Research And Improvement On Ad Hoc Networks Routing Protocol

Routing Protocol is a key technique of Ad Hoc networks and one of the most important factors affect the performance of the networks. Because of the dynamic and variable topology, those traditional routing protocols cannot be suitable for Ad Hoc networks and how to design new wireless routing protocols has been a very hot issue for current research on Ad Hoc networks. Besides, Considering of the limitation of the bandwidth and remaining energy, how to provide a QoS support routing path is another hot issue in Ad Hoc networks.In this paper, through deeply analyzing Ad Hoc networks routing protocols, two new Ad Hoc networks routing protocols are proposed. At first, base on AODV, an energy and RREQ flood-control routing protocol is brought up. When the remaining energy of one route node is lower than warning value, the node sends an alarm message to ask whether the source node finds a new route path in advance. This scheme may cause RREQ flood load. To control the scope of RREQ packets, hop count is used to guide RREQ packets toward to destination node. Secondly, in route discovery process of EMQMR, the forward of RREQ packet depends on the remaining energy and bandwidth of the intermediate node along the path. Link duration time (LDT), together with hop count, is used to construct the QoS-enabled and stable multicast tree.Finally, ED-AODV and EQEMR protocols have been simulated on NS-2 network simulation platform, and experimental results testify that ED-AODV improves performance in three aspects, including packets delivery ratio enhancement, end to end delay decrease, and extend Ad Hoc networks node survive time. Guaranteeing packets delivery ratio, EQEMR has reduced networks load. Hence, ED-AODV and EQEMR are both routing protocols of QoS assurance.