Mobile operators don’t need to wait until 2020 for speeds in excess of 1Gb/s
GUEST FEATURE: The future can sometimes feel as if it’s already here. Take AlphaGo, DeepMind’s artificial intelligence (AI) computer program. After thrashing Lee Sedol in a five-game bout of Go, a fiendishly complex board game, AlphaGo will face off against Ke Jie later this year. Although Lee Sedol is one of the best human Go players on the planet – so an impressive AlphaGo scalp – Ke Jie is currently ranked number one.
The Go breakthrough has implications for telecoms and people’s lives. AI advances of this sort – using ‘deep learning’ techniques that allow computers to extract patterns from masses of data with little in the way of human intervention – will power the Internet of Things (IoT) market. Smarter homes and cities, for example, or better e-health and logistics. Even self-driving cars.
Neither can mass-market virtual reality (VR), another emerging vertical industry, be safely dismissed as something for the distant future. Oculus started delivery of its long-awaited Rift consumer headsets in March. It’s arguably the first sophisticated consumer-ready VR headset to become available, and will be followed shortly by others. A headset for Sony’s PlayStation is due in October.
Waiting can be a dangerous game
To support these nascent services, some mobile operators might be tempted to hold back on network investment until 5G arrives. Widely expected in 2020, new 5G technologies and different frequencies will propel networks into Gigabit territory and give operators the extra capacity they need to tap into new markets.
It’s a risky strategy. It assumes new vertical sectors will not take off until four or five years’ time. A shorter timeframe, however, seems more likely.
The University of Milan, in its recent study of IoT in Italy, reported that the market was worth €2 billion in 2015 – up 30 per cent compared with 2014. A forerunner in smart meters and connected cars, Italy shows how fast IoT can gallop. New IoT applications are also spurring growth. Working with China Mobile, for example, Huawei is installing IoT modules in elevators to monitor performance and store data in the cloud. It’s a fast-growing market.
Industry visionaries see other new trends quickly emerging. Mark Zuckerberg, Facebook CEO, has high expectations for VR combined with 360-degree video. Speaking at this year’s Mobile World Congress in Barcelona – where a plethora of 360-degree video cameras were on display from the likes of LG, Nokia and Samsung – he predicted that VR was going to be the “most social platform”.
Add in the increasing use of 2K/4K video, augmented reality and drones, then mobile operators – if they want to support better video resolution to more users and sustain revenue from existing services – will likely need much higher throughput and greater capacity than is possible with conventional 4G networks.
The 4.5G shortcut
LTE-Advanced Pro – sometimes referred to as 4.5G – helps address the near-term technical challenges. Flagged by 3GPP as a “dramatic enhancement” to the LTE platform, 4.5G is capable of downlink speeds in excess of 1Gb/s, can support 100,000 connections per cell, and offers higher-definition voice and video than the current crop of 4G technologies.
4.5G is also largely backwards compatible with 4G. As an evolutionary approach, its deployment requires only software upgrades and minor hardware changes. Existing network investment is protected.
Numerous 4.5G trials around the world have already demonstrated speeds in excess of 1Gb/s, and the technology – according to Huawei estimates – is set to become mainstream. The Chinese supplier reckons more than 60 4.5G networks will be commercially deployed worldwide in 2016.
Worldwide Gb/s race on
A centrepiece of 4.5G is massive carrier aggregation (CA). While LTE-Advanced technologies typically combine two or three component carriers (CCs), 3GPP Release 13 opens the door to combine as many as 32 CCs. Given mobile operator spectrum holdings, however, five-band CA (5CA) is likely to be the typical maximum over the next few years.
Even so, this will be enough to dramatically increase data throughput, particularly for mobile operators which have a fragmented spectrum portfolio. Crucially, it also allows the combination of FDD and TDD airwaves, so giving operators the chance to fully exploit their spectrum assets. Moreover, the throughput can be much higher – above 1Gb/s – when used in conjunction with other 4.5G techniques, such as MIMO and 256QAM.
Examples of 5CC CA trials, combining TDD and FDD spectrum, include Australia’s Optus and China Unicom – both of which use equipment from Huawei. Optus, in February 2016, announced a 5CC CA trial with download speeds of up to 1.4Gb/s by aggregating 5CCs of 20MHz each. China Unicom, in July 2014, demonstrated 5CC CA at MWC Shanghai.
Speeds in excess of 1Gb/s can also be achieved with 4CC CA, as TeliaSonera Norway, Hong Kong’s HKT and Vodafone Turkey have shown.
Vodafone Portugal and Greece’s Cosmote, using equipment from Ericsson and Nokia respectively, have each implemented FDD/TDD 3CC CA on their commercial LTE networks. In the case of Cosmote, Nokia highlighted that the TDD CC was in the 3.5GHz band. While the majority of LTE TDD deployments have so far been in 3GPP-defined bands at 1.9GHz/2GHz, 2.3GHz and 2.6GHz, the emergence of bands 42 and 43 (3.5GHz and 3.7GHz) as a TDD CC option is significant. It opens up, in many countries, a potentially extra 400MHz of spectrum for 4.5G deployment. Band 42 is available almost globally.
When spectrum is limited
Not all operators have spectrum portfolios that lend themselves to Massive CA. For those with limited spectrum, data throughput can be ramped up by improving spectral efficiency via other 4.5G technologies, including multi-antenna and 256QAM. TDD operators also have the prospect of being soon able to use commercial Massive MIMO, to boost spectrum efficiency, following a number of successful trials around the world involving various suppliers.
Working with China Mobile Shanghai, Huawei, in September 2015, said it successfully deployed the world’s first Massive MIMO solution deployment on an LTE TDD commercial network using 128 RF channels and 128 built-in antennas. Tests revealed a downlink throughput per single cell exceeding 670Mb/s with a single 20MHz carrier. That’s around five times the speed usually achieved over a 20MHz chunk of TDD spectrum. Japan’s SoftBank, again with Huawei, is testing Massive MIMO on its LTE TDD commercial network in Tokyo, one of the most densely-populated cities in the world, where speeds of 617Mb/s were achieved via 20MHz.
Massive MIMO can also be used to support 3D beamforming – another pillar of LTE-Advanced Pro – which helps antennas to focus beams on specific users.
In February, Ericsson – using only 3CA – said it achieved 1Gb/s downlink speeds with Australia’s Telstra using Qualcomm’s Snapdragon x16 LTE modem and devices manufactured by Netgear, a UK company. 4×4 MIMO was used on two aggregated carriers, so doubling the number of unique data streams being transmitted to the user’s smartphone. LTE 256QAM encoding packed more bits into the available spectrum. Huawei conducted a similar trial with Qualcomm in the same month to achieve 1Gb/s speeds with UK operator EE.
The 4.5G ecosystem, then, is maturing. Suppliers are managing to eke out greater spectrum efficiencies through interoperability. Mobile operators, especially those able to harness their TDD spectrum assets, can now mount a much stronger and more timely assault on new business opportunities through 4.5G rollout.
Many already appear to agree. Time will tell if 4.5G momentum builds even further, but signs are that it will.