This blog is a repost from IWCE’s Urgent Communications, originally published on October 13, 2023.

This blog post is part of the "Tech Talk" series focused on the First Responder Network Authority’s (FirstNet Authority) standards development activities to support public safety. This post recaps discussions linked to public safety and other related topics from the 3GPP Plenary meetings that were conducted in September 2023. The FirstNet Authority represented public safety interests at the Plenary meetings.

The 3GPP Plenary meetings took place September 11-15, 2023, in Bangalore, India. The Technical Specification Group (TSG) reports below highlight continued progress on Release 18 (R18) features of interest for public safety, including steady development on the stage 3 protocol work, which is the last stage in 3GPP standards development.

The Plenary meetings included planning on Release 19 (R19) features, and the start of preliminary discussions for Release 20 (R20). The FirstNet Authority participated in R19 planning activities at this Plenary and submitted its preferences for R19 features. These discussions will continue through the December 2023 Plenary meetings, and we will report on R19’s final frozen topics in our next blog post.

The R19 planned December 2025 end date remains on track. 3GPP Releases 18 through 20 are the “5G Advanced” releases that build upon the 5G standards that were developed in Releases 15 through 17.

The Radio Access Network (RAN) Plenary

There were more than 350 in-person attendees at the TSG RAN September 2023 Plenary meeting. The RAN plenary is responsible for defining the requirements, functions, and interfaces of the 3GPP radio network.

The RAN physical-layer working group reported completing most of the R18 features relevant to public safety. Completed items include New Radio (NR)—a.k.a., 5G air interface—sidelink evolution; NR-non-terrestrial network or satellite (NTN) objectives, including network verified user equipment or mobile device (UE) location; expanded and improved NR positioning, enhanced support of reduced capability NR devices, NR Network-controlled Repeaters (NCR), and NR support for Uncrewed Aerial Vehicles (UAVs).

The Plenary approved a new feature proposed by FirstNet for High Power User Equipment (HPUE) Power Class 2 to add LTE Frequency Division Duplex Single Band 14 to R18. (Note: NR Power Class 2 was approved earlier this year.).

To ensure that the Specific Absorption Rate (SAR) regulation is not violated, R18 will include a UE-implementation-based method within the LTE framework. The HPUE Power Class 1 for Band 14 LTE and NR have been previously approved. Power Class 1 is more suitable for vehicle roof-mounted use cases. While the Power Class 2 is a slightly lower power HPUE, it will have a device form factor for uses, such as a hotspot router when taking SAR level concerns into consideration.

As discussed in our last blog, RAN Plenary has been discussing several topics for R19 to help enhance coverage for first responders. These topics include: Evolution of NTN; sidelink enhancements including specifying reference signals and procedures for beam management for higher frequency ranges; relay enhancements including multi-hop; enhancements to NCR; and Wireless Access Backhaul (WAB).

WAB is an enhanced version of a vehicle-mounted relay. WAB provides 5G access to onboard vehicles, planes, cruise ships, helicopters, and other vessels that could provide significant coverage enhancements for public safety.

Three additional topics are also being considered, which are broadcast/multicast work that will include a new capability to support even a larger number of UEs simultaneously; positioning enhancements to increase situational awareness; and UAV enhancements to improve drone use in public-safety incidents.

The freeze date for R19 work in TSG RAN is currently scheduled for September 2025, and the final completion date is planned for December 2025.

The Service and System Aspects (SA) Plenary

There were more than 240 in-person attendees at the TSG SA Plenary meeting. TSG SA is responsible for the overall architecture and service capabilities of 3GPP based systems. The group spent considerable time discussing R19 planning.

During the TSG SA R19 planning discussions, the plenary agreed on a set of initial features for R19 across all six of the SA working groups. This work requires coordination among RAN and SA working groups. We expect the final list of R19 features to be approved in the December 2023 plenary meetings.

If this list is included, several of these features will provide public safety with enhanced capabilities such as: architecture enhancements for extended reality and media (XRM) services; integration of satellite components in the 5G architecture; and enhanced mission-critical architecture. The XRM feature also will enhance user experience.

The integration of satellite components with the 5G core will improve availability and include support for public-safety features. Finally, the enhanced mission-critical architecture work will lead to future improvements in communication services for first responders.

As discussed in previous blogs, the SA1 working group typically works one release ahead of the other 3GPP working groups. SA1 continues its work to complete R19 requirements and is reporting overall progress at 90%, with planned completion by the December 2023 Plenary.

The plenary completed the study phase on integrated sensing and communications and 5G satellite enhancements. The specifications for these features are reported as 80% and 95% complete, respectively, with a completion targeted by the December 2023 Plenary. Integrated sensing uses 5G radio waves—much like radar—to sense the position and shape of objects, increasing situational awareness for the first responder.

SA1 has also started early discussions on R20 with a proposal to split the requirements development into two phases. The first phase will address the evolution of 5G Advanced, and the second phase may start to address 6G along with potential remaining 5G Advanced requirements.

The timeline for SA1 work is still under discussion. However, the proposal for the initial set of requirements is expected to be submitted to SA Plenary in June 2024, and the final set of requirements in the June/September 2025 timeframe.

As previously discussed, the SA2 working group declared that all stage 2 architecture technical specifications for R18 are 100% complete, including high-priority items for public safety.

During the September Plenary, SA2 reported that the working group only focused on change requests for maintenance and alignment with other working groups for completed R18 architecture specifications.

SA2 also reported its progress preparing potential R19 features. This work focused on finalizing the feature scope, work tasks, and time units required to complete each work task. SA2 prepared these features for the prioritization process mentioned above, expecting significant down-scoping for many of them.

The SA3 WG is responsible for security within the 3GPP network. The Plenary meeting reported that all R18 work has been completed. SA3 continues to progress work around enabling the 5G system to support use of cryptographic algorithms with 256-bit key sizes to provide enhanced security.

Most recently, an R19 work item has been approved for SA3 to document these 256-bit algorithms in 3GPP series technical specifications. This work is the first step to ensure 256-bit algorithms are ready when SA3 determines it is appropriate for the 5G system to support their use.

SA3 will host an R19 planning workshop virtually on Sept. 27-28, 2023, to prioritize and plan for R19 security-related features.

The SA6 working group agreed to several R19 features at the September Plenary meeting, including enhancements for mission-critical (MC) services and phase 3 of uncrewed aircraft systems, both of which are of interest to public safety.

We expect more features will be approved at the December Plenary, including sharing of administrative configurations between interconnected MC service systems; railway-specific enhancements to MC services, enhanced MC architecture; and a study on enhanced application-layer support for location services.

The Core Network and Terminals (CT) Plenary

There were more than 130 in-person attendees at the TSG CT Plenary meeting. The CT TSG covers the protocol details that follow the requirements and architectural work performed in the SA TSG. The CT plenary concentrated on advancing R18.

The R18 work continues to show solid progress for all aspects of the stage 3 protocol work. CT1 has several mission-critical features in progress, including MC over 5G multicast-broadcast (80% completed), MC protocol enhancements (50% completed), and ProSe phase 2 (85% completed).

These should be completed by the December 2023 Plenary meeting. Work recently began on MC gateway UE, and enhancements to MCPTT features will be completed by March 2024.

Further information on the 3GPP’s work and organization can be found at: www.3gpp.org.

Other contributors to this article: FirstNet Authority Senior Standards Engineers Jeff Cichonski, Mike Dolan, Ihab Guirguis, Mark Lipford, and Eshwar Pittampalli.