What is 5G Network Architecture?

The first question you might be asking is: What is 5G? The 2nd question might be: How is it architected differently to provide speed, low latency, capacity, and numerous other benefits?

In this short article, we'll tackle the 5G architecture question. We will look at some of the capabilities thanks to 5G network architecture and how connected applications can benefit from it. You'll find more resources within the links throughout this article and in the related resources in the footer. For a good basic 5G introduction, see the article, What Is 5G, Part 1. Our 5G overview continues in Part 2, Who'll Adopt 5G Technology, so when?

One thing is for certain: Our connected world is changing. 5G, using its next-generation network architecture, has the potential to support a large number of new applications in both the customer and industrial segments. The options for 5G seem almost limitless when speed and throughput are exponentially greater than current networks.

These advanced capabilities will enable applications across vertical markets such as manufacturing, healthcare, and transportation, where 5G will have a major role in everything from advanced manufacturing automation to fully autonomous vehicles. In order to develop profitable business use cases and applications for 5G, consider using at least an over-all understanding of the 5G network architecture that lies in the centre of all these new applications.

5G has received an enormous amount of attention, and most just a little hype. While the potential is enormous, it's important to know that the is still continuing of adoption. The process of deploying the 5G network started a long time ago and involved building the new infrastructure, many of which is funded by the major wireless carriers.

Full 5G deployment will require time, rolling in major cities long before it may reach less populated areas. Digi supports our customers in get yourself ready for 5G, with communications on migration planning and next generation products. While Digi is not directly involved with developing the 5G new radio (NR) core and 5G radio access network (RAN), Digi devices is going to be a fundamental element of the 5G vision and their use within an array of 5G applications.

5G Network Architecture

So – what is 5G and how does 5G network technology architecture vary from previous \”G's\”?

The 3GPP standards behind 5G network architecture were introduced by the next Generation Partnership Project (3GPP), the business that develops international standards for those mobile communications. The International Telecommunications Union (ITU) and its partners define the requirements and timeline for mobile communication systems, defining a brand new generation approximately every decade. The 3GPP develops specifications for all those requirements inside a number of releases.

The \”G\” in 5G stands for \”generation.\” 5G technology architecture presents significant advances beyond 4G LTE (long-term evolution) technology, which will come around the heels of 3G and 2G. As we describe within our related resource, Your way to 5G, there's always a period period where multiple network generations exist at the same time. Like its predecessors, 5G must co-exist with previous networks for two important reasons:

1. Developing and deploying new network technologies takes an enormous amount of time, investment and collaboration of major entities and carriers.
2. Early adopters will invariably would like to get their on the job new technologies as soon as possible, whereas anyone who has made major investments in large deployments with existing network technologies, such as 2G, 3G and 4G LTE, want to make use of those investments for as long as possible, and definitely before the new network is fully viable. (Note that 2G and 3G networks are being sunset to create room for 5G deployment. See our article 2G, 3G, 4G Network Shutdown Updates.)

The network architecture of 5g mobile technology improves vastly upon past architectures. Large cell-dense networks enable massive leaps in performance. And likewise, the architecture of 5G networks offers better security when compared with today’s 4G LTE networks.

In summary, 5G technology offers three principle advantages:

• Faster data transmission speed, as much as multi-Gigabit/s speeds.
• Greater capacity, fueling a massive amount of IoT devices per square kilometer.
• Lower latency, down to single-digit milliseconds, that is crucial in applications for example connected vehicles in ITS applicationsand autonomous vehicles, where near instantaneous response is necessary.

Does this mean that 5G is fully ready today? And will it mean 5G architecture suits all applications? Read on to see the way the new technology supports key applications, and which applications tend to be more suitable for 4G LTE.

5G Design and Planning Considerations

The design things to consider for a 5G network architecture that supports highly demanding applications is complex. For example, there isn't any one-size-fits all approach; the plethora of applications requires data to travel distances, large data volumes, or some combination. So 5G architecture must support low, mid and high-band spectrum – from licensed, shared and sources – to provide the entire 5G vision.

For this reason, 5G is architected to operate on radio frequencies which range from sub 1 GHz to extremely high frequencies, called \”millimeter wave\” (or mmWave). The low the regularity, the farther the signal can travel. The larger the frequency, the greater data it may carry.

There are three frequency bands fundamentally of 5G networks:

• 5G high-band (mmWave) offers the highest frequencies of 5G. These vary from 24 GHz to approximately 100 GHz. Because high frequencies cannot easily move through obstacles, high-band 5G is short range naturally. Moreover, mmWave coverage is limited as well as more cellular infrastructure.
• 5G mid-band are operating in the 2-6 GHz range and provides a capacity layer for urban and suburban areas. This frequency band has peak rates in the hundreds of Mbps.
• 5G low-band operates below 2 GHz and provides an extensive coverage. This band uses spectrum that is available as well as in use today for 4G LTE, essentially providing an LTE 5g architecture for 5G devices that are ready now. Performance of low-band 5G thus remains much like 4G LTE, and supports use for 5G devices currently available.

In accessory for spectrum availability and application requirements for distance vs. bandwidth considerations, operators must think about the power requirements of 5G, because the typical 5G base station design demands over twice the quantity of power of a 4G base station.

Considerations for Planning and Deploying 5G Applications

Systems integrators, and people developing and deploying 5G applications for that verticals we've discussed, will discover that it's vital that you consider trade-offs. (Our video, 5 Factors to Guide Your Preparation for 5G, is a superb resource.)

For example, listed here are types of a few of the key considerations:

• Where will your application be deployed? Applications which are optimized for mmWave won't operate not surprisingly within buildings so when extended range is needed. Optimal use cases include 5G cellular telecommunications in the 24- to 39-GHz bands, police radar in the Ka-band (33.4- to 36.0-GHz), scanners in airport security, short-range radar in military vehicles and automated weapons on naval ships to detect and take down missiles.
• What kind of throughput will be required? For autonomous vehicles and intelligent transportation systems (ITS) applications, the devices and connectivity must be optimized for speed. Near real-time communications – measured in millionths of the second – are crucial for vehicles and devices to \”make decisions\” on turning, accelerating and braking, and the most favorable latency is mission critical for these applications.
• Video and VR applications, by contrast, should be optimized for throughput. Video applications such as medical imaging can ultimately make the most of the huge amounts of data that 5G networks supports.

For 5G to provide its full vision, the network infrastructure must evolve too. The next diagram illustrates the migration with time, in addition to Digi’s 5G product plans.

The first uses of 5G technology will not be exclusively 5G and can come in applications where connectivity is shared with existing 4G LTE with what is called non-standalone (NSA) mode. When operating within this mode, a tool will first connect to the 4G LTE network, and if 5G is available, the unit can apply it additional bandwidth. For example, a device connecting in 5G NSA mode could get 200 Mbps of downlink speed over 4G LTE and the other 600 Mbps over 5G simultaneously, for an aggregate speed of 800 Mbps.

As increasingly more 5G network infrastructure goes online within the next several years, it'll evolve to allow 5G-only stand-alone mode (SA). This will bring the reduced latency and ability to connect with massive numbers of IoT devices which are one of the primary benefits of 5G.

Core Network

In this section we'll give a 5G core architecture overview and describe the 5G core components. We will also show how 5G architecture compares to the present 4G architecture.

The 5G core network, which helps the advanced functionality of 5G networks, is among three primary components of the 5G System, also referred to as 5GS (source). Another two components are 5G Access network (5G-AN) and User Equipment (UE). The 5G core utilizes a cloud-aligned service-based architecture (SBA) to aid authentication, security, session management and aggregation of traffic from connected devices, which necessitates the complex interconnection of network functions, as shown in the 5G core diagram.

The aspects of the 5G core architecture include:

• User plane Function (UPF)
• Data network (DN), e.g. operator services, Access to the internet or Third party services
• Core Access and Mobility Management Function (AMF)
• Authentication Server Function (AUSF)
• Session Management Function (SMF)
• Network Slice Selection Function (NSSF)
• Network Exposure Function (NEF)
• NF Repository Function (NRF)
• Policy Control function (PCF)
• Unified Data Management (UDM)
• Application Function (AF)

The 5G network architecture diagram below illustrates how these elements are associated.

4G Architecture Diagram

When 4G started out its 3G predecessor, only small incremental changes were made to the network architecture. The next 4G network architecture diagram shows the important thing components of a 4G core network:

Source: 3GPP

In the 4G network architecture, User Equipment (UE) like smartphones or cellular devices, connects over the LTE Radio Access Network (E-UTRAN) to the Evolved Packet Core (EPC) after which further to External Networks, like the Internet. The Evolved NodeB (eNodeB) separates the user data traffic (user plane) from the network's management data traffic (control plane) and feeds both separately into the EPC.

5G Architecture Diagram

5G was designed from the ground-up, and network functions are separate by service. That is why this architecture is also called 5G core Service-Based Architecture (SBA). The next 5G network topology diagram shows the important thing components of a 5G core network:

Source: Techplayon

Here’s how it operates:

• User Equipment (UE) like 5G smartphones or 5G cellular devices connect within the 5G New Radio Access Network to the 5G core and additional to Data Networks (DN), like the Internet.
• The Access and Mobility Management Function (AMF) provides a single-entry point for the UE connection.
• Based around the service requested by the UE, the AMF selects the respective Session Management Function (SMF) for handling the user session.
• The User Plane Function (UPF) transports the IP data traffic (user plane) between the User Equipment (UE) and also the external networks.
• The Authentication Server Function (AUSF) permits the AMF to authenticate the UE and access services of the 5G core.
• Other functions like the Session Management Function (SMF), the insurance policy Control Function (PCF), the Application Function (AF) and also the Unified Data Management (UDM) function provide the policy control framework, applying policy decisions and accessing subscription information, to manipulate the network behavior.

As you can observe, the 5G network architecture is more complex behind the curtain, however this complexity is needed to have better service that may be tailored to the wide range of 5G use cases.

Difference between 4G and 5G Network Architecture

In this, we'll discuss how 4G and 5G architectures differ. Inside a 4G LTE network architecture, the LTE RAN and eNodeB are usually close together, often at the base or near the cell tower running on specialized hardware. The monolithic EPC on the other hand is often centralized and additional away from the eNodeB. This architecture makes high-speed, low-latency end-to-end communication challenging to impossible.

As standards bodies like 3GPP and infrastructure vendors like Nokia and Ericsson architected the 5G New Radio (5G-NR) core, they broke apart the monolithic EPC and implemented each function so that it can run independently from one another on common, off-the-shelf server hardware. This allows the 5G core to become decentralized 5G nodes and very flexible. For instance, 5G core functions is now able to co-located with applications in an edge datacenter, making communication paths short and therefore improving end-to-end speed and latency.

Source: Techmania

Another advantage of these smaller, more specialized 5G core components running on common hardware is the fact that networks can now be customized through network slicing. Network slicing allows you to have multiple logical \”slices\” of functionality optimized for particular use-cases, all operating on a single physical core within the 5G network infrastructure.

A 5G network operator may offer one slice that's optimized for high bandwidth applications, another slice that’s more optimized for low latency, along with a third that’s optimized for any massive number of IoT devices. Depending on this optimization, a few of the 5G core functions might not be available at all. For instance, if you are only servicing IoT devices, you wouldn't require the voice function that is necessary for cell phones. And since not every slice must have exactly the same capabilities, the available computing power can be used more proficiently.

Source: SDX Central

The Evolution of 5G

Every generation or \”G\” of wireless communication takes approximately ten years to mature. The switch in one generation to the next is mainly driven through the operators' need to reuse or repurpose the limited quantity of available spectrum. Each new generation has more spectral efficiency, which makes it possible to transmit data faster and more effectively over the network.

The first generation of wireless communication, or 1G, started during the 1980s with analog technology. It was followed quickly by 2G, the very first network generation to make use of digital technology. The development of 1G and 2G was initially driven through the marketplace for cell phone handsets. 2G also offered data communication, but at very low speeds.

The next-gen, 3G, began ramping in the early 2000s. The growth of 3G was driven by handsets again, but was the first technology to offer data speeds within the 1 Megabit per second (Mbps) range, ideal for a variety of new applications both on smartphones but for the emerging Internet of Things (IoT) ecosystem. Our current generation of wireless technology 4G LTE, began ramping up in 2010.

It's worth noting that 4G LTE (Long Term Evolution) includes a long life ahead; it is a very successful and mature technology and it is likely to be in wide use not less than another decade.

5G Architecture and the Cloud and also the Edge

Let’s discuss edge computing within the 5G network architecture.

One more concept that distinguishes 5G network architecture from the 4G predecessor is edge computing or mobile edge compute. Within this scenario, you can have small data centers positioned close to the network, close to where the cell towers are. That’s very important for very low latency as well as for high bandwidth applications that are carrying exactly the same content.

For a high bandwidth example, think of video streaming services. The content comes from a web server that’s sitting somewhere within the cloud. If people are linked to a cell tower and let’s say, 100 people are streaming a well known TV program, it's more efficient to possess that content as close towards the consumer as possible, immediately around the edge, ideally around the cell tower.

The user streams the information from a storage media that's around the edge rather than having to stream and transfer these details and backhaul it for 100 people from the central location on the cloud. Instead, using the 5G structure, you can bring to happy to the tower just once and then distribute it out for your 100 subscribers.

The identical principle applies in applications requiring two-way communication where low latency is required. If your user has an application running at the edge, then the turnaround time is much faster because the data doesn’t need to traverse the network.

In the 5G network structure, these edge networks may also be used for services that are provided on the edge. Since it’s easy to virtualize these 5G core functions, you could have them running on the standard server or data center hardware and have fiber running towards the radio that sends the signal. So the radio is specialized, but everything else is fairly standard.

Today, 4G LTE continues to be growing. It offers excellent speed and sufficient bandwidth to support most IoT applications today. 4G LTE and 5G networks will co-exist over the next decade, as applications begin to migrate and then 5G networks and applications eventually supersede 4G LTE.

Devices Using 5G

5G will evolve over time, and 5G devices will follow suit. Early products will be \”5G-ready\”, which means that these products possess the processing power and Gigabit Ethernet ports needed to offer the higher bandwidth 5G modems and 5G extenders now coming.

Later 5G products may have 5G modems directly integrated and have a faster multi-core processor, 2.5 or even 10 Gigabit Ethernet interfaces and Wi-Fi 6/6E radios. These product changes will drive the price of 5G products up but they are required to handle the additional speed and lower latency that 5G networks will offer you.