Power Minimization for Age of Information Constrained Dynamic Control in Wireless Sensor Networks

• Published in: IEEE transactions on communications Vol. 70; no. 1; pp. 419 - 432
• Main Authors: Moltafet, Mohammad, Leinonen, Markus, Codreanu, Marian, Pappas, Nikolaos
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Age of information (AoI); Algorithms; Complexity; Computational geometry; Constraints; Control algorithms; Control theory; Convexity; Drift; Dynamic control; Heuristic algorithms; Lyapunov optimization; Mixed integer; Optimization; Performance evaluation; Power consumption; power minimization; Random processes; Resource management; Sampling; Sensor phenomena and characterization; Sensor systems; Sensors; stochastic optimization; Wireless sensor networks; wireless sensor networks (WSNs); power minimization; Lyapunov optimization; Age of information (AoI); wireless sensor networks (WSNs); stochastic optimization
• ISSN: 0090-6778; 1558-0857; 1558-0857
• DOI: 10.1109/TCOMM.2021.3124949

We consider a status update system where multiple sensors communicate timely information about various random processes to a sink. The sensors share orthogonal sub-channels to transmit such information in the form of status update packets. A central controller can control the sampling actions of the sensors to trade-off between the transmit power consumption and information freshness which is quantified by the Age of Information (AoI). We jointly optimize the sampling action of each sensor, the transmit power allocation, and the sub-channel assignment to minimize the average total transmit power of all sensors, subject to a maximum average AoI constraint for each sensor. To solve the problem, we develop a dynamic control algorithm using the Lyapunov drift-plus-penalty method and provide optimality analysis of the algorithm. According to the Lyapunov drift-plus-penalty method, to solve the main problem, we need to solve an optimization problem in each time slot which is a mixed integer non-convex optimization problem. We propose a low-complexity sub-optimal solution for this per-slot optimization problem that provides near-optimal performance and we evaluate the computational complexity of the solution. Numerical results illustrate the performance of the proposed dynamic control algorithm and the performance of the sub-optimal solution for the per-slot optimization problem versus the different parameters of the system. The results show that the proposed dynamic control algorithm achieves more than <inline-formula> <tex-math notation="LaTeX">60~\% </tex-math></inline-formula> saving in the average total transmit power compared to a baseline policy.