The future of 4G according to EE – double-speed, LTE Advanced and roaming

Given that we live in a world full of data, the rise of 4G is an exciting one. As the first mobile technology designed purely for data, it eclipses what 3G can offer opening up new possibilities, not just for smartphones, but for wireless broadband too. It’s coming up for a year since EE first launched 4G at the end of October 2012, but with O2 and Vodafone now having launched their own networks, it’s fair to say that the technology is set to really take off over the next year. To find out exactly what the technology can offer now and where we’re going with it, we sat down with Paul Ceely, head of network strategy at EE.

In terms of rolling out 4G, the technology has like-for-like coverage for 3G, which means there are no shortcuts and like-for-like infrastructure has to be installed. EE plans to have 98 per cent of the population covered by the end of next year; O2 and Vodafone trail behind, with 98 per cent coverage not expected until the end of 2015. Full UK coverage of the technology is going to take a while, although most major cities already have 4G or will have it soon.

Once installed, 4G has advantages over 3G, particularly when it comes to performance. Thanks to the technology being designed for data, its performance when you reach the edge of a cell is excellent; with 3G you can find you either get a very slow connection or your phone drops down to 2G.

“4G is built for data,” explained Ceely “Standardisation did a good job with cell edge performance; 3G has some issues where as 4G has much better performance.”

As well as raw performance, 4G also handles contention (the number of simultaneous devices using the network competing for the shared bandwidth) much better. In fact, contention shouldn’t be a problem with this technology.

“Contention is much better on a 4G and there’s an efficiency gain in spectrum utilisation: you get more data through the same amount of spectrum.” said Ceely. “We don’t plan to have contention in the network.”

For the layman, 4G means that regardless of how many people there are around you using the network, you shouldn’t suffer from any massive slowdowns or an inability to connect to the network.

DOUBLE SPEED 4G

Even though the technology is still in its infancy, it’s already being dramatically improved. On the 4th July 2013 EE launched double-speed 4G in 12 cities, although it plans to roll the service out over its entire network. As the name says, it double the speeds of the network, so that users move from an average of around 12Mbit/s download speeds to 24-to-40Mbit/s – a theoretical peak is 150Mbit/s. That’s a big increase and a lot faster than many people’s fixed-line broadband.

Of course, there are technical issues to deal with in order to get double-speed working. Surprisingly, these have less to do with 4G than they do with the old 2G network. When EE launched it used spare capacity on its 1,800MHz network, which was used for 2G, for the new service. Getting faster speeds means the company has to free up even more spectrum.

“To get to double speed, we doubled the amount of spectrum,” said Ceely, explaining that EE had to “refarm” spectrum assigned to its 2G network.

This change means that the 2G network had to be upgraded, offering better service along the way. From the 4G equipment point of view, the upgrade was much more straightforward. In fact, most of the work had to be done in the backhaul, where 4G meets a traditional wired network that hooks into the internet: with double the speed of 4G, EE needed to make sure that it didn’t have a bottleneck.

LTE ADVANCED

While double-speed is an impressive step forwards, it’s not the end of the technology. With carrier aggregation, also known as LTE Advanced, it’s possible to join together spectrum on different frequencies, increasing speeds even further.

“We’re running a [carrier aggregation] trial in London using the 2600 and 1800 spectrum,” said Ceely.

He then went on to explain that the technology as it stands would allow for a theoretical peak of 300Mbit/s, although “in real life you get to 200Mbit/s”.

Having multiple frequencies also gives you more capacity, so at busy points you can have different handsets using different spectrum, again avoiding the problem of contention. The ability to use 2,600MHz is already there with a lot of handsets ready for that frequency.

“All of our launch devices supported 2,600MHz except the iPhone 5, which was 1,800MHz only,” said Ceely.

That’s only half the story, as even handsets that support the necessary frequencies can’t use carrier aggregation. For even faster 4G speed we’re going to have to wait until the next generation of handsets.

“To get the high speeds you will need new devices,” confirmed Ceely.

In addition, the existing range of devices typically have limitations on speed, only supporting throughputs of up to 100Mbit/s; this is fine for today’s networks, but would prove to be a bottleneck for carrier aggregation networks.

4G ROAMING

One of the big issues with 4G has been the lack of roaming available: you buy a fast handset in the UK, but go abroad and you’re knocked back to 3G speeds. This is something that is being looked into now.

“We don’t have a roaming set up, we’re looking to do that quite soon,” said Ceely. “We’re testing things, but I can’t tell you which operators yet.”

All we were told is that there will be something “next year”. Largely, 4G roaming isn’t down to a lack of companies wanting to do it, more that the way the technology works means it’s rather complex worldwide. In particular, different countries have used different spectrum, so a handset that works in place won’t work in another.

“LTE is good as you can use all kinds of spectrum,” explained Ceely, pointing out that the “US is quite different and the LTE iPhone 5 US version is different to the UK version”.

Global standardisation in technologies and the spectrum that phones support is required before roaming can really take off. At the moment, EE is looking at countries it “has a lot of roaming to and from, and align that where we have networks and spectrum”.