If you’ve had a phone contract with mobile data for a long while, you’ll know exactly how much things have improved over the last few years.

The introduction of 4G saw speeds increase significantly, but only where you can get coverage. And even in cities with supposedly good 4G, you can still end up with a poor signal or poor speeds.

5G aims to fix all of this, as well as vastly expanding the mobile network’s ability to handle the millions of new devices that will be connecting over the next few years.

See all the 5G phones coming this year.

So what is 5G?

As with 1G, 2G, 3G and 4G before it, it’s an umbrella term for the fifth-generation of mobile networks. Within 5G there’s lots of jargon, most of which you really don’t need to know about or worry about – at least not until you need to buy a 5G phone. At that point, you must ensure it has the right specs to work with your mobile operator.

5G will be much faster than 4G. In technical lab tests, 4.5Gb/s (4500 megabits per second) and more has been achieved, but in the real world you can expect between 10 and 20 times better speed than 4G. That’s according to companies including Qualcomm, Huawei and Samsung.

In recent tests in real-world conditions (at Canary Wharf, for example), it has demonstrated that over 1Gb/s is possible, which is a big increase over the fastest 4G speeds.

It means the internet connection on your phone is likely to overtake your home broadband speed by quite a margin. And that applies to upload speeds as well as downloads, so posting a 4K video you’ve just shot on your iPhone 13 to YouTube as you walk along the high street in 2020 should become a reality. Possibly even before summer 2019 if the current claims are to be believed.

Qualcomm says that 5G is installed and working at various locations already, and that the Snapdragon 855 platform is ready and waiting for phone makers to build it into their 2019 models.

We've even seen a prototype from Samsung in action at Qualcomm's Tech Summit in December 2018. Could it be an early version of the Galaxy S10?

What is 5G? Samsung prototype phone

Currently, 4G speeds are around 10-15Mb/s on average for downloads, which means actual 5G speeds should be between 200 and 400Mb/s - on average. It's possible you'll get up to 800Mb/s or even more.

It’s estimated that by 2020 mobile traffic will have increased more than 30 fold since 2014. That’s partly because people want to stream video when they’re out and about, but also because of the number smartphones has increased considerably.

And it’s about to get a whole lot more crowded. We’re already seeing car manufacturers put 4G SIMs in their vehicles, but when self-driving cars hit the roads they’ll all have a 5G connection. Before long so will all your wearable tech, always-connected laptops and tablets, and eventually even your smart home devices.

Infrastructure such as traffic lights could communicate via 5G to work with cars to ensure the speediest flow of traffic, with other smart city tech no doubt to follow.

As well as being faster than 4G, 5G will be a whole lot more responsive, so you won’t have to wait those few seconds before your YouTube video starts playing. The lower latency and faster speeds should also mean you’ll be able to have much higher quality video calls, which are currently poor quality and often laggy when using 4G.

Do I need a new phone for 5G?

Yes, but don’t rush to buy one. Current phones have 4G LTE modems, which are incompatible with the new technology used in 5G. The only phone right now which will be upgradeable to 5G is Motorola’s Moto Z3, shown below. But you’ll have to snap on a 5G Moto Mod to get it to work then 5G arrives, and even then it’ll only be on Verizon in 4 US cities. Hardly a fantastic solution.

More 5G phones will be arriving in 2019, and you'll want to wait until at least then before you think about investing in the technology.

Motorola Moto Z3 will support 5G with a Moto Mod

Which phones will support 5G?

Every major phone manufacturer is working on a 5G device, with many of them confirming support at Qualcomm's Tech Summit in October 2018.

22 manufacturers including Samsung, Sony, LG, Motorola and Google were all confirmed to be working on 5G phones for 2019 using Qualcomm's Snapdragon X50 modem, along with Chinese companies like Xiaomi, Oppo, and Vivo. Those first phones are expected to arrive in Q2 2019, though it'll take longer for 5G support to make it anywhere except expensive flagships.

Naturally there'll be a race to be the first company to release a 5G phone, and one of the contenders is OnePlus. Co-founder Carl Pei announced that his company has been working on a 5G device since 'late 2016', claiming that OnePlus would be "the first, or one of the first" to release a 5G phone using the X50 - a strong hint to expect 5G support in the OnePlus 7 in early 2019.

When will 5G arrive?

Trials are already happening, such as EE’s test in East London, and it’s likely the UK will get the first public 5G coverage in 2019, either together with or shortly after the first commercial handsets, though not across the full bandwidth spectrum.

It will help that most 5G infrastructure can be built on top of existing 4G LTE sites, a model which has been successfully tested in multiple global cities. Still, new antennae need to be built and installed - much like this one being tested on London's Cheapside House:

EE 5G trial in East London

South Korea is typically ahead of others, but 5G is set to be switched on in 2019 in many regions. China is also attempting to roll out 5G by next year. The UK and US will also be among the first, with EE's 5G Executive Advisor Fotis Karonis telling us that the UK "will be in the first wave" of countries to offer public 5G.

As we'll explain below, 5G is a mixture of different technologies. The graphic below shows that millimetre wave - the stuff which enables the really fast speeds - won't be available in most regions initially. Instead, most places will use 'Sub-6' technology, which runs on a much lower frequency than mmWave.

What is 5G? Samsung prototype phone

In the UK EE has said it will roll out 5G support to 1,500 sites across 16 UK cities in 2019, starting with Belfast, Birmingham, Cardiff, Edinburgh, London and Manchester.

“These 1,500 sites, which is 10 per cent of our site portfolio, will serve 25 per cent of our customers," said EE CEO Marc Allera. "One site at Waterloo station carries more than 100TB of data per day. We’ve picked these sites based on where customers need it.”

The company has however been quick to emphasise that it "won’t have 90 per cent 5G coverage to begin with," and says that 5G will be complementary to the existing 4G LTE network, which the company is going to continue to invest in.

Three is also keen to be one of the first 5G networks in the UK. The company says it's investing more than £2 billion into 5G infrastructure, including what it says is "the UK’s leading 5G spectrum portfolio" and the development of new 5G cell sites and rolling out carrier aggregation tech. Though it's worth noting that even with all that, Three still says its 5G network will be ready for the second half of 2019 - likely a few months after the first commercial 5G phones hit the market.

As with 4G, there's unlikely to be widespread 5G coverage for a while regardless, as it will be rolled out gradually starting with major cities. It probably isn’t going to be worth paying more for a 5G contract in the early days unless you happen to live and work in a town or city with excellent 5G coverage.

By the time 5G coverage approaches the level 4G is at now, almost everyone will have a 5G compatible phone. And that’ll probably be around 2025.

How does 5G work?

That’s a tricky question to answer, as it’s a complex technology.

In essence, it mainly uses much higher frequencies than 4G where there is plenty of ‘spectrum’ available. 4G works on frequencies between 2 and 8GHz. 5G will use these frequencies - a type of 5G called Sub-6 - as well as the higher band between 24 and 100GHz.

5G frequencies - mmWave

These higher frequencies are being called ‘millimetre wave’. It refers to the fact that, as frequency increases, wavelength decreases. These shorter waves – just as with 802.11ac Wi-Fi compared with 802.11n – mean much faster internet speeds, but at the cost of shorter working distances.

The simplest way to understand it is with a pipe. Sub-6 is like a longer, thinner pipe that offers slower speeds but over a longer distance. mmWave is like a very short, fat pipe which can deliver huge speeds, but only at short distances.

The problem is that 5G ‘mmWave’ signals can’t easily pass through walls and will be affected by obstacles such as tree branches and even rain. What it means in practice is that there will need to be a lot more mobile transmitters located much closer to the ground to create the necessary coverage. The principle of more, smaller transmitters also means there should be excellent indoor 5G coverage as well as outdoor.

Support for Sub-6 and mmWave will vary from country to country, but the UK will get both in certain cities and Qualcomm's X50 5G modem also features the option to support both types of 5G.

Will roaming work with 5G?

In the UK and Europe 5G will be provided in the sub-6GHz spectrum rather than mmWave - at least to start with - while the US will most likely be the other way round. Most phones and infrastructure will probably support both types of frequency, but the early days of the tech could see companies focus on one or the other.

That means that it's very possible that in the first year or two of 5G access you won't be able to roam worldwide and access 5G connections, though there probably will be consistency across Europe at least.

It's worth pointing out that you'll still be able to access 4G signals when you roam - any 5G phone will be able to handle 4G and below too - so you'll still be able to make calls and access the internet, you just won't get the highest possible speeds.

Will 5G be in rural areas too?

Millimetre wave is currently a good solution for densely populated areas – i.e. cities – but this kind of technology is too expensive to cover rural areas, so unfortunately your 5G phone will simply use existing 4G signals if you go out of 5G coverage.

Some experts say that 5G will fix the currently awful mobile signal on railway lines, offering ‘seamless’ connectivity so you should be able to binge watch Orange is the New Black on your commute to and from work.

However, that will depend upon how much rail operators – that’s Network Rail in the UK – are willing to invest, as upgrading to 5G isn’t cheap. So don’t expect to see much improvement for several years after 5G is first introduced.

Will 5G affect battery life?

Right now: maybe.

Qualcomm's 5G chipset has been designed to optimise battery around 5G by using 4G for the idle internet connection, only switching to 5G when it needs to actually download or upload data, and turning it off again when it's done.

In theory that means there's shouldn't be too great an impact on battery life for 5G devices, but Qualcomm warns that it does expect the first wave of 5G phones to boast slightly larger batteries - and thus probably thicker designs - to compensate for any extra drain.