End-to-end Speech Quality

Speech transmission quality has been topical for the last decade because of two major changes in telecommunications.

First liberalization and competition have been changing the framework for telecommunications such that responsibilities for end-to-end speech transmission performance are no longer clear and it is no longer possible to use a single simple reference model for connections.

The ETSI technical committee STQ has worked to address these issues by using the E-model and by developing guidance on network design.

ETSI STQ originally developed the principle that the service provider or operator who charges the customer should be responsible for the transmission quality of the segment of the connection for which the charge is made. This principle has been accepted generally by regulators in Europe.

Work is continuing for the maintenance of the E-Model which has been adopted by the ITU-T as the principle tool for predicting voice quality.

Secondly the use of packet networks for voice services is raising important new issues such as call set-up time, echo control and cell loss which affects codecs. ETSI STQ and ETSI TISPAN are working actively on these issues.

ETSI is also involved in activities to harmonize the terminology and more recently the methodology for transmission planning for private and corporate networks. To achieve this there is collaboration with TR-41 committee of the Telecommunications Industry Association (TIA) of North America and the NATO defence community.

Download the Speech and multimedia Transmission Quality Technology leaflet

The ETSI technical committee STQ is centre of expertise in ETSI for Speech Transmission and Quality aspects.

ETSI technical committee for Telecoms & Internet converged Services & Protocols for Advanced Networks (TISPAN) is working actively with ETSI STQ on use of packet networks for voice services; call set-up time, echo control and cell loss which affect codecs.