Research On QoS Aware DSR Protocol In Ad Hoc Networks And NS2 Simulations

Mobile Ad Hoc Networks (MANET) is a kind of multi-hop wireless mobile networks, and is a self-configuring network of mobile routers with receiving and sending equipments connected by wireless links. In MANET, multimedia applications require the network to guarantee Quality-of-Service. However, because of the multi-hop wireless mobile nodes, limited storage capacity as well as unstable topology in MANET, the research related with MANET based on QoS is a challenge.In this thesis, firstly the recent research progresses about the Ad Hoc Networks based on QoS are overviewed. Then, it analyzes strategies about the QoS-aware routing protocols. It also improves the Dynamic Source Routing Protocol and designs QoS-DSR routing protocol.The Dynamic Source Routing protocol (DSR) is a simple and efficient routing protocol designed mainly for medium-sized mobile Ad Hoc Networks. As DSR is based on Source Routing, nodes needn't to save routing information and broadcast routing information periodically. However, DSR protocol only supports best-efforts applications. It is not a QoS routing protocol. So, this thesis firstly focuses the shortcoming of DSR and overviews the research progresses related with QoS-ware routing protocols based on DSR. Different strategies are then compared and the advantages and disadvantages are analyzed.Secondly, A new QoS-aware routing protocol based on DSR named QoS-DSR is further proposed. QoS-DSR makes the following modification based on DSR. (1) While retaining the main fields in RREQ, it adds the QoS parameters such as bandwidth, delay etc; (2) it selects rout according to bandwidth, delay, buffer and routing lifetime; (3) the strategies of single-path and multipath are merged into protocol. QoS-DSR discovers the path which satisfies the QoS of application according to the network information and balances the load, improves the efficiency by making good use of advantages of single path routing and multipath routing.Finally, QoS-DSR was simulated with NS-2, and the result shows that (1) the QoS-DSR performs better than DSR in throughput. (2) The overhead of routing protocol is acceptably. (3) QoS-DSR guarantees the QoS, such as bandwidth and delay. So it comes to the conclusion that QoS-DSR is an efficient QoS-aware routing protocol.