All about 5G
WHAT DOES THE NEXT GENERATION OF MOBILE TECHNOLOGY MEAN FOR YOU?
5G HAS BEEN making the news lately. Telstra has said it plans to start rolling out the new technology in 2019, and the other major telcos have been talking up the technology as well. Optus has said it plans on introduced fixedwireless versions of 5G in 2019. Before you get too excited, however, you should know that 5G is a different beast from the generations that came before it. It won’t replace 4G, but complement it for certain areas and applications. At the Mobile World Congress in Barcelona this year, Telstra predicated that the reach of 5G would be about one million homes in Australia, a far cry from universal coverage. That’s because the requirements and capabilities of 5G are quite specific, and this month, we’re going to look at those. First, though, let’s take a look back at how we got here.
THROUGH THE GS
Mobile telecommunications has gone through a number of iterations over the years, and we commonly refer to these by ‘G’ or generations. 1G — The pre-digital generation of mobile handsets. In Australia, we used AMPS (Advanced Mobile Phone System), in which each user was given a dedicated slice of radio spectrum during the call, making it very bandwidth hungry and incapable of servicing a large number of people at once. AMPS was first introduced to Australia in 1987 and was finally retired in 2000.
2G — Also known as GSM (Global System for Mobile Communications), this was first released in 1991. It brought mobile communications into the digital age, using digital modulation to carry voice signals to cell towers. This made it much more efficient, with dozens or hundreds of calls possible on a single cell. It was later updated to support raw data through GPRS (general packet radio service, also known as 2.5G) which could provide internet access at a whole 40kbps. Later came EDGE (Enhanced Data Rates for GSM Evolution, also called 2.75G), which enabled 1Mbps data transfers. The GSM networks finally started to be retired in 2016 and 2017. The only operator that still runs one is Vodafone, and that was planned for shutoff by the end of April (so possibly by the time you read this).
3G — Here’s where the generational nomenclature gets a little fuzzy. 3G is generally used to refer to mobile data networks capable of carrying data at 200kbps or more. Technically, EDGE could meet this definition, but it was more commonly used to refer to networks that used UMTS or CDMA2000 technology. UMTS could theoretically go to 42Mbps, though practical speeds were much lower (Telstra advertised speed of “up to 21Mbps” on its Next G network for example). 3G was first introduced by Hutchison Telecommunications in 2003, and is still used today in many areas as a fall-back for 4G.
4G — LTE (Long Term Evolution) was originally seen as just a late-gen extension of 3G (essentially 3.9G), but marketing teams wanted to sell it as a whole new generation of product, and so 4G was born. Telstra introduced it in 2011, offering speeds of up 40Mbps. It was later upgraded to LTE Advanced, with theoretical user speeds of up to 100Mbps, and that’s what we’re using today.
AND NOW: 5G
And so we come to the next generation of mobile technology, called 5G. The first thing to know about 5G is that there is no 5G, at least not officially. While the groundwork for the spec was released in December, there’s still no official standard, and 3GPP (3rd Generation Partnership Project), the international group behind most of the world’s current mobile standards, has said that it has a tentative 2020 date for something it can definitively call ‘5G’.
Still, a number of vendors around the world, including Telstra, are pushing ahead with projects that they’re going to call 5G, regardless of any existing framework. The goal of these projects is to provide higher speeds and lower latencies to mobile users and Internet of Things devices.
Although it’s possible to deploy 5G in the sub-6GHz band, many 5G projects will likely use so-called millimetre-wave (mmWave) frequency bands. These are extremely high frequencies, in the 26–60GHz range.
We’ve actually touched on what higher frequencies mean for wireless transmission earlier in this column. Experienced Wi-Fi users have probably encountered this for themselves. When it comes to Wi-Fi, for example, 2.4GHz signals generally travel further than 5GHz signals. That’s because lower frequency radio waves travel better through intervening objects. On the other side, higher frequencies offer greater data rates and more bandwidth to play with.
Some 5G projects also intend to use large numbers of antennae for additional MIMO streams, the same way that MIMO on Wi-Fi can add extra spatial streams to increase the available bandwidth, although it remains to be seen how well that can be implemented in mobile phone handsets and other mobile receivers.
There are also other techniques being employed in early ‘5G’ products, such as signalling structures designed to reduce latency, which is needed for fast responses from things like autonomous vehicles and drones, as well as online gaming and video communications.
But the thing about all this is that it won’t be available for everyone. The high-frequency signals will bounce off walls and objects rather than travel through them, and so will require a large number of cells with fancy directional antennae and beamforming tools to be able to provide coverage, and even then black spots are likely to be very common inside buildings or in hilly or built-up areas.
For this reason, the deployment area of 5G is likely to be quite small and 4G will definitely have to stick around to provide coverage for when 5G is blocked. So while 5G will offer higher speeds and lower latency, it’s probably not going to be available for everyone, everywhere. Instead, it’s more likely to be deployed in localised areas and for specific applications such as autonomous vehicles, medical data transmission and smart factories deploying thousands of IoT sensors.
If you’re thinking that you can completely ditch your landline when 5G comes along, you’re probably going to be very disappointed. After all, even Telstra is saying that it expects only about a million homes and businesses will get it — compared to the five million already connected to the NBN (and the ten million that will be connected when the NBN is done). According to Telstra, however, speeds of 2Gbps and latencies of under 6ms will be available to those who can get it, which is going to be transformative for a lot of applications.