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Spectrum scarcity has driven enhancements of Long-Term Evolution (LTE) in utilizing unlicensed bands in conjunction with licensed bands for delivering mobile data, resulting in the introduction of LTE unlicensed technologies such as Rel-13 LTE–Licensed-Assisted Access (LAA), Rel-14 LTE–Enhanced Licensed-Assisted Access (eLAA), and LTE-Unlicensed (LTE-U). The next-generation radio access technology, 5G New Radio(NR), faces greater technical challenge due to the need to support frequency bands covering various spectrum licensing regimes and a wide range of frequencies (up to 100 GHz) with very different signal propagation characteristics. This paper presents an overview of LAA and eLAA technical features and 5G NR design considerations to achieve a unified access in licensed and unlicensed bands.

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.