On the design of optimal active/sleep scheme for aggregator node in wireless sensor networks

Data aggregation and active/sleep mode are widely used for saving energy in wireless sensor networks. However, little research has been done on optimizing the active/sleep scheme design for the aggregator node. In this paper, we propose a novel stochastic model for the aggregator node with active/sleep mode as well as derive the analytical results for the optimal design metrics such as the Complete Aggregation Packet (CAP) rate, the Total Aggregation Packet (TAP) rate and the Success ratio which is defined as the CAP rate divided by the TAP rate. To simplify the optimal design problem, an approximation of the relation between the data arrival rate, the mean time in active phase and the Success ratio is established. The simulation results adequately reflect the analytical results through extensive numerical simulations. An illustrative example demonstrates the effectiveness of the proposed design technique.