5G Standards

Let’s throw ourselves right in the deep end and start with one of the more technical topics you are likely to encounter in discussions around 5G - standards. Just to give a little background, standards, which can be thought of as a set of technical specifications, play a crucial role in how mobile technology works. One of the great strengths of mobile - and something which we as mobile users have come to expect - is that it offers consistency in network access and connectivity wherever you go.

That would not work if all of the world’s operators were building their networks differently, or if device manufacturers were using their own proprietary technologies to connect to networks. For consistency and universal access, you need everyone singing from the same hymn sheet. You need standards.

Mobile standards are therefore very important and technically very detailed pieces of documentation, setting out everything from how networks and base station cells should be configured to the spectrum used to access protocols and security. With each new generation of mobile, new standards come along (sometimes more than one), usually as a result of work by large mobile industry bodies.

In reading around and talking about the subject, you are likely to come across reference to two different sets of 5G standards - the IMT-2020, a piece of documentation drawn up by the International Telecommunication Union’s Radiocommunication wing (the ITU-R), and the 5G New Radio (NR) standard developed by 3GPP, a body which has taken the lead on mobile standards development since 3G.

How do these two 5G standards relate to each other? Well, rather than being in competition, the IMT-2020 is best understood as a theoretical framework for what 5G should look like and be able to achieve (such as the peak 20Gbps download target), while 5G NR is a practical proposal for how these objectives can be met. We will outline some of the key technologies described in the 5G NR standard below.

Three Use Cases

One of the best-known features of the IMT-2020 documentation is that it outlines three specific use cases for fifth generation mobile which, since its publication in 2015, have served as the primary source of reference in most discussions about what 5G might achieve. This is a classic example of the abbreviated names for these proposed use cases sounding much more technical and daunting than they actually are, so let’s unpick what they actually refer to.

• Enhanced Mobile Broadband (eMBB): Since the arrival of 3G and then 4G mobile, mobile phones have become as much about accessing data services and the internet as making calls and sending texts. eMBB is the promise of 5G taking mobile broadband access to the next level - rivalling and even exceeding wireline broadband services in speed and efficiency, allowing us to access data intensive applications like ultra-HD video streaming on the move without a hitch, perhaps even providing a platform for eventually replacing fibre connections with wireless.
• Ultra-Reliable Low-Latency Communications (uRLLC): In setting out its 5G standard, the ITU-R was clear that it wanted the technology to go much further than simply improving on mobile services as we already know them. It wanted 5G to break the glass ceiling on cellular capabilities and enable a much wider range of use cases for mobile, ushering in a brand new era for wireless connectivity. uRLLC is one specific example of this ambition - to create mobile connections so reliable and data communications so close to instantaneous that 5G would become a viable option for use cases where any slip, any lag in the connection could literally be a matter of life or death. Examples of where uRLLC is expected to be applied include autonomous vehicles which need to respond to signals from on-road infrastructure and other vehicles with minimal delay in order to avoid collisions, and surgical robots performing procedures under the guidance of specialists based at a distant hospital, where any issue in data communication could put the well-being of the patient at risk.

• Massive Machine-Type Communications (mMTC): Finally, the ITU-R recognised that if licensed cellular services were to become the network option of choice for industrial IoT applications in sectors like manufacturing, utilities and agriculture, they would have to deliver solutions that were more focused on connection density than data speeds, and low cost rather than low latency. Individual IoT sensors only transmit data in low volumes, so speed and capacity is not such an issue. But to make something like a fully automated smart factory or warehouse viable, you have to deploy such sensors in their thousands. So while much of the focus on 5G centres on the potential for data-intensive, mission-critical applications, mMTC outlines how 5G can also become a key enabler in the next phase of development of IoT, by delivering low data, low energy connections at massive scale.

5G Technologies

So how will 5G deliver on all of these promises? Here are some of the key technologies set out by 3GPP’s 5G NR standard and proposed elsewhere.

• Network virtualization: Virtualization is a concept that has, over the course of the past decade or so, been perfected in IT and is best known as the underlying technology which enables cloud computing. In brief, virtualization involves using software to mimic the functions of a physical asset (like a computer server or a mobile network). This is often referred to as ‘abstracting’ functions from the underlying physical resource. The key benefits are that virtualized versions of servers, routers, networks and so on are much more efficient, flexible and scalable than the hardware equivalents. Network virtualization started with 4G, but 5G networks will be completely virtualized, meaning mobile services are managed and provisioned by software, not by physical hardware. This is viewed as critical to achieving many of the core ambitions of 5G, from increasing available capacity through more efficient use of spectrum to handling millions connections within a relatively small area simultaneously to managing and prioritising traffic so there are no signal log jams causing latency. For example, virtualization opens the door to techniques like ‘network slicing’, a multiplexing approach which makes it possible to run multiple services over the same piece of spectrum.
• Millimeter Wave (mmWave) Spectrum: Radio waves operate at a range of frequencies defined by their wavelength. Longer frequencies in the lower range of the spectrum have long been used by TV and radio because they are capable of travelling long distances, but their bands are narrow and are now close to capacity in terms of how much signal traffic they can carry. 3G and 4G mobile in particular has made extensive use of mid-range bands, but again, we’re getting close to a stage where these bandwidths are overcrowded. Higher frequencies, or so-called millimeter wave spectrum, represent a huge untapped spectrum resource, not least because shorter wavelengths also mean wider channels - which means lots and lots of extra capacity. 5G is unique amongst the five generations of mobile network technology to date in that it proposes to make use of spectrum at low, mid and high frequencies, as well as high capacity wide bands and lower capacity, lower power narrow bands (i.e. for mMTC). The drawback with short waves is that they only travel short distances. Network providers are proposing to solve this problem by creating incredibly dense networks made up of very small cells. Although such high-density networks are expensive to build, in heavily populated urban centres especially they are viewed as a more efficient long term solution than fibre-to-the-premises (FTTP) wired internet connections. High frequency, high density 5G networks would therefore provide the foundations for a wholesale switch to wireless broadband, a long-term ambition of eMBB, as well as provide infrastructure for public IoT initiatives like Smart Cities.
• Massive MIMO: 5G also promises to transform the way devices connect to a mobile network. All previous generations of mobile technology have involved base stations transmitting spectrum like a floodlight across their allocated area, with phones connecting to this broadly dispersed signal. But this leads to a lot of waste. 5G will make use of a technology known as multiple input multiple output (MIMO) which transmits signal as beams rather than dispersed fields, with individual beams tracking a user throughout the cell area. Massive MIMO - massive here being a reference to the high density of beams required - is expected to vastly increase the how efficiently signal available spectrum can be used, which in turn will lead to increases in speed and available capacity.