26.1313GPPRelease 18RequirementsTerminal acoustic characteristics for telephonyTS
The present document specifies minimum performance requirements for the electro-acoustic characteristics of 3G, LTE, NR and WLAN terminals when used to provide narrowband, wideband, super-wideband or fullband telephony.
The objective for narrowband services is to reach a quality as close as possible to ITU-T standards for PSTN circuits. However, due to technical and economic factors, there cannot be full compliance with the general characteristics of international telephone connections and circuits recommended by the ITU-T.
The performance requirements are specified in the main body of the text; the test methods and considerations are described in TS 26.132.