Activity report 2018-2019

Technical Committee (TC) Terrestrial Trunked Radio and Critical Communications Evolution (TCCE)

Chairman: Brian Murgatroyd, P3 Communications GmbH

Responsible for the design and standardisation of TErrestrial Trunked RAdio (TETRA) and its evolution to critical communications mobile broadband solutions.

TETRA (Terrestrial Trunked Radio) is the leading technology choice for critical communications users. With a projected 5 million terminals in use by 2020, the use of TETRA in security as well as other business-critical markets such as the transportation, military, commercial and utilities sectors is forecast to grow by 15% annually up to 2023.

TETRA is designed to address a specific set of communication requirements. These include high reliability, single and group calling capabilities, PTT (Push-To-Talk), and the possibility for direct peer-to-peer communications in situations such as natural disasters and emergencies when the supporting network is unavailable. Accordingly, much of the work of our TETRA and Critical Communications Evolution committee (TC TCCE) is driven by the requirements of Public Protection and Disaster Relief and other mission-critical services.

In 2018 a number of standards and specifications were revised in response to feedback from manufacturers and users. These include the publication of 15 technical specification documents relating to interworking at the inter-system interface (ISI) between two TETRA systems. This work involved revising the original ISI European Standard to take account of the introduction of Internet Protocol (IP)-based networks, dividing the content into several new parts to produce a family of specifications for IP, circuit switched networks and transport layer-independent aspects. These technical standards have been converted into European Norms (ENs). These completed their public enquiry phase during the year, with publication scheduled in September 2019.

Designed as a narrowband system, TETRA today cannot support the growing demands of emergency services for additional Mission-Critical capabilities such as streaming high-quality video from the scene of an accident. Reflecting these evolving needs – and an opportunity to benefit from the economies of scale of the mobile broadband ecosystem – the community of TETRA users asked the Third Generation Partnership Project (3GPP™) to determine how this functionality can be realized using LTE™ or 5G systems running over public network operators’ licensed spectrum.

We continued to explore ‘hybrid’ methods to integrate TETRA into current broadband solutions. To optimize the standardization process, existing standards for technologies such as LTE and later 5G will be enhanced by interfaces and applications that make them suitable for Mission-Critical applications.

In response to feedback from 3GPP, we revised specifications covering the mobile-to-network interface architecture of a critical communications application operating over a broadband IP interface. Work also progressed on a specification for the mobile-to-infrastructure interface.

Work meanwhile continued on encapsulating TETRA speech coding, packet format and rate, end-to-end encryption synchronization and secure key management messaging for use in 3GPP Mission-Critical Push-To-Talk (MCPTT) over LTE systems.

Reflecting evolution of the public safety sector, in 2018 we renamed our Mission Critical Push To Talk (MCPTT) testing programme as the MCX testing programme, embracing Talk, Data and Video. 

Look out for in 2019 – TC TCCE work in progress:

  • Revision to Harmonised Standard (EN) on Voice plus Data (V+D) (Part 9: General requirements for supplementary services)
  • Revision to EN on Voice plus Data (V+D) (Part 7: Security)
  • Revision to EN on Voice plus Data (V+D); (Part 3: Interworking at the Inter-System Interface (ISI)) - various sub-parts
  • Revision to Technical Specification (TS) on Voice plus Data (V+D); Part 2: Air Interface (AI), with improvements for group addressed packet data for pi/4 DQPSK and QAM applications
  • TS on Voice plus Data (V+D); Part 19: Interworking between TETRA and Broadband systems (Sub-part 1: Critical Communications Architecture for Interworking between TETRA and broadband applications)
  • EN on TETRA radio equipment using non-constant envelope modulation operating in a channel bandwidth of 25 kHz, 50 kHz, 100 kHz or 150 kHz; covering essential requirements of article 3.2 of the Directive 2014/53/EU