Method of and apparatus for multiplexing and demultiplexing digital signal streams
First Claim
1. A multiplexer of a plurality of first signal streams into a second signal stream, the first signal streams having a substantially similar first rate and the second signal stream having a second rate higher than the first rate, comprising:
- a buffer for buffering the first signal streams;
an SRTS circuit for receiving SRTS values of each first signal stream;
a local SRTS circuit for generating local SRTS values of each first signal stream based on a reference clock rate;
a stuffing circuit for stuffing the plurality of first signal streams in response to a stuff command signal which has been generated for each first signal stream in response to its respective sequences of SRTS values and local SRTS values; and
a combiner circuit for combining all the first signal streams into the second signal stream.
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Accused Products
Abstract
Multiplexing and demultiplexing are commonplace for an efficient bandwidth utilization in telecommunications. SRTS (Synchronous Residual Time Stamp) technique is widely used for timing recovery in processing of digital signal streams. The bit stuffing is also prevalent for various purposes, one being rate adjustment. The invention performs the SRTS technique entirely digitally to monitor the rate of slower speed signal streams in relation to the rate of a higher speed stream. The digital implementation permits the use of context switching for processing a plurality of digital signal streams. As the result, hardware requirement is greatly reduced.
100 Citations
8 Claims
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1. A multiplexer of a plurality of first signal streams into a second signal stream, the first signal streams having a substantially similar first rate and the second signal stream having a second rate higher than the first rate, comprising:
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a buffer for buffering the first signal streams; an SRTS circuit for receiving SRTS values of each first signal stream; a local SRTS circuit for generating local SRTS values of each first signal stream based on a reference clock rate; a stuffing circuit for stuffing the plurality of first signal streams in response to a stuff command signal which has been generated for each first signal stream in response to its respective sequences of SRTS values and local SRTS values; and a combiner circuit for combining all the first signal streams into the second signal stream. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification