US5504810A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telecommunications fraud detection scheme
Assignee: AT&T Inc
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Filing: 1993-09-22
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Granted: 1996-04-02
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Expires: 2013-09-22
Abstract
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.
Inventors
- 👤 Bruce E. McNair
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 04:20
CPC Classifications
H; H04; H04M; H04M15/00; H04M15/47; H04M3/00; H04M3/22; H04M3/2281; H04M3/36; H04M3/38; H04M2215/00; H04M2215/01; H04M2215/0148; H04M3/002; H04M3/42; H04M3/42314
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
63 words
A method comprising the steps of: analyzing echo characteristics of a path of a telephone call to determine whether the telephone call is a multiple-leg call; collecting data representing attributes of the telephone call when the echo characteristics indicate that the telephone call is a multiple-leg call; and processing the data to generate an indication of whether the telephone call was established fraudulently.
Claim 2
Independent Claim
63 words
A method comprising the steps of: analyzing echo characteristics of a path of a telephone call to determine whether the telephone call is a multiple-leg call; collecting data representing attributes of the telephone call when the echo characteristics indicate that the telephone call is a multiple-leg call; and processing the data to generate an indication of whether the telephone call was established fraudulently.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein the processing step comprises determining whether the condition of at least one call attribute indicates that the telephone call was established fraudulently.
Claim 4
Dependent Claim
52 words
The method of claim 1 wherein the analyzing step comprises the steps of: generating echo data for the telephone call from a predetermined point in the network to a point where the call originated; and responding to the echo data to generate an indication of whether the telephone call comprises multiple legs.
Claim 5
Dependent Claim
39 words
The method of claim 3 wherein the responding step comprises: filtering the echo data to identify echo peaks; and generating an indication that the telephone call is a multiple-leg call if there are at least two identified echo peaks.
Claim 6
Dependent Claim
77 words
The method of claim 3 wherein the responding step comprises: determining from the echo data the echo return loss between the predetermined point and the point where the call originated; and comparing the determined echo return loss with an expected echo return loss for the telephone call; and generating an indication that the telephone call is a multiple-leg call if the determined echo return loss exceeds the expected echo return loss by more than a predetermined amount.
Claim 7
Dependent Claim
68 words
The method of claim 3 wherein the responding step comprises: determining from the echo data the approximate distance between the predetermined point and the point where the call originated; and comparing the determined distance with an expected distance for the telephone call; and generating an indication that the telephone call is a multiple-leg call if the determined distance exceeds the expected distance by more than a predetermined amount.
Claim 8
Dependent Claim
32 words
The method of claim 1 wherein the step of processing call attribute data comprises determining whether the call is placed to a country which belongs to a predetermined group of high-fraud countries.
Claim 9
Independent Claim
68 words
A method comprising the steps of: detecting the echo characteristics of the path of a telephone call; collecting data representing attributes of the telephone call; determining whether the collected data and the echo characteristics of the path are consistent with each other; and generating an indication that the telephone call was established fraudulently when the collected data and the characteristics of the path are inconsistent with each other.
Claim 10
Independent Claim
68 words
A method comprising the steps of: detecting the echo characteristics of the path of a telephone call; collecting data representing attributes of the telephone call; determining whether the collected data and the echo characteristics of the path are consistent with each other; and generating an indication that the telephone call was established fraudulently when the collected data and the characteristics of the path are inconsistent with each other.
Claim 11
Dependent Claim
28 words
The method of claim 8 wherein the detecting step comprises determining the approximate distance between a predetermined point in the path and a point where the call originated.
Claim 12
Dependent Claim
27 words
The method of claim 9 wherein the determining step comprises comparing said distance with a country code which identifies a country from which the telephone call originated.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-04-02 | 1999-10-02 | 2000-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-02 | 2003-10-02 | 2004-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-02 | 2007-10-02 | 2008-04-02 | $7700.00 | Window Closed / Lapsed |