Power-Aware Link Maintenance (PALM) for Mobile Ad Hoc Networks

We propose a power-aware link maintenance (PALM) algorithm for mobile ad hoc networks (MANETs) that simultaneously performs transmission power control and route connectivity maintenance. Unlike most topology control algorithms, PALM manages the transmission power of active nodes only, and thus eliminates energy and channel resource waste due to unnecessary beaconing. The basic idea of PALM is that by recording the received signal strength on packets, each node continuously estimates the required transmission power, and adapts to location changes due to mobility. We also introduce some efficient local link repair schemes. When a route change is needed due to node movement, overhearing nodes participate in data forwarding, and locally repair the route before disconnection without the need to propagate route error messages. Through these operations, PALM prevents frequent link breaks due to node mobility, reduces the occurrence of rerouting, and significantly improves network performance. Experimental results with the ns simulator confirm that PALM effectively conserves communication energy with modest overhead.