by Caroline Gabriel, Research Director Maravedis-Rethink
Big wireless suppliers try to influence operators' and regulators' agendas as they dream up visions of the next generation.
While the big network vendors have mainly confined their MWC announcements and previews to relatively short term developments, none of them could resist breathing the '5G' word, seeking to convince their audiences that they had somehow stumbled on the secret ingredients for the next generation of wireless, well ahead of the actual standards bodies.
Ericsson promised to demonstrate "fundamental 5G functionality" in Barcelona, to support both human and machine applications. The Swedish vendor even unveiled results from its 5G testbed, which it says has performed the remarkable feat of already achieving two 5G milestones (even before anyone knows what 5G will be). The testbed includes base stations and concept devices operating in the 15GHz band, indicating the importance most vendors are placing on high frequency spectrum for next generation standards.
Of course, like all the vendors, Ericsson hopes that by calling its R&D efforts '5G' it will improve their chances of being included in the standards, or at least the basic concepts, which do go on to underpin the next generation.
Its two supposed milestones are 5G/LTE dual connectivity and 5G multipoint connectivity, the company said. The first supports a 5G device moving between LTE and the new network, establishing simultaneous connections with both before seamlessly handing over, in order to smooth the user experience. The second allows the 5G device to connect to two 5G base stations simultaneously, improving bit rate performance with multiple downlink streams, as well as signal strength and resilience.
Both of these are 4G concepts, adapted for the supposed characteristics of the new generation network (ultra-small cells, ultra-low power, support for millions of sensors, and so on). As in 4G, multipoint connectivity will be particularly important to enable multilayer HetNets with macrocells, small cells and WiFi interworking seamlessly.
Nokia, too, has been giving a glimpse of what 'future 5G' demonstrations it will make in Barcelona. It will show off radios running in high frequency millimeter and centimeter wave bands (3.5GHz to 70GHz), which will boost capacity, and will be combined with new frame structures to support latency down to single-digit milliseconds. These will be particularly focused on the IoT.
Its good customer Korea Telecom will be partnering with Nokia in the MWC 5G and IoT demonstrations and the operator's head of networks, Seong-Mok Oh, said: "I hope that the strategic partnership with Nokia, including the joint demonstration at MWC 2015, will lay a foundation for the two companies' leadership position along the journey towards an IoT world."
Nokia has also been working on massive MIMO trials with KT's rival, SK Telecom, though these are looking to a shorter timeframe than 5G, initially at least. The two companies said this week they had achieved peak downlink speeds of 600Mbps using 4x4 MIMO. They first got to 300Mbps by implementing the MIMO array in a 20MHz block of spectrum, and then doubled that speed by doing the same in a second 20MHz chunk and aggregating the two. Devices with four antennas and carrier aggregation support have not been developed, so Nokia used a simulated device supplied by test and measurement specialist Aeroflex.
And 4×4 MIMO will be challenging to deploy in a commercial network, because of the need to squeeze four antennas into a small device, and also because it is difficult to maintain the right RF conditions for the 4x4 airlink, so real world user experience may be patchy.
Japan's NEC promises to outline its 5G vision with demonstrations and three white papers outlining what it believes will be the key enabling technologies in 2020 and beyond. These focus on the access network, the backhaul, and massive MIMO, particularly its development of a 'massive-element antenna' for future small cells.
Like Huawei, its post-2020 vision is heavily geared to machine services, from intelligent transport to the use of big data to save energy consumption, as well as next generation consumer multimedia offerings and ultra-accurate logistics systems. The heart of this platform will be SDN, virtualization and Cloud-RAN, all areas where NEC has engaged in advanced R&D and trials.
And Samsung says it will show off three 5G "technology candidates" at MWC. Chang Yeong Kim, head of the DMC R&D Center at the Korean firm, said in a statement: "We consider 5G to be a transformation of how networks are constructed and how radio resources are used. To support 100 times greater throughputs at a fraction of the latency, we need to consider more than just a single network component; we need to look at how everything works together."
The three candidates highlighted by Samsung are a nearly-commercial implementation of wireless backhaul in 60GHz spectrum, combining active and passive radio steering techniques to increase the range of the radio without exceeding unlicensed-band power output limits. An active antenna array enables a beamformed radio signal to be directed at a passive lens antenna, which further concentrates the radio signal toward a fixed point with high precision and multi-gigabit data rates.
The second technology is 'full dimension MIMO' (FD-MIMO). Current MIMO solutions have antennas configured to form beams only horizontally. Users who are at the same horizontal angle from the antenna (even at different vertical angles) still receive the same signal and continue to share radio resources. With the introduction of FD-MIMO and 2D-array antenna technology, wireless signals can be adaptively beamformed to specific users in both horizontal and vertical domains. That delivers a more targeted signal to more than eight users per cell at a time and is good for high rise buildings, stadiums and other crowded locations.
Samsung said it is leading the standardization of FD-MIMO in the upcoming 3GPP Release 13.
It also says it will demonstrate peak stationary data rates of 7.5Gbps - or 1.2Gbps when moving at 100 kilometers per hour - using 28GHz millimeter wave spectrum and Samsung's Hybrid Adaptive Array antenna technology.
However, amid all this cleverness, Peter Merz, head of radio systems technology and innovation at Nokia Networks, injected a note of realism in a recent interview with Telecom.com. He said: "I want to stress that 5G is not around the corner. We're expecting the first commercial roll-outs and deployments starting in 2020. We still have five years to go in order to research technologies, go through standardization, free up spectrum, verify the technologies and then iron out specifications in order to have a ready-made, lean-cut, efficient technology that can be deployed by operators starting in 2020. 5G is like a marathon, it's not a race."
We can only hope that vendors are bearing such words in mind in Barcelona and focusing most of their efforts on real world requirements for 2016 to 2018, even while they seek to influence operators, standards bodies and regulators building their long term plans.