Patent US2779827A successfully refreshed from Google Patents.
Patent EP0058482A1 successfully refreshed from Google Patents.
EP0058482A1
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EP
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Method and apparatus for transmitting data with digitally encoded speech
Assignee: British Telecommunications PLC
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Filing: 1982-01-27
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Granted: —
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Expires: 2002-01-27
Abstract
Abstract A technique for transmitting data with digitally encoded speech samples involves replacing at least two of the least significant bits of each speech sample so that one of the bits is representative of the data to be transmitted and another is a control bit. The technique can be implemented using an interface circuit which includes a codec 61 for producing digitally encoded speech samples. Data signals from a data terminal are stored in shift register 72 and inserted bit by bit into the bit 7 position of each sample by circuit 68. A control bit is inserted into the bit 8 position using circuit 69. Data in incoming speech samples is sensed by circuits 84, 85, 86.
Inventors
- 👤 Robert Ernest Walters
- 👤 Robert Edward Barrett
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 21:07
CPC Classifications
H; H04; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04J; H04J3/00; H04J3/02; H04J3/12; H04J3/125; H04M; H04M11/00; H04M11/06; H04M11/068; H04Q2213/00; H04Q2213/13031; H04Q2213/13103; H04Q2213/13106; H04Q2213/13216; H04Q2213/1322; H04Q2213/13292; H04Q2213/13299; H04Q2213/1332
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
69 words
A method of transmitting data with digitally encoded speech samples in a digital transmission system in which one or more of the least significant bits of a speech sample is replaced by a bit or bits representative of data to be transmitted characterised in that at least two of the least significant bits are replaced, one of the replaced bits being a control bit and another a data bit.
Claim 2
Independent Claim
69 words
A method of transmitting data with digitally encoded speech samples in a digital transmission system in which one or more of the least significant bits of a speech sample is replaced by a bit or bits representative of data to be transmitted characterised in that at least two of the least significant bits are replaced, one of the replaced bits being a control bit and another a data bit.
Claim 3
Independent Claim
50 words
A method of transmitting data through a telephone exchange which is arranged to switch digitally encoded speech samples characterised in that at least two of the least significant bits of each sample are replaced so that one of the replaced bits is a control bit and another a data bit.
Claim 4
Independent Claim
50 words
A method of transmitting data through a telephone exchange which is arranged to switch digitally encoded speech samples characterised in that at least two of the least significant bits of each sample are replaced so that one of the replaced bits is a control bit and another a data bit.
Claim 5
Dependent Claim
30 words
A method as claimed in claim 1 or claim 2 characterised in that the control bits are arranged to define a valid data code of binary 1 followed by 0000000.
Claim 6
Independent Claim
49 words
A method as claimed in any preceding claim characterised by the step of separating the speech bits from the data bits at a receiving port so that the data bits can be transmitted to a data terminal and the speech bits decoded prior to transmission to a telephone instrument.
Claim 7
Dependent Claim
89 words
A digital transmission arrangement for transmitting digitally encoded speech samples between two or more terminals in which data is transmitted with the speech samples by replacing one or more of the least significant bits of each speech sample by a bit or bits representative of the data characterised in that each terminal has associated therewith circuit means (68, 69) for replacing at least the two least significant bits of each speech sample so that one of the replaced bits is a control-bit and another bit is a data bit.
Claim 8
Dependent Claim
89 words
A digital transmission arrangement for transmitting digitally encoded speech samples between two or more terminals in which data is transmitted with the speech samples by replacing one or more of the least significant bits of each speech sample by a bit or bits representative of the data characterised in that each terminal has associated therewith circuit means (68, 69) for replacing at least the two least significant bits of each speech sample so that one of the replaced bits is a control-bit and another bit is a data bit.
Claim 9
Dependent Claim
54 words
A digital transmission arrangement as claimed in claim 5 characterised in that each terminal includes a circuit (64, 65, 66) which, when data is not inserted in the speech samples, operates to prevent that bit of each speech sample corresponding to the control bit from being in a condition indicative of data being present.
Claim 10
Dependent Claim
54 words
A digital transmission arrangement as claimed in claim 6 characterised in that said circuit includes a counter (65) which is arranged to be incremented when the least significant bit of each speech sample has a predetermined binary value and means (66) for sensing when the count of the counter (65) reaches a predetermined value.
Claim 11
Dependent Claim
35 words
A digital transmission arrangement as claimed in claim 6 or claim 7 characterised in that each terminal includes means (84, 85, 86) for detecting bits representative of data in speech samples received by the terminal.
Claim 12
Dependent Claim
158 words
An interface circuit for a telephone exchange which is arranged to switch digitally encoded speech samples, said interface circuit being characterised in that it comprises a first input/output terminal (60) for connection to a telephone instrument, coding and decoding means (61) connected to said first input/output terminal for coding and decoding speech signals, said coding and decoding means (61) having an output (62) from which digitally encoded speech samples can be transmitted to a digital switching device of the telephone exchange and an input for receiving digitally encoded speech samples from the switching device, a second input/output terminal (70) for connection to a data terminal device, and bit insertion means (72, 68, 69) coupling the said second input/output terminal (70) to the output of the coding and decoding means (61) and arranged to replace at least the two least significant bits of a speech sample so that one bit is a control bit and another a data bit.
Claim 13
Dependent Claim
158 words
An interface circuit for a telephone exchange which is arranged to switch digitally encoded speech samples, said interface circuit being characterised in that it comprises a first input/output terminal (60) for connection to a telephone instrument, coding and decoding means (61) connected to said first input/output terminal for coding and decoding speech signals, said coding and decoding means (61) having an output (62) from which digitally encoded speech samples can be transmitted to a digital switching device of the telephone exchange and an input for receiving digitally encoded speech samples from the switching device, a second input/output terminal (70) for connection to a data terminal device, and bit insertion means (72, 68, 69) coupling the said second input/output terminal (70) to the output of the coding and decoding means (61) and arranged to replace at least the two least significant bits of a speech sample so that one bit is a control bit and another a data bit.
Claim 14
Dependent Claim
49 words
An interface circuit as claimed in claim 9 characterised by including a circuit (64, 65, 66) which, when data is not inserted in the speech samples, operates to prevent that bit of each sample corresponding to the control bit from being in a condition indicative of data being present.
Claim 15
Dependent Claim
44 words
An interface circuit as claimed in claim 9 or claim 10 characterised by including means (84, 85, 86) for detecting bits representative of data in speech samples received from digital switching device and for directing the data bits to said second input/output terminal (70).
References Cited (Backward Citations)
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