An efficient adjustable grid-based data replication scheme for wireless sensor networks

Wireless Sensor Networks (WSNs) consist of hundreds or thousands of sensor nodes connected to each other through short-distance wireless links. Because sensor nodes are energy-constrained, efficient energy use is a critical issue for WSNs. In WSNs, the energy of popular nodes may be quickly depleted when a large number of sensor nodes are interested in the same popular events, and they are frequently queried. This paper proposes a data replication scheme called adjustable data replication (ADR), which is based on a virtual grid in order to improve the lifetime of data nodes. In each grid, a head node is selected as a manager, and is responsible for receiving or transmitting packets from or to other nodes in the same virtual grid. The head nodes around data nodes or replica nodes will compute the number of requested packets in order to determine how best to build a replica node in an appropriate location. ADR repeatedly builds data replica nodes close to query nodes in order to balance the overhead and energy consumption of sensor nodes. Simulation results show that the proposed ADR scheme outperforms existing approaches.