This dissertation, "Quality of Service Support in Mobile Ad Hoc Networks" by Wenjian, Shao, 邵文簡, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Abstract of thesis entitled "Quality of Service Support in Mobile Ad Hoc Networks'' Submitted by Shao Wenjian for the degree of Doctor of Philosophy at The University of Hong Kong in August 2006 In this thesis, we investigate the quality of service (QoS) routing and media access mechanisms for mobile ad hoc networks (MANET). Our work is treated from two perspectives: TDMA-based MANET and contention-based MANET. For TDMA-based systems, it is possible to achieve end-to-end QoS through resource reservation, as the integrated services (IntServ) QoS paradigm. In previous approaches, the time slot reservation scheme led to the shortcut collision problem. In this thesis, we use the contention graph to clearly identify the shortcut collision problem, and propose a distributed end-to-end time slot reservation algorithm to solve this problem. Performance evaluation shows that our algorithm can achieve performance close to the theoretical upper bound, but with much lower complexity. Based on the reservation algorithm, we propose a QoS routing protocol in TDMA-based MANET. The purpose of our research is to enhance the reliability of the routes. Multiple paths are set up between the two communication terminals, and created in a sequential manner, to avoid the link collisions along the paths when they are reserved simultaneously. Erasure coding is used to further improve the link reliability. With the help of erasure coding, the destination can still receive the data even when some paths break down during the transmission. Implementing IntServ in TDMA-based systems usually involves high signaling overheads and complexity. The resources, once reserved, cannot be re-allocated to other connections even if they are not actually used. A more flexible way is to differentiate the traffic of different services, and this model corresponds to differentiated services (Di ffServ) in QoS . To support DifPServ in contention-based MANET, we research the media access scheme with power control. Previous studies have shown that system capacity can be increased through power control. However, this severely penalizes the nodes that are far apart, making it difficult for them to reach each other. In our research, we devise a busy tone based approach, through which a node can announce media access requests. Nodes overhearing the announcement will then refi-ain from transmission. If a node fails to access the channel several times, the node can utilize the busy tone for the purpose of quick channel access. In this way, the unfairness problem for the power-controlled protocols can be greatly alleviated. As an alternative, we apply the busy tone based quick channel access scheme to DifPServ in contention-based MANET. A high priority node is allowed to use achieve the busy tone channel with fewer channel access failures, while a low priority node can use it after more channel access failures. In this way, the high priority nodes can achieve better performance in terms of throughput, delay, loss rate and fairness than the lower priority ones. More importantly, we integrate in-station access categories (AC) into our protocols, enabling a station to support different classes of traffic to meet the different QoS requirements of the users. DOI: 10.5353/th_b3704215 Subjects: Routing (Computer network management) Computer network protocols Mobile communication systems