The Challenge of On Demand Routing Protocols Improvement in Mobility Context

International audienceMobile Ad hoc NETworks are characterized by rapid changes in their topology and the lossy nature of wireless links. In this context, achieving respect the QoS constraints of multimedia communications is a real challenge. Routing protocols play an important role in achieving the required performance. They should be smart enough to select better paths for data transmissions. Several routing approaches are used. Most are derived from adapting those used in wired networks. They are not suited to the context of wireless networks. We focus on the well-known Ad-hoc On-demand Distance Vector (AODV) protocol, commonly used protocol in ad hoc network. Standard route discovery process used in AODV is expected to obtain the best path in term of delay. However, in lossy-links context, multimedia data packet transmission success, on path established thanks to control packets, may require several attempts. These retransmissions increase delay and overhead. Many QoS-based methods failed to make a meaningful improvement due to added complexity and additional delay and overhead. In this paper, we use a convenient and practical way to evaluate quality of links in mobile context. With these measures relating to the number of retransmissions, we produce a new metric. Thereafter, we use this metric to highlight the limitations of QoS approaches used to improve the performance of AODV. We show that improving performance of on-demand routing protocols, in the mobility context, lies on effective control of node neighborhood