Techsplainer: 5G (and a brief history of 1 to 4)

June 13, 2019

The cold war over Huawei, and a glitch in a live BBC broadcast, has made sure that 5G is in the headlines almost every day at the moment. The first thing to understand is that the G stands for ‘generation’. 5G is the fifth generation of mobile telephony standards, as defined by the Third Generation Partnership Project (3GPP), a global consortium of telecommunications associations.

While you may have had a 2G-, 3G-, or 4G-capable device in the past, you haven’t been progressing along a sliding scale, rather moving across different protocols that are loosely banded into  generations’. These generations are delineated by a break in backward compatibility (3G, for  instance, encompasses a lot of different technologies that are distinct from those used for 2G), and a minimum speed.

Gs: a brief history

1979: You probably didn’t refer to it as 1G at the time, but early mobile phones used it when they were essentially broadcasting your voice as analogue radio: anyone scanning those frequencies could simply listen in.

1991: Similarly, you probably didn’t think of the next generation of devices as 2G, though the change in technology was massive. The signal type will have shown up on your phone as GSM, GPRS, or EDGE. The biggest change here is that the signal was digital, which obfuscated the communication slightly, but also enabled devices to send short messages, also known as SMS (Short Message Service).

1998: 3G was the first time the generations were used heavily in marketing. It described a range of protocols fast enough to provide smartphones. While the 3G standard only guaranteed a transfer rate of 200 bits/second, it evolved into 3.5 and 3.75G, which upped that rate to megabits/second, making mobile internet access viable. As well as 3G, your phone may have displayed your connection as HSDPA (High-Speed Downlink Packet Access).

2009: Next came 4G, which dictated that networks should provide a transfer rate of up to 1 gigabit. In truth, users rarely enjoy such speeds, but 4G rates are invariably quicker than 3G. There were other requirements: for networks to be entirely IP-based; to provide both IP4 and IP6 addressing; to dynamically manage the resources within each cell more effectively; to use a broader range of frequencies; and to manage the transition between different networks smoothly without significant signal interruption (something that would render those faster network speeds redundant on, say, a moving train).

So, what is 5G really?

The fifth generation of mobile communications is still in flux, but is currently accepted to mean systems that conform to the International Mobile Communications 2020 Standard (this is still in development, to be completed in 2020, as the name suggests) to:

  • provide a peak data rate of 20Gbit/s; with
  • an average user-experience data rate of 1Gbit/s in hotspots, and 100Mbit/s in general;
  • using no greater energy than 4G required; and
  • coping with 10,000,000 devices per square kilometre (empowering IoT through the use of low-power communications).

To achieve this, 5G also dictates the use of the 5G New Radio interface, which broadened the range of frequencies dramatically (allowing signals below 6GHz and above 24GHz). It’s this interface that has fuelled fears of health risks, falling foul of actual laws in some countries, though there have been no studies so far to prove any actual health impact. 

Simon Forrester has been writing about technology since 1992 when he started at Future Publishing. He has since gone on to develop their online presence and as a freelance working as a developer and technical adviser to many organisations, including 14 years working with SCL.