Data centric storage in non-uniform sensor networks

Dependable data storage in wireless sensor networks is becoming increasingly important, due to the lack of reliability of the individual sensors. Recently, data centric storage (DCS) has been proposed to manage in network sensed data. DCS reconsiders ideas and techniques successfully proposed in peer to peer systems within the framework of wireless sensor networks. In particular it assume that data are uniquely named and data storage and retrieval is achieved using names instead of sensor nodes addresses. In this paper, we discuss the limitations of previous approaches, and in particular of Geographic Hash Tables (GHT), and introduce DELiGHT, a protocol which provides fine QoS control by the user and ensures even data distribution, also in non uniform sensor networks. The merits of DELiGHT have been evaluated through simulation in uniform and Gaussian distributed sensor networks. The simulation results show that the protocol provides a better load balancing than the previous proposals and that the QoS is ensured without appreciable overhead.