2005 13th IEEE International Conference on Networks jointly held with the 2005 7th IEEE Malaysia International Conference on Communications, Proceedings Volume 1, 2005, Article number 1635527, Pages 469-474 2005 13th IEEE International Conference on Networks jointly held with the 2005 7th IEEE Malaysia International Conference on Communications; Kuala Lumpur; Malaysia; 16 November 2005 through 18 November 2005; Category number05EX1235; Code 69262 Robust data gathering for wireless sensor networks (Conference Paper) Ortolani, M. , Gatani, L. , Lo Re, G. Dipartimento di Ingegneria Informatica, Università degli Studi di Palermo, Viale delle Scienze Parco d'Orleans, 90128 Palermo, Italy View references (17) Abstract 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.