Home / Standards / GB/T 5442-1985 GB/T 5442-1985 Abolished The test methods for the technical specifications of inband pulsing single frequency line signalling system for automatic telephone switching network 电话自动交换网带内单频脉冲线路信号技术指标测试方法 Standard Type GBT ICS 33.040.30 CCS M15 Status 废止 Issue Date 1985-10-30 Implementation 1986-06-01 Responsible Dept 工业和信息化部（通信） Drafting Unit 工业和信息化部（通信）