Research On Multicast Routing Protocols With Qos Guaranteed In Ad Hoc Networks

With the development of wireless technology and the popularization of portable devices, the need for new mobile communication service has increasingly expanding. Conform to this trend, as a multi-hop, infrastructure-less and self-organized network, Ad Hoc network received increasing attention and is becoming one of the hot networks for researching. In recent years, research results show that the Ad Hoc multicast become the first choice of network routing, and QoS multicast routing also give full consideration to tensioning bandwidth resources and limited system resources of the Ad Hoc network.Multicast is a method of transmitting data packets to a group of nodes identified by a single destination address. This thesis mainly research multicast routing protocol for Ad Hoc network, which considers QoS constraints of the group of nodes. For the service qualities, It mainly deals with the delay, delay jitter, bandwidth and cost metrics, and describes a network model for researching the mobile Ad Hoc networks QoS multicast routing problem, then presents a QoS based Multicast Routing Protocol in mobile Ad Hoc networks (QMRPA). QMRPA is based on the definition of feasible links, and uses two steps to complete the establishment of multicast tree. First of all, establish a single link from the multicast source to a destination node, which satisfies the multiple QoS constraints, to constitute the initial multicast tree. Secondly, other destination nodes join the multicast tree. In the course of each routing process, each node only needs to know the information of adjacent nodes, without having to grasp the overall information. This improves the success rate of the routing and reduces the complexity of the algorithm. At the same time, the thesis gives the process of pruning and maintenance, and designs the routing backup mechanism. The proof of correctness and the complexity analysis of the QMRPA are also given. It also describes a multicast routing protocol with multiple QoS constraints in clustering mobile Ad Hoc networks (QMRPA-CL), which improved on QMRPA. In this protocol, each intracluster node only needs to maintain its cluster's routing information, and the each bridge node need to maintain the cluster in and the summary information of other same level clusters of this higher level cluster. The QMRPA-CL also allows any ad hoc group member can join/leave the multicast group dynamically, and supports multiple QoS constraints.The performance of QMRPA is evaluated using simulation. The studies show that QMRPA is effective, and provides a new solution to multicast routing decision with multiple QoS constraints for mobile ad hoc networks.