Qos And Routing Strategies For Mobile Ad Hoc Networks

Mobile Ad hoc network (MANET) is a kind of mobile multi-hop and self-organized wireless network, it is getting more and more attractive and can be used in battlefield, disaster relief and short-term scenarios such as meetings for its independence of a fixed infrastructure and its instant deployment and easy reconfiguration capabilities. Unlike in the wired networks where bandwidth is usually abundant, bandwidth of MANET is always scarce. Providing QoS guarantee in MANET is necessary to help deliver multi-media applications or mission-critical data. But the features of wireless channel and the mobility of nodes made it very difficult to support QoS in MANET. The article first introduces background and related concepts about QoS support in MANET, then present an overview, discussion and analysis of the current researches in this area. Currently there are many QoS strategies proposed, we have classified them in Route-Based and Route-Independent Approaches. This paper mainly focuses on Route-Based solutions, which called QoS routing. Routing protocols are the foundation of these Route-Based schemes; they also have significant effect on the performance of the network. Several routing protocols are standardized by IETF, e.g. AODV, TBRPF and OLSR, among them, AODV is a mature and widely accepted routing protocol that has low processing and memory overhead and low network utilization, and works well even in high mobility situation. But it has scalable problem for large mobile networks. To solve this problem, a new AODV based clustering routing protocol (called AODV-Clustering) was proposed in this paper. AODV-Clustering works on AODV at the beginning, and then gradually becomes a clustered routing protocol. Simulation results shows it performed better than AODV in large network while keep the good features of AODV. To developing a satisfying QoS routing protocol, current existing QoS routing protocols such as Q-AODV, AQOR, CEDAR are discussed first, then the Q-AODV protocol is improved to offer better QoS support. Also, a QoS version of the AODV-CIuster protocol which called Q-AODV-Clustering is also proposed, the protocol can provide bandwidth support for adaptive real time flows. Finally, an end-to-end QoS architecture for MANET isproposed. The architecture includes many components such as QoS signing, admission control, QoS routing, resource management, congestion control, rate control and QoS MAC. Simulation programs are designed and a simulation-based evaluation is presented on JiST/SWANS platform, the result confirmed the effectiveness of the architecture.