical resource at base station (BS) is limited practically. It will cost service operators to install the additional the equipments, for example, receiver processors at BS. Hence, it is necessary to operate efficiently systems with finite equipments. The receiver processors in BS, in general, are shared by new calls and handoff calls. However, CDMA systems adopts soft handoff which gives handoff calls priority to new calls so that handoff calls occupy large amount of resource from view of equipments as well as radio channels. This results in reducing the carried traffic in entire system. In this thesis we propose a scheme to maximize carried traffic in a CDMA system with finite receiver processors. Next we propose another CAC scheme which belongs to guard channel scheme. The CAC for wireless systems has to efficiently support handoff and maintain high resource utilization. Since premature drop of...