Multicast Operation of the Ad - hoc On - Demand Distance VectorRouting

An ad-hoc network is the cooperative engagement of a collection of (typically wireless) mobile nodes without the required intervention of any centralized access point or existing infrastructure. To provide optimal communication ability, a routing protocol for such a dynamic self-starting network must be capable of unicast, broadcast , and multicast. In this paper we extend Ad-hoc On-Demand Distance Vector Routing (AODV), an algorithm for the operation of such ad-hoc networks, to ooer novel multicast capabilities which follow naturally from the way AODV establishes unicast routes. AODV builds multicast trees as needed (i.e., on-demand) to connect multicast group members. Control of the multicast tree is distributed so that there is no single point of failure. AODV provides loop-free routes for both unicast and multicast, even while repairing broken links. We include an evaluation methodology and simulation results to validate the correct and eecient operation of the AODV algorithm. 1 Introduction The idea of ad-hoc networks of mobile nodes dates back to the days of the DARPA packet radio network 11]. In more recent years, interest in these networks has grown along with improvements in laptop computers. These improvements include greater power, longer battery life, and decreased weight. Because so many laptop computers are now in use, and because these computers are easily portable due to their compact and lightweight design, the ability to communicate from one such computer to another, and from one such computer to a xed network, is desired. To facilitate such communication, many routing protocols have been developed 5, 10, 13, 14, 16]. While each of these protocols is able to provide unicast capability to network nodes, none ooers multicast communication ability. Although multicast is not necessary to establish