Mission Critical Services Standards: Advancing Critical Communications Across Industries

Aug 31. 2021
  • Suresh Chitturi

    Senior Director, Samsung Research-Bangalore and 3GPP SA6 Chair

Mission Critical (MCX) services refer to broadband critical communications applications and the underlying infrastructure that supports public protection and disaster relief management. Public Safety (PS) agencies around the world, specifically first-responders such as police, firefighters, and medical services, rely on critical communications to respond to emergencies, with stringent requirements to ensure a responsive, robust, and secure network for their successful operations.


While traditional narrow-band Land Mobile Radio (LMR) technologies such as TETRA and P25 systems have been capable of meeting push-to-talk (PTT) voice requirements, they are unable to meet the fast-changing needs of critical communications infrastructure. These include demands for interoperability across diverse public safety networks, support for multimedia capabilities, and other emerging communication paradigms. As a result, PS agencies around the world have turned their attention to mobile broadband technologies such as 4G and 5G for the future of critical communications.


In order to meet the expectations of PS agencies, a technical body responsible for 4G and 5G standards—the 3rd Generation Partnership Project (3GPP)—became a home for global MCX services standards. MCX services standardization was initiated in 2013 through the creation of a new working group, System Architecture WG6 - SA6, with the responsibility to define, develop, and maintain the technical specifications for MCX services standards including Mission Critical Push-To-Talk (MCPTT), Mission Critical Data (MCData), and Mission Critical Video (MCVideo) services.


The first global MCPTT standard was published in 2016 (Rel-13) and has continued to evolve with 3GPP, through service enhancements in Releases 14, 15, 16, and 17. The success of these 3GPP-based MCX services standards have formed the basis for global commercial rollouts of nationwide broadband critical communication deployments in many leading markets such as Korea, the United Kingdom, and the United States.


But while the initial focus of MCX services is public safety, there is significant interest in deploying MCX-based services for other vertical industries that require mission-critical communications, such as railways, maritime, aviation, and any industry that requires critical communications with stringent requirements. Today, I’ll highlight the increasingly important role next-generation MCX solutions play across several industries, starting with an essential element in ensuring its swift and strategic deployment: standards development.

Samsung’s Role in MCX Services Standards


While Samsung’s advancements in mobile devices and 5G networks, are well known, Samsung has also been at the forefront of MCX services standards development since the inception of MCX with 3GPP. Also, the company is proud to be elected consecutively as the 3GPP SA6 Chairman position since 2018. Additionally, Samsung’s delegates have contributed significantly to various technical standards, including Rapporteur roles in the development of MCPTT, MCData and D2D (Device-to-Device) specifications. The company is actively engaged in the MCX evolution through its leadership in MCX services standards, and continues to build on its reputation as a trusted industry partner in large scale commercial deployments for public safety networks and device solutions across several regions, including Korea.

Evolution of 3GPP MCX Services Standards


The evolution of 3GPP MCX application features occurred from Release 13 until Release 16 with the support of key services, mainly MCPTT, MCData and MCVideo. Further evolution occurred through interworking with legacy systems and by expanding to other verticals that rely on critical communications, such as Railways. Below is a timeline of the evolution of these services, along with further details on the impact each service has made on the public services arena: 



Introduced with Release 13, MCPTT service supports voice communication services between a pair of users or a group of several users, with features such as group, private calls, and advanced call capabilities, including audio cut-in and first-to-answer calls. In addition to providing communications within pre-defined groups, MCPTT service also enables administrators to merge multiple groups or users in real-time for effective handling of incidents reported. 



Introduced in Release-14, MCData service offers messaging, file distribution, and data streaming functionalities, which enables public safety users to have a more sophisticated experience. By using MCData service, first responders can share pre-configured command messages, and instantaneously report pictures and videos of the reported incident to the control room, which helps in increased situational awareness and better decision-making among dispatchers. 



Also introduced in Release 14, MCVideo enables public safety users to leverage video communications capabilities, including group and private video calls. MCVideo service supports live streaming of video, which aids dispatchers in making accurate decisions for better handling of situations. It allows users to mark their video communications as “emergency” to elevate the priority of the communication. Additional functionalities such as video-pull and video-push enable dispatchers and first-responders to remotely retrieve and share videos from peer devices, providing real-time access to visual information.



With the railway industry’s legacy Global System for Mobile- Rail (GSM-R) technology—which is set to be retired in 2030—there was an essential need for evolution in this space. So the Future Railway Mobile Communication System (FRMCS) Functional Working Group (FWG) of the International Union of Railways (UIC) partnered with 3GPP to standardize the next-generation railway communication system.


While many of the basic MCX capabilities can readily serve UIC requirements, 3GPP introduced new service capabilities in Release 15, such as multi-talker, functional alias to support multiple roles, and call forwarding capabilities specifically designed for railway communications. Support for service migration from GSM-R rail systems and gateway devices to FRMCS rail systems and gateway devices is expected to be completed in Release 18, offering a complete system for the deployment of next-generation railway communications.

Interworking with Legacy Systems


LMR systems such as TETRA and P25 are widely deployed by public safety agencies across the globe. These narrow-band systems have been used for more than two decades. Therefore, replacing the legacy technology with 3GPP-based MCX services standards is a process that may take a few years in some settings (e.g. due to long-term contracts). Under these conditions, legacy systems continue to exist, and therefore standards-based interoperability between LMR and MCX systems is considered a key feature by many public safety agencies. Deploying standards-based interworking solutions would ease the transition from legacy to modern technology and reduce costs.3GPP completed the standardization of interworking with LMR systems as part of Release 16, providing a framework for the basic functionalities required for interworking of MCPTT and MCData services with legacy LMR systems. From an architecture standpoint, the Interworking function along with legacy system will appear as a peer interconnected MCX system.

Going Forward: Next-Generation 5G Capabilities for MCX Services


With the next-generation of MCX now becoming embedded within a range of industries, businesses are now preparing for the next wave of what is possible through 5G. Advancements in 5G technology coupled with future Releases of 3GPP-based application features, will deliver new benefits to the critical communications industry. Simply put, the high speed and ultra-reliable connectivity with extremely low latency will enable MCX services to be more sophisticated, reliable and smarter.


This means massive machine-type communications will now be possible for scaling the deployment of Internet of Things (IoT) devices, enabling first responders to make better and timely decisions during emergency situations. 5G also increases coverage for both macro cells and D2D/Sidelink communications. Below are some of the key 5G capabilities which provide enriched experience to MCX services.

▷  5G System (5GS) QoS Model: It is based on the new concept of Quality of Service (QoS) flow, where a flow is the finest granularity of QoS differentiation. Different QoS flows may belong to a single bearer.


▷  Network Slicing: It creates logically independent virtual networks within the same physical network which can be used for distinct applications with specific requirements.


▷  5G Multicast-Broadcast Services (5MBS): 5G system is further enhanced to provide an efficient solution to simultaneously share the data of a group of end points.


▷  Sidelink communication: The D2D/Sidelink communication capability in 5G enhances the coverage with advanced relay mechanisms including both UE-to-network relay for extending network coverage and UE-to-UE relay for extending sidelink communication coverage.


5G standardization has progressed significantly since its first release from 3GPP Release-15. While initial MCX services standards are 4G-based, there is interest in the industry to enhance existing MCX services standards to leverage 5G capabilities to the fullest potential. Architectural enhancements to support MCX services over 5G are being fast tracked and expected to be completed in a phased manner in Release 17 and 18. 

Advancing Critical Communications Industry


The 3GPP-based MCX services standards initiative has become the gold standard for the global critical communications industry. It is backed by successful nationwide deployments in the United States and Korea. Samsung is proud to be the leading partner in powering 3GPP-based deployments around the world and continues to engage with several countries.


About Samsung’s MCX solutions:
Samsung has been a leader in MCX technologies to advance and enhance public safety. With the company’s complete line-up of mission critical solutions, first responders are able to assess critical situations more accurately and swiftly. Since 2017, our solutions have been commercially deployed across six different railway lines as part of Korea’s LTE-Railway (LTE-R) network, providing communications for station staff and train crews (Link). Recently, Samsung's Mission Critical Push-to-Talk (MCPTT) solutions, based on 3GPP standards, commercially launched in Korea, empowering first responders with a nationwide public safety LTE (PS-LTE) network (Link) that fully integrates with the existing LTE-R and LTE-Maritime (LTE-M) networks. 


With our strong technical leadership in MCX services standards from 4G to 5G, and end-to-end solutions, we will continue to expand our expertise to meet the growing needs of the critical communications industry, including public safety, railway communications, maritime, utilities, airports, and more. 



1.    3GPP TS 23.379: Functional architecture to support Mission Critical Push To Talk (MCPTT);

2.    3GPP TS 23.281: Functional architecture to support Mission Critical Video (MCVideo);

3.    3GPP TS 23.282: Functional architecture to support Mission Critical Data (MCData);

4.    3GPP TS 23.283: Mission Critical Communication Interworking with Land Mobile Radio Systems.

5.    3GPP TS 23.289: “Mission critical services using 5GS”

6.    3GPP TS 23.247: “Architectural enhancements for 5G multicast-broadcast services”.

7.    3GPP TS 23.304: “Proximity based Services (ProSe) in the 5G System (5GS)”

8.    Samsung Powers World’s First 3GPP-Compliant Nationwide Public Safety Network With MCPTT Service in Korea

9.    Expanding to Serve: FirstNet Surpasses 2.71 Million Square Miles Supporting More Than 2 Million Connections

Acknowledgements: The author would like to acknowledge the contributions from Arunprasath Ramamoorthy, Basavaraj Pattan, Wuk Kim, and Sangsoo Jeong, and the entire Samsung MCX-standards team.