Telecommunications companies across the globe, as well as their suppliers and regulators, all met together this week keenly focused on one topic: What's next after 4G?
Wandering through the maze of halls at Mobile World Congress (MWC) in Barcelona this week, it was clear that 5G isn't going to be about connecting more handsets; it's about everything else you could ever possibly want to be connected to the internet.
This week has seen major new handset announcements by almost all of the major manufacturers including Samsung, LG, HTC, ZTE, and BlackBerry, but attendees at the event appear to be far more drawn to what else those companies are offering.
There are two things that almost every major vendor has had at their stand: A car or a watch.
In LG's case, both.
Watches and cars are the two most obvious use cases for wearables and connected machines, but the industry is predicting many more to come, up from almost 5 billion connected devices at the end of this year to 50 billion by 2020, according to both Cisco and Ericsson.
The networks will need to be in place to be able to handle the rise of the machines.
4G will continue to advance, gaining speeds of up to 450Mbps with carrier aggregation, but network operators are beginning to think of what is needed beyond just a simple speed upgrade, when almost every device in the world could be connected.
The path to 5G in 2020 is going to be driven largely by Korea and Japan, both playing host to the Winter Olympics and Olympics in 2018 and 2020, respectively.
The two nations are some of the fastest adopters of new technology, and will be keen to get something in the market before then.
But first, the world needs to agree on what exactly will make up 5G, and work out a set of common standards.
European Union Commissioner Günther Oettinger announced on Tuesday at MWC with Alcatel-Lucent, Ericsson, Nokia, Orange, Thales Alenia Space, and others a European vision for 5G, ahead of planned standardisation in 2016.
Oettinger said that 5G should open up the possibility for new applications, including driverless cars, remote surgeries, real-time automation, and robots.
"I am convinced [5G] represents a bold opportunity to create a more competitive industry, growth, and jobs for our citizens," he said.
Germany-based Deutsche Telekom CEO Tim Höttges said that 5G will help drive productivity.
"The productivity gain we are going to get from all these connected devices is going to be big for society," he said.
Telstra's chief operating officer Kate McKenzie said 5G will be the network for getting devices connected to the internet differently to the way we think about it today.
"It's not just mobile phones; it's a whole lot of different things, and all those different things will have different requirements in terms of latency, and power, speed, and capacity," she said.
"I think we're well down the path of doing that."
According to Ericsson wireless network research director Magnus Frodigh, 5G should have roughly 1,000 times the mobile data volume, and support up to 100 times the number of connected devices. Latency should be close to zero, download speeds should be up to 100 times faster, and 5G should have significantly lower power consumption for connected devices.
"It's a starting point for where we want to be," he said.
"Think about this as a way to get at least an order of magnitude higher than where we are with a 4G system. Although there is no fixed requirements ... this is basically the aim to make sure we take the technology to build it 10 times better than 4G."
The need for speed
Initial radio bed tests by Samsung in the 28GHz spectrum band yielded download speeds of up to 7.5Gbps. Ericsson's initial radio bed tests achieved 5.8Gbps in the 15GHz spectrum band.
The push for higher speeds well above the up to 450Mbps achievable today on what Telstra has labelled its "4GX" network will largely come from video, network executives at MWC have indicated, particularly with the rise of 4K video.
5G will likely require telcos and regulators across the globe to rethink how they use spectrum. For a comparison, the Samsung test used 800MHz of spectrum, while most telcos are using between 20MHz and 40MHz of spectrum for their 4G networks today.
The higher frequencies will likely require regulators to rethink how spectrum in those higher bands are licensed. Oettinger said this would be an opportunity for Europe to allow each member nation to align their spectrum bands.
"With 5G, Europe has the opportunity to reinvent its telecommunications landscape," he said.
This would mean that as a person travels from country to country in Europe, they can be sure that their device will continue to be able to work in each country. Today, most devices overcome this issue by being compatible with multiple spectrum bands. This, however, is more expensive to build into the devices.
Driverless cars and net neutrality
Remote working, automation, and driverless cars will mean that latency will need to be significantly lower than it is on 4G. The arrival of driverless cars, cities using connected cars to manage traffic, and other services such as remote surgery will bring the need for prioritised traffic to ensure low latency.
This will also bring back any ongoing debates about net neutrality, according to Deutsche Telekom's Höttges.
"What is happening if a car is driving and is connected to the infrastructure while at the same time someone is watching a video and listening to Spotify? Should we then [say] 'first comes first'?
"The car should be always prioritised. Health services should be prioritised depending on the technical and the beneficial need for the services."
This would mean that the net neutrality debate should evolve to allow for "quality classes" of higher-priority traffic, he said.
One of the key drivers for 5G will need to be low power consumption. If the projections of 50 billion connected devices by 2020 comes to fruition, there will be a need to ensure that those devices are using as little power as possible.
For sensors connected via 5G, Frodigh said the aim should be to use only enough power so that the battery could last 10 years, or the sensors could be powered by alternative energy sources.
"We need to drastically reduce energy consumption. Then we can do this efficiently with solar power," he said.
One way to achieve this, he said, would be to have those devices only consume power when they are absolutely needed.
"We have very large variations in our traffic. That means most of the time in most places, we have very low traffic. The energy savings potential is in that part," he said.
"We think we need to integrate high-energy performance from concept into specifications, and then into products to really take it all the way.
"The default state in low traffic should be that things are in sleep mode."
One big happy 5G family
There were disagreements between network companies and countries over what defines 4G and 3G. For instance, in some parts of the world, Wi-Max has been considered "4G", but the dominance of LTE in other markets meant that the technology was not as widely adopted, and ultimately not supported as LTE has been in smartphones and tablets.
Oettinger expressed hope that with competing vendors looking to work together on standards for 5G, the outcome would be better for everyone.
"It is also very encouraging that industry targets one global set of standards for 5G, ensuring interoperability from the start. I am optimistic that with your leadership, we will avoid a 'war' on standards, contrasting clearly with the situation at the start of the previous generations of communications systems," he said.
McKenzie said the global discussions over 5G will ensure that the best standards are formed at the end of the process.
"The way of doing it that makes the most sense will emerge at the end of the day, and we'll study that closely and make sure we get it right."
Frodigh said the journey has a long way to go, but the initial work with industries that stand to gain from connecting to 5G is a good start.
"This is actually the best foundation, we believe, in terms of taking on new industries. Not only with smartphones and tablets, but everything from the censors, cars, and all the other industries that are coming online, and we can actually get scale in some of those industries where they haven't had that scale," he said.
After early tests in 2014, telecommunications companies, vendors, and regulators will spend the next year working out the standards before implementing pre-commercial 5G networks in 2017 and 2018, with operators to begin full 5G rollouts in 2020.
Josh Taylor travelled to MWC in Barcelona as a guest of Ericsson.