5G concepts and drivers

In this section, we will analyze key drivers for the need for 5G technology, key requirements, and the standardization of 5G.

Key drivers

Mobile technologies such as 3G, 4G, and 5G were initially governed by the International Mobile Telecommunications (IMT) requirements of the International Telecommunication Union – Radiocommunication (ITU-R). IMT-2000 was established by ITU-R with detailed specifications for the first 3G deployments that took place around 2000. In early 2012, ITU-R established the specifications of IMT Advanced for 4G wireless cellular technology. Similarly, for the 5G technology, ITU-R defined IMT-2020.

Figure 1.1 – ITU-R and the IMT technologies

IMT-2020 is the benchmarks and guidelines that the ITU-R has set down for what a 5G network should be. Today, organizations such as the 3rd Generation Partnership Project (3GPP) are working toward fulfilling the requirements of IMT-2020. Within IMT-2020, there are three use cases that are the main focus of 5G. Those use cases include Enhanced Mobile Broadband (eMBB), Ultra-Reliable and Low Latency Communications (URLLC), and Massive Machine-Type Communications (mMTC). We will consider each of these in turn.

Enhanced mobile broadband

From 2G all the way through to 4G we have seen constant increases in the mobile broadband data rates that subscribers can expect to achieve. 5G is no exception with its promise of eMBB. To be able to market 5G, some high data rates need to be provided to subscribers to show how competitive it is against 4G. The headline data rates are roughly in the high hundreds of megabits per second. Certainly, 5G will deliver data rates that satisfy applications such as Augmented Reality (AR), ultra HD videos, or 3D applications.

Figure 1.2 – Evolution to ultra broadband

But certainly, with 5G, subscribers will typically experience data rates in the high hundreds of megabits per second.

Ultra-reliable and low-latency communications

The second key use case is URLLC. When we consider URLLC, we need to consider the fact that 5G will really be an enabler network. So, we see a variety of different applications here that might be able to use the 5G Core (5GC) Network. Remote surgery, autonomous driving, industrial control, and drone control are examples of applications that require low latency and high reliability.

Figure 1.3 – URLLC

URLLC has stringent requirements in terms of latency and reliability. The latency for the network is set at around 1 ms. The network for certain applications needs to be super reliable as well, with 99.999% (five 9s) reliability.

Massive machine-type communications

The third key use case is mMTC and fundamentally, it is the cellular-Internet of Things (IoT). Although we already had a cellular-IoT with earlier technologies, we see it again with 5G as well. There are numerous different IoT applications that can use the services of the 5G infrastructure. The network must be super flexible and super adaptable from the 5G service providers’ perspective. The network needs to be able to provide exactly the correct requirements for the IoT applications that are using it. Network function virtualization, network slicing, and edge computing came into prominence as the three key aspects of 5G. These three aspects will be examined later in the upcoming chapters.

5G (IMT-2020) performance synopsis

The following table lists the enhancements of the minimum technical requirements of IMT Advanced to IMT-2020:

Requirement	Unit	IMT Advanced	IMT-2020
Peak data rate	Gbits/s	1	20
User-experienced data rate	Mbits/s	10	100
Spectrum efficiency	bits/s/Hz	1x	3x
Mobility	km/h	350	500
Latency	ms	10	1
Connection density	devices/km2	105	106
Network energy efficiency	bit/Joule	1x	100x
Area traffic capacity	Mbit/s/m2	0.1	10

The following list expands on the preceding performance synopsis and key areas that service providers today are moving toward:

• Peak data rate (Gbits/s): This is the peak throughput target that can be achieved by a single user in the ideal radio conditions, and it is measured in Gigabits per second.
• User-experienced data rate (Mbits/s): Shows the user-experienced throughput target, which needs to be achieved by 95% of the users in dense urban areas. This is the speed the user will experience in the field.
• Spectrum efficiency (bits/s/Hz): This is the number of bits per second per Hertz achieved by 95% of users in the coverage area. It indicates how efficiently the subscribers can use the valuable radio spectrum.
• Mobility (km/h): Shows how fast the subscribers can move while maintaining a specific normalized traffic channel data rate.
• Latency (ms): Represents the one-way delay between the time from when the source sends an application packet to when the destination receives it.
• Connection density (devices/km2): Shows how many devices can be supported per kilometer squared. This is something closely related to the cellular-IoT.
• Network energy efficiency (bit/joule): Indicates how much energy is used in the network to send a bit each time.
• Area traffic capacity (Mbit/s/m2): How many megabits of information can be sent per meter squared per second.

5G standardization

Like many of the preceding technologies, 2G, 3G, and 4G, it is 3GPP that really defines the standards. 3GPP has defined the specifications for 5G, which are there to address the IMT-2020 requirements. Some of the techniques that were introduced in Release 14 were carried on to Release 15 to be used as 5G techniques.

5G was first standardized in Release 15. The first drop of Release 15 back in December 2017 provided a standard for service providers for Non-Standalone (NSA) operation within the network. However, Release 15 did not completely standardize every aspect of 5G. Release 16 and Release 17 includes further enhancements to 5G to provide full capability and address IMT-2020’s requirements.

In terms of a timeline, back in 2017 and 2018, the earlier proprietary 5G systems started to appear; however, standardization was not complete at the time, so some NSA 5G networks started to emerge. The period of 2019-2020 was really the time in which the first Phase-1 deployments of standardized 5G based on 3GPP Release 15 commenced. However, most of the networks that were deployed in 2019 centered around NSA operation, which is composed of 5G RAN with Evolved Packet Core (EPC). Phase-1 deployments are only centered on eMBB services. It is Phase 2 where we see those additional two pillars of 5G, namely URLLC and mMTC.

Phase-2 deployments are based on a combination of Release 15 and Release 16 features. We see full SA operations take place with the various features relating to URLLC and mMTC as well as eMBB.

In this section, we looked at the key drivers, performance synopsis, and standardization of 5G, which will help us understand the forces driving the technology we will be studying in this book.

We will now look at 5G NR and NG-RAN.