铁路人工话务系统设备技术要求和试验方法
The specification and test methods for manual telephone system for railway
2005-03-29
YD/T 1004-1999
多路电话计费系统技术要求及测试方法
Technical specifications and test methods of multi-port telephone accounting system
GB/T 5443-1985
电话自动交换网铃流和信号音技术指标测试方法
The test methods for the technical specifications of ringing and tone for automatic telephone switchingnetwork
1985-10-30
TB/T 2355-2005
铁路区间电话通话柱技术要求和试验方法
The specification and test methods of communication column for railway track-side telephone
2005-03-29
GB/T 5444-1985
电话自动交换网用户信号技术指标测试方法
The test methods for the technical specifications of subscriber line signalling for automatic telephone switching network
1985-10-30
GB/T 3971.3-1983
电话自动交换网多频记发器信号技术指标测试方法
The test methods for the technical specifications of multi-frequency register signalling for telephone auto-matic switching network