The Road to 5G
The first mass-market mobile networks in the UK began in 1985 using an adapted version of American analogue technology. Around the same time, countries around the world were installing analogue systems, with at least six different technologies. This is regarded as the first generation of mobile phones.
2G began in Europe in 1991 with the launch of GSM (originally named after a committee but later renamed Global System for Mobile). This was a European initiative that became so successful that it spread round the world and is still in use today.
Generations are not single leaps forward, there are gradual, small steps that get us from one to the next. 2G has been continuously evolving since 1991. The first big step came around 2000 when GPRS added data at up to 38kb/s followed by faster EDGE in 2003. Meanwhile in 2002, 3G (also called Wideband CDMA) launched with 384kb/s download. 3G top speed reached 14Mb/s with HSDPA by 2005 and even more today. The 4th generation in 2012 and was the first to have a single global standard. It had the not-so-snappy name of LTE – “Long Term Evolution”. While 3G had brought us a taste of internet access at a reasonable speed, 4G was designed from the bottom up for high speed data. Further enhancements have followed. With the mouthful of names that each technology has featured it’s not surprising that we’ve preferred to label them simply 2G, 3G, 4G, 5G. The industry has also got used to the idea that a new generation comes every 10 years.
The important thing to understand is that, in spite of the hype, a new generation is not quite as much of a revolution as some would suggest. Each brings a valuable set of new features, some of which may start to enable new uses and businesses, but each will evolve. Rollout of any new generation will also take time, so that an application that relies on ubiquitous coverage of a new technology will not be viable until long after the start of deployment.
How is 5G Different?
So what’s special about 5G and what new applications will it enable? The traditional explanation is that there are three strands to 5G:
- Enhanced Mobile Broadband,
- Ultra Reliable Low Latency Communications (URLLC), and
- Massive Internet of Things (IoT) .
The first is the most obvious, and the way 5G has begun. It’s more of the same, but faster and with capacity to support more users. This is important. Every generation starts with demonstrations that tend to show what the network can do with only one user. It was never realistic to expect 4G networks to support large amounts of data rates to many users at the same time. With 5G it may be, so that things you can just demonstrate on a new generation often become viable as a real service on the next. You can be sure that our demand for high capacity mobile broadband networks will continue increasing for some time yet. Maybe the next wave of mobile communications will allow mass-market immersive virtual reality.
The second strand, URLLC, suggests that 5G will offer much lower delays of a few milliseconds for highly interactive applications, along with an increase in the reliability of the connection. In fact, these two things could each eat up a lot of network capacity. The early 5G being deployed today has slightly lower delay than 4G, but the standards for true URLLC are still being finalised. So it’s a while before we’ll be able to trial applications that really need them and find out how many users of such applications the networks will support.
The third strand involves a big increase in the number of machines connected to the network, rather than people via their smartphones. The range of IoT applications is vast. Some things will need the high capacity of a 5G radio. Others may need only to measure something occasionally or switch something on or off. The data throughput needed may be trivial, but they may need to run on a battery for years and the network may need to support many millions of them.
Once again, specific standards for these things are still being developed, but a standard has already been created to handle the low data rate, low power applications. It’s called NarrowBand Internet of Things (NBIoT) and is designed to be built into existing 4G base stations. Nevertheless it can be regarded as the foundation of 5G Massive IoT.
Building the 5G Core Network
Along with the obvious changes in radio technology, with each generation come new ways of building the core network behind the scenes and the allocation of extra spectrum to support more users and higher speeds. These two things open up some new possibilities to build local private networks using 5G.
The most obvious uses lie in industrial automation. Wiring up factories is expensive and Wifi is not always reliable. 5G private networks may be the answer. As well as auctioning spectrum for 5G to traditional mobile operators, Ofcom has reserved some for local licensing to enable new applications and business models.
There have been other developments in parallel with the generations of public mobile network technology. One example is in mmWave technology. While the 5G radio standards include mmWave licensed spectrum around 26-28GHz, other mmWave technologies have been developed in other frequency bands, notably around 60-70GHz. These technologies, while strictly not part of the 5G standards, have a place in delivering gigabit mobile networks, whether to connect a cellular base station over a short hop to the nearest fibre, or to connect users on high speed trains. Other radio systems have been developed to exploit unused TV broadcast spectrum in rural areas.
So what is 5G and what is a 5G application? In our 5G Trials and Testbeds Programme in DCMS we have deliberately adopted a broad definition, to encompass new, innovative technologies and applications that can help to deliver the connected communities that we will take for granted in the future.
From health and social care, to fish farming and from traffic management to tourism or manufacturing, the networks of the future will enable an efficient and competitive economy with improved outcomes for businesses and individuals alike. In summary, 5G applications could encompass a wide variety of uses, from increasing efficiency and productivity in factories and social services, to enhancing visual experiences in museums and galleries. It’s not a one-size-fits-all, but it can be tailored to specific uses.
Even if a single generation is not a revolution, the progress over the last 35 years since the first generation can truly be described as a revolution that has changed the world. We can expect a lot more to come.
Trevor Gill FREng MA CEng FIET
5G Technical Advisor