Multi-media Communication QoS Guarantee In Ad Hoc Home Network

Ad hoc home networks is a new type of wireless networks withoutsupporting of any physical infrastructure, which make the network is easy todeployment, flexible to operate, and is expected to have promising applications.Recently, with the popularization of multimedia applications and the developmentof commercial applications in ad hoc home network, providing Quality of Service(QoS) over such networks is a significant issue. However, because of thelimited resources, shared channel and dynamic topology of ad hoc home network,,traditional QoS guarantee schemes do not applicable to such special networks forconstructing a high QoS multimedia application. Therefore, the implementation ofstable real-time end-to-end transmission with QoS guarantee needs global,comprehensive and dynamic considerations.The objective of this paper is to investigate the issue of QoS guarantee formultimedia applications in ad hoc home network. This work proposed severaloptimizing schemes from the view of distributed caching,multipath QoS routing,hierarchy routing, had achieved the following conclusions:(1) Distributed caching based QoS guarantee for multimedia streamingWith the analysis on the characteristics of ad hoc networks and the accessmodel of multimedia program, this paper proposes an optimized cache-dataplacement algorithm OCPA, which is especially for multimedia application and issuitable for ad hoc network architecture. In this algorithm, given by thetransmission costs among proxy nodes, and between the source node and eachproxy node, and the buffer size of each proxy node, and then distributing thesegmented prefixing caching data into multiple proxy nodes to minimize thetransmission cost of requested media data at the client node end. The resultsdemonstrate that the proposed OCPA algorithm achieves smaller transmission cost,improved system robustness and scalability.(2) The construction of Multimedia cache backbone for heterogeneous adhoc networksThis work is target for constructing a Multimedia cache backbone forheterogeneous ad hoc networks. Most of existing work are based on the conceptof minimum connect dominating set (MCDS), which is only target for minimizingthe number of backbone nodes, but not take the real characteristics of nodes into account when constructing the backbone. In the way, some low performancenodes could be the bottleneck of the backbone. In our work, we select morecapable nodes as candidates to construct a high performance backbone, and aminimum connected dominating set with high node performance (MCDS-HNP)algorithm is proposed. We also present the approximation ratio of the proposedalgorithm. The simulation results demonstrate that the MCDS-HNP algorithmachieves better backbone performance while maintaining approximately the samebackbone size.(3) Genetic algorithm based multi-path QoS routing for streaming mediaA multi-path QoS routing algorithm MOMR for multimedia application hasbeen proposed. The objective is to find the most suitable route for transmittingstreams, and thus minimize the whole distortion of packets. This paperinvestigates the issue of multi-traffic transmission and then proposes a suitablenetwork model, where the metric of distortion is measured according to theachieved cross-layer information, and an optimized routing model is constructed.These issues are solved through genetic algorithms. The simulation shows that theproposed algorithm outperforms other traditional algorithms that are constrainedin network layer.(4)Traffic-prefer-based Multi-QoS Object Decision layer Routing TMQODRBased on the research background of multi-path choosing between gatewaysin hierarchy routing, with the idea "server in demand", this work exploit theguarantee method of traffic flow's specific QoS requirements and put forwardsome relevant policies and methods, including representation, transition andcomputation of traffic flows' QoS preference. On the basis of trffic flows' QoSpreference, the strategy of optimal service selection is brought forward in thework, and at the same time QoS satisfying degree with its computation method forusers is defined. Then, this work put forward a traffic-prefer-based multi-objectivehierarchy routing TMQODR in accordance with above achievements. Theanalysis on relevant performance for the algorithm has confirmed its feasibilityand effectivitly.