Ad-hoc multicast routing on resource-limited sensor nodes

Many emerging sensor network applications involve mobile nodes with communication patterns requiring any-to-any routing topologies. We should be able to build upon the MANET work to implement these systems. However, translating these protocols into real implementations on resource-constrained sensor nodes raises a number of challenges. In this paper, we present the lessons learned from implementing one such protocol, Adaptive Demand-driven Multicast Routing (ADMR), on CC2420-based motes using the TinyOS operating system. ADMR was chosen because it supports multicast communication, a critical requirement for many pervasive and mobile applications. To our knowledge, ours is the first non-simulated implementation of ADMR. Through extensive measurement on Motelab, we present the performance of the implementation, TinyADMR, under a wide range of conditions. We highlight the real-world impact of path selection metrics, radio link asymmetry, protocol overhead, and limited routing table size.