Managing the Future of Cellular:
What 5G Means for theRadio Access Network (RAN)White Paper

Radio Access Networks (RANs), which link end-user equipment
and the core network, are an essential part of new 5G networkarchitectures. Having a high-level understanding of what 5G
entails can help make it easier to manage expectations whendeveloping a 5G RAN. This paper explains the current status of
5G standards and rollout, summarizes the three categories ofuse cases that 5G RANs will need to support, and highlights theconsiderations for 5G RAN design. We also explain how the
Arm Neoverse supports the optimization of 5G RAN architectures.
The Factors That Influence 5G RANs
Ask a dozen people what 5G is, and you’re likely to get a dozen very different answers.
That’s because 5G is such a multi-faceted subject, intended to address a complex technologythat needs to evolve in many different areas.
Any way you look at it, 5G is a massive undertaking. Designed to accommodate every type ofelectronic device that will eventually access the network – today, tomorrow, and years fromnow – 5G addresses everything from tiny sensors and smartphones to industrial robots andautonomous vehicles. With 5G, tens of thousands of devices can access individual cells, andedge devices will perform increasingly complex processing tasks that involve large amountsof data. The network will need to be resilient enough to handle all this, yet flexible andresponsive to manage traffic while maintaining the extremely low latencies required forreal-time operations.
The Radio Access Network (RAN), which manages traffic and transmits data between
end-user equipment and the core network, is an essential part of this new way of operating.
To place the RAN into a 5G context, and anticipate what next-generation RANs will be asked
to do, it can help to step back and take a high-level look at 5G – the standards involved,
the use cases addressed, and the network architectures required.

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“Introducing 5G functionality
in stages provides a stable
platform for development

That’s what we aim to do in this paper. We summarize where we are in the phased rollout
of 5G standards, define the use cases that 5G standards are designed to enable, summarize
the network architecture that will support those use cases, and describe the role of RANs inthat architecture. We also introduce Arm’s approach to 5G, which includes technologies thatenable the RANs to perform in this new 5G environment.

while ongoing refinements
are made .”5G Has Arrived. And It Will Keep Arriving For Years To Come.
The 3GPP (3rd Generation Partnership Project), the global industry organization developing
the technical specifications for 5G, is itself a complex entity. Made up of representatives fromregional standards bodies, as well as people from roughly 400 companies in 39 countries,
the 3GPP identifies present and future use cases for cellular, defines the technical featuresneeded to deploy those use cases, and manages the details that ensure interoperability on a
global scale.
The 3GPP model uses planned “Releases” to introduce functionality in stages. This lets
network providers and device manufacturers move ahead with development, based on astable platform, while some of the details are still being worked out.
2019 was a big year for 5G, since it saw the main drop of Release 15, the first Release todirectly address 5G operation. But Release 15 is just the beginning:

3GPP Timeline	
Release 15, which defines much of the basic operation of 5G, was completed in2019 = Release 15

June 2019. It defines the 5G New Radio, or 5G NR, along with the 5G core network,

2020 = Release 16

or 5G system, and several important use cases, including the Internet of Things (IoT).

2021 = Release 17

	
Release 16, which is the second phase of 5G definitions, is expected to be completed by
the end of 2020. Along with further definitions of 5G NR and core network operation,
Release 16 will define services for latency-sensitive devices in applications like factory
automation, autonomous driving, and remote surgery (more on that in the next section).

	
Release 17, which will include various incremental enhancements and support features,is still under discussion, but is scheduled to be completed by the end of 2021. As of thiswriting, Release 17 topics under consideration include nearly 30 possible refinements tothe standalone 5G architecture and more than 15 RAN features.

2The 3GPP in Numbers

What’s Included in Release 15 and Release 16

 epresentation: North America (22%),
R
European Union (36%), Asia (42%)
9 regional standards bodies~400 companies from 39 countries
50,000 delegate days per year
40,000 documents per year
1,200 specifications per Release
New Releases every 18 to 24 months

https://www.3gpp.org/release-15

https://www.3gpp.org/release-16

What Use Cases Will 5G RANs Need To Support?
As one of their first steps in defining 5G, the International Telecommunication Union Telecommunications (ITU-T) standards identified the ways that cellular is and will be usedby consumers, enterprises, and industry. 3GPP then set about implementing the standards
to support this. As part of what the 3GPP called their “SMARTER” project (Study on New
Services and Markets Technology Enablers), they identified high-level use cases for cellular,
now and in future, and identified the features and functionality 5G would need to deliver toenable those use cases.
In addition to a category called fixed broadband, they came up with three categories of mobile
use cases: Massive Machine Type Communications (mMTC), Enhanced Mobile Broadband(eMBB), and Ultra-Reliable, Low-Latency Communications (URLLC).
Now, admittedly, these category names aren’t particularly catchy and don’t exactly roll
off the tongue, but they’ve become industry-standard terms so it’s best to keep using them.
Here’s a closer look:	
Massive Machine Type Communications (mMTC)
This category covers machine-to-machine interactions happening on a very large scale
and includes battery-operated devices operating in the IoT. By and large, these devices needrelatively low latency and highly reliable connectivity while they operate on efficient power
capacities. The challenge is to provide scalability and consistent connectivity for the billions
of IoT devices that communicate relatively infrequently and in short bursts. Wide coverageand deep indoor penetration are important, as are low cost and energy efficiency.

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Enhanced Mobile Broadband (eMBB)
If mMTC mostly addresses how machines use cellular, eMBB mostly addresses how people
use cellular. It includes activities like 8K video streaming, immersive Augmented Reality/
Virtual Reality (AR/VR), connected transportation infotainment, and enterprises supporting
mobile broadband connectivity. The key requirements in this category are ultra-highspectral efficiency, extreme data transmission rates, and ultra-low interrupt time.
All these things are addressed by the 5G NR defined in Release 15. As infrastructure
support for the 5G NR begins to expand, these use cases will become more widely available.
This category can be considered a mix of evolutionary and revolutionary, since laptops using
cellular for connectivity isn’t exactly new, while immersive AR/VR and other data-intensive
applications haven’t really been possible with previous generations of cellular.
Ultra-Reliable, Low-Latency Communications (URLLC)
This is, for many, the truly revolutionary aspect of 5G, since it delivers a level of 		
performance not yet seen in real-world applications. It’s essentially the IoT on steroids.
It covers things like intelligent transportation, including vehicles that can navigate
complex road situations and avoid collisions by cooperating with each other, and use cases
associated with the fourth industrial revolution, including time-critical factory automation.
It also includes remote healthcare, which includes devices that measure vital signs andeither automatically or semi-automatically respond as needed, as well as remote treatment,
including surgeries performed in ambulances, during disaster situations, or in remote areas
while using real-time guidance from an offsite doctor. In all these situations, the connectionneeds to be exceptionally stable and needs to operate with end-to-end latency rates on theorder of a millisecond or less. The features needed to support URLLC are still being defined
and will be included in Releases 16 and 17. In other words, URLLC is the future of 5G,
even if that future is only a few years away.
The various features added to each Release are intended to address different aspects ofthese three categories. The specific use cases that are already in use today or close to arriving
are addressed in earlier Releases, while use cases that are farther in the future are addressedin later Releases. It’s all part of the ongoing evolution of 5G.

NGMN Association

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3GPP Focus Areas
Release 15 = mMTC, eMBB
Release 16 = URLLC with enhancements
for mMTC, eMBB
Release 17 = Ongoing enhancements for
mMTC, eMBB, and URLLC

Sample 3GPP Use Cases
mMTC
Lighting & roadsign control
Smart waste
management

eMBB

URLLC

Immersive AR/VR

Industrial automation

Advanced gaming
8k video streaming

Intelligent
transportation

Enterprise broadband

Remote healthcare

Asset tracking

connectivity

Structure andenvironmental
monitoring

Connected
transportation
infotainment

How Will 5G RANs Support 5G Use Cases?
RANs will continue to be an essential part of the 5G network, but they will take on new
functionality to support the broader 5G cellular architecture, which covers everything fromthe client device to the cloud data center. Multiple pieces of equipment will be required tosupport this connectivity.
Today’s IoT is a good example of how the network architecture needs to evolve to support
5G use cases. With current setups, data from a connected device is typically transferred,using backhaul equipment, to a hyperscaler data center, for application processing, and thentransferred back to the device. This proves to be inefficient and costly to the IoT provider
while delivering sub-par performance to the IoT device user.

“5G is both evolution andrevolution. Release 15
brings upgrades to IoT,
enterprise, and consumer
applications, while Releases
16 and 17 will enableentirely new applications.”

As we approach a trillion connected devices, the steady increase in data traveling throughthe network forces a change. If, for example, today’s cellular network carries a total of
150 Exabytes per month of data. Assuming, in the future, the network was to evolve tosupport a billion connected image sensors over 5G, this would, on its own, increase thebandwidth required to service these sensors and the resultant image data to 400 Exabytes.
Simply adding capacity to the backhaul channel won’t keep pace with this need and would
be prohibitively expensive for network operators to keep adding additional capacity to theirbackhaul network.
This is why there will be a move to push computing power towards the edge of the network.
Having processing capability closer to the client device connected through 5G means there’s
less need to transfer data to backend data centers. Intelligence to make decisions on theimages captured will be provisioned closer to the edge of the radio network.
5G RANs will enable these newer use cases at the edge, by supporting the necessary
features, including higher performance levels whilst meeting strict power requirements.
At the same time, as URLLC capabilities come online, with their strict requirements for
exceptionally fast response times, 5G RANs will filter workloads and react to edge-based
applications – with latency rates around 1 or 2 milliseconds.

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Round-Trip Latency Requirements for
Emerging Applications
Robotics/Medical

2.2 msV2X Augmented Apps

10 ms

Smart City, IoT Control

15 to 20 ms

The transition to 5G requires existing building blocks to perform new functions. As shownin the diagram, the RAN needs to support legacy devices running 4G as well as new devices
that use the 5G NR radio, and the network-access mechanisms must support local
decision-making.
Edge processing is used to filter and react, using content caches in smaller, more localized
data centers referred to as edge clouds. The edge cloud acts as an intermediary, forwarding
data as needed to the core network and hyperscaler clouds so it can be analyzed and stored.
The core network, managed by the MNO, provides supervision of edge-based network
components, including the RAN.

Building Blocks for 5G Network Architectures

Network Numbers
Global Mobile Traffic

2018 = 28 Exabytes/Month2025 = 130 Exabytes/Month

Unique Mobile
Broadband Subscribers

2019 = 8 Billion

2025 = 9 Billion

Mobile Data Traffic

2017 = 46% Video

2025: 74% video

IoT Connectivity

2019 = 7.5 Billion

2025 = 25 Billion

Sources: Ericsson Mobility Report, ReThink, Cisco“With 5G, RANs need to takeon new tasks, and they needto perform those tasks withremarkable efficiency.”

Considerations influencing the evolution of 5G
Because 5G is relatively new and covers such an extensive list of features and operating
requirements, it can be hard to know what to expect from the development effort for thosefeatures. At Arm, our work developing and deploying 5G technology has uncovered fiveissues that are likely to need attention as hardware and software teams begin defining thenext generation of 5G RANs.

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The 5G Learning Curve

1. Data Processing – To achieve higher spectrum efficiency and meet end-to-end 		New algorithms

latency requirements, a 5G RAN will need to perform more complex algorithms for data

New architectures

processing. When considering the requirements for these algorithms, it’s important to

New spectrum

find the right balance between hardware and software tasks, so the system meets its

New suppliers
New standards

goals for performance, power, and cost.
2. Deployment Scenarios – The specific use cases to be supported by a given RAN have astrong influence on the system as a whole. Since each use case (mMTC, eMBB, URLLC)
has its own unique characteristics, one size probably won’t fit all. Deciding how to divide
network functionality across different pieces of equipment, to support a given set of use
cases, can impact the RAN design.
3. Radio and Spectrum – 5G uses more of the spectrum, with devices operating in 		
low bands (below 1 GHz), mid bands (between 1 GHz and 2.6 GHz or between 3.5 GHz
and 8 GHz), and high bands (between 24 GHz and 40 GHz). Each band has its own setof requirements for edge performance, capacity, speed, and latency. As new spectrum
assets become available, these various requirements will need to be addressed by the
RAN system.
4. Supply Chain and Ecosystem – 5G is disrupting the supply chain in several ways.
There are initiatives that aim to reduce vendor dependence and there is growing 		availability of proprietary and open software platforms. The level of infrastructure
support also varies from region to region. OEMs may need to reassess and revise
their ecosystem partnerships.

“Working with anexperienced partner makes
it easier to navigate
the newness of 5G.”

5. Emerging Standards – In addition to the 3GPP, there are independent industry
organizations, such as the Telecom Infra Project (TIP) and the Open RAN Alliance 		(O-RAN), that are working on aspects of 5G operation and deployment. There is a
growing convergence towards O-RAN alliance as the key industry body that drives
interface specifications.

Arm Neoverse: The Foundation for 5G Cloud-To-Edge Infrastructure
Building on our industry-leading success in markets like mobile and smart IoT,
Arm has developed Neoverse, a comprehensive portfolio for the 5G infrastructure thatprovides end-to-end coverage from the cloud to the edge. As 5G evolves and expands,
our infrastructure business is developing, and in many instances inventing, the technologies
needed for a 5G world that includes a trillion edge devices.

A Modern Architecture
The Arm Neoverse considers the current and long-term trends influencing 5G development
and addresses the need for a strong 5G ecosystem:
High Performance, Secure IP, and Architectures – We deliver the highest levels 		
of performance for each power/area budget and support competitive, single-thread
performance with exceptional power efficiency. Security is a crucial aspect of 5G 		
operation, which is why Arm Neoverse platforms are built around a very specific security
model supported by our own secure platforms and compliance programs.

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Diverse Solutions and Ecosystem – We give designers the freedom to integrate custom
accelerators and to supplement operation with open-source software capabilities thatare pre-integrated into the Arm environment. We enable different approaches, so Proof
Of Concept (POC) designs can accurately verify and validate capabilities. We also workwith a broad range of silicon and software vendors to push innovation, with features
like multi-chip module (MCM) capability, FPGA integration, and chip-to-chip (C2C) 		
interconnects.
Scalable from Hyperscale to the Edge – We offer the performance per socket needed
to deploy servers on standardized, Arm-based blades, and the performance per thread
for throughput processing in the RAN. What’s more, all this IP is scalable across all the
points in between.

“Arm Neoverse solutions
are uniquely designed for
unprecedented levels of
performance, security,and scalability.”

An Expanding Ecosystem
Beyond the tools, software, and solutions that we supply to support Neoverse IP,
we’re working with a strong ecosystem that enables every kind of design for 5G deployment.
That means everything from modeling and emulation to closer integration with leading
software vendors.

Realizing the full potential of 5G requires new thinking and new system architectures.
This is especially true for 5G RANs, because they will need to manage increasingly complex
processing tasks that involve an unprecedented number of cellular-connected devices.
The Arm Neoverse is specifically designed to help developers meet this challenge.
To learn more, visit www.arm.com.

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