Kenneth B Swanson

US Patent:

42700302, May 26, 1981

Filed:

Nov 27, 1979

Appl. No.:

6/097699

Inventors:

Stephen J. Brolin - Livingston NJ
Jeffrey L. Gottesman - Morristown NJ
Dennis H. Morgen - Roseland NJ
Kenneth H. Swanson - Mendham NJ

Assignee:

Bell Telephone Laboratories, Incorporated - Murray Hill NJ

International Classification:

H04B 346
H04J 314

US Classification:

1791752D

Abstract:

A testing system is disclosed for telephone subscriber loops which are in part derived by multiplex facilities in what have come to be known as pair gain systems. In this testing arrangement, the local drop wires from the remote terminal of the pair gain system to the subscriber are separated from the carrier system itself and tested by connecting them to a separate metallic pair extending from the central office to the remote terminal location. Simultaneously, the carrier-derived portion of the subscriber loop is connected to automatic testing apparatus which sequences through a plurality of automatic tests for not only transmission characteristics of the carrier-derived channel but also tests for the ability of the derived channel to transmit supervisory information such as ringing, coin control and party identification information. The remote terminal of the pair gain channel is selectively terminated by a reflective or absorptive termination to assist in these testing procedures. The testing system is designed so as to make carrier-derived channels appear to the central office testing personnel as if they were identical to metallic loops, thus saving considerable administrative burden in testing subscriber loops.