Since the release of 4G LTE in 2010s, the lives of millions of people of all ages and walks of life have been transformed in ways few of us could have imagined only a short while before. The rise of high-speed data has fueled an explosion of innovative Over-the-Top (OTT) applications that bring streaming video and other content to consumers through a myriad of online services. 5G promises to continue this pace of innovation by expanding upon existing LTE technology and infrastructure in ways that allow for the creation of new applications and services that extend far beyond what is currently possible.
ITU has defined three usage scenarios for 5G services - eMBB, URLLC, and mMTC. In this article, we’ll look at some of the new services associated with these usage scenarios and the key building blocks that will be used to make these services a reality.
Enhanced Mobile Broadband (eMBB)
Without a doubt, the main selling point of LTE has been its ability to deliver broadband services to mobile subscribers. Early on, wireless operators adopted a “build it and they will come” approach. The strategy: build a network capable of sustaining broadband speeds (say, about 75 Mbps peak data rate) and let the marketplace decide what to do with it. As a result, the developers of applications and content rose to the occasion and developed a whole host of services that have left the general consumer wanting more. The reality is that even while network operators continue to race to expand coverage and capacity, it simply is not enough!
What should be our response to this unprecedented embarrassment of riches? Quite simply, we have no choice but to meet the challenge. With supported peak data rates of to 20 Gbps in downlink and 10 Gbps in uplink, 5G standards provide operators with a technological framework to do just this.
eMBB defines a class of services that demand very high throughput for multiple users simultaneously. Typical use cases for this service include the streaming of ultra-high definition video, cloud storage, and to some degree, Virtual Reality (VR)/Augmented Reality (AR) applications. In short, eMBB is about opening up the pipe and bringing even higher data rates to many subscribers.
Ultra-Reliable Low-Latency Communications (URLLC)
Imagine an application where the most important part is not the sheer volume of data being transmitted but the swiftness and reliability with which the network is able to deliver packets across from the base station (gNB) to the device (UE). URLLC defines a class of services that, as the name implies, demand extremely low user plane latency and extremely reliable service. Typical use cases for this service include industrial automation, self-driving vehicles, and remote surgery. Note that an application or service may have characteristics of multiple usage scenarios. For example, AR/VR applications have some characteristics of eMBB (e.g., high data rates) and some characteristics of URLLC (e.g., low latency).
How does this service compare to “classic” LTE? Depending on the scenario, 4G LTE supports user plane latency of around 10 ms for the radio network, whereas URLLC seeks to reduce user plane latency to around 1 ms for the radio network. This is even faster than the human nervous system is capable of responding!
Massive Machine Type Communication (mMTC)
The last service usage scenario envisions a network in which subscribers are not human beings sharing content between themselves, but small, low-cost devices sending small amounts of data to centralized servers. Think of electricity meters, traffic lights, vending machines, or even a medical device implanted in your own body. Moreover, imagine all of these devices uploading data on a daily, weekly, or even monthly basis to facilitate a variety of services.
This use case upends many of our historical assumptions about data usage. In this scenario, we are not trying to support a few hundred people, each downloading a high-resolution video on Netflix on a Friday night. Rather, we are asked to support millions of connected devices, each transmitting an occasional trickle of data. These devices tend to be small and inexpensive, and may support a battery life of up to 10 years! While LTE has defined technologies such as LTE Cat-M1 (LTE-M) and Narrowband Internet of Things (NB-IoT), 5G supports such IoT devices on a more massive scale (e.g., 1 million devices instead of 100,000 devices in an area of one square kilometer).
Key Building Blocks
Each of these three service usage scenarios represents a wildly divergent set of performance requirements. The ability to deliver on these requirements requires a detailed understanding of the current LTE standards and how they can be applied in fresh new ways. For example, while 4G LTE has traditionally been deployed in frequencies below 3 GHz, the availability of millimeter wave bands (e.g., around 28 GHz and 39 GHz) make it possible to tap into huge swaths of spectrum that were previously unavailable. Expanding upon the existing LTE framework to allow channel bandwidths of 100 MHz or even larger (e.g., 400 MHz) allows operators to exploit these bands and feed the need for speed.
To support the unique service profiles associated with eMBB, URLLC, and mMTC, basic changes to the fundamental LTE frame structure are required. These changes will allow for more flexible radio resource allocation such as longer transmission times for eMBB, shorter transmission times for URLLC, and limited resource allocation for mMTC. This flexible frame structure allows many different types of devices and applications to access the network.
Enhancements such as massive Multiple Input Multiple Output (MIMO) and advanced coding techniques help increase throughput and reliability. New radio and core network architectures, Multi-access Edge Computing (MEC), and network slicing, and virtualization technologies such as Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) facilitate the implementation of services.
LTE has proven itself to be wildly successful as the recognized global standard for wireless transmission over commercial networks. The future success of LTE hinges on the ability to support new consumer behaviors and new usage requirements as they evolve. 5G promises to do just that – and understanding the key 5G usage scenarios provides a unique entry point for understanding 5G and why it is so important. For many consumers and developers, 5G means the ability to support higher data rates, even at the cell edge. For others, 5G is all about developing applications with extremely stringent reliability and latency requirements, such as AR/VR. Finally, as consumers embrace the concept of IoT, 5G introduces support for millions of small, low-cost connected devices that could never be supported by “classic” LTE networks due to their sheer number. These capabilities, along with several key enablers, such as the availability of new untapped spectrum assets, massive MIMO, MEC and new network virtualization technologies, pave the way for a bright and exciting future for the wireless industry.
About the Authors
David Walker is a Consultant for Award Solutions. David joined Award Solutions in 2013 and has more than 16 years of experience in the wireless industry with a focus on the development and delivery of high-impact wireless technical training.
Khyati Tripathi is a Senior Consultant for Award Solutions. Khyati is an experienced and accomplished Telecommunications Technical Project Manager of software development projects consisting software development cycle of traditional (waterfall) and agile (scrum) methodologies.
About Award Solutions, Inc.
Award Solutions is the trusted training partner to the world's best networks. We help companies tackle new technologies by equipping their teams with knowledge and skills. Award Solutions invests heavily in technology, research, engineering, and labs to ensure our customers make the most of their resource and network investments.
Award has expertise across all technologies that touch wireless: 5G, Artificial Intelligence, Machine Learning, Network Virtualization, Data Visualization, Data Manipulation, 4G LTE, and more.