Simultaneous transmission of voice and data signals over a digital channel
First Claim
1. A method for the transmission of information in any one of three modes, said modes being digitally encoded voice signals, data signals, or a combination of said digitally encoded voice signals and said data signals, over a single, bidirectional digital transmission channel interconnecting first and second customer locations by the steps of(1) selecting said information transmission mode,(2) initiating said transmission,(3) providing a unique digital signature for identifying each of said information modes, and(4) multiplexing said signals and said unique signature for transmission between said first and second locations.
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Accused Products
Abstract
A transmission system comprises apparatus for the transmission of voice signals only, data signals only, or a combination of both voice and data signals in a multiplexed stream of eight bit time slots over a single, bidirectional digital channel for a point-to-point connection. In the combined mode, the encoded voice signals, using low bit rate voice encoders, are assigned to four bit positions of the eight bit time slot; the data signals are assigned to the remaining four bits. Up to two bit positions normally used for data may be used for signature bits, thereby identifying whether the multiplexed stream comprises voice signals only, data signals only, or a combination of both voice and data signals. Also, a minimum of one "1" bit per eight bit time slot is thereby guaranteed.
91 Citations
13 Claims
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1. A method for the transmission of information in any one of three modes, said modes being digitally encoded voice signals, data signals, or a combination of said digitally encoded voice signals and said data signals, over a single, bidirectional digital transmission channel interconnecting first and second customer locations by the steps of
(1) selecting said information transmission mode, (2) initiating said transmission, (3) providing a unique digital signature for identifying each of said information modes, and (4) multiplexing said signals and said unique signature for transmission between said first and second locations.
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8. A method of simultaneous transmission of a combination of voice signals and data signals in a multiplexed stream of information bits over a single, bidirectional digital transmission channel comprising the steps of
(1) encoding a sample of said voice signals using four bits, (2) assigning said four bits of encoded voice signal sample to four-bit positions of an 8-bit information time slot, (3) assigning up to four bits of information from said data signals to the remaining four bit positions of said 8-bit time slot, and (4) assigning a distinctive signature comprising a sequence of bits said bits using up to two-bit positions in said remaining four-bit positions instead of said data bits.
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9. A method of simultaneous transmission of a combination of voice signals and data signals in a multiplexed stream of information bits over a single, bidirectional digital transmission channel comprising the steps of
(1) encoding a sample of said voice signals using four bits, (2) assigning said four bits of encoded voice signal sample to four-bit positions of an 8-bit information time slot, and (3) assigning up to four bits of information from said data signals to the remaining four bit positions of said 8-bit time slot, said step of encoding a sample of said voice signals using four bits uses the method of adaptive differential pulse code modulation.
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10. A method of simultaneous transmission of a combination of voice signals and data signals in a multiplexed stream of information bits over a single, bidirectional digital transmission channel comprising the steps of
(1) encoding a sample of said voice signals using four bits, (2) assigning said four bits of encoded voice signal sample to four-bit positions of an 8-bit information time slot, and (3) assigning up to four bits of information from said data signals to the remaining four bit positions of said 8-bit time slot, (4) assigning a distinctive signature comprising a sequence of bits said bits using up to two-bit positions in said remaining four-bit positions instead of said data bits, said step of encoding a sample of said voice signals using four bits uses the method of adaptive differential pulse code modulation.
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11. Apparatus for the transmission of voice signals only, data signals only, or a combination of said voice signals and said data signals, over a single, bidirectional, digital transmission channel comprising
means for encoding said voice signals using low bit rate voice encoders, and means for multiplexing said encoded voice signal samples and said data signals, and means for providing a distinctive signature comprising a sequence of bits using up to two-bit positions, and means for multiplexing said signature bits with said encoded voice signal samples and said data signals, said distinctive signature being used by a receiving terminal for determining whether said multiplexed stream comprises said voice signals only, said data signals only, or said combination of said voice signals and said data signals.
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12. Apparatus for receiving a multiplexed stream of encoded voice signals only, data signals only, or a combination of said encoded voice signals and said data signals over a single, bidirectional, digital transmission channel comprising
means for demultiplexing said multiplexed stream, means for extracting up to two bits from each of a plurality of successive 8-bit time slots to derive a sequence of said bits, and means for determining from said sequence of said bits whether said multiplexed stream is comprised of said encoded voice signals only, said data signals only, or said combination of said encoded voice signals and said data signals.
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13. A pulse code transmission system for combined encoded voice and data signals comprising
a source of encoded voice signals, a source of data signals, a source of transmission mode signature bits for uniquely identifying voice, data or combined voice and data pulse groups, and multiplexing means for combining signals from said sources into fixed pulse groups, said signature bits ensuring at least one binary "1" in each said pulse group and simultaneously uniquely identifying the appropriate one of said transmission modes.
Specification