Transmission control policy design for decentralized detection in tree topology sensor networks

A Wireless Sensor Network (WSN) deployed for detection applications has the distinguishing feature that sensors cooperate to perform the detection task. Therefore, the decoupled design approach that is typically used to design communication networks, where each network layer is designed independently, does not lead to the desired optimal detection performance. Cross-layer design has been recently explored for the design of MAC protocols for parallel topology (single hop) networks, but little work has been done on the integration of communication and information fusion for tree networks. In this work, we design the optimal Transmission Control Policy (TCP) that coordinates the communication between sensor nodes connected in a tree configuration, in order to optimize the detection performance. We integrate the Quality of Information (QoI), Channel State Information (CSI), and Residual Energy Information (REI) for each sensor into the system model. We formulate a constrained nonlinear optimization problem to find the optimal TCP design variables. We solve the optimization problem using a hierarchical approach where smaller local optimization problems are solved by each parent node to find the optimal TCP design variables for its child nodes. We compare our design with the max throughput and decoupled design approaches.