Chinese Journal of Computers   Full Text
Title	A Cross-Layer Improved Efficient AODV Routing Algorithm
Authors	REN Zhi GUO Wei SU Jing LIU Jun
Address	(National Key Laboratory of Communication, University of Electronic Science and Technology of China, Chengdu 610054)
Year	2007
Issue	No.5(838—844)
Abstract &   Background	Abstract To improve the performance of AODV routing algorithm in mobile Ad Hoc networks, the authors adopt the cross-layer method to improve its HELLO message mechanism and present a novel routing algorithm: CLAODV. The algorithm not only changes the controller of HELLO messages from network layers to the MAC layers, but also reduces the quantity and size of HELLO messages. From performance analysis and simulation results, it can be found that CLAODV has many advantages. Compared to the classic AODV algorithm, CLAODV reduces the overhead, improves the efficiency and other performances, such as the throughput, the end-to-end delay and the success ratio. keywords mobile Ad Hoc networks; routing algorithms; cross-layer design; AODV; HELLO messages background A "mobile Ad Hoc network" (MANET) is an autonomous system of mobile routers (and associated hosts) connected by wireless links—the union of which form an arbitrary graph. The routers are free to move randomly and organize themselves arbitrarily; thus, the network’s wireless topology may change rapidly and unpredictably. Ad hoc networking is one of the most vibrant and active "new" fields today. It is a multi-layer problem. The physical layer must adapt to rapid changes in link characteristics. The multiple access control (MAC) layer needs to minimize collisions, allow fair access, and semi-reliably transport data over the shared wireless links in the presence of rapid changes and hidden or exposed terminals. The network layer needs to determine and distribute information used to calculate paths in a way that maintains efficiency when links change often and bandwidth is at a premium. The transport layer must be able to handle delay and packet loss statistics that are very different than wired networks. Finally, applications need to be designed to handle frequent disconnection and reconnection with peer applications as well as widely varying delay and packet loss characteristics. The issue in "A Cross-Layer Improved Efficient AODV Routing Algorithm" belongs to the domain of cross-layer optimization of routing algorithms. In recent years, there is a tendency to optimize network algorithms and protocols with cross-layer information and cooperation. The cross-layer information derives from all layers in a wireless network, such as the MAC layer, the physical layer, the application layer, etc. This paper addresses the cross-layer optimization of AODV routing algorithm with the information sharing and cooperation between the network layer and the MAC layer. Related issues are still studied extensively around the world. The cross-layer optimization mechanism of this paper utilizes the characteristics of AODV routing algorithm and IEEE802.11 standard to improve the performance of AODV successfully. The subject of this paper is supported by the following three projects: the Natural Science Foundation of China under grant No.60472052, the Program for New Century Excellent Talents in University under China’s Ministry of Education (2004), the National Key Laboratory of Communication, UESTC under the grant No.51434020105ZS04. These projects aim to improve our country’s academic and applied study on wireless networking and are helpful to make advances in wireless communication technologies. The research team of this paper has developed some creativity and published many papers in journals and proceedings. As a part of cross-layer optimization of routing algorithms, this paper presents a novel method to improve manifold network performance with little overhead.