5G New Radio (5G NR) is a completely new air interface being developed for 5G. It is being developed from the ground up in order to support the wide variety of services, devices and deployments 5G will encompass, and across diverse spectrum, but it will build on established technologies to ensure backwards and forwards compatibility.
What is 5G NR?
5G NR is a new air interface being developed for 5G. An air interface is the radio frequency portion of the circuit between the mobile device and the active base station. The active base station can change as the user is on the move, with each changeover known as a handoff.
5G will initially be made available through improvements in LTE, LTE-Advanced and LTE Pro technologies. But it will be soon be followed by a major step-up with the introduction of a new air interface.
The 3GPP (3rd Generation Partnership Project) made decisions on some of the technologies to be used in 5G NR as part of the 5G NR Release 14 Study Item which officially began in March 2016. The first 3GPP 5G NR specification will be part of Release 15, on which work began in June 2016 and is set to complete in September 2018. With Release 14 frozen (completed) in June 2017, from the second half of 2017 3GPP’s work has been focused on Release 15 to deliver the first set of 5G standards.
In March 2017 the 3GPP’s RAN Group committed to accelerate the 5G NR workplan with an agreement for the early completion of an intermediate milestone for the enhanced Mobile Broadband (eMBB) use case (See below). This Non-standalone (NSA) 5G NR variant was to be finalised by March 2018 but in fact was approved in December 2017, the first 5G standard. It uses the existing LTE radio and core network. The Standalone (SA) mode is to be completed by September 2018 and implies full user and control plane capability using the 3GPP’s new 5G core network architecture.
The agreement also defined a framework to ensure commonality between the two variants. It also puts compatibility at the heart of 5G NR design so that new capabilities and features can be introduced in subsequent releases of the standard.
The accelerated schedule will enable large-scale trials and deployments compliant with 3GPP standards from 2019, earlier than the originally envisaged timeline of around 2020.
What will 5G NR do?
In a nutshell, the 5G NR is being designed to significantly improve the performance, flexibility, scalability and efficiency of current mobile networks, and to get the most out of the available spectrum, be that licensed, shared or unlicensed, across a wide variety of spectrum bands.
Furthermore, the 5G NR air interface is just one component of the future 5G network so it must also be designed to work as part of a wider flexible network architecture.
The 5G NR must be able to: deliver a huge number of varied services provided across a diverse set of devices with different performance and latency requirements; support a wide range of deployment models from traditional macro to hotspot deployments; and allow new ways for devices to interconnect, such as device-to-device and multi-hop mesh. And it must do all this at unprecedented levels of cost, power and deployment efficiencies.
How will 5G NR work?
The core 5G NR design will encompass three foundational elements:
Optimised OFDM-based waveforms and multiple access. An early decision was taken to use the OFDM (orthogonal frequency-division multiplexing) family of waveforms for 5G, although the exact waveform and multiple access implementation has not yet been decided and multiple OFDM variants are being considered for different use cases and deployments.
OFDM waveforms are used by both LTE and WiFi, which will make 5G the first mobile generation that will not be based on a completely new waveform and multiple access design. They will be optimised with more advanced capabilities to deliver high performance at low complexity; support diverse spectrum bands, spectrum types and deployment models; and efficiently support and multiplex all the different use cases.
A common flexible framework to enable efficient multiplexing of diverse 5G services and provide forward compatibility for future services. It will enable lower latency as well as scalability at far lower latencies than is possible with current LTE networks.
Advanced wireless technologies to deliver the new levels of performance and efficiency that will enable the wide range of 5G services. There are three general designations of 5G services and we’ve outlined these here, along with some of the advanced wireless technologies that will be needed to make them reality:
- Enhanced Mobile Broadband (eMBB): Data-intensive applications that need lots of bandwidth, like video streaming or immersive gaming, to give the same experience on a mobile device that we’d get from fixed fibre-optic. The technologies that will make it happen include Gigabit LTE, massive MIMO, mmWave technologies, spectrum sharing techniques and advanced channel coding.
- Ultra-reliable and Low-latency Communications (uRLLC) or Mission-Critical Control: Latency-sensitive services needing extremely high reliability, availability and security, such as autonomous driving and Tactile Internet applications . Technologies are being developed that are specific to particular use cases, like cellular vehicle-to-everything (C-V2X) and real-time command and control for cellular drone communications, as well as those to support the ‘no-failure’ requirement, such as multiplexing to prioritise mission-critical transmissions over regular traffic or redundant links so that mission-critical devices can connect across multiple networks.
- Massive Machine Type Communications (mMTC) or Massive IoT: Low cost, low energy devices with small data volumes on a mass scale, such as smart cities. Narrowband IoT will be enhanced with capabilities like voice support, lower latency, location services, device mobility and broadcast for efficient over-the-air (OTA) firmware updates. Qualcomm is proposing the RSMA (Resource Spread Multiple Access) uplink multiple access design for more efficient uplink transmission, as well as a new WAN-managed multi-hop mesh architecture to extend network coverage.
As with LTE, much of the work on 5G NR is being led by Qualcomm and, as with the rest of 5G, every mobile carrier and equipment maker of note is in the game. In addition to Qualcomm, the main players involved in the 3GPP work are Ericsson and Nokia on the equipment side and AT&T, NTT DoCoMo, SK Telecom and Vodafone on the operator side, although over 40 companies signed the March 2017 agreement to accelerate 5G NR development.
Qualcomm has developed optimised OFDM-based wavelengths that will scale in both the frequency and time domains, as well as optimised multiple access for different use cases and a new 5G NR framework to efficiently multiplex 5G services and features. By early 2017, Qualcomm, in partnership with Ericsson and ZTE, had announced 5G NR trials with AT&T, China Mobile, NTT DoCoMo, SK Telecom, Telstra and Vodafone. It had also expanded its Qualcomm Snapdragon X50 5G modem family to include new multi-mode modems to support the global 5G NR standard, both sub-6GHz and multi-band mmWave, and Gigabit LTE on a single chip. In October 2017, Qualcomm announced the first data connection on a single-chip 5G modem (the Snapdragon X50) and previewed its first mmWave 5G smartphone reference design.
In November 2017, Qualcomm, ZTE and China Mobile completed the first end-to-end 5G NR Interoperability Data Testing (IoDT) system, demonstrating a data connection based on the standard being finalised by 3GPP.
Ericsson announced its AIR 3246 radio in September 2017, with commercial availability slated for Q218. It supports both 4G/LTE and 5G NR technologies.
The March 2017 3GPP agreement to accelerate development of 5G NR was a significant step forwards along the road to 5G. Pre-commercial 5G NR trials are already well underway, and it won’t be long before the first NR-capable commercial products are available to buy. There is still a lot of work to be done to make the stand-alone 5G NR a reality, but the progress made thus far indicates commercial 5G deployments could begin as soon as 2019.