ETSI ES 202 738-2017 语音和多媒体传输质量(STQ);用户从QoS角度感知到的窄带VoIP扬声器和免提终端的传输要求(V1.6.1)
Speech and multimedia Transmission Quality (STQ); Transmission requirements for narrowband VoIP loudspeaking and handsfree terminals from a QoS perspective as perceived by the user (V1.7.1)