Research On QoS Multicast Routing Techniques In Mobile Ad Hoc Networks

A Mobile Ad Hoc Network (MANET) is an autonomous system of mobile nodes connected by wireless links. There is no static infrastructure such as base station as that was in cell mobile communication. In Ad Hoc network, if two nodes are not within radio range, all message communication between them must pass through one or more intermediate nodes. All the nodes are free to move around randomly, thus changing the network topology dynamically. These types of networks have many advantages, such as self-reconfiguration and adaptability to highly variable mobile characteristics like the transmission conditions, propagation channel distribution characteristics and power level. They are useful in such as situations military applications, natural calamities, scientific investigation, exploraties, interactive lectures, commercial meetings of shared information, and urgent communication. However, such benefits come with new challenges which mainly resides in the unpredictability of the network topology due to mobility of nodes and the limited available bandwidth due to the wireless channel. These characteristics demand an improvement in the designing and operating of this type of networks. For such networks, an effective routing protocol is essential for adapting to node mobility as well as possible channel error to provide a feasible path for data transmission.The use of multicasting with the network has many advantages. Multicasting reduces the communication cost for the sending of the same data to many recipients. Instead of sending via multiple unicast, multicast reduces the channel bandwidth, time of processing and delivery delay. In addition, multicast gives robust communication whereby the receiver address is unknown or modifiable without the knowledge of the source within the wireless environment.The Quality of Service (QoS) routing in Ad Hoc network is complicated due to the constant change of the network topology. QoS support for multimedia applications is closely related to resource allocation, the objective of which is to decide how to reserve resources so that QoS requirements of all the applications can be satisfied. However, it is a significant technical challenge to provide reliable high-speed end-to-end communications in these networks, due to their dynamic topology, distributed management as well as, and multihop connections.