Performance Issues of Ad Hoc Routing Protocols in a Network Scenario used for Videophone Applications Glaucia Campos Informatics Departament Federal University of Rio Grande do Norte Campus Universitário, Lagoa Nova Natal, RN, Brazil, 59.072-970 glaucia@ppgsc.ufrn.br Glêdson Elias Informatics Departament Federal University of Paraíba Cidade Universitária, Campus I João Pessoa, PB, Brazil, 58.059-900 gledson@di.ufpb.br Abstract In ad hoc mobile networks, the user mobility level, the range of possible network scenarios, and the traffic load generated by their typical applications are key aspects that make challenging to select a given routing protocol. In such a context, this paper presents a simulation-based performance analysis of ad hoc routing protocols in a hybrid ad hoc network scenario, which is used by mobile users to estabilish videophone sessions. The average packet delivery rate, end-to-end delay and routing load are measured and evaluated by varying the routing protocols, network range, number of nodes and user mobility. Keywords. Ad hoc wireless networks, routing protocols, videophone. 1. Introduction Recently, mobile wireless network technologies have become progressively more popular and have been responsible for the growing variety and availability of portable devices. Consequently, mobile wireless networks are enabling the concept of mobility, which is becoming an extremely relevant requirement, and certainly, will redefine conventional paradigms of work, learning and entertainment. Traditional cellular and mobile networks are still, in some sense, limited by their need for infrastructure (base stations, routers). Ad hoc networks are a key in the evolution of the wireless networks [17]. Ad hoc networks are typically composed of mobile nodes, which communicate over wireless links without any central control. Each mobile node can communicate with each other within its transmission radius, establishing connections in a dynamic and temporary way. To extend the coverage area of an ad hoc network, mobile nodes must act as routers. Although ad hoc networks provide a superior mobility level, many issues ought to be evolved yet [8]. As a central issue, routing facilities must quickly discover valid and efficient routes among pairs of nodes, whenever topological changes occur due to frequent user mobility [17]. In ad hoc networks, conventional routing protocols, which are used in fixed networks, are not enough. Ad hoc networks have many particular features, and so, require routing protocols that take such features into account. Several ad hoc routing protocols have been proposed. Nonetheless, the user mobility level, the coverage range of possible network scenarios, and the traffic load generated by their typical applications are key aspects that make the selection of a given routing protocol a quite complex task. Consequently, the adoption of a given routing protocol ought to be guided by a comparative analysis that evaluates the particular network scenario and the interested application class. Among the diverse types of information that can be handled by users of mobile devices, digital video applications are a consequence of the advance in digital video compression techniques. Currently, video transmission over a wireless medium already represents a solution for systems, such as digital image monitoring, which provides institutional or personal security. In such a context, this paper presents a simulation- based performance analysis of four ad hoc routing protocols (DSDV [15], AODV [18], DSR [11] and TORA [14]) in a hybrid ad hoc network scenario, which is employed by mobile users to establish videophone sessions in a digital image monitoring system. Three performance metrics are quantified and evaluated: average packet delivery rate, average end-to-end delay, and average routing load. Such an analysis has as variability points the routing protocols, network coverage range, number of nodes and user mobility. Although some comparative analyses of ad hoc routing protocols already exist [2, 10, 16], none of them takes into account such a hybrid network scenario and the videophone application. This paper is organized as follows. Section 2 presents a brief classification of ad hoc routing protocols, identifying some properties. Then, Section 3 describes the adopted simulation model, characterizing the videophone application and identifying network scenarios and user mobility model. As the main contribution of this paper, 0-7695-2268-8/05/$20.00 (C) 2005 IEEE Proceedings of the 38th Hawaii International Conference on System Sciences - 2005 1