The Latest Iteration of 5G Standards Nailed Down

Article By : John Walko

The 3GPP organization — which has been overseeing the specifications and standards for cellular technologies from the early days — last month nailed down the latest iteration for 5G, dubbed Release 16.

The 3GPP (3rd Generation Partnership Program) organization — which has been overseeing the specifications and standards for cellular technologies from the early days — last month nailed down the latest iteration for 5G, dubbed Release 16.

Why is it Important? The update includes some key enhancements that will offer consumers improved data rates and better coverage, higher reliability, and for the operators, potentially new markets for 5G communications. The Release was delayed by a few months, primarily as a consequence of the COVID-19 pandemic.

What is New in Release 16

Image source: Qualcomm

Arguably the most important new concept that Release 16 brings to the 5G scene is 5G NR-U — the emphasis being on the “U,” which refers to the unlicensed spectrum involved.

Back in April 2020, the Federal Communications Commission (FCC) was loudly praised by the wireless sector for making more spectrum available to the Wi-Fi world, by adopting updated rules for the 6GHz band and allocating 1,200 MHz for (unlicensed) Wi-Fi.

Now, with NR-U, the balance is restored and cellular network operators will also be able to utilize unlicensed spectrum to expand their coverage, for both public and private networks.

Release 16 defines two operational modes: standalone and a Licensed Assisted Access (LAA) deployment mode in the unlicensed 5 GHz and 6 GHz bands being set aside for that purpose. This is the first time that the 3GPP has defined a cellular technology for “standalone” use.

The mix will greatly expand 5G’s reach beyond traditional operators, including wireless ISPs, service providers, and operators of private 5G networks. So, in regions where it is already available, such as the U.S., NR-U will also be used to deploy services in the 6 GHz band.

Release 16 specifies 400MHz of unlicensed spectrum for downlink, and up to 100 MHz of that for the upward direction.

Image source: Qualcomm

While earlier versions already supported some aspects of cellular-vehicle-everything (C-V2X) communications for basic safety, the NR-U based Sidelink specified in Release 16 greatly extends C-V2X capabilities. It now supports advanced applications such as coordinated driving and sensor sharing, where the sensor data from one car can be readily communicated to another nearby vehicle.

These enhancements offer significant improvements in the form of higher throughput; lower latency; reliable multicast communications (which uses distance as a new dimension at the physical layer, enabling on-the-fly multicast groups based on distance and applications); distributed synchronization and unified QoS control.

Taken together, these are expected to enhance and speed the development of autonomous and semi-autonomous driving systems for both safety and efficiency. It should also spur governments around the world to certify car-to-car communications standards.

Power saving
5G devices across the board are expected to be more power hungry than those for previous generations, so power saving will be a crucial enhancement. Release 16 includes several novel power saving features including a new wake-up signal (WUS) format that can let the device know if and when a transmission is pending or allowing it to stay in low-power mode, skipping the next low-DRX (discontinuous reception and more efficient power control mechanisms.

Aligned to this, enhancements have also been specified for improved mobility. Important techniques to achieve reduced handover interruption times — and thus more efficient mobility performance — now include device-driven conditional handover; early measurement reporting; and dual-connectivity master cell group (MCG) failure recovery.

Reliability enhancements

Image source: Qualcomm

In an effort to address a wider range of vertical use cases, such as factory automation, ultra-reliable, low-latency communications (URLLC), Release 16 incorporates uprated specifications for reliability to 99.9999%, while retaining millisecond level latency.

This updated e-URLLC has been achieved by, among other innovations, improved re-transmission request capability; coordinated multi-point (CoMP) communications — which uses multiple transmission and reception points to create spatial diversity with redundant communication paths — and channel polarization when supporting multiple use cases for the same devices.

High Precision Monitoring

Image source: Qualcomm

Release 16 enhances the capabilities of cellular, when complementing Global Navigation Satellite Systems (GNSS), with a novel technology dubbed Positioning Reference Signal (PRS). Based on multi-/single –cell and device-based positioning, PRS relies on 5G positioning techniques such as round-trip time (RTT), angle of arrival/departure, and time difference of arrival (TDOA).

Qualcomm pushed very hard to get this included in Release 16, and much of the standard is based on its technology in this area.

RTT-based positioning does away with the need for very tight network timing synchronization across nodes (as necessary in legacy techniques such as TDOA) and offers extra flexibility in network deployment and maintenance.

Of course, emerging use cases, such as Industrial IoT (e.g. robotic systems in warehouses and factories) will always need ever more exact positioning accuracy, but this Release will meet requirements up to 3 meters indoors and 10-meter positioning outdoors.

Work is already under way to improve in these parameters, and Release 17 is expected to specify sub-meter accuracy for many IIoT use cases.

Integrated Access and Backhaul (IAB)

One of the major challenges to expanding 5G NR mm Wave network coverage is the cost of deploying extra mm Wave base stations, which requires new fiber optics and backhaul installations. The IAB specified in Release 16 allows a base station to provide both wireless access for devices and wireless backhaul connectivity. This densification eliminates the need for a wired backhaul, and thus allows operators to quickly and cost-effectively add new base stations dynamically, before having to incur the additional costs of laying fiber to increase backhaul capacity.

Deployment Models

Image source: Qualcomm

There are numerous enhancements, all of which were included to broaden the reach and thus expand the use cases for 5G networks.

An important one focuses on extended support for non-public networks and should prove a huge boost for the fast expanding private networks segment, as well as for IoT deployments.

Time-Sensitive Networking (TSN) is already widely used in the wired world, and Release 16 will open up more possibilities in particular for industrial applications.

Again, the focus is on improved latency, and the idea is to integrate TSN “over the top,” so that it will have minimal impact on the radio access network (RAN). The key is the way integration is achieved to ensure time-deterministic delivery of packets.

Release 16 specifies new and novel interference measurement techniques that allow robust deployments. This sets the stage for future dynamic TDD operation with base station to base station and mobile-to-mobile interference mitigation.

MIMO advances
Not surprisingly, a key underlying component of Release 16, and building on previous advances, is the enhancement of Massive MIMO to be able to offer improved performance and efficiency. One important element has been the additional support for multiple transmission and reception points (multi-TRP) and improved multi-beam management. Both advances will allow better link reliability — particularly important for millimeter-wave bands). The spec also mandates improvements in reference signals so as to reduce peak-to-average power ratios.

Release 16 also supports full-power uplink to improve coverage at the cell edge.

What Next
While Release 16 has been “frozen,” the usual procedure is for the numerous working groups to work on a corrections phase, a procedure that generally takes several weeks.

And if precedent is followed, as expected, we will likely see standard-compliant chipsets and subsystems being introduced over the next 12 to 18 months. Expect some early developers to be heralding availability within months. Vendors that have the expertise for adapting current designs are likely to be the ones leading the pack. Companies that have been participating most closely with the 3GPP Working Groups and inputting technologies for advancements in different areas will clearly have an advantage.

Features such as the NR-U and IAB — which as noted are expected to have the greatest impact on 5G rollouts, capabilities and uptake — are the ones likely to be commercialized the soonest. Some of the other enhancements, for instance TSN and Sidelink, will probably have longer gestation periods.

And, as already noted, new working groups are already assembled to work on Release 17. The restrictions on travel and face-to-face meetings are likely to slow progress.

Some of the more interesting enhancements the industry is seeking include novel ways for a wider range of devices — not just automobiles — and entirely new work items such as extended reality — a catch-all term for applications such as VR and AR. Other possibilities include the so-called NR-Lite, a version of New Radio capable of utilizing the 20MHz band, that could address the gaps in IoT coverage.


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