Robust data gathering for wireless sensor networks

In this paper we propose a data gathering model for wireless sensor networks that provides a reasonable tradeoff between robustness and efficiency, with special regard to energy saving. We design a routing algorithm that exploits implicit acknowledgment of reception and smart caching of the data to implement an efficient strategy for retransmission of lost packets and alternative path discovery; in order to do that, we build upon the general framework presented in recent works, that provided a formulation of duplicate and order insensitive aggregation functions, taking advantage of some intrinsic characteristics of the wireless sensor networks. The advantages of the proposed approach become more evident when one parts from an ideal scenario in which all nodes have available data to transmit in favor of a more practical one in which data originates from only a subset of all sensors. In this practical case, the approach provides a better usage of the resources and a minimization of the traffic in the network, and, as a consequence, of the overall consumed energy.