Flooding-Assisted Threshold Assignment for Aggregate Monitoring in Sensor Networks

The research community has witnessed a large interest in monitoring large scale distributed systems. In these applications typically we wish to monitor a global system condition which is defined as a function of local network elements parameters. In this paper, we address Aggregate Threshold Queries in sensor networks, which are used to detect when an aggregate value of all sensor measurements crosses a predetermined threshold. The major constraint in designing monitoring applications is reducing the amount of communication burden which is the dominant factor of energy drain in wireless sensor networks. In this study, we address the aggregate threshold monitoring problem by proposing a distributed algorithm to set local thresholds on each sensor node so as to minimize the probability of global polling. We adopt the FPTAS optimization formulation of the problem [2] and propose a distributed algorithm as the solution to the problem. Simulation results demonstrate the validity of the proposed distributed algorithm in attaining very close performance as the centralized schema.