Automatic surveillance network for telecommunication circuit 通信回线自动监视网
2.
Electrical coordination of primary and secondary surge protective devices for use in telecommunications circuits 用于电信电路的第一和第二电涌保护装置的电气协调
3.
Telecommunications - information interchange - structure for the identification of telecommunications circuits for the north american telecommunications system 电信.信息交换.用于北美电信系统的电信电路的识别用结构
