URLLC

by Yigang Cai, PhD

Introduction:

On July 3, 2020, 3GPP (the organization that generates all the specifications for cellular networks) announced that its Release 16 (R16) specification was frozen, and thereby declared the completion of the first evolution of “5G New Radio (NR).” As 3GPP’s specs have “no official standing,” they must be transposed by SDOs, like ITU, ETSI, ATIS, TSDSI (India), etc. The international standard for 5G Radio aspects is known as IMT 2020.specs, which includes the Radio Interface Technology (RIT) and Set of Radio Interface Technologies (SRIT) from various proponents, including 3GPP (IMT-2020/14, and /IMT-2020/13, respectively).

3GPP R16 is the first technical specification in the history of 3GPP that was reviewed and finalized through an e-meeting (due to the COVID-19 travel and meeting restrictions). The declared R16 completion was the result of collaboration and coordination amongst many global companies, government agencies and telecom regulators.

From the 3GPP website: “Rel-16 is now officially Frozen. Rel-15 and Rel-16 constitute the basis for 5G and this is a great achievement and recommended that delegates hold a personal celebration for this.”

The complete R16 spec not only enhances the functions of 5G, but also allows 5G to enter a new digital ecosystem. It takes into account factors such as cost and efficiency, so that the basic investment in wireless communications infrastructure can play a greater role and further help the digital transformation of the social economy. Let’s examine 3GPP’s 5G NR in the context of R15 and R16:

“5G NR” in R15 was frozen in 2018. It strived to produce a “usable” specification for Physical (PHY) layer transmit/receive in 5G trials/pilots and early (pre-IMT 2020 standard) 5G networks.
In contrast, “5G NR” in R16 will achieve an “easy to use” and more robust 5G transmit/receive capability.
3GPP R16 is a major release for the project as noted in an earlier IEEE Techblog post. It brings the specification organization’s ITU-R WP 5D submission “IMT-2020 Radio Interface Technology/Set of Radio Interface Technologies (RIT/SRIT)” to a more complete 5G system; what 3GPP calls “5G Phase 2.”

3GPP R16 is supposed to enhance Ultra-Reliable (UR) Low Latency Communications (URLLC), support V2V (vehicle-to-vehicle) and V2I (vehicle-to-roadside unit) direct connection communications, and support 5GS Enhanced Vertical and LAN Services as reported in the earlier IEEE Techblog article. Please refer to References below for further information.

URLLC is 1 of 3 use cases for 5G/IMT 2020. It is intended for mission critical, precise, accurate, always ON/never down, real time communications that require low latency in the 5G access and core networks.

SOURCE: 3GPP

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Editor’s Note: ONLY the 3GPP “5G Radio Aspects” are included in the forthcoming ITU-R IMT 2020.SPEC (RIT/SRIT) recommendation, which is expected to be approved in late November 2020 by ITU-R SG D. All the non-radio aspects, such as 5G Core Network, network slicing, network management, privacy and security, etc. will NOT be part of IMT 2020. However, those declared R16 completed work items are likely to be transposed by ETSI into international standards.

From 3GPP: “5G non-radio specs in R16 are handled by 3GPP Working Groups. None of the work is done in the SDOs – 3GPP does all of the work. See the 3GPP Work Plan at to see how the work is split between groups.”

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Perspective on 5G Standard Essential Patents (SEPs):

The announcement of the 3GPP R16 freeze also means the “War of SEPs (Standard Essential Patents [1.]),” i.e. those patents that are related to 5G NR standards/specifications might come to the end of a critical stage. However, it’s likely that a new SEP war will start soon. But that is a subject for another day.

Note 1. A standard essential patent (SEP) is a patent that claims an invention that must be used to comply with a technical standard or specification to be standardized by an accredited standards development organization (SDO).

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During 5G NR specification development, industries and companies have competed in a 5G patent race and generated thousands of SEPs. A recent study, published in the IEEE Techblog, found that Huawei was the undisputed leader in 5G SEPs. Some companies tried to convince the world they are leading the SEP war. However, the news and hype about published SEPs has often misled the public.

From this author’s standards and patent experiences, there are some facts of 5G SEPs which have been neglected in the SEP war:

There is no one-to-one mapping between declared SEP and 5G standards feature. In fact, one standards contribution (e.g., WID, CR, WF or others in 3GPP) may be declared with one or multiple SEPs, or one SEP is declared in multiple contributions. SEP number declared does not match standards features.
Many of SEP relevant standards contributions are not taken or baselined by standards bodies in standards specifications. Someone can do statistics what percentages (overall and/or per contributing company) of SEP relevant standards are agreed or approved in standards bodies.
Some declared SEPs, including filed and published patents, may not be granted, or may even be rejected, after standards contributions are baselined.
One standards contribution may be co-authored/co-signed with multiple companies, it is very likely multiple companies filed multiple patents for the same standards contribution.

There is no doubt SEPs can accelerate 5G standards development and enhance standards feature quality. But, the war of SEPs also brings some confusions in 5G technology development, implementation, deployment and applications.

First of all, the patent war lead to industries creating numerous patents which actually may not be “essential.” We all understand that a considerable percentage of those patents have no real value, i.e. they are not implementable or deployable and so not at all profitable.

Companies try to earn IPR revenues from SEPs and spend enormous efforts and finances focusing on creation of SEPs (for example, giving over the half of total IPR budget to SEP generation) because they probably believe licensing of granted SEPs can bring IPR revenue much quick. However, simple number of declared SEPs is much less important than innovation of critical 5G features and functions.

The 5G SEP war we have recently experienced concentrates on patent number; not patent quality. In fact, a feature critical invention can be much better and heavier than dozens of banal and non-essential SEPs which have been seen almost every aspect.

Conclusions:

Industry success relies on innovations, such as technique innovation, cultural innovation, and business innovation. There is no single high-tech company that has succeeded by starting numerous DEPs. Relying on licensing of granted patents cannot produce a great company. It does not mean patent productivities not important. Inventions in 5G should create more useful and reliable features, products, applications and capability to meet commerce and consumer needs (unfortunately, we have not seen many consumer-related 5G features so far).

5G and “5G Beyond” or “6G” (?) SEPs can strive for implementable and economic inventions, including investment and cost saving, energy saving and green communications. Innovations should drive ecosystem end-to-end solutions and use cases. Currently there are hundreds of 5G use cases that have been identified. Unfortunately, many of them (like the IoT use cases) can also be realized by existing 4G/LTE or enhanced WiFi.

Closing Note on URLLC (Ultra Reliable, ultra Low latency Communications):

URLLC is one of three use cases defined by ITU for the IMT 2020 standard and “5G” networks worldwide. It is included for both the 5G RAN and 5G Core Network in 3GPP Release 16. From a 3GPP report on URLLC:

“New 3GPP R16 URLCC use cases with higher requirements include: Factory automation Transport Industry, including the remote driving use case, and Electrical Power Distribution. A 3GPP “Study on Physical layer enhancements for NR ultra-reliable and low latency communication (URLLC)” concludes that it is beneficial to support a set of enhancements to URLLC, and further establishes detailed recommendations as given in Section 9.2 in TR 38.824.”

However, URLLC 5G NR enhancements for the RAN is currently only 53% complete (as per the 3GPP Work Plan for Release 16). That’s because no performance testing has been done yet to validate if the URLLC enhancement to 5G NR will meet 3GPP’s targeted performance requirements. We have been told by 3GPP marketing manager Kevin Flynn that such URLLC performance testing will be completed in three to six months, however there is no official 3GPP target completion date set at the time this article was published (July 10, 2020).

For URLLC to be successful, we first need standardized URLLC requirements (such as 1 millisecond synchronization accuracy, 0.5-to-1 millisecond air interface (in the RAN) latency, <5 milliseconds end-to-end latency (including the 5G Core Network), and six 9’s reliability) to be achieved on paper as clearly specified 5G NR enhancements. Then the performance parameters must be verified/validated in duplicable performance tests (by independent testing agencies) and reliably implemented in both 5G endpoint and network products. Only then can new 5G system and use cases (e.g. mission critical and/or low latency applications. autonomous vehicles, etc) achieve economic benefits and gains.

Along with the IEEE Techblog Editorial Team, I’ve been carefully researching and studying all aspects of URLLC in 3GPP Release 16 and hope to provide you with a co-authored article which will provide more clarity on that topic. Stay tuned!

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About Yigang Cai:

Yigang Cai, PhD is an IEEE Fellow (2018) and former Senior Research Scientist at Bell Labs. As a long time IEEE volunteer, Yigang served as IEEE ComSoc director of North American Region (NAR) (2012-2013), ComSoc global coordinator of Distinguished Lecturer Tour (DLT) (2010-2011), and ComSoc Chicago chapter chairman (2003-2006).

Dr. Cai is one of most prolific telecommunications industry inventors. He received the Bell Labs Inventor Award three times (2008, 2010 and 2011), and was honored with a first-ever lifetime Alcatel-Lucent “Distinguished Inventor Award” (2013) with his inventive accomplishments and patent contributions throughout his career with the company. Yigang has filed a total of 1000+ patents globally, of which 665 are granted patents (including 193 U.S. granted patents).

Many of his inventions in wireless networks have been built into products and systems of 2G/3G/4G and 5G, and deployed worldwide. He is one of the pioneers and leaders in developing the principles and components of Machine Type Communications (MTC). Dr. Cai generated many 5G inventions, including 5G New Radio (NR), 5G end-to-end architectures and use cases (both Access Networks and Core Networks), Network Slicing, MEC, 5G Machine Type Communications (MTC), and Device-to-Device Communications.

Yigang worked with Verizon Wireless to incorporate his work on Core Network MTC architecture, into 3GPP specifications. He was the first inventor in the area of radio interface physical resource sharing [between LTE and eMTC (Category M, or CatM)]. Dr. Cai filed dozens of patents related to that subject matter. Feature software with those pending patents were developed and delivered to Verizon (2016) and AT&T networks in 2017 (over 40,000 base stations), and twenty some other operators worldwide.

Together with ComSocSCV Chair Emeritus Alan J Weissberger, Yigang published an IEEE Global Communications Newsletter (GCN) article on Substantial Progress in ComSoc North American Region which appeared in the December 2013 issue of IEEE Communications magazine.

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Editor’s Addendum : 3GPP R16 5G work items related to IMT 2020.specs and 5G Non-Radio Aspects:

The two ATIS contributions from 3GPP on the latter’s IMT 2020 RIT/SRIT (based on 3GPP documents PCG45_07 and PCG45_08), were submitted to ITU-R WP5D on 21 May 2020. They were discussed and accepted at the 5D meeting which ended 9 July 2020. There were no other 3GPP/ATIS contributions related to IMT 2020 at that 5D meeting, which was the deadline for submission of material for inclusion in ITU-R Rec. M.[IMT 2020.SPECS].

Therefore, we do not know what the disposition will be of any other 5G radio related work items in 3GPP R16 that were completed after 21 May 2020. In particular, the state of 3GPP’s 5GNR enhancements for URLLC.

We understand that the 5G NON-RADIO aspects of R16, e.g. 5G architecture, 5G core, network slicing, network management, security, etc. will NOT be sent to ITU-T. Rather, they will likely be transposed and standardized by ETSI.

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References:

https://techblog.comsoc.org/2020/03/25/3gpp-delays-release-16-and-17-by-3-months/
https://techblog.comsoc.org/2019/10/06/3gpp-release-16-update-5g-phase-2-including-urllc-to-be-completed-in-june-2020/
https://techblog.comsoc.org/2020/03/24/5g-patent-war-are-nokias-3000-5g-patent-declarations-legit/
https://techblog.comsoc.org/2020/06/24/greyb-study-huawei-undisputed-leader-in-5g-standard-essential-patents-seps/
https://www.nokia.com/about-us/news/releases/2020/03/24/nokia-announces-over-3000-5g-patent-declarations/
https://telecoms.com/503274/5g-patent-chest-beating-is-an-unhelpful-distraction/
https://www.wsj.com/articles/qualcomm-5g-security-and-patent-wars-11576096074
https://www.statista.com/chart/20095/companies-with-most-5g-patent-families-and-patent-families-applications/
https://www.iplytics.com/wp-content/uploads/2020/02/5G-patent-study_TU-Berlin_IPlytics-2020.pdf
https://www.ericsson.com/en/blog/2019/10/5g-patent-leadership
https://www.kidonip.com/news/iplytics-patent-counting-fallacy/
https://www.epo.org/news-events/news/2020/20200312.html