Home / Standards / GB/T 12171-1990 GB/T 12171-1990 Abolished Specification for TDM/FDM 60-channeltransmultiplexing equipments used in the telecommunication network TDM/FDM 60路复用转换设备进网要求 Standard Type GBT ICS 33.040.40 CCS M14 Status 废止 Issue Date 1990-01-12 Implementation 1990-08-01 Responsible Dept 工业和信息化部（通信） Drafting Unit N/A