Quickest Change Detection in Adaptive Censoring Sensor Networks

TL;DR

This paper introduces an adaptive censoring strategy combined with the CuSum algorithm for quickest change detection in sensor networks with communication constraints, achieving asymptotic optimality and effective trade-offs.

Contribution

It proposes the CuSum-AC algorithm that adaptively censors sensor data based on the CuSum statistic, optimizing detection speed under communication and false alarm constraints.

Findings

CuSum-AC is an equalizer rule.

It is asymptotically optimal for any positive communication rate.

Numerical results show effective trade-offs between detection delay and communication rate.

Abstract

The problem of quickest change detection with communication rate constraints is studied. A network of wireless sensors with limited computation capability monitors the environment and sends observations to a fusion center via wireless channels. At an unknown time instant, the distributions of observations at all the sensor nodes change simultaneously. Due to limited energy, the sensors cannot transmit at all the time instants. The objective is to detect the change at the fusion center as quickly as possible, subject to constraints on false detection and average communication rate between the sensors and the fusion center. A minimax formulation is proposed. The cumulative sum (CuSum) algorithm is used at the fusion center and censoring strategies are used at the sensor nodes. The censoring strategies, which are adaptive to the CuSum statistic, are fed back by the fusion center. The sensors only send observations that fall into prescribed sets to the fusion center. This CuSum adaptive censoring (CuSum-AC) algorithm is proved to be an equalizer rule and to be globally asymptotically optimal for any positive communication rate constraint, as the average run length to false alarm goes to infinity. It is also shown, by numerical examples, that the CuSum-AC algorithm provides a suitable trade-off between the detection performance and the communication rate.