Abstract
The fifth generation (5G) of mobile communication system aims to deliver a ubiquitous mobile service with enhanced quality of service (QoS). It is also expected to enable new use-cases for various vertical industrial applications-such as automobiles, public transportation, medical care, energy, public safety, agriculture, entertainment, manufacturing, and so on. Rapid increases are predicted to occur in user density, traffic volume, and data rate. This calls for novel solutions to the requirements of both mobile users and vertical industries in the next decade. Among various available options, one that appears attractive is to redesign the network architecture-more specifically, to reconstruct the radio access network (RAN). In this paper, we present an inclusive and comprehensive survey on various RAN architectures toward 5G, namely cloud-RAN, heterogeneous cloud-RAN, virtualized cloud-RAN, and fog-RAN. We compare them from various perspectives, such as energy consumption, operations expenditure, resource allocation, spectrum efficiency, system architecture, and network performance. Moreover, we review the key enabling technologies for 5G systems, such as multi-access edge computing, network function virtualization, software-defined networking, and network slicing; and some crucial radio access technologies (RATs), such as millimeter wave, massive multi-input multi-output, device-to-device communication, and massive machine-type communication. Last but not least, we discuss the major research challenges in 5G RAN and 5G RATs and identify several possible directions of future research.
Highlights
The mobile network witnesses tremendous growths in the data traffic, the amount of user equipment, the diversity of applications, and the polymorphism of service scenarios
We present the state-of-the-art, the ongoing standardization activities, and the motivation of reconstructing & redesigning legacy radio access network (RAN) architectures with respect to the requirements of generation mobile networks
We have surveyed existing literature related to RAN architectures for 5G mobile network, namely C-RAN, Heterogeneous Cloud RAN (H-CRAN), Virtualzied Cloud RAN (V-CRAN) and Fog RAN (F-RAN)
Summary
The mobile network witnesses tremendous growths in the data traffic, the amount of user equipment, the diversity of applications, and the polymorphism of service scenarios. In [7], the authors address ten key enabling technologies towards 5G communication, including wireless SDN, NFV, mmWave, massive MIMO, network ultra-densification, big data & mobile cloud computing, scalable Internet of Things (IoT), device-to-device connectivity with high mobility, green communications, and new radio access techniques They have provided the challenges and limits for every presented technology. Various telecommunication vendors, operators and research institutions have been contributing to the research and development of various aspects of 5G systems such as key technologies and enablers, spectrum, requirements, network architecture, use-cases, applications, etc They have reported the progress of their contributions in a number of white-papers including [20]–[38]. Standardization organizations around the world have already initiated the standardization process for a global
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call