A sensor deployment optimization model of the wireless sensor networks under retransmission

Wireless sensor networks (WSN) are widely applied in the supervisory control of the agriculture, biology, transportation, military and many other fields. An excellent node deployment strategy can largely reduce the energy consumption and optimize the lifetime of WSN. In this paper, a new node deployment model based on regular hexagon grids is proposed for a homogeneous flat WSN. Both the data transmission and energy consumption of each sensor in a data gathering cycle are analyzed based on energy consumption models, a routing algorithm, a retransmission model and a sleep/wakeup mechanism. Two optimization models for uniform and non-uniform sensor deployment schemes are proposed to minimize the energy consumption under the constraints of connectivity and coverage requirements. The results of our case studies show that when retransmission is considered, there are much less nodes and initial energy needed in the deployment of the WSN.