Location-Based Multicast Routing Protocol for Mobile Ad Hoc Networks TZAY-FARN SHIH 1  , CHAO-CHENG SHIH 2 , and CHIN-LING CHEN 1 1 Department of Computer Science and Information Engineering Chaoyang University of Technology Taichung, Taiwan 41349, R.O.C 2 Department of Information Management Shih Hsin University Taipei, Taiwan 116, R. O. C tfshih@cyut.edu.tw, ccshih@cc.shu.edu.tw, clc@mail.cyut.edu.tw Abstract: - Wireless network offers freedom moving around the effective transmission area and the flexibility and easy to use function for Internet application. Many applications of computer network involve multiple users that will rely on the ability of the network to provide multicast services. Thus, multicasting will be concerned as an essential part of Ad Hoc networks. Some of the proposed routing algorithms require maintaining a global network state at each node, the imprecision of global state and the large amount of storage and communication overhead induce poor scalability. In this paper, we propose a distributed cluster-based QoS multicast routing algorithm which only requires maintaining a local state at each node. The location information provided by positioning device is aided in route discovery and route maintenance procedure. Our protocol partitions the network into square clusters. In each cluster, a cluster head and gateways are selected by a cluster head selection algorithm and a gateway selection algorithm respectively. After the construction of cluster heads and gateway nodes, a distributed computation collectively utilizes the local state information to construct multicast tree in a hop-by-hop basis. Simulations are conducted to evaluate the performance of our algorithm. As it turns out, our protocol has better performance and lower routing overhead than the non-cluster based algorithm. Key-Words: - Mobile ad hoc networks, Multicasting, QoS, GPS, Proactive routing, Reactive routing † Corresponding author. 1 Introduction The advancement in wireless communication and portable computing devices has made mobile computing possible. Without any typical wiring requirements, wireless networking offers freedom moving around the effective area. Temporary workgroups can also be assembled, conference rooms made network ready without extensive rewiring of corporate offices. There are currently two variations of mobile wireless networks. The first is known as the infrastructure networks that have fixed base stations. A mobile unit within these networks connects to, and communicates with, the nearest base station that is within its communication range. The second type of mobile wireless network is the infrastructureless mobile network, commonly known as a mobile ad hoc network. An ad hoc mobile network is a collection of mobile nodes that are dynamically and arbitrarily located in such a manner that the interconnections between nodes are capable of changing on a continual basis. Unlike conventional wireless networks, ad hoc networks are wireless network with no fixed routers, hosts, or wireless base stations. Nodes of these networks function as routers, which discover and maintain routes to other nodes in the network [1]. According to how route information is collected, ad hoc network routing protocols can be classified as proactive and reactive [2-8]. Many applications of computer network such as videoconferencing will involve multiple users that will rely on the ability of the network to provide multicast services. Thus, multicasting will likely be an essential part of networks. In multicast WSEAS TRANSACTIONS on COMPUTERS Tzay-Farn Shih, Chao-Cheng Shih and Chin-Ling Chen ISSN: 1109-2750 1270 Issue 8, Volume 7, August 2008