CCT: Can you discuss the enhancements and features that mission-critical users can expect to see in Releases 16 and 17? Which do you feel will have the most positive impact?
EG: We can see incremental progress of mission-critical features in Release 16 and Release 17. A notable and important feature is the support for group re-grouping and broadcast group calls for MCPTT, and the support for conversation history and content server for MCData. A key consideration will be the support of mission-critical services over 5G, which is expected to be ready within Release 17.
CCT: What are your thoughts on the potential to augment ProSe (both in terms of its capabilities and the size of its potential market) with the work on V2X that has/is taking place in Releases 14, 15 and 16?
EG: There is work currently to develop the ‘New Radio (NR) sidelink’ in the framework of the RAN Study on NR V2X (Vehicle to Everything). While this study focuses specifically on V2X use-cases at this point, there is a clear overall goal of developing general Proximity Services for 5G. A system-level study in SA2 (the architecture) working group will likely bear fruit in the Release 17 timeframe (that is, the study will likely begin in the course of 2019).
CCT: Since our previous article on this topic in early 2018, how has the work to enable LMR/LTE interworking progressed and are there any remaining challenges?
EG: The LMR/LTE work has been progressing quite well. The first version of the architecture specification was concluded in early 2018, and the detailed protocol specifications are being worked through, and these are expected to be completed in June 2019. Work on the second version of the architecture is ongoing mainly to align with new features that were introduced in MCPTT, eg, functional alias, talker location, etc.
The 3GPP specifications provide support between mission-critical systems and the interworking function which acts as the gateway to TETRA and P25 systems. Therefore there is no dependency for 3GPP and no need to wait for other organisations to make progress. However, for the complete interworking solution to be deployed, it is essential that the interfaces between the interworking function and the LMR systems are defined. This work would be undertaken by organisations outside of 3GPP, eg, in the realm of the Alliance for Telecommunications Industry Solutions (ATIS) and ETSI TCCE.
CCT: In our previous article, you mentioned that the tight pairing between MC Services and LTE was removed in Release 15, but “none of the implications of that decision have been investigated” – has this changed?
EG: SA6 has begun a study of implications and opportunities presented by 5G for Mission Critical Services. There has not been a lot of rapid progress because there are several fundamental service enablers that the Enhanced Packet System (EPS) supports and the 5G system will have to add. Of primary relevance to Mission Critical Services are Proximity Services, MBMS (Multimedia Broadcast/Multicast Service) support and evolution of the IMS architecture to work optimally in the 5G environment. These studies will progress in the Release 17 timeframe, though some enhancement to IMS might be included in Release 16.
An aside on the importance of enablers: The 3GPP system offers many functions and components upon which services can be based. Mission Critical Services in 3GPP make extensive use of the Internet Protocol Multimedia Subsystem (IMS), MBMS, Proximity Services and Group Communication System Enablers for LTE.
These enablers are tightly coupled to the 4G Enhanced Packet Core to deliver optimised services. It will take time to provide these enablers for the 5G core network. This work has already begun.
CCT: During the 3GPP plenary meetings in September, a new study item for SA6 (mission-critical applications) on “location enhancements for Mission Critical Services” was approved. What is this expected to deliver and how will it benefit mission-critical organisations?
EG: Mission-critical service requirements in technical specifications 22.179, 22.280, 22.281 and 22.282 were defined in Releases 13 and 14. In 3GPP, requirements correspond to work that is done on the architecture (the interactions between functional entities over time, including their state, configuration, policies, etc). These architectural specifications are then defined as protocols, behaviour definitions (eg, timers and states), all based upon standardised encodings (eg, citing Internet Engineering Task Force Remote Function Calls). The requirements defined in Releases 13 and 14 have mostly been satisfied by architecture and protocol specifications in Releases 13, 14 and 15. These requirements are also iteratively enhanced. These ‘still to be fulfilled requirements’ motivate and guide the continuing process of enhancement of Mission Critical Services in 3GPP.
Some of the requirements related to mission-critical location information were not supported in past releases.
This study concerns location enhancements for Mission Critical Services supported over the EPS. A separate study considers what is needed to support this over the 5G System (5GS). The study has begun to investigate enriching the information present in location information reports, including location history reporting and how it is triggered. Several use-cases and key issues have been identified for these areas, and the study is expected to conclude in June 2019.
CCT: What were the major developments that took place at the recent SA6 meeting in Kochi?
EG: Steady progress was made, advancing the Release 16 activities. Substantial progress was made on the FRMCS2 study (Railways), which is expected to conclude at the Montreal meeting (25 February-1 March). We also expect to conclude work on the MC Services access aspects (MCSAA) study and the normative specification for MBMS MC APIs. Besides mission-critical features, SA6 has progressed work on V2X and SEAL (common architecture for 3GPP vertical applications).
CCT: What will SA6 be looking to focus on at its next few meetings?
EG: In the next few meetings, SA6 will focus on finalising Release 16 functionality for all of the mission-critical enhancements, ie, MCPTT, MCData, MCVideo and Interworking, and well as making progress on the key studies such as MC over 5GS, location enhancements and support for discreet listening and logging, and the completion of architecture specification for future railway communication that is based on the common mission-critical functional architecture.
CCT: Turning to the work that has been going on in 3GPP outside of SA6, is there anything that you feel has interesting implications for the mission-critical community?
EG: With the completion of the 5G Phase 1 standard, there is a strong emphasis within 3GPP to support new vertical industries and related technologies. Some examples of this work are V2X and Unmanned Aerial Systems (UAS).
These new technologies can beneficially complement the mission-critical community’s operations, eg, the use of drones for surveillance, and support for advanced vehicle communications using 3GPP technologies.
CCT: You have previously highlighted the need for greater engagement/participation from vendors and end-users within 3GPP. Is that still an issue? If it no longer is, has anything replaced it as a concern?
TP: Work progress in 3GPP depends upon the efforts of committed organisations – including end-user agencies, vendors and other interested parties. These parties have come together successfully to complete each past release. I do not believe this is a matter for concern, rather one must be realistic and acknowledge that progress made arises from the resources committed to do the work.
In TSG SA, we are happy to note that new members have joined our efforts, such as BDBOS (Germany) and Suomen Virveverkko Oy (Finland), and this increased participation is certainly very useful.
Erik Guttman CV
Samsung Electronics’ Erik Guttman has been actively involved in networking and telecommunications standardisation for more than 20 years. He is the chairman of the 3GPP Service and System Aspects Technical Specification Group. Before this, he held the position of chairman of the 3GPP System Architecture working group for two terms. He has also chaired and contributed to numerous IETF working groups, including SRVLOC (Service Location Protocol) and ZEROCONF (Zero Configuration Networking).
Guttman has led advanced development teams, implementing emerging standards to launch new products. His current interest is emerging standards efforts in 3GPP to develop the potential of the ‘vertical’ business sectors that are becoming active in telecommunications standardisation.
