Why is 5G so important?

Wow. We have truly come a long ways in this industry. Just think, just 120 years ago, phone calls were made using crank phones like my granddads phone (that's not it above, thats another phone in my vast collection - granddads phone wouldn't fit in the picture), connected through an operator manually. Today, we not only connect our voices, but send pictures, files, and access our bank accounts through pocket sized computers!

All through my lengthy career in telecom, we have talked about convergence. We have talked about merging voice and data. Yet we have always fallen short of that goal, with awkward solutions that just didn't quite deliver the speeds and bandwidth we dreamed. Until now. 5G really represents true convergence where the network is transformed into a Web-based service.

When we talk about 5G, we need to understand why 5G is so important, and for what it was really designed. Its not about voice services, and our smartphones. Its about data and connecting billions of things to other things. Its about the Internet of Everything.

The reality is, 5G will not really deliver speeds you would be willing to spend +$500 for a new phone on. And there is not discernible voice quality in 5G. So what is the big deal? Let's take a look at 5G specifications, and understand a little more about the requirements.

What is 5G?

First, 5G is not really the next iteration of wireless technology. In fact, 5G is not really a wireless network. 5G is defined to support all types of access; cellular, WiFi, fixed line, broadband, and Satellite. It was defined this way because there are use cases for IoT that may not require cellular connectivity.

But here is another thought. Operators may have multiple networks supporting all these different access types. In reality, they all have to support the same functions. Authentication, Authorization, and Accounting. Yet the networks to support this are all disparately different. There is no reason for this other than we have not been able to support all these different access types in one network. 5G changes this, and provides an architecture that is access agnostic.

The architecture of 5G is also a major game changer. I like to say there is no telco technology in 5G. SS7, Diameter, even GTP are being replaced with IT technologies. 5G is designed as a Web-based set of applications in a service-based architecture, using HTTP/JSON over RESTful APIs. These of course are all IT technologies that are more cloud-friendly.

5G networks are not built in central offices with purpose-built appliances. They are built in data centers, and accessed through cloud services. This is a huge departure from traditional telecommunications networks. But why such a major change in the architecture and the technology? Why not just build on 4G and add enhancements?

While 4G supports IoT, it leaves a lot to be desired. Devices must have more powerful radios to reach cell towers. This requires a larger battery, which means the device must be larger, and must have an ability to recharge the battery. This is not very conducive to IoT applications where we need very small sensors, with very low power and very long battery life.

Latency is also an issue, especially if you are connecting a camera with a live video feed to an application. 4G architectures are not able to deliver lower latency designed as they are, requiring a massive change in network architecture. To achieve the requirements set forth by the ITU, the network had to be completely redesigned. To better understand why, let's look at the ITU and 3GPP requirements.

5G Requirements

First, there are three use cases that were defined for 5G;

• enhanced Mobile BroadBand (eMBB)
• Ultra Reliable Low Latency Communications (URLLC)
• massive Machine Type Communications (mMTC)

eMBB supports requirements for our smartphones. There really are not many requirements for eMBB specifically, as most of the requirements are set for IoT. URLLC requirements focus mostly on speed, bandwidth and latency (think First Responders sending critical video for situational awareness to a command center). Most of the requirements in 5G were driven by IoT.

The ITU defined requirements for 5G in ITU-R M.2410-0. These requirements can be condensed to:

• Peak data rates: 20 Gbits/s download (DL) and 10 Gbits/s upload (UL)
• Connection Density: up to 1M devices per square km
• Device battery life: +10 years
• Mobility: up to 500km per hour
• Latency for user data: 1ms for industrial IoT and mission critical communications; 4ms for mobile phones

Note that peak data rates are not the data rates you and I would actually experience on our phones. The ITU defines peak data rates as the rate realized under ideal conditions with all radio resources supporting one device in close proximity (so pretty much a lab environment).

Real-life data rates will be closer to 100M bits/s DL, and 50M bits/s UL, which by the way is not too far from 4G speeds today. Really the only smartphone specific requirement seems to be the data rates. All the other requirements are more focused on supporting IoT use cases.

Even mobility is defined with IoT in mind, breaking down into the following scenarios:

• Stationary: 0 km/h
• Pedestrian: 0 km/h to 10 km/h
• Vehicular: 10 km/h to 120 km/h (think vehicle to vehicle communications)
• High Speed (as in high speed trains): 120 km/h to 500 km/h

The 3GPP adds a few more requirements in 38.913:

• Control plane latency less than 10ms
• User plane latency of 4ms DL, 4ms UL for eMBB
• User plane latency of 0.5ms DL, 0.5ms UL for URLLC
• User plane latency of 600ms RTT for GEO satellite
• User plane latency of 180ms RTT for MEO satellite
• User plane latency of 50ms RTT for LEO satellite
• Battery life of +10 years, with a goal of 15 years

The Network Architecture

I won't go into a full description of the architecture here. We have all seen the diagrams and depictions of the various network functions. I will say that we need to separate the network into two functions;

• Access
• Network core

When we talk about 5G, the conversation immediately focuses on the radio access. First of all, the radio is nothing more than an access method. While there are some 5G specific features in the radio itself, the features that support the requirements for IoT are not delivered by the radio. They are delivered by the 5G network core.

This means that if a network operator is delivering 5G using their 4G network core (which is the case for just about everybody today), they are not delivering true 5G features. I am sure I will get a lot of grief for this, but I refer to this as 4.5G, and not 5G.

The 5G features defined by the 3GPP in 23.501 are only available when you have a stand-alone 5G network core. And let's not forget that the radio is only one method of access. Cellular is not necessary to reach the 5G core. Why would a broadband provider want to have a 5G core, when they don't have a cellular network?

The answer comes back to what I have been saying since the start. 5G is about delivering IoT services, with massive connectivity, low latency, extended battery life, and supporting very small devices that do not require SIM cards. This is some of what 5G can provide to any service provider supporting IoT applications, regardless if they provide cellular services.

So to wrap it up

5G is important to all types of service providers; cellular, broadband, fixed line, and cloud service providers because it is 5G that provides unique capabilities for supporting IoT use cases. All kinds of IoT use cases.

So why do we treat 5G as the next evolution of wireless? Habit. We always treat these technologies as the next wireless service, because its what telco's sell. Until now. For the first time, we are seeing cloud service providers building their own 5G networks to support IoT services. We are seeing enterprise building their own private 5G networks to support the devices in their factories.

Voice is not important. In fact 5G voice is not even a thing yet. Voice is supported on a 4G IMS core, and not the 5G network because the specification for 5G voice has not been completed. Its about the data, and the devices that need to send that data. Its about IoT. And its about the cloud.

So when thinking about 5G implementations, and wondering how best to support your IoT devices, think about the true reason for 5G (and its not new $500+ smartphones). Think about a cloud Software-as-a-Service (SaaS) model providing everything you need to connect your devices and collect their data using applications in the cloud. That is what 5G is really all about.

Of course, as always, this represents my own personal opinion and not that of my employer.