Walking around Mobile World Congress, it was easy to see all sorts of demos marked "5G," as if the next generation of wireless technology–the step beyond 4G or LTE–is right around the corner. It's not.
In fact, formal proposals for 5G technology aren't due to the International Telecommunications Union (ITU) until the fall of 2017, and it's unlikely we'll see a final technical specification and networks that meet those requirements until 2020 at the earliest. Instead, the demonstrations mostly were of technologies that individual companies think could be part of that next standard, or maybe bridges to 5G. These include a lot of work on using unlicensed spectrum, perhaps with millimeter waves; on aggregating together both licensed and unlicensed spectrum, including LTE-Advanced and Wi-Fi; and on making the network itself more intelligent, reliable, and secure.
Meanwhile, the operator-led Next Generation Mobile Networks (NGMN) alliance published its "5G White Paper," detailing what many carriers want in 5G, and the outlines of these various efforts seem to be starting to converge.
The most interesting demos of the pre-5G technologies came from the big infrastructure hardware providers–Alcatel-Lucent, Ericsson, and Nokia; as well as a few of the carriers trying to position themselves to be early in 5G rollouts.
Almost all of the vendors defined 5G as hoping for a 1,000x increase in capacity of the networks, so that they will be able to handle 1,000 times more devices hooked into the network. Note this increased capacity may not mean that an individual user will actually download information 1,000 times as fast as they do today, but instead that the network as a whole will be faster. Still, connections for many users could be faster–the idea is to get a device the information it needs as quickly as possible, and then get it off the network.
Such a solution will likely use a much more dense collection of cells to transmit and receive information, in new configurations. A number of companies including Intel were showing demos of how they could "densify" the network.
Another part of the solution is to use more spectrum, both the licensed spectrum where LTE and older technologies currently operate and unlicensed spectrum. Unlicensed spectrum includes some bands such as the 2.4 and 5 GHz bands that are often used for Bluetooth and Wi-Fi; and increasingly spectrum above 6 GHz includes what is often called millimeter wave (mmWave) bands. All of the major radio companies, and even research groups such as IMEC, were showing mmWave demos.
Indeed, almost everyone agrees the next stage will involve more seamless connections between licensed and unlicensed spectrum. For instance, the Wireless Broadband Alliance set up its Next Generation Hotspot technology (using the Wi-Fi Alliance's Passpoint certification) at the show, and users with valid SIM cards on some networks could connect to these hotspots, with technology that let you move between LTE and Wi-Fi networks without noticing. (It could have been better publicized and offered in more locations, but it worked quite well.)
Here were some of the more interesting demos on the show floor:
SK Telecom was showing a new RAT (radio access technology) that was capable of 7.55Gbps peak data over a 28 GHz connection.
Haesung Park, manager of SK Telecom corporate R&D, said the company was looking mostly at spectrum above 6 GHz, such as the spectrum used by WiGig, since spectrum below that is covered under existing 3GPP regulations. For this to make the most sense, he said, a "continuous wide band is key" so carriers will be looking at larger bands of spectrum. But he noted that higher frequencies tend not to have the penetration of today's 4G bands, so that the lower frequency would still be needed.
The company said its plan would involve seamless networking between LTE-Advanced and any new radio technology; and would likely include Network Function Virtualization (NFV) capabilities to better manage the network. Park said SK Telecom would like to build a test network to showcase a pre-5G solution in 2018, with plans for a final rollout in 2020.
Nokia was actually talking about aiming for a 10,000x (!) increase in capacity, by using a complete 5G system with macro cells, denser cells, and an ultra dense layer of even smaller cells, mostly using spectrum above 6 GHz. In an emulation of such a system, Nokia can deliver "several gigabit per session" according to Agnieska Szufarska, manager of radio research.
Nokia's demos at MWC included a phased array attention system, using mmWave technology in the 70 GHz range. This beam-tracking demonstration included 64 beams each covering three degrees controlled by a high-gain directional antenna. The whole assembly was behind glass, but quite interesting to watch a device moving and being tracked.
Ericsson had a number of interesting demos, including showing how a mobile device might be able to get more than 5 Gbps of connectivity hooked to a next-generation base station using beam-forming radios.
According to Miguel Blockstrand, director of product line device connections, 5G is "not a big bang," but rather will happen through the implementation of different technologies at different times. LTE will actually be part of 5G solutions, he noted, as will many technologies that use unlicensed spectrum.
One big driving factor, he said, is the increasing use of mobile-to-mobile (M2M) technologies, and the evolution of the Internet of Things. Making all this work will require analytics and behavior prediction, bringing more reliability, resilience, and coverage to the network while reducing latency. This is important for applications such as autonomous cars, remote surgery, or remote excavation (such as a demo Ericsson had in its booth).
Interestingly, Qualcomm didn't label its demos as 5G, because it sees room to roll out many of its new technologies as part of continuing advances to LTE. Already, the company says it is assessing ways to work with traditional licensed spectrum as well as unlicensed spectrum (LTE-U), while aggregating together LTE and Wi-Fi bands, and including such features in its LTE-Advanced modems as they are ready. Qualcomm sees a more gradual introduction of 5G, rather than a big bang, in which we end up with a unified platform, incorporating new advanced forms of LTE, Wi-Fi, and 5G technologies together. This will use both traditional base stations and many more small cells.
"In our view you need to look at different uses [of 5G], not just higher rates or more capacity," said Rasmus Hellberg, Qualcomm senior director of technical marketing. With the growth of the Internet of Things, 5G needs to be able to connect a massive number of devices, and support new services and industries, he said.
New uses of wireless networking such as directing self-driving cars will require reliability, ultra low latency, and security, he noted. One thing I thought was interesting about Qualcomm's approach is its view of an "edgeless network" where the user devices are actually part of the network, using cognitive technology or machine learning to choose among multiple possible network paths.