Improving Quality of Service in AOMDV Routing Protocol using Available Bandwidth and Buffer Size in MANET

Mobile ad hoc network (MANET) is wireless network that has feature of frequent topological changes, node mobility, and insufficient central coordination. In MANET routing scenario source & destination act as a host while other intermediate nodes act as a router this characteristic makes routing in MANET challenge. Again, Provide Quality of Services (QoS) application in MANET environments is more difficult task due to character of nodes. AOMDV routing is a typical MANET routing protocol which deliver services without any guarantee of QoS; only used best effort delivery techniques. Several empirical studies have discovered routing protocol with QoS improvement, but few relate to various protocols regarding routing and quality of service (QoS) and none of them are investigated AOMDV Routing protocol related to bandwidth and buffer size in MANET. Thus, this thesis proposed to modify AOMDV protocol to improve QoS by using available bandwidth and buffer size to select a path in addition to hop count in original AOMDV routing protocol which we named as modified AOMDV (MDAOMDV). To estimate the available bandwidth each node calculates by listening to its channel and finally to encapsulate route request (RREQ) packet during the route discovery process. In route reply (RREP) message back to that paths through different path from which RREQ have been received in MDAOMDV routing protocol. Source node receives multiple RREP messages from multiple paths. Finally, the source chooses the best path on basis of the available bandwidth and buffer size in addition to hop count as routing metric which is better from the available active path from multiple RREP message. The proposed MDAOMDV routing protocol implemented using NS2.35 simulator tool. We have evaluated the performance of MDAOMDV and AOMDV routing protocol using the following four output metrics: throughput, packet delivery ratio, end to end delay and residual energy. Finally, we have compared original AOMDV with MDAOMDV routing protocols within the selected four performance metrics and based on the summary of the simulation result in table 4.2, the MDAOMDV outperform the original AOMDV protocol.