EP0228096A2
Expired / Lapsed
EP
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Signal detection and discrimination using waveform peak factor
Assignee: Wang Laboratories Inc
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Filing: 1986-12-30
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Granted: —
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Expires: 2006-12-30
Abstract
Abstract Apparatus and method for detecting and discriminating among various signals indicative of progress while making a telephone connection. A particular waveform parameter known as peak factor is advantageously employed in a call progress analyzer (68). The illustrative call progress analyzer uses the average magnitude peak factor (ratio of the peak of the waveform to the average of the absolute value of the waveform) to distinguish among single-tone signals (e.g., special service information tones), double-tone signals (e.g., dial tone, audible ring, and busy), and speech. Waveform ON and OFF times (duration above and below an energy threshold) are combined with signal-type determinations (made using peak factor) to automatically determine the status of a call.
Inventors
- 👤 Richard L. Freudberg
- 👤 Marshall B. Garrison
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 05:48
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/446; H04Q1/448; H04Q1/45; H04Q1/457
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
96 words
A call progress analyzer for receiving waveforms from a telephone line and for providing an indication of call status, the improvement comprising: means defining a peak factor range (90) said range being associated with a particular signal type; measuring means for determining whether peak factors of waveforms received from the telephone line fall within said range and for providing a signal-type indication of said particular signal type in response to a determination that a peak factor falls within said range (88,90,92); call status decision logic for receiving said signal-type indication and for determining call status (86).
Claim 2
Dependent Claim
96 words
A call progress analyzer for receiving waveforms from a telephone line and for providing an indication of call status, the improvement comprising: means defining a peak factor range (90) said range being associated with a particular signal type; measuring means for determining whether peak factors of waveforms received from the telephone line fall within said range and for providing a signal-type indication of said particular signal type in response to a determination that a peak factor falls within said range (88,90,92); call status decision logic for receiving said signal-type indication and for determining call status (86).
Claim 3
Dependent Claim
77 words
The call progress analyzer as claimed in claim 1, wherein said measuring means further comprises: means for creating digital samples representing a waveform received from the telephone line (44,60,64); means for defining measurement intervals and for associating a block of samples with each of the measurement intervals (88); means for determining the peak sample value in a measurement interval (88); means for making a determination of the signal level of the samples in a measurement interval (88).
Claim 4
Dependent Claim
63 words
The call progress analyzer claimed in claim 1 wherein said means defining a peak factor further defines two additional peak factor ranges and wherein the ranges are: less than about 2, which range is associated with single tone signals, between about 2 and about 3, which range is associated with double-tone signals, greater than about 3, which range is associated with speech-type signals.
Claim 5
Dependent Claim
237 words
An automatic call delivery system for connection to a telephone line, the improvement comprising: means for defining at least first and second peak factor ranges (90), said ranges being associated with first and second signal types, respectively; peak factor determination means for determining whether peak factors of waveforms received from the telephone line fall within either of said ranges and for providing a signal-type indication of the associated signal type in response to a determination that a peak factor falls within one of said ranges (88,90), said peak factor determination means comprising means for receiving a waveform and for creating a series of digital samples representing the waveform (24,44,60,64), means defining measurement intervals and for associating samples with the measurement intervals (88), peak measurement means for determining the peak sample value for each measurement interval (88), signal level measurement means for making a signal level determination for each measurement interval (88), means for defining a peak factor range characteristic of signals of the first type and for defining a peak factor range characteristic of signals of the second type (90), scaling means for scaling the signal level determination according to scale factors characteristic of peak factor ranges (90), means for comparing the determined peak value with the scaled forms of signal level and for producing signal-type determinations (90), delivery indication means for for receiving said signal-type indications and for indicating that a call has been answered (86).
Claim 6
Dependent Claim
237 words
An automatic call delivery system for connection to a telephone line, the improvement comprising: means for defining at least first and second peak factor ranges (90), said ranges being associated with first and second signal types, respectively; peak factor determination means for determining whether peak factors of waveforms received from the telephone line fall within either of said ranges and for providing a signal-type indication of the associated signal type in response to a determination that a peak factor falls within one of said ranges (88,90), said peak factor determination means comprising means for receiving a waveform and for creating a series of digital samples representing the waveform (24,44,60,64), means defining measurement intervals and for associating samples with the measurement intervals (88), peak measurement means for determining the peak sample value for each measurement interval (88), signal level measurement means for making a signal level determination for each measurement interval (88), means for defining a peak factor range characteristic of signals of the first type and for defining a peak factor range characteristic of signals of the second type (90), scaling means for scaling the signal level determination according to scale factors characteristic of peak factor ranges (90), means for comparing the determined peak value with the scaled forms of signal level and for producing signal-type determinations (90), delivery indication means for for receiving said signal-type indications and for indicating that a call has been answered (86).
Claim 7
Independent Claim
94 words
A system for discriminating between the presence in a waveform of signals of a first type and signals of other types comprising: means defining a peak factor range associated with signals of the first type (90); measuring means, adapted to receive a representation of the waveform, for making at least one determination of peak factor of the waveform (88); indicating means, responsive to the measuring means and to the range defining means, for indicating the presence of a signal of the first type when the determined peak factor is within the defined range (90,92).
Claim 8
Independent Claim
94 words
A system for discriminating between the presence in a waveform of signals of a first type and signals of other types comprising: means defining a peak factor range associated with signals of the first type (90); measuring means, adapted to receive a representation of the waveform, for making at least one determination of peak factor of the waveform (88); indicating means, responsive to the measuring means and to the range defining means, for indicating the presence of a signal of the first type when the determined peak factor is within the defined range (90,92).
Claim 9
Independent Claim
143 words
A system for discriminating among the presence in a waveform of speech signals, double-tone signals, and single-tone signals comprising: means defining a first peak factor range associated with speech signals, defining a second peak factor range associated with double-tone signals, and defining a third peak factor range associated with single-tone signals (90); measuring means, adapted to receive a representation of the waveform, for making at least one determination of peak factor of the waveform (88); indicating means, responsive to the measuring means and to the range defining means, for indicating the presence of a speech signal when the determined peak factor is within the first defined range, indicating the presence of a double-tone signal when the peak factor is within the second defined range, and indicating the presence of a single-tone signal when the peak factor is within the third defined range (90,92).
Claim 10
Independent Claim
143 words
A system for discriminating among the presence in a waveform of speech signals, double-tone signals, and single-tone signals comprising: means defining a first peak factor range associated with speech signals, defining a second peak factor range associated with double-tone signals, and defining a third peak factor range associated with single-tone signals (90); measuring means, adapted to receive a representation of the waveform, for making at least one determination of peak factor of the waveform (88); indicating means, responsive to the measuring means and to the range defining means, for indicating the presence of a speech signal when the determined peak factor is within the first defined range, indicating the presence of a double-tone signal when the peak factor is within the second defined range, and indicating the presence of a single-tone signal when the peak factor is within the third defined range (90,92).
Claim 11
Dependent Claim
41 words
The system claimed in claim 6 wherein the peak factor range for single-tone signals is less than about 2, the range for double-tone signals is between about 2 and about 3, and the range for speech signals is above about 3.
Claim 12
Independent Claim
149 words
A system for discriminating between the presence in a waveform of signals of a first type and signals of a second type comprising: means for receiving a waveform and for creating a series of digital samples representing the waveform (24,44,60,64); means defining measurement intervals and for associating samples with the measurement intervals (88); peak measurement means for determining the peak sample value for each measurement interval (88); signal level measurement means for making a signal level determination for each measurement interval (88); means for defining a peak factor range characteristic of signals of the first type and for defining a peak factor range characteristic of signals of the second type (90); scaling means for scaling the signal level determination according to scale factors characteristic of peak factor ranges (90); means for comparing the determined peak value with the scaled forms of signal level and for producing signal-type determinations (90).
Claim 13
Independent Claim
149 words
A system for discriminating between the presence in a waveform of signals of a first type and signals of a second type comprising: means for receiving a waveform and for creating a series of digital samples representing the waveform (24,44,60,64); means defining measurement intervals and for associating samples with the measurement intervals (88); peak measurement means for determining the peak sample value for each measurement interval (88); signal level measurement means for making a signal level determination for each measurement interval (88); means for defining a peak factor range characteristic of signals of the first type and for defining a peak factor range characteristic of signals of the second type (90); scaling means for scaling the signal level determination according to scale factors characteristic of peak factor ranges (90); means for comparing the determined peak value with the scaled forms of signal level and for producing signal-type determinations (90).
Claim 14
Independent Claim
32 words
A method of determining the progress of a call comprising: receiving waveforms from a telephone line; making peak factor measurements of the received waveforms; determining call status using the peak factor measurements.
Claim 15
Independent Claim
32 words
A method of determining the progress of a call comprising: receiving waveforms from a telephone line; making peak factor measurements of the received waveforms; determining call status using the peak factor measurements.
Claim 16
Independent Claim
81 words
A method for discriminating between the presence in a waveform of speech-type signals and tone-type signals comprising: defining first and second peak factor ranges associated with speech-type signals and tone-type signals, respectively; receiving a representation of the waveform; making a determination of peak factor of the waveform; indicating the presence of a speech-type signal when the determined peak factor is within the first range and indicating the presence of a tone-type signal when the peak factor is within the second range.
Claim 17
Independent Claim
81 words
A method for discriminating between the presence in a waveform of speech-type signals and tone-type signals comprising: defining first and second peak factor ranges associated with speech-type signals and tone-type signals, respectively; receiving a representation of the waveform; making a determination of peak factor of the waveform; indicating the presence of a speech-type signal when the determined peak factor is within the first range and indicating the presence of a tone-type signal when the peak factor is within the second range.
References Cited (Backward Citations)
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