Research On QoS Routing Strategies For Ad Hoc Networks

The features of Ad Hoc Networks are multi-hop and self-organized wireless network without a fixed network infrastructure. It is employed in commercial communication gradually from its earlier application in military communication. With the developing of multi-operation of network, it has became the emphasis of research that providing QoS (Quality of Service) guarantee in Ad Hoc Networks. Now most of the QoS routing researches focus on studying single metrics in QoS routing, e.g., the QoS routing with Bandwidth constraint.It comes out the conflict of the limited Bandwidth resource and providing guaranteed Bandwidth QoS routing because of the limitative Bandwidth resource in Ad Hoc Networks. This thesis sums up the relational research result aiming at the conflict at home and aboard, and does some further studies on the mathematical model constraining QoS routing and the mechanism of competitively sharing the limitative Bandwidth resource. This thesis is trying to make a compromise between two sides of the conflict, giving routing discovery based on interzone Bandwidth constraint and the Bandwidth allotment rule based on reserving Bandwidth resource for un-communication nodes. From the studies above, this thesis introduces improved protocol FAQ_AODV (Fair Aware QoS AODV) on AODV protocol.FAQ_AODV protocol is a QoS routing with fair aware. In routing discovery operation, Bm in , The lower limit of Bandwidth, is tolerable Bandwidth just for meeting Quality of Service, while Bm ax, the upper limit, is the optimal Bandwidth for optimizing Quality of Service. Routing nodes allot Bandwidth value Ba llot to routing, which is based on the premise of satisfying Bm inaccording to definite fair rule. The restriction of allotting Bandwidth Ba llot is [ ]Ba llot∈Bm in ,Bmax, and the ultimate routing Bandwidth is the minimum among the whole routing nodes allot. FAQ_AODV gives consideration to fairness of sharing Bandwidth resource as well as satisfying Quality of Service to some degree. This paper, utilizing OPNET Modeler simulation platform, comparatively analyses the advantage and disadvantage of FAQ_AODV from original AODV. The result shows FAQ_AODV has better network throughput than AODV.