Noise-tolerant address transmission system for digital telecommunication network

An address acknowledgment system for enabling a first line element interconnected to a first digital transmission line in a telecommunication network to communicate with a remote facility interconnected to said network, the digital transmission line carrying an incoming data stream and an outgoing data stream, and the line element defining an address, the system comprising, in combination:

• means for introducing into said outgoing data stream an inversion of said address;
• and
• means at said remote facility for receiving the inversion of said address and for interpreting the inversion of said address as an acknowledgement.

An improvement in a digital transmission line network having digital transmission lines interconnecting at least a first line element, a second line element and a remote facility, said first line element defining an address, said first line element arranged and configured to communicate said address along said transmission lines to said remote facility, said second line element being receptive and responsive to said address communicated along said transmission lines, said improvement comprising:

• means for inverting the address of said first line element and transmitting an inversion of said address along said transmission lines to said remote facility;
• and
• means for detecting and interpreting said inversion of said address at said remote facility.

A maintenance communication system for a line element interconnected to a digital transmission line, the digital transmission line carrying an incoming data stream and an outgoing data stream, and the line element defining an address, the system comprising, in combination:

• a repeater for receiving the incoming data stream along the digital transmission line and for passing a repeated data stream along the outgoing transmission line;
• and
• a first controller at said repeater for (i) detecting a maintenance code in the incoming data stream, and responsively (ii) inverting the address of said line element and (iii) introducing the inverted address of the line element into the outgoing data stream.

A method for enabling maintenance communication by a line element interconnected to a digital transmission line, said digital transmission line carrying a stream of coded data, said element defining an address, said method comprising the steps of:

• detecting a maintenance code;
• and
• introducing a responsive communication signal into said stream of coded data, said responsive communication signal comprising an inversion of said address.