| The control overhead is a crucial contributing factor to the scalability of multicast routing in mobile ad-hoc networks. We propose two algorithms that reduce the control overhead of the on-demand source-initiated multicast routing protocol for mobile ad hoc networks. Our approach consists of working with the framework of on-demand multicast routing protocol (ODMRP) and using its transmissions in different ways such that the total number of control transmissions is effectively smaller than in the case of the standard ODMRP implementation. Moreover, our proposed protocols retain all of the advantages of ODMRP such as simplicity of design, soft state approach to mesh formation, and no dependency on a separate unicast protocol. The protocols are experimentally verified. It is shown that in the presence of high number of sources, both protocols significantly reduce the control packet load, increase the multicast efficiency, and improve the data delivery ratio of the on-demand multicast routing protocol. |
