Mobile Communications and Networks

Thomas Alexander, Wojciech Mazurczyk, Amitabh Mishra, Alberto Perotti
2020 IEEE Communications Magazine  
W hile the core architecture and radio aspects for 5G are starting to achieve a degree of consensus in 3GPP Rel-15 and Rel-16, a huge number of ancillary proposals and functional areas are still being worked on. The anticipated pervasive nature of 5G into every nook and cranny of mobile communications drives many functions that were not required in previous generations. Further, 5G seeks to bring a large number of previously disparate areas of wireless communications under one umbrella, i.e.,
more » ... hicular communications, railway signaling, mission-critical services, and Internet of Things, to name but a few, resulting in a multi-layered, heterogeneous architecture with many challenges. We explore some of these dimensions in this issue. Readers of this magazine are aware that 5G has been targeted to support enhanced mobile broadband (eMBB), ultra-reliable low latency (URLLC), and massive machine type (mMTC) communications on a new radio (NR) hardware platform. What they may not be aware of is the power-hungry nature of these applications. Standardization bodies such as 3GPP now have several efforts related to conservation of energy and enhancing the battery lifetime of user equipment (UE). One such application happens to be DRX (Discontinuous Reception) developed for 4G LTE. DRX conserves energy of mobile devices by turning some components of the cellular system off or putting them in sleep mode for a time interval. Recently a wakeup radio-based access scheme (WS) that enhances the power efficiency of mMTC has been introduced for 3GPP Release 15, a candidate for 5G-NR. The article "Wakeup Radio Based 5G Mobile Access: Methods, Benefits and Challenges" describes the architecture of WS, its main building blocks such as wakeup signaling, and wakeup receiver. This well written article compares the energy consumption of WS with respect to DRX and computes the impact of latency on the average power consumption. Dynamic sharing of underutilized spectrum in licensed bands has posed several challenges among incumbents and secondary users which can also be mobile network operators. Recently, several new ideas related to efficient spectrum utilization have been investigated. For example, Licensed Shared Access (LSA) and Spectrum Access System (SAS) can be both integrated with Dynamic Spectrum Access (DSA) to specifically boost the overall spectrum utilization in the licensed bands in different areas. The article "Advanced Dynamic Spectrum 5G Mobile Network Employing Licensed Shared Access" provides an overview of recent activities of the Radio Spectrum Policy Group of the European Commission related to LSA advocating its adoption in commercial networks to demonstrate a range of spectrum efficiencies that can be achieved. This article takes a deep dive into relevant scenarios that would take advantage of LSA and develops architectures and enabling technologies for integrated LSA, SAS, and DSA for deployments. The increasing amount of available radio communication spectrum combined with the multitude of radio access technologies and the diversified requirements of new use cases make radio resource management increasingly complex and difficult in contemporary wireless networks. The article "A Hierarchical and Modular Radio Resource Management Architecture for 5G and Beyond" deals with that increasing complexity by developing a generic and adaptive radio resource management scheme that guarantees efficient operation of heterogeneous networks. The architecture of the proposed schemes is hierarchical and modular, and can be extended by adding new items according to a "plugin"-type structure. The authors also show how their framework can be conveniently applied to mobile cellular networks of 4th and 5th generation.
doi:10.1109/mcom.2020.9161987 fatcat:cvio4w65ijgtvde7xhb3pcfqty