Forecasts of future mobile data usage continue to inflate, just as the hype value of 4G is in decline. No surprise, then, that the public discussion ‘ if not real operator projects ‘ is shifting to ‘5G’. This is yet to be defined even in top level terms, but vendors, carriers and academics are starting to consider what sort of networks will cope with wireless data from 2020.
The European Commission is determined to regain a leadership in 5G which it lost in 4G, and has a major umbrella program called Metis already underway. Feeding into this will be the work of projects like the UK’s 5G R&D center at the University of Surrey, which is backed by Huawei, Samsung and others. Though 5G hype is also mounting alarmingly, these research initiatives are sufficiently real to prompt standards organization ETSI to run a summit on the topic last week in France.
The ETSI Future Mobile Summit discussed the factors which will shape the development of the next generation of wireless network technology, after the capabilities of LTE-Advanced and its successors are exhausted. Given patterns of broadband usage, this point is likely to come more quickly than it did for 3G, not just because of rising data loads, but also because of the need for technologies which will support far lower costs ‘ to operators and consumers ‘ and which will be optimized for non-human ‘internet of things’ services too.
So, the criteria being set for 5G are to enable a very fast, (multi-gigabit) ubiquitous and low cost network, able to support all kinds of devices including sensors and probes. Higher data rates, lower latency, better quality of service and improved device autonomy will all be important. And the summit looked beyond the enhancement of these known factors ‘ it also discussed more bluesky items which will affect networks, such as the emergence of the ‘tactile internet’, advanced augmented reality, new cloud services, and the perception of infinite capacity.
Key technologies to enable all this are expected to include massive MIMO antenna arrays, use of very high frequency bands and a far more complex definition of ‘HetNet’.
The European Commission has committed €700m to support and coordinate industry investment in 5G R&D between 2014 and 2020, and its 5G Public Private Partnership program aims to accelerate and structure research and innovation for interoperable 5G networks and standards. Meanwhile, the work on 3GPP standards ‘ the LTE and even the W-CDMA/HSPA families ‘ is far from over, and the capabilities of these technologies are being extended far beyond what was originally thought possible. The summit paid tribute to the work of the 3GPP, which celebrated its fifteenth anniversary at the event. The 3GPP is a joint initiative of six telecoms standards bodies, including ETSI, which since 1998 have pooled their mobile standards activities from GSM to LTE-A.
Meanwhile, the European Commission will formally launch its 5G Public-Private-Partnership (PPP) association on December 17. The aim is to create a community to support the EU’s efforts in 5G R&D. Bernard Barani, deputy head of the EC’s DG Connect division, said he did not know what 5G was yet ‘ ‘at the moment it’s a group of requirements’ including ubiquitous availability and seamless interoperability of intelligent, high capacity mobile networks, using virtualization to reduce cost and boost flexibility. However, key issues ‘ such as whether a new air interface will be needed ‘ remain to be decided.
Meanwhile, even before ‘5G’, operators continue to push the boundaries of LTE at a far faster rate than we saw in the 3G era. SK Telecom of Korea, always in the forefront, is promising to boost peak download speeds to 225Mbps in the second half of next year, and then to 300Mbps after that.
Earlier this year, the South Korean cellco was the first in the world to deliver peak rates of 150Mbps by using LTE-Advanced carrier aggregation techniques. That feat has since been emulated by a rising number of operators worldwide, most using LTE-A’s CA options (although the UK’s EE did it just by using wider channels for original LTE). SKT’s aggregated network uses 10MHz in the 1.8GHz band and 10MHz in 800MHz and this was available in 84 cities as of the end of July.
Its next move will be to add a further 10MHz of 1.8GHz spectrum, having been allocated new airwaves in August, in order to reach 225Mbps during the second half of 2014. To get to 300Mbps, it will need to aggregate three carriers in different bands, though the operator is not revealing timescales, nor which other frequency it might use. It may well be a higher band such as 2.3GHz or 2.5GHz.
The operator said its 225Mbps network would enable users to download an 800Mbytes file in less than 30 seconds, compared to 7.5 minutes with 3G, and doubling its current LTE speeds. It said in a statement: ‘By successfully demonstrating 20MHz + 10MHz CA, SK Telecom moves one step closer to realizing the next level of LTE-Advanced technology – aggregating three component carriers (20MHz + 10MHz + 10MHz) to support up to 300 Mbps.’
Another habitual pioneer, Telstra of Australia, has demonstrated speeds of up to 300Mbps with its main supplier Ericsson, using carrier aggregation of 20MHz in each of the 1.8GHz and 2.6GHz bands. The speeds were demonstrated on the incumbent’s live commercial network and it will deploy high speed services from next year, and add 700MHz when that spectrum is available. Mike Wright, Telstra’s executive director of networks, said that the tests were an important step towards being able to deploy Cat-6 LTE-Advanced CA when those digital dividend frequencies are freed up.
In Europe, Telefonica and Vodafone are both testing LTE-A carrier aggregation in Germany, while EE has switched on the capability in trial areas in the UK. While EE is using 2x20MHz channels to deliver speeds up to 300Mbps, Telefonica and Vodafone are combining a single 10MHz channel plus one 20MHz channel for up to 225 Mbps.
In October, SFR said it completed the first trials of LTE-A technology in France, achieving download speeds of up to 174Mbps thanks to carrier aggregation in the 800MHz and 2.6GHz bands.
Looking even further in speed terms, Japan’s NTT Docomo has achieved the world’s first transmission exceeding 1.2Gbps in a field test using a single-size antenna and a new technology called Smart Vertical MIMO for LTE-A. Docomo’s technology uses adaptive grouping of vertical antenna components according to the reception quality for mobile devices in the transmission area, enabling a single-size antenna to achieve throughput equivalent to that of a four-antenna system.