The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 02, 1996
Filed:
Sep. 22, 1993
Bruce E McNair, Holmdel, NJ (US);
AT&T Corp., Murray Hill, NJ (US);
Abstract
Methods and apparatus are disclosed for providing increased security in a telecommunications network by using quasi-time domain reflectometry techniques to identify those telephone calls which comprise multiple legs. Echo data are collected for the telephone call from a predetermined point in the network to a point where the call originated. The data are processed to generate an indication of whether the telephone call comprises multiple legs, thus identifying those calls most susceptible to unauthorized use. The indication that a telephone call comprises multiple legs is advantageously used together with call attribute information, such as whether the call is placed to an international destination, to determine whether a given multiple-leg call is most likely a valid access to the communication system or most likely fraudulent.