Minimizing the Age of Information from Sensors with Correlated Observations
The Age of Information (AoI) metric has recently received much attention as a measure of freshness of information in a network. In this paper, we study the average AoI in a generic setting with correlated sensor information, which can be related to multiple Internet of Things (IoT) scenarios. The system consists of physical sources with discrete-time updates that are observed by a set of sensors. Each source update may be observed by multiple sensors, and hence the sensor observations are correlated. We devise a model that is simple, but still capable to capture the main tradeoffs. We propose two sensor scheduling policies that minimize the AoI of the sources; one that requires the system parameters to be known a priori, and one based on contextual bandits in which the parameters are unknown and need to be learned. We show that both policies are able to exploit the sensor correlation to reduce the AoI, which result in a large reduction in AoI compared to the use of schedules that are random or based on round-robin.
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