4G and LTE: everything you need to know

Not so long ago mobile networks were relying purely on 3G/UMTS technology, which is now more than 10 years old and struggling to cope with the needs of today's data hungry users.

4G/LTE (Fourth Generation / Long Term Evolution) is the next stage in mobile network development and provides users with much faster data speeds than 3G was able to.

So here's what you need to know if you're thinking of getting your hands on one of the superfast 4G handsets everyone keeps going on about these days. 

• What's the best 4G handset?

What are the differences between 4G frequency bands?

4G can be a confusing beast, particularly when there are three different frequency bands in use in the UK alone.

The 2.6GHz band is one of the two frequencies that were auctioned off by Ofcom in February 2013. It has a greater data capacity than the other two bands so it can deal with loads of people connecting at once, but it doesn't fare so well over long distances, making it ideal for cities and other compact, densely populated areas but not so good for rural locations.

The 800MHz band is the other spectrum that was sold off in February 2013. It was used to provide analogue terrestrial TV, but has been freed up since the big Digital switchover.

While it doesn't provide the same data capacity as the 2.6GHz band, the 800MHz frequency can easily travel over long distances and will be used to provide broadband speeds to rural areas where telephone exchanges can't reach.

Being low frequency it's also better at penetrating walls than the 2.6GHz or 1800MHz bands, so it will provide an improved signal when indoors.

The 1800MHz band is used by EE and Three, as while EE did own the lot of it the numerical network purchased a chunk of it from its rival.

However, as part of the deal to get the spectrum off the brand formed from the merger of T-Mobile and Orange, Three had to agree not to launch 4G on the spectrum before October 2013, which is the main reason for why it was the last to launch.

The 1800MHz band strikes a balance between coverage and capacity (falling between the extremes of the 2.6GHz and 800MHz bands) which makes it a good 'middle-ground' for getting 4G around the country.

Ofcom's 4G spectrum auction

The 4G spectrum auction held by Ofcom at the beginning of the 2013 saw winning bids from O2 (Telefónica UK), Vodafone, Three (Hutchison Whampoa) and of course EE. Interestingly BT also came away with a piece of the pie through its subsidiary Niche Spectrum Ventures.

Remember, more MHz means a better connection, so the more 'x GHz' of spectrum, the more widespread and robust a network can be.

Vodafone spent the most at the auction- a whopping £790,761,000 and came away with 2 x 10MHz of 800MHz spectrum, 1 x 20MHz of 2.6GHz spectrum and a further 1 x 25MHz of 2.6GHz spectrum.

EE spent £588,876,000 and secured 2 x 5MHz of 800MHz spectrum and 2 x 35MHz of 2.6GHz spectrum, which is less spectrum overall than Vodafone has.

Don't forget that EE can also call upon the 1800MHz spectrum that it's been using since before the other networks even launched a 4G service though.

O2 spent £550,000,000 on 2 x 10MHz of 800MHz spectrum. The company completely neglected the 2.6GHz band which may hurt its inner city performance, but with its extensive network of Wi-Fi hotspots in cities the bubbly brand thinks it will be OK without it.

Three spent £225,000,000 on 2 x 5MHz of 800MHz spectrum. Like O2, the company passed on the 2.6GHz band, however Three also has access to some 1800MHz spectrum, as noted above.

BT was something of a surprise bidder and secured 2 x 15MHz of 2.6GHz and 1 x 20MHz of 2.6GHz spectrum. While it was unclear what BT planned to use it on at the time it's now emerged that it will be getting back into the mobile game, albeit primarily as an MVNO through EE, but with a bit of its own spectrum to fall back on, as well as possibly using the spectrum to boost its existing services.

EE's position

4G arrived in the UK on 30th October 2012 courtesy of a joint venture between Orange and T-Mobile named Everything Everywhere, or 'EE' for short.

EE was granted permission by Ofcom to use part of its existing 3G bandwidth for 4G, which is why it got a head start on everybody else in October 2012. As you can imagine, rival networks were somewhat unhappy about this decision, but part of the deal for EE to get this head start was that it had to sell off a chunk of its 1800MHz spectrum.

• EE vs O2 vs Vodafone vs Three: which will be the best 4G network?

This chunk was promptly snapped up by Three, though despite getting a hold of 4G spectrum before O2 or Vodafone, Three was the last network to launch a 4G service, which was part of the sale deal with EE.

For almost a year EE was the only provider of 4G services in the UK and it's made the most of that head start as its 4G network is currently available in well over 200 UK towns and cities. In fact at the time of writing EE's 4G service covers 73% of the UK population.

If you don't live in one of those numerous 4G-imbued areas you can still buy one of EE's 4G handsets and use the 4G services in any of the towns and cities which do have coverage, but you'll have to wait a bit longer to get 4G where you live.

Tariffs used to be fairly expensive but in the face of competition they've become a lot more reasonable – for example for £13.99 per month you can get 500MB of data, unlimited texts and 500 minutes on a 24 month contract with a handset.

That puts EE in a very competitive position and EE has the advantage of far wider 4G coverage than any of the other UK networks.

What's more, EE has access to a huge amount of 4G spectrum and is the only network with access to all three of the 4G spectrum bands that are in use in the UK, making it the best prepared for data demands of the future.

EE has also begun improving its 4G network in certain locations, leading to 'double speed' 4G being available in a number of towns and cities and the company has even started trialling 300Mbps LTE-Advanced in London's Tech City with plans to roll it out across London and presumably beyond. This all means that it's got a substantial technological advantage over O2, Vodafone and Three, but it hopefully won't be long until the rest have caught up.

EE hasn't neglected the extras either, as customers also get two for one cinema tickets every Wednesday.

O2's position

O2 finally launched its 4G network on August 29 of 2013, although as yet the network can't really match up to EE's coverage. As of April the network announced that it had brought 4G to 191 towns and cities across the UK, but that only amounted to an outdoor UK population coverage of around 41%.

Though it can be hard to directly compare each networks 4G pricing, O2's starting prices aren't great. A phone on a 24 month O2 Refresh contract will cost you at least £17 per month (£13 for the airtime and £4 for the handset). That's with 500MB of 4G data, unlimited texts and 500 minutes, which is the same as you get on EE's cheapest tariff albeit for slightly more money.

However like EE the network now offers 4G as standard, at least on Pay Monthly tariffs for 4G handsets, so in many cases you don't actually pay any more for 4G data than 3G and the network has even been gradually moving existing 3G customers with 4G phones over to 4G contracts.

Still, its starting prices are more expensive than EE and O2 doesn't have the coverage to back up its prices so it seems like a tough sell. On top of that, the fact that O2 doesn't have access to the 2.6GHz frequency may result in it not having the data capacity to adequately serve 4G to cities once customers become more data hungry.

Another problem O2 faces is that the iPhone 5 isn't compatible with its network, but anyone who purchased an iPhone 5 from O2 between the September 21 2012 and March 31 2013 is eligible for an early upgrade deal, wherein O2 will knock off 25% of the remaining line rental and give you up to £280 for your old handset (depending on model and condition), making it much more affordable to upgrade to a phone that can get 4G.

Of course the fact that the iPhone 5 is incompatible is less of an issue now that the iPhone 5S and iPhone 5C are out, but it could be a sticking point for anyone still using the 5.

On the plus side O2 4G customers will have access to exclusive deals, competitions and vouchers as well as the ability to purchase gig tickets early through O2 Priority.

Vodafone's position

Vodafone also launched its 4G network on August 29 2013, seemingly just to steal some of O2's thunder as the network was previously talking about launching later. It also has a site-sharing deal with the effervescent provider, so that's likely to have played a big part in making the August 29 switch-on more efficient.

Initially Vodafone's 4G signal was only available in London, but it's come a long way since then and can now be accessed in 239 towns, cities and districts, including Birmingham, Glasgow, Leicester, Liverpool, Manchester, Nottingham, Edinburgh, Leeds, and Newcastle.

In all it amounts to a similar amount of the population as O2, though still a long way short of EE's coverage.

Vodafone's pricing isn't all that competitive either. For example at the low end for £31.50 a month Vodafone will give you 4GB of data, unlimited calls and unlimited texts on a 24-month contract with a handset.

That's a lot more expensive than O2 or EE's entry level tariffs and while it also includes a lot more data it's still not competitive, as EE for example offers the same allowances for £26.99 per month.

Vodafone has stuck by its existing customers though, as assuming you have a 4G-ready handset then for £5 extra a month you can switch to a 4G tariff - which will also double your data allowance.

Better yet, Vodafone 4G customers who take up a 24 month contract with a handset will also get access to a choice of Spotify Premium (which usually costs £9.99 a month), Sky Sports Mobile TV (usual price £4.99 a month) or Netflix (which usually costs £5.99 per month) for no extra charge.

Whichever service you choose will be free for anything from six months to the full two years of the contract, depending on your choice and tariff.

Much like O2, Vodafone is unable to provide 4G to the iPhone 5, but customers who purchased an iPhone 5 from Vodafone between the September 12 2012 and June 30 2013 will be able to return their handset to a Vodafone store and have 75% of their remaining line charges taken off to minimize the cost of an upgrade.

Similar deals are also available for those with a Samsung Galaxy S3 or Samsung Galaxy Note 2.

With sizeable chunks of both the 800MHz and the 2.6GHz band, Vodafone should have the capacity to deliver a fast, reliable 4G connection to customers in both urban and rural locations.

Three's position

Three finally began rolling out its 4G network in December 2013, which was a bit later than the Big Three. However, it has an ace up its sleeve: no additional cost for 4G.

If you already have a 4G handset and a Three SIM then 4G speeds won't cost you any extra - all you'll have to do is install a software update from the network to activate it.

Those on monthly plans with all you can eat data won't see any caps imposed on their data limits either, meaning those running on plans from as little as £15 per month on SIM-only or £19 per month with a handset can get unlimited 4G data, and nigh-on unlimited calls and texts (providing they already have a 4G-enabled phone) which means the network massively undercuts its rivals.

London, Manchester and Birmingham were the first cities to get the 4G network and since then it's been steadily expanding. By the end of 2014, Three intends to have 4G coverage in 50 cities and 200 towns across the UK, and nearly the whole country covered by the super-fast connection by the end of the following year.

This is thanks to the numerical network managing to nab some of the 800MHz spectrum to deploy 4G speeds to the rural parts of the British Isles, as mentioned above.

That combination of low prices and large data allowances could be enough to topple the scales in Three's favour and may, we hope, force the other networks to further lower their prices.

However, long term things don't quite so rosy for the network, as with only a small amount of 800MHz and 1800MHz spectrum it may struggle to keep up with its customers data needs.

4G coverage: When will the whole of the UK have it?

All of the networks now have live 4G services, but so far they've been focused primarily on cities and large towns.

Ofcom's targets say that 4G must reach 98% of the population and 95% of the country by the end of 2017, but EE claims that it will cover 98% of the country by the end of 2014 and already covers over 70% of the UK population, while O2, Three and Vodafone are all aiming to cover 98% of the country by the end of 2015, so UK-wide 4G coverage may be closer than you think.

EE is also upgrading its 3G network to DC-HSPA in an effort to improve speeds when 4G services aren't available, while customers of Three can fall back on the network's Ultrafast service.

What are the 4G download speeds?

EE boasts speeds typically five times faster than current 3G networks, though on several occasions we found it to be ten or more times faster than a comparable 3G handset in the same area.

In use it just makes everything feel much snappier and ensures tasks like checking image-laden emails and browsing complex web pages is a breeze.

EE claims average download speeds of 12-15Mbps and typical maximum speeds of 40Mbps, with upload speeds averaging around 5-6Mbps with a typical maximum of 15Mbps.

EE has also started rolling out 'double speed' 4G in select locations. So far it's available in 20 cities and, according to EE, average download speeds in those locations are 24-30Mbps, while the maximum speed is 60Mbps. Average upload speeds are said to be 11Mbps.

EE has achieved this by making network improvements which allow customers to use 2 x 20MHz of spectrum, where before they would have been using 2 x 10MHz of spectrum – essentially a bigger (virtual) pipe allowing a faster rush of data to enter your phone.

EE has even started experimenting with 300Mbps LTE-Advanced, though so far that's only available to select companies in London's Tech City.

O2, Three and Vodafone can't come close to that yet, but all three networks standard 4G speeds are similar to EE's, coming in at around five times faster than 3G.

Why is 4G so fast?

4G's impressive speed increase is achieved with the use of OFDM (Orthogonal Frequency Divison Multiplexing), a transmission technology used by the likes of ADSL, Wi-Fi, DVB-T, DVB-H and DAB.

Not only does it reduce latency (the amount of time taken to buffer and connect to webpages), but it also minimises interference and is able to cram greater amounts of data into the same slice of radio bandwidth.

Simply put, this enables 4G/LTE phones and tablets to stream video and play online games like never before, largely because 4G has been designed primarily as a data network, rather than a voice one and it uses the same TCP/IP protocols that underpin the internet.

The upshot for you is that the data is 'flatter', as in it's easier for the networks to stream, so should theoretically be cheaper. Whether those cost savings are ever passed on remains to be seen – it's not cheap to roll out 4G, especially at this rate of deployment across the UK, though we're already seeing costs drop down towards 3G levels.

It's possible that further increases in speed could be achieved with MIMO (Multiple Input Multiple Output) technology, which uses multiple antennas on transmitters and receivers like 802.11n Wi-Fi equipment.

Nokia has reportedly achieved 173Mbps from 4G with a 2x2 MIMO configuration (two antennas on both the transmitter and receiver), so a 4x4 arrangement could potentially offer as much as 326.4Mbps, although this isn't something we need to think about right now… although perhaps we'll see these speeds on the iPhone 10?

LTE-A and the future of 4G

The UK may only just be fully embracing 4G but some parts of the world are already looking to the next generation of high speed mobile data. That next step is LTE-A (the 'A' is for 'advanced', fact fans).

Essentially it works by increasing the number of antennas in use as detailed above, alongside 'carrier aggregation' which allows a device to combine multiple 4G signals or even multiple different frequencies, rather than just using one at a time as standard 4G does.

In theory LTE-A can deliver far greater data speeds than the 4G of today. In fact it could potentially reach real world speeds of well over 160 Mbps, which is comparable to a 20MB home broadband connection.

LTE-A won't work on 4G-ready phones as they'll specifically need an LTE-A chip in them, however there are already a few LTE-A compatible handsets out.

For example there's an LTE-A version of the Samsung Galaxy S5 which is available in South Korea, but if you're considering importing it, don't, because other than a very small scale trial by EE none of our networks currently support LTE-A.

The UK will certainly get in on the act one day, in fact EE is talking about making an LTE-A network commercially available across London sometime in early 2015. But the technology is still in its infancy and the networks are still rolling out normal LTE, so we've probably got a while to wait before it's widely available.

• If you're keen to know about the next generation of networks, check out our guide to everything you need to know about 5G

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