Efficient Rendezvous Schemes for Mobile Collector in Wireless Sensor Networks with Relay Hop Constraint.

Recent research shows that huge energy saving can be achieved in wireless sensor networks by introducing mobile collector (MC) that visits sensor nodes and collects data from them via short-range communications. One bottleneck of such approach is the large data collection latency incurred by the slow-moving MC. It is observed that the latency can be effectively shortened by performing local data aggregation. In this paper, we formulate this problem as rendezvous-based mobile data collection (MDC-RN), and prove that it is NP-hard. In MDC-RN, the locally aggregated data is first relayed to rendezvous nodes (RNs) under the constraint of relay hop d, and then the data cached by RNs is uploaded to MC when it arrives. In order to minimize the MC tour and optimize the routes in aggregation trees, we propose two efficient rendezvous-based algorithms. The centralized algorithm selects RNs according to the load priority, while the distributed scheme determines RNs based on underlying aggregation trees. The effectiveness of our algorithms is validated through both theoretical analysis and extensive simulations. [ABSTRACT FROM AUTHOR]