Wireless Network Design for Intelligent Services: From An Age-Energy Efficiency Perspective

With the sixth-generation (6G) vision of connecting everything, integrating real-time sensing, communication, computing, and control together in Internet of Everything (IoE) becomes essential to support intelligent services. Such a tendency is facing great challenges in terms of information freshness, energy sustainability, and energy efficiency (EE). Thus, network requires to satisfy multiple objectives, including low age of information (AoI) and high EE. Nevertheless, existing designs mainly focused on AoI and EE separately and has no unified rule in various wireless communications scenarios. In order to efficiently describe the system performances from both information timeliness and energy saving perspectives, this article presents a novel utility-aware performance metric, i.e., age-energy efficiency (AEE), to measure the achieved AoI gain by consuming per joule energy, which takes both age and energy into account. To show the evocativeness of AEE, we explore the AEE in several typical network scenarios, such as the point-to-point (P2P) network, the wireless powered communication network (WPCN), the mobile edge computing (MEC) network and the multi-user network, as examples. The optimal policies to maximize the AEE performance of such network scenarios are also presented. Numerical results show that the AEE is a concave function of the transmit power, and can be employed to pursue the maximal age gain by consuming as less as energy in 6G intelligent network design. Additionally, some insightful promising directions on AEE for research are also presented for 6G networks.