Access and terminals (AT) - Analogue access to the Public Switched Telephone Network (PSTN); Protocol over the local loop for display and related services; Terminal Equipment requirements - Part 1: On-hook data transmission (Endorsement of the English version EN 300778-1 V 1.2.1 (2001-05) as German Standard)
接入和终端(AT)-公共交换电话网(PSTN)的模拟接入;用于显示和相关服务的本地环路协议;终端设备要求第1部分:挂机数据传输