Automatic number identification in subscriber loop carrier systems
AssigneeBell Telephone Laboratories, Incorporated
InventorsStephen Joseph Brolin, Samuel Colodner
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Abstract
A subscriber loop carrier system using digital transmission techniques is disclosed in which remote subscriber loops include two-party lines equipped for automatic number identification. The calling party going off-hook causes an automatic number identification (ANI) test request to be sent to the subscriber location. The ANI response signal is then encoded and transmitted to the central station to indicate which party is initiating the call. The same test for automatic number identification is repeated for any substantial discontinuity in the central office loop current to obtain an updating of the automatic number identification information. Encoded pulse signals are used for both the ANI test request and the ANI response signal.
Claims10
An automatic number identification circuit for subscriber loop carrier systems comprising
- means at a central office location for initiating a timed automatic number identification test signal;
- means for transmitting said test signal on said carrier system;
- means responsive to said test signal at said subscriber location for generating an automatic number identification response signal;
- means for transmitting said response signal on said carrier system;
- and
- means at said central office location for storing said response signal.
An automatic number identification circuit comprising
- a timing circuit at a central office location with a timed output for enabling an automatic number identification test signal generation;
- and
- a storage circuit at said central office location for storing an automatic number identification response signal between successive generations of said test signal.
Dependencies are inferred from the claim text.