ETSI PRI-ETS 300 302-1-1994 综合业务数字网(ISDN).可视电话远程业务第1部分:使用脉冲编码调制(PCM)编码时手机功能的电声特性
Integrated Services Digital Network (ISDN); Videotelephony Teleservice Part 1: Electroacoustic Characteristics for Handset Telephony Function When Using Pulse Code Modulation (PCM) Encoding