The ITU has said the main objective of IMT-2020 (5G technology) is to support diverse sets of services on the same network. These services are grouped into three broad categories:
Taken together, these categories mean that 5G will support a wide array of phones, tablets, computers, other end-user devices, peripherals, sensors, data-collection-devices, and control systems. The standards committees also have defined different classes of mobility, digital traffic, and traffic patterns. Other objectives for 5G include reliability, energy efficiency, data security, and network management –such as compatibility with legacy network systems.
These objectives are addressed with more detailed specifications on peak data rate, spectral efficiency, user-experienced data rate, area traffic capacity, connection density, energy efficiency, reliability, mobility, and bandwidth. Examples of the targets for these specifications are shown in following slide 5.
The ITU’s IMT-2020 work included a schedule for approving sections of the standard and completing the final standard. The ITU said work to define the new radio interfaces, undertaken by independent external groups, is to be completed in 2018 and 2019 for review by the ITU’s committees. Then, according to the ITU, “the whole process is planned to be completed in 2020,” with a final draft of the new ITU-R recommendation having detailed specifications for the new radio interface to be approved.
A key external standards group working on the 5G radio interfaces is the Third-Generation Partnership Project (3GPP). The 3GPP in turn is a consortium of seven other standards organizations: ARIB, ATIS, CCSA, ETSI, TSDSI, TTA, and TTC. The 3GPP organization has multiple committees working on 5G radio access network (RAN) technologies. As of June 2018, the 3GPP committees had completed two important RAN standards, sometimes also called “new radio” standards. One is called “Non-Standalone” (NSA), and it allows for interoperability with key equipment in 4G network infrastructure. The other is called “Standalone” (SA), and it operates without use of the 4G core network.
In December 2017, the 3GPP working group completed the NSA new-radio specification. Initially, this specification was scheduled for completion in June of 2018, at the same time as the SA specification. In late February 2017, the committee voted to accelerate work on the NSA specification, so that large-scale trials and commercial deployments could begin in 2019. The work was completed before the new, deadline in December, 2017.
Then as scheduled for June 2018, the 3GPP committee completed the Standalone (SA) version of the 5G new-radio standards. The 3GPP statement said, “Now, the whole industry is taking the final sprint towards 5G commercialization. The completion of SA specifications which complements the NSA specifications, not only gives 5G NR the ability of independent deployment, but also brings a brand new end-to-end network architecture, making 5G a facilitator and an accelerator during the intelligent information and communications technology improvement process of enterprise customers and vertical industries. New business models will be enabled and a new era where everything is interconnected will be opened up for both mobile operators and industrial partners.”
The 5G SA architecture gives carriers and equipment makers the option of deploying 5G without depending on an underlying 4G LTE network. Unlike SA standards, the Non-Standalone (NSA) architecture will use the existing 4G LTE core network along with the 5G new-radio air interfaces to increase data rates and reduce latency.
China’s three main telecom operators are among the carriers with aggressive plans for 5G. With 4G technology, the three were several years behind carriers in Japan and other advanced markets, having started field trials in 2012 and commercial deployments in 2014. And China’s carriers were still building out their 4G networks in 2017. Despite this, the Chinese operators have announced multi-city 5G trials to begin in 2018 and 2019 and commercial service beginning in 2020. The operators in China are among those planning to adopt the SA new radio standard from the beginning. This means that the 5G core network will not use the existing 4G infrastructure for the base-station systems.
Most carriers outside of China will adopt the NSA standard initially as a way of reducing time and cost to market, while ensuring good coverage and mobility. However, the SA version ultimately offers the potential for lower operating costs, economies of scale, better performance, and less complexity. Over time, the operators initially using the NSA standard are expected to upgrade their 4G core networks with 5G SA technology.
The 3GPP committees’ completion of the two main 3GPP radio-access-network standards was critical. At the same time, the ITU workshops and committee meetings have progressed on schedule. As a result, the final IMT-2020 specification is on track to be finalized with an official ITU-R announcement in October 2020.
In parallel with the standards work, the key chip and equipment manufacturers have been demonstrating pre-standard prototypes and gearing up for production as soon as standards are finalized. Also in parallel, the carriers have been running trials to evaluate network performance with the new frequencies that are an integral part of the 5G standards. The reports from carriers generally indicate that the technology being trialed has met or exceeded performance expectations.
By mid-2018, many carriers had publicized findings from 5G trials with high-quality streaming video, multiple video streams, dense urban environments, large crowds in sports stadiums, high-speed vehicles, driverless cars, drones, and many demanding “use cases.” Reports from these trials generally show that the prototype equipment has behaved as expected or better than expected. Of course, failures probably are not publicized. Some publications, however, have highlighted challenges being addressed, including backhaul speeds, equipment interoperability, transmission distances, and bit rates.
One problem area is the propagation characteristics of the high-frequencies in some of the spectral bands specified for 5G. The longer waves, as in the millimeter-wave band, do not penetrate foliage, glass, building materials and other obstructions as well as the frequencies used in 3G and 4G systems. This was well known, and the trials have focused on evaluating the sophisticated arrays and other antenna concepts designed to help overcome these limitations. Such trials also have evaluated the quality of received signals with rain, fog, and other atmospheric conditions.
South Korea’s equipment manufacturers and carriers are among the world leaders in 5G R&D. The country’s two largest mobile operators, Korea Telecom (KT) and SK Telecom are positioning themselves as early leaders in developing 5G technology and demonstrating new services. At the 2018 Winter Olympics, held in Pyeongchang, South Korea, KT and SK demonstrated new services on pre-commercial 5G networks. Examples included applications to track cross-country skiers, including streaming video from overhead cameras, multi-view screens during live events, and 360-degre virtual reality systems to show the perspective of the athletes in some events, using helmet-mounted cameras and other sources.
SK Telecom also has demonstrated a transportation and traffic control system based on 5G wireless technology. For trials conducted in December 2017, SK deployed 5G infrastructure in K-City, the country’s pilot city for self-driving. SK worked with the Korean Transportation Safety Authority and Samsung Electronics.
The system used 20-Gbps downloads for high-capacity video files, a control centre that transfers data to a test vehicle in less than a millisecond, and advanced tracking systems. Traffic related infrastructure such as CCTVs and traffic lights also were linked to the self-driving cars and control centres with 5G technology. The self-driving car communicated more than 100 times a second via the 5G network, both with the control center and another vehicle, to successfully minimize the risk of accidents on the road. The 5G equipment used 28 GHz ultra-high frequency broadband.