Research On QoS Routing Techniques And Security Routing Techniques In MANET

Along with the development of WLAN technology, Mobile Ad hoc Network (MANET) is getting more and more popular among researchers. Unlike the traditional WLAN, MANET needs no fixed infrastructure, and it is much flexible as a result. MANET communicates in a multi-hop style, thus makes it possible for nodes far away from each other to keep in touch with the forwarding of intermediate nodes. To support this forwarding, every node in MANET must have the function of routing.The thesis makes an in-depth study of MANET and its routing protocols, and proposes a QoS routing solution. The solution comprises a MAC-dependent QoS Routing Discovery mechanism (MQRD) and a Probe-based Routing Maintenance mechanism (PRM). In MQRD, delay is estimated at MAC layer, accumulated by routing request message (RREQ) while it travels from source to destination and finally given back to source with the routing reply message (RREP). The source node will choose a routing meeting the demand in delay. According to PRM, the source node sends a probe to destination and in terms of the delay from the time the probe leaves source to the time it comes back from destination, it decides whether the routing still supplies the required QoS and whether to initiate a routing recovery. The simulation shows that the QoS routing solution we put forward reduces the end-to-end delay obviously while increase only a little overhead.Both encryption techniques and trust models can be adopted in security routing. However, each of the two has its strong point. Encryption techniques focus on the protection of routing information while trust models on the detecting of malicious nodes. The security routing solution we proposed has integrated the both advantages. In our solution, the node makes the evaluation of trust on its neighbors by observing their behaviors——the node is informed the number of packets its next-hop node forwards by R_ACK sent from its"second-hop"node (the next-hop node of its next-hop node). After finding out the malicious node, it is isolated from other nodes by a trust-based routing discovery mechanism. The theoretic analysis shows that the security routing solution we bring forward can prevent the attack aimed at routing information and data packets.At the end of the thesis, we design a QoS security routing protocol based on the routing solution proposed above.