The 5G world begins to take shape

The 5G World Summit held at Olympia in London (29-30 June 2016) provided a range of sessions covering the key areas of development required to make 5G a reality. James Atkinson reports on the keynote sessions from mobile operators Korea Telecom and NTT Docomo and infrastructure OEMs Huawei and Ericsson

The 5G world begins to take shape

Korea Telecom
Mr Kim, Young-Sik, Senior Vice President, Head of Network Technology Department at Korea Telecom, began the opening keynote by saying that the big difference between 5G and previous generations is that previously services have been human centric, but in 5G they are expected to extend into ‘connectionable IT’ – machine to machine (M2M) and Internet of Things (IoT) transactions, in other words.

It is this IoT connectivity that is really set to explode, with 5G use cases being built around the needs of industry, rather than people. Kim explained that these connected devices will largely split between massive 5G IoT deployments versus critical MTC (machine type communications). Examples of the former include connected devices in homes, buildings, factories, energy, logistics/tracking and smart agriculture.

Critical MTC applications that require more stringent performance criteria in terms of low latency and high network availability, security and robustness, include autonomous driving, healthcare (eg remote operations) and so on.

The key technical requirements for 5G cover data and voice, multimedia, IoT and mission critical applications. In terms of speeds, 100Gbps is being aimed at, along with less than 1ms latency and the capability to support one million IoT devices in a square kilometre.

Kim pointed out that the latest iteration of LTE, LTE-A Pro, is moving towards some of these goals already and among the kinds of solutions currently in development are: Private LTE networks; Public Safety LTE (via drones/portable base stations); LTE SOS; Satellite LTE; GiGA stadium services; and Bilateral VoLTE roaming

Korea Telecom’s stated ambition is to have a 5G trial service ready for the PyeongChang 2018 Winter Olympics in South Korea. Kim told delegates: ‘We are almost done with the specifications for PyeongChang. They will be complete by the end of this year and we will be building them in 2017 and trial them in 2018 at the Winter Olympics.’

Kim said the kind of 5G related applications to be used at PyeongChange will include: Sync view, where viewers see the sporting activity from the players’ point of view; 360 degree virtual reality; holograms of athletes in the distance from spectators; facial recognition technology; and OmniView, which views the action from various angles.

NTT Docomo
Takehiro Nakamura, VP and Managing Director of 5G Lab at Japanese mobile operator NTT Docomo, began by saying that 5G will be a phased realisation, rather than a big bang. ‘It will evolve by incorporating new frequency bands and technologies and future compatibility is key for system design to continue the evolution,’ he said.

He observed that 5G requires a new radio access technology (RAT) including tight interworking with LTE. It is likely to use both existing frequency bands and new bands due to by licensed by the ITU in 2019. He also mooted the notion that unlicensed bands might also be incorporated into 5G.

As has been generally agreed, 5G will utilise more higher and wider frequency bands (including 60-80 GHz millimetre wave) than have been used up to now, and more advanced technologies such as Massive MIMO.

He added that the current 3GPP programme to define and write the specifications for 5G is: 2017-18 - Proposals; 2019-20 – Specifications. NTT Docomo’s goal is to have a 5G network in place for the 2020 Tokyo Olympics.

However, agreement on potential 5G frequency band candidates is still very much open to question. The difficulty is that no candidate bands are currently available all over the world to ensure global harmonisation of frequencies.

Despite that he said NTT believes the following bands are the strongest candidates, but he acknowledged they are not available universally: below 6GHz - 3.4-3.8GHz and 4.4-4.99GHz; and above 6GHz - 27.5-29.5GHz.’

He reported that NTT has carried out some 5G experimental field trials at Chengdu, in China, with Huawei in sub-6GHz bands to test multi user MIMO (MU-MIMO) and two of the new air interface technologies Huawei is working on: sparse code multiple access (SCMA) and filtered orthogonal frequency-division multiplexing (F-OFDM).

The operator has also conducted demonstrations with Samsung in the 28GHz band to test super wide band transmission in a vehicle moving at 60km, and with Nokia at 73GHz (using a beam visualizer to show the beam tracking performance) with 1GHz bandwidth.

This was trialled in the Roppongi Hills high-rise complex area in Tokyo on 13 Oct 2015. ‘We tested both line of sight and non-LOS, which was a bit degraded, but we could still achieve more than 1Gbps throughput thanks to reflection,’ said Nakamura.

Ying Weimin, President of R&D, Huawei Wireless Network Product Line, then outlined Huawei’s technical progress on 5G. He said Huawei expects to have a standalone 5G radio by June 2018.

‘By the end of 2019, we believe the full IMT-2020 standard will be ready and we hope it will be just one unified standard for all countries. We believe this will benefit the whole industry and all users,’ said Weimin, voicing a fervent hope that 5G will not fragment into different regional variants.

According to Weimin, the new elements that need to be developed and agreed on are:

• Cloud architecture enabling one network, supporting multiple industries
• A new unified air interface (UAI) capable of supporting everything from ultra narrowband to massive broadband with a 3x spectrum improvement
• Intelligent operation enabling deep mind/learning for network slice auto-creation and optimisation.

The new Cloud native architecture will support end-to-end network slicing: eMBB (enhanced mobile broadband) - enable plane; uRLLC (ultra reliable low latency communications) – control plane; and mMTC (massive machine type communication) – user plane.

Weimin said: ‘All this needs to run over one physical infrastructure to enable end-to-end physical network slicing – a common network architecture across different technologies and layers. We will develop a mobile CloudRAN engine to enable this with a unified interface to network operations, so MNOs can simplify network functions.’

5G will require a new unified air interface to cater for the very diverse use case scenarios being proposed for 5G. The company thinks an F-OFDM (Filtered-OFDM) waveform solution is the best candidate.

Filtered-OFDM, as opposed to LTE’s OFDM, enables different sub-bands to be filtered to create different configurations, which is how 5G will, in theory, be able to handle very different use cases ranging from NB-IoT to massive broadband.

Other applications the UAI needs to handle include: SCMA (sparse code multiple access), which combines CDMA and OFDMA to improve spectral efficiency by supporting much higher levels of connectivity, lower latency and energy saving.

Others include: Massive MIMO; Multi-connectivity; Full Duplex (ie send and receive on the same channel); and Polar Code (a new and superior coding scheme, seen as ‘a perfect candidate for the forward error correction (FEC) module in 5G air interface design’, according to Huawei).

Weimin concluded: ‘I still think we have a lot of big challenges and uncertainty for the future: what will the new spectrum frequencies be, for example?’ He added that the best strategy is to ensure spending and innovation is not being replicated around the world.

Arun Bansal, SVP and Head of Business Unit-Radio, Ericsson, reiterated the view that 5G will be use case driven, rather than person to person. He said the future will be characterised by: broadband and media everywhere; sensors everywhere; smart vehicles and transport; infrastructure monitoring and control; critical control of remote devices; and the interaction of human beings and IoT.

Bansal noted that the Cloud and Network Functions Virtualisation (NFV) are key building blocks for a 5G-ready network core. ‘We need network slicing as it is fundamental for 5G to be successful and for MNOs and enterprises to monetise it. If we cannot differentiate the use cases there will hardly be any money to be made out of it,’ asserted Bansal.

He added that a 5G network architecture has five key components: Management and Control – ‘it is extremely important that MNOs are able to do this to monetise their 5G networks’; Access – for Applications; Cloud Infrastructure; and Transport – ‘in many parts of the world there is no fibre, but transport is critical for low latency applications’.

Bansal said: ‘When planning for 5G we need to think that it will not be a big leap from 4G – do it step by step. We have 1Gbps on LTE today and this capability will be delivered to devices by the end of the year, while NB-IoT will be available later in 2016.’

He added that 5G involves a fundamental mind shift not just in technology, but in business cases. ‘5G will require totally different business cases for operators to make money out of, but MNOs cannot wait for 2020 to figure that out. They need to make money out of NB-IoT now, for example. That’s why Ericsson has prepared its five 5G Plug-Ins for 4G networks to enable MNOs to be ready to migrate to 5G.’

Bansal noted that many 5G concepts can be deployed now. Massive MIMO provides better user experience, coverage and capacity using beamforming and MIMO. ‘We can do multi-user MIMO now. We can also start on RAN virtualisation to centralise resources to enhance performance, and work towards the less than 1ms latency.’

Bansal encouraged MNOs, saying: ‘You can use the same resources as you do now. So, start planning your network now, not in 2020. 5G will not be a revolution from a technical or implementation point of view.

‘MNOs are already doing Cloud and virtualisation. 5G is about the business and the business model, and that will decide which operators will be successful, so work on the use cases now with businesses,’ said Bansal. He argued that the Ericsson Lean Carrier offering uses 5G concepts today available to MNOs through a software upgrade on the network.

Bansal concluded: ‘5G technology is moving faster than many realise and standardisation is also moving faster than many people realise. It is driven by enterprise use cases and not by consumers. 5G is exciting industries that are global by nature, so I really hope one standard emerges, and I am convinced 5G take up will be even faster than for 4G.’

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