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Title: Cross-layer optimization of WiMAX system with quality of service guarantee
Author: Noordin, Kamarul Ariffin
ISNI:       0000 0004 2720 9269
Awarding Body: Lancaster University
Current Institution: Lancaster University
Date of Award: 2009
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The increasing demand for last mile high speed internet access has contributed to the popularity of the broadband wireless access (BW A) systems for fulfilling such requirement since they can realized it with lower cost compared to the wired solutions. WiMAX which is based on the IEEE802.16 standard and is one of the latest offerings in the BW A systems promises to provide high speed access with Quality of Service (QoS) support. Different service classes are defined together with their associated QoS parameters in order to support different types of user applications. However, no scheduling architecture is defined to guarantee these defined QoS requirements. In this thesis, a scheduling algorithm which observes the QoS requirements of all service classes in both uplink and downlink directions has been proposed. Using the service class type to determine the priority for transmission and the calculation of required slots, the QoS of users from higher service- classes could be guaranteed without starving users from the lowest service class. To gain from multiuser diversity, channel-aware scheduling algorithm based on cross-layer optimization in band Adaptive Modulation and Coding (AMC) has also been developed. The algorithm not only aims to fulfil the QoS requirements and increase the system throughput but also aims to be practical and conform to the standard. Instead of finding the optimal solution which is too complex for practical implementation a suboptimal solution using heuristic method has been proposed. The cross-layer approach has been extended to provide cross-system optimization in which WiMAX and WiFi networks are selected for the case study. The optimization between the Medium Access Controls (MACs) of the two networks has been facilitated by QoS mapping of the application types between the two networks. Combined with the cross-layer optimization, the system throughput could be increased while guaranteeing the end-to-end QoS.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available