摘要：Problem statement: The application of Mobile Ad hoc NETworks (MANETs) has been increasing every day. Most applications that attract interest for use in current wired networks (e.g. video conferencing, on line movies and camera enabled instant messenger) would attract interest for MANETs also. Many applications that use MANETs include multimedia data that require Quality of Service (QoS) support for effective transmission. Basically meeting QoS is a mesh of multiple parameters. QoS routing based on multiple independent constraints has been proven to be NPcomplete. Hence, hardly any exact algorithms were proposed for this kind of problems. In this study we propose a new approach for QoS routing based on multiple constraints. Approach: QoS support can be achieved by finding a route satisfying the application requirements. This needs an admission control along the route to prevent new flows from consuming too many resources and disrupting the guarantees made to existing flows. In our work, the normal AODV is extended to perform QoS routing based on bandwidth requirement and link stability constraints. Link stability parameter is considered in an opportunistic way so that effective path meeting the required bandwidth and will last for complete session is established. Results: Simulation results show that our contention aware, link stability based route finding technique performs better than AODV in terms of throughput and control message overhead. It improves packet delivery ratio greatly without affecting the overall end-to-end throughput of existing flows. Conclusion: This multi constraint based AODV performs path finding with less overhead by adopting passive approach of listening to the medium. Hierarchical treatment of the metrics enables QoS robustness hence reduces subsequent route finding latency.
关键词：Quality of service; bandwidth estimation; contention aware; link stability; multiconstraints; Probability Distribution Function (PDF); Medium Access Control (MAC); simultaneous transmission; ad hoc networks; mobility model
