A survey on the optimisation of age of information in wireless networks

This article comprehensively surveys the area of age of information (AoI) in the wireless networks and focuses on categorising and reviewing the current progress on AoI from an optimisation perspective. We first present the multiple definitions of AoI and its variants. Then, we give an overview of AoI-optimal sampling policies and packet management strategies from data source. We also summarise the work of minimising AoI in the case of resource-constraint source nodes, such as energy harvesting and UAV-assited sampling. We provide a summary of many kinds of scheduling policies for efficiently managing the use of resources in different network settings, which consist of various data sources and servers. In addition, we discuss some other applications focusing on the optimisation of AoI. Finally, we explore the performance of those policies in practical implementation and some potential future directions on AoI research.