Telephone line repeater and method of testing same

In a telephone line network of the type having a set of repeaters connected on first and second sides of the line network between central offices of the network, the improvement comprising:

• a transmitter for transmitting a interrogating signal on a first side of the line network, the interrogating signal being a digital, in-band, signal including a constant-length address field having a plurality of subfields including at least one unique subfield thereof corresponding to each repeater included in the set of repeaters, wherein for a repeater in the set to be interrogated, its corresponding subfield is configured according to a predetermined interrogate select convention;
• signal recognizer provided in the repeaters included in the network for examining the interrogating signal, whereby each examining repeater determines if it is the repeater to be interrogated;
• and,
• a controller provided in the repeaters for changing, in the address field, a position of at least one of the subfields and for causing the repeater which determines that it is the repeater to be interrogated to transmit test-indicative information on a second side of the line network.

A telephone line repeater comprising:

• a regenerator for regenerating an input signal on a first side of a telephone line network;
• means for applying an output signal to the second side of the network;
• a signal recognizer for recognizing, in the regenerated input signal on the first side of the network, an interrogating signal, the interrogating signal being a digital, in-band, signal including a constant-length address field having a plurality of subfields therein, wherein the signal recognizer determines that the repeater is to be interrogated if a predetermined subfield of the interrogating signal is configured according to a predetermined interrogate select convention;
• and,
• a controller for changing, in the address field, a position of at least one of the subfields therein and for causing the transmission of test-indicative information on the second side of the network when the signal recognizer determines that the predetermined subfield of the interrogating signal is configured according to a predetermined interrogate select convention.

A method of testing a telephone line repeater comprising:

• regenerating an input signal on a first side of a telephone line network;
• recognizing, in the regenerated input signal on the first side of the network, an interrogating signal, the interrogating signal being a digital, in-band, signal including a constant-length address field having a plurality of subfields therein, and determining whether a predetermined subfield thereof is configured according to a predetermined interrogate select convention;
• changing, in the address field, a position of at least one of the subfields therein;
• and,
• transmitting test-indicative information on a second side of the network when it is determined that the predetermined subfield is configured according to a predetermined interrogate select convention.