Wake-up Radio-Based 5G Mobile Access

Future mobile networks will enable new use cases, requiring further enhanced data rates, latency, coverage, capacity, and reliability. In this article, to emphasize sustainable energy consumption and improved device battery lifetime, the concept, benefits, and challenges of utilizing wake-up radio-based access in 5G networks are reviewed and discussed. To this end, the operating principle and associated wake-up signal structures are first reviewed, together with the corresponding power consumption and buffering delay trade-offs. Then the applicability of wake-up methods at mmWave bands and beamforming systems is addressed and highlighted. Additionally, an energy-efficient mobility management procedure for wake-up radio-based devices is described and demonstrated, utilizing narrowband uplink reference signals. Overall, the article provides an overview of wake-up-based access in 5G systems as a promising power-saving mechanism, and discusses the associated prospects, benefits, and challenges.