1
Introduction

Harri Holma1, Antti Toskala1, Takehiro Nakamura2, and Tommi Uitto1

1Nokia, Finland

2NTT DOCOMO, Japan

CHAPTER MENU

• Introduction
• 5G Targets
• 5G Technology Components
• 5G Spectrum
• 5G Capabilities
• 5G Capacity Boost
• 5G Standardization and Schedule
• 5G Use Cases
• Evolution Path from LTE to 5G
• 5G-Advanced
• Summary

1.1 Introduction

5G radio represents a major step in mobile network capabilities. So far, mobile networks have mainly provided connectivity for smartphones, tablets, and laptops for consumers. 5G will take traditional mobile broadband to the extreme in terms of data rates, capacity, and availability. Additionally, 5G will enable new services including industrial Internet of Things (IoT) connectivity and critical communication. 5G targets are set very high, with data rates up to 20 Gbps and capacity increases up to 1000 times, and also provides a flexible platform for device connectivity, ultra-low latency, and high reliability. A number of new use cases and applications can be run on top of 5G mobile networks. It is expected that 5G will fundamentally impact the whole society by improving efficiency, productivity, and safety. 4G networks were designed and developed more than ten years ago, mainly by telecom operators and vendors for the smartphone use case. There is a lot more interest in 5G networks by other parties, including different industries and communities, to understand 5G capabilities and to take full benefit of 5G networks. 4G was about connecting people. 5G is about connecting everything.

5G has the ingredients to have a much more profound impact on society and enterprises compared to earlier mobile technology generations, relatively speaking. First, 2G, 3G, and 4G were predominantly about people connectivity – enabling persons to call one another, or access the internet from virtually anywhere, anytime. 5G, with its capabilities for Ultra Reliable Low Latency Communication (URLLC) connectivity, has been designed from the outset for high-performance IoT. 5G will enable operators to help their corporate customers to automate their business processes. It is worth noting that productivity improvements in physical business processes, such as manufacturing, construction, and logistics, have been lagging in service industries that have been able to digitalize and automate their processes during the last decades. Hence, industry verticals have shown great interest in 5G and plan to build their own private dedicated wireless network or use operator spectrum and network with slicing technology.

Second, we are seeing an interesting coinciding of the three inflection points – 5G as a new radio standard, the proliferation of cloud concepts in wireless networks, and the rapidly increasing use of artificial intelligence (AI) and machine learning (ML). Hyper-successes often happen in business when several major inflection points coincide. An example of earlier success was the 2G Global System for Mobile Communications (GSM); the first ever global standard for mobile communication, deregulation of the operator field, and electronics component price reduction making mobile telephone accessible to the masses. The major inflection points around 5G technology are illustrated in Figure 1.1.

3G and 4G brought enhanced capability for data connectivity. There were some attractive technological improvements happening at the same time, including touchscreen devices, tablet form factors, and new business models with application stores. These inflection points boosted the success of 4G technology globally. IoT capability was added later on top of 4G, while IoT optimization was inbuilt into 5G from the beginning, providing better performance and economics. URLLC will cross the chain for robust low latency communication enabling, for example, wireless robots. Further massive Machine Type Communication (mMTC) makes it more economical than previous generations to connect a very large number of objects wirelessly to the network, than with previous generations.

5G system design and deployment need to be different from the earlier mobile network generations because of the new requirements. 4G solutions are not good enough to deliver the true 5G promises. This book describes 5G specifications, technologies, network architectures, and 5G deployment and optimization aspects as well as some practical aspects related to implementing 5G devices.

Figure 1.1 Major inflection points leading to potential success.

Figure 1.2 Main 5G targets.

1.2 5G Targets

5G targets are illustrated in Figure 1.1. The three main cornerstones are extreme mobile broadband, massive IoT communications, and Ultra Reliable Low Latency Communication (URLLC). Extreme mobile broadband focuses on higher data rates beyond 10 Gbps, more consistent data rates with a minimum capability of 100 Mbps everywhere, and 10.000× more traffic capacity. Massive IoT aims at optimizing networks and devices for connectivity with billions of low-cost devices with long battery lifetimes. The third corner targets to provide very low latency below 1 millisecond (ms) with ultra-high 99.9999% reliability (Figure 1.2).

1.3 5G Technology Components

The targets of 5G networks are beyond the capabilities of existing mobile networks. A number of new technologies are needed to fulfill all those targets. The main new technology components are shown in Figure 1.3.

1. New spectrum: 5G is the first mobile radio technology that is designed to operate on any frequency band between 400 MHz and 90 GHz. The low bands are needed for coverage and the high bands are for high data rates and capacity. The initial 5G deployments use Time Division Duplex (TDD) between 2.5 and 5.0 GHz, Frequency Division Duplex (FDD) below 2.5 GHz, and TDD at millimeter waves at 24–39 GHz.
2. Massive Multiple Input Multiple Output (MIMO) beamforming can increase spectral efficiency and network coverage substantially. Beamforming becomes more practical at higher frequencies because the antenna size is relative to the wavelength and the antenna size gets smaller at higher frequencies. In practice, massive MIMO can be utilized at frequencies above 1 GHz in the base stations, and millimeter waves even in the devices. Massive MIMO will be part of 5G specifications and deployments from day 1.
3. Network slicing: Physical and protocol layers in 5G need flexible design in order to support different use cases, and different frequency bands, to maximize the energy and spectral efficiency. Network slicing will create virtual network segments for the different services within the same 5G network. This slicing capability allows operators to support different use cases and enterprise customers without having to build dedicated networks.
4. Dual connectivity and LTE co-existence: 5G can be deployed as a standalone (SA) system but, more typically, 5G will be deployed together with LTE in the early phase. 5G devices can have simultaneous radio connections to 5G and to LTE. Dual connectivity can make the introduction of 5G simpler, increase the user data rate, and improve reliability. 5G is also designed for LTE co-existence which makes spectrum sharing feasible and spectrum refarming simpler.
5. Support for cloud implementation and edge computing: The current architecture in LTE networks is fully distributed in the radio and fully centralized in the core network. The low latency requires bringing the content close to the radio which leads to local break out and edge computing. The scalability requires bringing the cloud benefits to the radio networks with edge cloud architecture. 5G radio and core are specified for native cloud implementation, including new interfaces inside the radio network.

Figure 1.3 Key 5G technology components.

1.4 5G Spectrum

5G radio is designed for flexible utilization of all available spectrum options from 400 MHz to 90 GHz including licensed, shared, and unlicensed, FDD and TDD duplexing, narrowband and wideband allocations. The three main spectrum options are illustrated in Figure 1.4. Millimeter wave spectrum above 20 GHz can provide wide bandwidths up to 1–2 GHz, which brings very high data rates up to 5–20 Gbps for extreme mobile broadband capacity. Millimeter waves are mainly suited for local usage like mass events, outdoor and indoor hotspots, and fixed wireless use cases. Millimeter waves can also be used for offloading traffic from low bands in busy hotspot areas. One use case for millimeter waves is providing very high capacity to public transport systems like trains or trams.

Figure 1.4 5G can utilize all spectrum options.

Mid-band spectrum at 2.5–5.0 GHz will be used for 5G coverage and capacity in urban areas by reusing existing base station sites. The spectrum around 3.5 GHz is attractive for 5G because it is available almost globally, and the amount of bandwidth can be up to 100 MHz or more per operator at that frequency. The peak data rate...