MWC: Pressure to accelerate 5G mounts; ITU shares its requirements

AT&T has secured big-name support for its bid to accelerate the process of getting first 3GPP 5G standards finalized, and looks in a better position to be able to deploy before year end, and to outwit Verizon and its semi-proprietary platform.

The later months of 2016 saw the two leading US operators grabbing the 5G limelight from the east Asian frontrunners, promising to trial 5G prototypes this year and deploy commercial systems at a very early stage. However, Verizon and AT&T – while both focusing heavily on fixed wireless in high frequency spectrum for their initial trials – have one deep difference of approach.

Verizon has worked with a group of large vendors and chip suppliers to create its own proprietary 5G platform, which it promises will be easily tweaked to support 3GPP standards when they are finalized, but which will enable it to roll out services well ahead of that. Currently the standards are expected to be ratified around May 2018, which would see initial standard equipment coming to market in 2019 and a full ecosystem of infrastructure and devices only emerging from 2020.

AT&T, by contrast, has said it will stick to the 3GPP agenda – it will deploy pre-standard equipment and prototypes as these are devised by vendors, but it will not go the proprietary route. Instead, it has been campaigning to speed up the process of finalizing the first standard in 3GPP’s Release 2015, 5G NR (New Radio), so that operators can make their moves more quickly. So far that has been blocked by Verizon, for obvious reasons, but on the eve of Mobile World Congress, the AT&T coterie upped the ante.

A group of mobile big names all announced collective support for acceleration of the 5G NR
standardization schedule to enable large-scale trials and deployments as early as the start of 2019. The group consists of 16 tier one operators and six large vendors (Intel, Qualcomm, Huawei, Ericsson, LG and ZTE, but not Nokia or Samsung). The operators are AT&T, NTT Docomo, SK Telecom, Vodafone, British Telecom, Telstra, Korea Telecom, LG Uplus, KDDI, Telia, Swisscom, TIM, Etisalat, Sprint, Vivo and Deutsche Telekom.

These companies will support a work plan proposal for the first phase of the 5G NR specification at the next 3GPP RAN Plenary Meeting on March 6-9 in Croatia. They are basically reviving the AT&T proposal of last year, which would split the two halves of the Release 15 NR specs, non-standalone NR (which needs an LTE anchor network) and standalone NR. The group wants the former to be fast-tracked as an intermediate release which would allow large-scale trials and deployments to start in 2019 (an added bonus might be that new mobile entrants would have to wait their turn, since this spec would only work with an LTE radio and packet core).

The group said in a statement: “Non-Standalone 5G NR will utilize the existing LTE radio and evolved packet core network as an anchor for mobility management and coverage while adding a new 5G radio access carrier to enable certain 5G use cases starting in 2019. The new proposal and the intermediate milestone also re-affirm and solidify the schedule for the complete standard, including Standalone 5G NR in Release 15.”

Both standards would be fully compatible with one another, and forward compatible with future Releases so that new features can be introduced in-band after 2020, “enabling yet to be identified industries and use cases and achieving the 5G vision to connect everything to everything”.

Among the statements made by the various companies in support of the proposal, Tom Keathley, SVP of wireless network architecture and design at AT&T, said: “We support both the Standalone and Non-Standalone configurations of 5G New Radio. Our focus is on prioritizing important specifications in the standards to bring 5G to market as quickly as possible. In the process of defining any standard, it is normal to make some decisions earlier than others. These accelerated decisions on key components of 5G New Radio standards will allow an earlier start on the development of the infrastructure and devices of tomorrow’s 5G deployments.”

Seizo Onoe, Docomo’s CTO, said: “Docomo plans a commercial launch with Non-Standalone 5G NR by 2020. Acceleration of the standardization schedule will facilitate early implementation of the standard-compliant 5G NR.”

And on the vendor side, Arun Bansal, head of Ericsson’s  Business Unit Network Products, added: “The faster we commercialize 5G based on 3GPP specifications, the faster we will realize its benefits for the entire industry. We are thrilled to participate in this initiative to accelerate the 5G ecosystem and commercial deployment.”

Once 3GPP has completed the specifications for Release 15, whether in one or two phases, they will be submitted to the ITU as a candidate technology for that body’s IMT-2020 standard.

In previous eras, there have been other candidates too – CDMA2000 and TD-SCDMA were accepted along with 3GPP’s W-CDMA for 3G, while IEEE’s WiMAX was accepted as a 4G alternative to LTE. It is not clear that there will be any other submissions this time around, perhaps because the WiMAX experience demonstrated just how hard it is for an upstart technology to weaken the grip of the 3GPP ecosystem.

In any case, 5G and other possible technologies will have to support a range of requirements set out by the ITU (though this sometimes fails to materialize in the commercial world – IMT-Advanced, or 4G, was meant to support gigabit speeds while stationary, but that is only just happening now with later releases of LTE standards).

The ITU says it has completed its studies on key performance requirements of 5G technologies for IMT-2020 and, according to the director of its radiocommunications bureau, Francois Rancy, “the next step is to agree on what will be the detailed specifications for IMT-2020, a standard that will underpin the next generations of mobile broadband and IoT connectivity”.

A draft of that document has been published and is expected to be approved by the ITU in November. Though some of its details may change by then, the core requirements listed include:
The minimum requirements for downlink peak data rate is 20Gbps
The minimum requirements for uplink peak data rate is 10Gbps
Target downlink ‘user-experienced data rate’ is 100Mbps
Target uplink ‘user-experienced data rate’ is 50Mbps
Downlink peak spectral efficiency is 30bps/Hz
Uplink peak spectral efficiency is 15bps/Hz
Minimum requirement for user plane latency for eMBB is 4ms
Minimum requirement for user plane latency for URLLC is 1ms
Minimum requirement for control plane latency is 20ms
A lower control plane latency of around 10ms is encouraged though
Minimum requirement for connection density is 1,000,000 devices per km2.
Requirement for bandwidth is at least 100 MHz
Bandwidths up to 1 GHz are required for higher frequencies (above 6 GHz)
Four classes of mobility are defined:
Stationary: 0km/h
Pedestrian: 0km/h to 10km/h
Vehicular: 10km/h to 120km/h
High speed vehicular: 120km/h to 500km/h

One of the sources of inputs for these detailed requirements is the ongoing series of pre-standard tests and trials. Testing firms come into their own at the start of a new generation of technology, since of necessity they must be engaged in the very first trials and implementations of the emerging solutions. And they gain unique insights into the state of carrier readiness and interest in a new technology.

At MWC this year, there will be a Global 5G Test Summit (Tuesday from 2pm to 4.30pm), involving the ITU, GSMA, 3GPP, NGMN and GTI, as well as four operators (AT&T, China Mobile, NTT Docomo and Vodafone) and several vendors.

One testing firm, Viavi Solutions, is sharing some of those insights by publishing a list of global 5G trials. This shows that 25 operators have started testing 5G prototypes in labs so far, and 12 of those have progressed to field trials. There is strong interest in higher frequency bands, with eight operators testing equipment at 28 GHz, and seven at 15 GHz, and some tests going up to 86 GHz.

According to Viavi, five operators have reached data speeds of 35Gbps or more in 5G trials – two in the Middle East (Etisalat and Ooredoo) and three in Asia-Pacific (Optus, M1 and Starhub).

“The pace of 5G development is already beyond the expectations of many observers,” said Sameh Yamany, CTO of Viavi. “Now, as the technical delivery of data is starting to coalesce, it is time to think ahead to how future 5G networks can manage the disparate requirements of high data rates, very low latency applications and large-scale IoT services while maintaining quality of service.”

He added: “Service providers and their partners will require solutions that are virtualized from one end of the network to the other and have automated and correlated intelligence across each network slice for monitoring, optimization and service assurance.”

Test and measurement firm Keysight is working on a variety of 5G-related projects, and is involved in Phase II of the China 5G Technology Trial, working with both Huawei and ZTE.

The partners have set up seven test scenarios and, using Keysignts signal analyser and related software, they have conducted the first integration tests with Huawei’s 5G prototype base station, covering numerology, frame structure, and new waveforms in the 5G NR.

Led by the IMT-2020 (5G) Promotion Group, and kicked off in January 2016, the China 5G Technology R&D Trial involves operators, equipment manufacturers, chip suppliers and testing service providers. The tests are divided into three phases—key technology verification, technical program validation, and system program validation. Phase I tests were successfully completed in 2016; Phase II is running now and will conclude before year end. It is focused on the verification and validation of wireless air interface and networking technologies used in four major 5G scenarios – continuous broad coverage, hotspot high capacity, URLLC, and massive connectivity.

More 5G tests:

Samsung and KDDI have demonstrated 5G multi-cell handover in the 28 GHz, in Tokyo. One test involved a car travelling at 60 km/hour between two base stations on a highway; while a second focused on driving in the dense city center, where speeds of 3.7Gbps were still achieved, the partners said.

“We are pleased to have proven the feasibility of 5G mobility services in Tokyo, one of the densest cities in the world,” said WooJune Kim, head of next generation strategy at Samsung. “Through today’s demonstration, we have proven that challenges that are likely to occur at highly dense metropolitan areas can be successfully overcome when the right technologies are implemented.”

Now that it is back in the mobile game after the acquisition of EE, UK incumbent BT says it wants to be first to market with 5G services, and is involving itself in a wide variety of tests and trials. Its latest move is to sign a multiyear collaboration pact on 5G testing and development with existing partners Ericsson and King’s College London. The latter, part of the University of London, has been prominent in UK academic 5G activities and says it will contribute experience with low latency use cases, robotics and haptic control. The new partnership will focus heavily on real world use cases, especially those in mission critical environments, such as medical applications.

BT has already worked with Ericsson to build a 5G Proof of Concept Center at the telcos Labs in Adastral Park, Ipswich. This has access to the 5G for Europe core network, which links multiple R&D centers and universities across Europe, and this is being used to test network architectures and share results.

While Keysight is focusing on its Chinese collaborations in Barcelona news this year, Cobham Wireless is talking about 5G testing activities with Verizon Wireless. It will demonstrate a software-defined 5G user equipment (UE) simulator, based on Verizon’s pre-standard specifications. The UE simulator enables the development of a virtualized test solution, supporting a Lab-as-a-Service model for 5G testing.