US4924501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dial pulse selection
Assignee: British Telecommunications PLC
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Filing: 1989-03-30
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Granted: 1990-05-08
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Expires: 2009-03-30
Abstract
Abstract A dial pulse detection system 20 has an analogue input buffer 22, an analogue to digital converter (ADC) 24, a processor 25, and an output buffer 26. Processor 25 operates on the digitally encoded samples produced by ADC 24 from the received signal to achieve detection of the dial pulse signalling data in the received signal. This detection process involves a training process and a recognition process. The training process extracts amplitude and timing characteristics of a first part of the received signal from a dialling instrument. These characteristics are then used to form a template for recognition of subsequent dialled digits. Detected digits are then made available at output buffer 26. Processor 25 includes a facility for sending an error signal to the user to indicate that dialled digits have not been correctly received.
Inventors
- 👤 David S. Cheeseman
- 👤 Arthur J. Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:04
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/32
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
100 words
A method of detecting dial pulse signalling data in a received signal comprising the steps of: performing a training process to train a dial pulse detector by processing a known dialled signal to extract information relating to the timing of the dialled pulses in a known dialled digit; and performing a recognition process by using said information to assist said detector in detecting dial pulse signalling data in the received signal, wherein said information includes measured values for a maximum make pulse level, a maximum break pulse level, a make period, a break period, and a total dial pulse period.
Claim 2
Independent Claim
100 words
A method of detecting dial pulse signalling data in a received signal comprising the steps of: performing a training process to train a dial pulse detector by processing a known dialled signal to extract information relating to the timing of the dialled pulses in a known dialled digit; and performing a recognition process by using said information to assist said detector in detecting dial pulse signalling data in the received signal, wherein said information includes measured values for a maximum make pulse level, a maximum break pulse level, a make period, a break period, and a total dial pulse period.
Claim 3
Dependent Claim
35 words
A method of detecting dial pulse signalling data as claimed in claim 1, wherein the training process is re-started if a value obtained for the total dial pulse period is outside of a given tolerance.
Claim 4
Dependent Claim
42 words
A method of detecting dial pulse signalling data as claimed in claim 1, wherein the recognition process comprises measuring the maximum make pulse level of received signals during time periods spaced according to the measured spacing of pulses during the training process.
Claim 5
Dependent Claim
22 words
A method of detecting dial pulse signalling data as claimed in claim 3, wherein said time periods are less than 25 milliseconds.
Claim 6
Dependent Claim
47 words
A method of detecting dial pulse signalling data as claimed in claim 3, wherein the recognition process includes comparing the level of received signals during said time periods with the pulse levels derived from the training process to detect the presence or absence of valid dial pulses.
Claim 7
Dependent Claim
43 words
A method of detecting dial pulse signalling data as claimed in claim 5, wherein the recognition process includes storing information upon the detection of the presence or absence of valid dial pulses for each time period in respective locations of a data store.
Claim 8
Dependent Claim
28 words
A method of detecting dial pulse signalling data as claimed in claim 3, wherein said recognition process is terminated and/or re-started according to a count of pulse absences.
Claim 9
Dependent Claim
35 words
A method of detecting dial pulse signalling data as claimed in claim 7, wherein said count of pulse absences is reset by subsequent detection of the presence of at least two consecutively valid dial pulses.
Claim 10
Dependent Claim
46 words
A method of detecting dial pulse signalling data as claimed in claim 6, wherein said recognition process derives a detected value of a dialled digit by examination of the information stored in the locations of the data store representing at least two consecutively valid dial pulses.
Claim 11
Independent Claim
93 words
A method of detecting dial pulse signalling data in a received signal comprising the steps of: performing a training process to train a dial pulse detector by processing a signal known to be a dialled signal; said step of performing a training process including the steps of extracting timing information relating to the dialled pulses in a dialled digit in said dialled signal and processing said timing information; and performing a recognition process by using said processed timing information to assist said detector in detecting dial pulse signalling data in the received signal.
Claim 12
Independent Claim
93 words
A method of detecting dial pulse signalling data in a received signal comprising the steps of: performing a training process to train a dial pulse detector by processing a signal known to be a dialled signal; said step of performing a training process including the steps of extracting timing information relating to the dialled pulses in a dialled digit in said dialled signal and processing said timing information; and performing a recognition process by using said processed timing information to assist said detector in detecting dial pulse signalling data in the received signal.
Claim 13
Dependent Claim
36 words
A method of detecting dial pulse signalling data as claimed in claim 10, wherein if the training process fails to extract said timing information from said received signal, the training process will transmit a failure message.
Claim 14
Dependent Claim
29 words
A method of detecting dial pulse signalling data as claimed in claim 10, wherein said recognition process includes transmitting a message to indicate the detected dial pulse signalling data.
Claim 15
Dependent Claim
25 words
A method of detecting dial pulse signalling data as claimed in claim 10, wherein the received signal comprises digitally encoded representations of telephone dial pulses.
Claim 16
Dependent Claim
30 words
A method of detecting dial pulse signalling data as claimed in claim 13 wherein said received signal processed by the training process comprises representations of at least four dial pulses.
Claim 17
Dependent Claim
38 words
A method of detecting dial pulse signalling data as claimed in claim 10, wherein said step of performing a training process includes the step of measuring time intervals between successive peak signals and storing time information relating thereto.
Claim 18
Dependent Claim
41 words
A method of detecting dial pulse signalling data as claimed in claim 15, wherein said step of performing a training process includes the step of measuring an amplitude relating to the peak of the signals and storing amplitude information relating thereto.
Claim 19
Dependent Claim
51 words
A method of detecting dial pulse signalling data as claimed in claim 15, wherein the step of performing a training process includes the steps of detecting the presence of erroneous signalling information from the stored time information, erasing the stored time information, and restarting the training process using further received signals.
Claim 20
Dependent Claim
35 words
A method of detecting dial pulse signalling data as claimed in claim 15, further including the step of providing a series of analysis windows computed from the stored information for use in the recognition process.
Claim 21
Dependent Claim
47 words
A method of detecting dial pulse signalling data as claimed in claim 18, further including the step of determining during each analysis window whether a signal has been received corresponding to that anticipated as a result of the training process and if so storing an indication thereof.
Claim 22
Dependent Claim
79 words
A detector for dial pulse signalling data comprising: means for processing a received signal including training means and recognition means, said training means including means for processing a signal known to be a dialled signal to extract and process timing information relating to the dialled pulses in a dialled digit in said dialled signal, and said recognition means including means for operating on said processed timing information to assist in detecting dial pulse signalling data in the received signal.
Claim 23
Dependent Claim
79 words
A detector for dial pulse signalling data comprising: means for processing a received signal including training means and recognition means, said training means including means for processing a signal known to be a dialled signal to extract and process timing information relating to the dialled pulses in a dialled digit in said dialled signal, and said recognition means including means for operating on said processed timing information to assist in detecting dial pulse signalling data in the received signal.
Claim 24
Dependent Claim
109 words
Interactive terminal equipment comprising a detector for detecting dialled digits comprising means for processing a received signal including training means and recognition means, said training means comprising means for processing a signal known to be a dialled signal to extract timing information relating to the dialled pulses in a dialled digit in said dialled signal, said recognition means including means for using said timing information to assist in detecting dial pulse signalling data in dialled digits, and including means to transmit messages to a user inviting the user to dial digits according to the user's requirements and to provide a service to the user dependent on the digits dialled.
Claim 25
Dependent Claim
109 words
Interactive terminal equipment comprising a detector for detecting dialled digits comprising means for processing a received signal including training means and recognition means, said training means comprising means for processing a signal known to be a dialled signal to extract timing information relating to the dialled pulses in a dialled digit in said dialled signal, said recognition means including means for using said timing information to assist in detecting dial pulse signalling data in dialled digits, and including means to transmit messages to a user inviting the user to dial digits according to the user's requirements and to provide a service to the user dependent on the digits dialled.
Claim 26
Dependent Claim
38 words
Interactive terminal equipment as claimed in claim 21, wherein the equipment is associated with an exchange to provide an automatic operator service so that an outside exchange line user is able to dial any extension on the exchange.
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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) | 1993-05-07 | 1993-11-06 | 1994-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-07 | 1997-11-06 | 1998-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-07 | 2001-11-06 | 2002-05-08 | $7700.00 | Window Closed / Lapsed |