| In this paper we propose and analyze ALBA, a novel packet forwarding protocol for ad hoc and sensor networks. ALBA follows an integrated approach that combines geographic routing and medium access control (MAC), and exploits the knowledge of node positions in order to achieve energy--efficient data forwarding. The scenario we consider is very critical for medium--high traffic, as channel access contention and the resulting collisions lead to performance degradation. To counter this effect, we leverage on network density, choosing only relay candidates that are not in overload. With our protocol, nodes strive to channelize traffic toward uncongested network regions, rather than just maximizing the advancement towards the final destination. We carry out extensive simulations that compare ALBA to GeRaF and to another recently proposed cross--layer approach with similar goals, MACRO. Simulations results show that our design achieves very
good delivery and latency performance, and can greatly limit energy consumption. |