Joint Age of Information and Energy Minimization in Wireless Sensor Systems

Timely transmission of sensor perception information and continuous working time are two very important performance metrics of wireless sensor networks. Motivated by this, we allocate the transmission power of sensors and the transmission bandwidth for each sensor to minimize the age of information (AoI) and the energy consumption in the wireless sensor network. We derive the closed-form expression of the average AoI of the wireless sensor network. The optimization problem with the objective of simultaneously minimizing AoI and energy consumption is then formulated. The optimization problem is non-convex, and we design a gradient descent (GD) approach and an iterative convex optimization (ICO) approach to effectively solve the problem. Numerical results reveal that the proposed methods can achieve a satisfying performance on AoI and energy with enough bandwidth resource, and have an excellent result of AoI with insufficient bandwidth resource.