Dept. of CSE, Indian Institute of Technology Madras, Chennai, INDIA
Independent Consultant, Chennai, INDIA
Abstract—Networking connectivity is increasingly based on wireless network technologies, especially in developing nations where the wired network infrastructure is not accessible to a large segment of the population. Wireless data network technologies based on 2G and 3G are quite common globally; 4G-based deployments are on the rise during the past few years. At the same time, the increasing high-bandwidth and low-latency requirements of mobile applications has propelled the Third Generation Partnership Project (3GPP) standards organization to develop standards for the next generation of mobile networks, based on recent advances in wireless communication technologies. This standard is called the Fifth Generation (5G) wireless network standard. This paper presents a high-level overview of the important architectural components, of the advanced communication technologies, of the advanced networking technologies such as Network Function Virtualization and other important aspects that are part of the 5G network standards. The paper also describes some of the common future generation applications that require low-latency and high-bandwidth communications.
The explosive growth in the number of mobile devices, especially smart-phone and tablet family of devices has been well recognized. The fact that most of the Internet users primarily rely upon wireless network technologies for access is also established. The mobile user traffic is predominantly from video-based applications (such as streaming, etc.). There is also contributions to the high network traffic from gaming, virtual-reality, vehicular communications, and other high-bandwidth applications. In addition, these applications also require low-latency for enhanced user experience.
At the same time, there has been significant interest in deploying billions (and more) of small devices, broadly classified as the “Internet of Things”. These are also expected to generate significant amount of network traffic with applications ranging from Smart Manufacturing and Smart Power Grids to Smart Healthcare and Smart Cities. These include communication models such as Machine-to-Machine (M2M) and Device-to-Device (D2D) Communications. Thus, the demands for supporting high-bandwidth connections with low-latency has been increasing for the past few years. A summary of different user group’s perspectives on future mobile traffic demands is available in .
To address these needs, the 3GPP standards group has been working on developing a new set of standards, collectively referred to as the 5G cellular network standards.
The standards address different aspects of the network including several novel: (i) physical layer (PHY) technologies including Massive-MIMO, adaptive beamforming, and so on (ii) Radio Access Network (RAN) technologies including Cloud-based RANS  and edge- and fog-computing; (iii) Evolved Packet Core (EPC) network architectures based on software defined networking (SDN) and Network Function Virtualization (NFV) technologies, including Network Slicing and programmable control and data planes; and
(iv) Application development frameworks.
This paper presents a high-level summary of some of these important aspects. Section II presents the key network architectural components of the 5G network. Section III presents the NG-RAN technology standards. Section IV presents the EPC architectural components, while Section V provides additional details on Network Slicing. Section VI provides a brief discussion of some of the key challenges faced in realizing 5G networks and concludes the paper.
Figure 1: 5G Service Based Architecture.
II. Overview of 5G Architecture
This section presents an overview of the 5G application-level requirements and the network architecture.
A. Service Requirements
A set of requirements has been defined as part of the IMT-2020 specifications in 2017  and in the 3GPP standards . There are three major application/service categories specified: (i) Enhanced Mobile Broadband (eMBB), (ii) Massive Mac machine Type communications (MMTC), and (iii) Ultra-reliable and low-latency communications (URLLC).
Each of these services has very different performance requirements and traffic demands for network control functions. Each service dimension requires its own set of control functions, existing mobile networks has tightly coupled control functions with fixed interfaces.