Evolution of Power Saving Technologies for 5G New Radio

Battery life of mobile terminals has been a key performance indicator (KPI) for user experience since the early days of wireless communications. This KPI has become even more important for fifth generation (5G) cellular systems due to higher requirements such as the support of carrier frequency up to 100 GHz, carrier bandwidth up to 400 MHz, peak data rate up to 20 Gbps, latency as small as 1 ms, and enhanced receiver performance. In response, various power saving techniques have been studied and implemented so that devices can be used over a longer period without noticeable decrease in performance. In this article, we provide a comprehensive overview of the latest terminal power saving techniques which were specified in 5G New Radio (NR) over the last couple of years. The key feature and benefit of each power saving technique is analyzed with simulation results under various traffic scenarios. In addition, some of the candidate techniques for the next phase of NR on terminal power saving enhancement are proposed targeting not only conventional data services but also various vertical services.