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Terms of Reference for Technical Committee (TC) Speech and multimedia Transmission Quality (STQ)

Revised at Board #114, September 2017


The main objectives of TC STQ standardization activities are:

  • Terminals and networks for speech and media quality,
  • Quality of Virtual Reality (VR) and Augmented Reality (AR) technologies and VR/VR based services,
  • End-to-end single media and multimedia transmission performance,
  • Voice Control and Internet of Things (IoT) – performance parameters and test methods,
  • Quality of Service (QoS) parameters and related measurement methodology for fixed and mobile networks and services, as well as respective Quality of Experience (QoE) descriptors and methods. 

The objective of TC STQ is to ensure the co-ordination, production (where appropriate) and maintenance of end-to-end quality related deliverables, for the timely and economic development of equipment for use with existing and future fixed and mobile network telecommunications service offerings. In addition, these deliverables facilitate the continuous quality assessment of the respective services.

Areas of activity

TC STQ forms the ‘horizontal’ technical nucleus for speech and multimedia transmission quality and therefore will not produce deliverables, where work is within the Terms of Reference of another ETSI TC. TC STQ is focusing work on the following main areas: Voice and Multimedia over IP (e.g. VoIP, VoLTE, ViLTE); excessive acoustic pressure and relevant measurement methods; wideband, super-wideband and fullband speech, including terminals, modelling and assessment; VR and AR technologies for speech, audio and multimedia; voice control in IoT and other applications including test procedures and test environment; user-oriented QoS and related QoE. The work of TC STQ covers applications and services where user perception, QoS and QoE are affected.

Specifically, TC STQ will monitor, contribute to and give guidance on:

  • the speech transmission characteristics of networks and terminals including acoustic interfaces and their requirements; 
  • the definitions for speech processing techniques (e.g. speech recognition, echo cancellation, coding); 
  • the impact on the transmission quality of speech processing devices, as defined above, implemented in networks and terminals; impacts and consequences of those equipment on the transmission quality of other types of signals; 
  • the specification of end-to-end speech transmission quality in fixed, mobile networks and interworking situations; 
  • QoS parameters and associated objectives for the elements and scenarios of multimedia services; 
  • the end-to-end (Network Termination Point (NTP)-to-NTP) Network Performance (NP) parameters and associated objectives necessary to support the elements of multimedia services in both public and private networks based on packet, circuit-switched and hybrid network technologies; 
  • the performance requirements of terminals intended to support multimedia services;
  • the performance requirements of terminals and networks intended to support VR/AR technologies;
  • the performance requirements of voice control e.g. in IoT; 
  • the definition of appropriate test methodologies and related test equipment requirements  for network performance measurements and QoS and QoE  testing from a users perspective (including considerations of encrypted media when necessary);
  • the validation of existing transmission rating models, maintaining existing or creating new deliverables as appropriate; 
  • the impact and limits of the individual transmission parameters (e.g. delay, echo, signals level and (background-) noise, coding impairments); 
  • the relations between signalling mechanism (e.g. echo cancellers are not being switched on or off) and transmission quality aspects;
  • the definition of application and user-centric quality of service (QoS) parameters, objectives and, measurement and monitoring methods; 
  • the definition of network-centric performance parameters, objectives and, measurement and monitoring methods necessary to meet the QoS objectives identified; 


TC STQ specifies the procedures for ETSI test events where appropriate, supports the organization of the event and publishes the results. TC STQ supports ETSI in the organization of workshops dealing with TC STQ topics in the areas QoS and QoE, Speech and Multimedia Quality, and any new topics relevant to STQ.

The working group on mobile services (STQ Mobile) is working on the Technical Specification on QoS aspects for popular services in mobile networks and related documents. 

TC STQ will work in close co-operation with all relevant TCs within ETSI and 3GPP. TC STQ will contribute to work relating to media performance, QoS and QoE within the ITU-T and other standards bodies.

The work area of TC STQ covers dedicated tasks which are of relevance to the European Regulatory Framework for electronic Communications Networks and Services. 

Annex (informative): collaboration with other bodies

TC STQ will set-up the appropriate communication channels to the following groups both within and outside of ETSI.

ETSI groups
  • TC HF
  • SC User Group 
External groups
  • 3GPP SA4
  • ITU-T SG12
  • ITU-T SG16
  • TIA TR.41
  • IEEE Communication Electroacoustics WG