Efficient joint call admission control and bandwidth management schemes for QoS provisioning in heterogeneous wireless networks
Doctoral Thesis
2008
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University of Cape Town
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Abstract
Next generation wireless network (NGWN) will be heterogeneous where different radio access technologies (RATs) coexist. This coexistence of different RATs necessitates joint radio resource management (JRRM) for enhanced QoS provisioning and efficient radio resource utilization. Joint call admission control (JCAC) algorithm is one of the joint radio resource management algorithms. The basic functions of a JCAC algorithm are to decide whether or not an incoming call can be accepted into a heterogeneous wireless network, and to determine which of the available RATs is most suitable to admit the incoming call. The objective of a JCAC algorithm is to guarantee the QoS requirements of all accepted calls and at the same time make the best use of the available radio resources. Traditional call admission control algorithms designed for homogeneous wireless networks do not provide a single solution to address the heterogeneous architecture, which characterizes NGWN. Consequently, there is need to develop JCAC algorithms for heterogeneous wireless networks. The thesis proposes three JCAC schemes for improving QoS and radio resource utilization, which are of primary concerns, in heterogeneous wireless networks. The first scheme combines adaptive bandwidth management and joint call admission control. The objectives of the first scheme are to enhance average system utilization, guarantee QoS requirements of all accepted calls, and reduce new call blocking probability and handoff call dropping probability in heterogeneous wireless networks. The scheme consists of three components namely: joint call admission controller, bandwidth reservation unit, and bandwidth adaptation unit. Using Markov decision process, an analytical model is developed to evaluate the performance of the proposed scheme considering three performance metrics, which are new call blocking probability, handoff call dropping probability, and system utilization. Numerical results show that the proposed scheme improves system utilization and reduces both new call blocking probability and handoff call dropping probability. The second proposed JCAC scheme minimizes call blocking probability by determining the optimal call allocation policy among the available RATs. The scheme measures the arrival rates of different classes of calls into the heterogeneous wireless network. Using linear programming technique, the JCAC scheme determines the call allocation policy that minimizes call-blocking probability in the heterogeneous network. Numerical results show that the proposed scheme reduces call-blocking probability in the heterogeneous wireless network.
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Includes bibliographical references (leaves 150-157).
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Falowo, O. 2008. Efficient joint call admission control and bandwidth management schemes for QoS provisioning in heterogeneous wireless networks. University of Cape Town.