Patent ID: 7486701

Claim:
A system for encoding an ATS-QSIG standard-based content transmitted on a 64 kb/s clear channel, representing three voice sub-channels and one data sub-channel, onto an output stream of bytes for transmission over a 56 kb/s clear channel, the system comprising: a clock extractor receiving from the 64 kb/s clear channel and extracting an input stream of payload bytes, frame data and clock data; a payload splitter receiving the input stream, frame data and clock data from the clock extractor and separating the input stream into: a voice stream of bytes each having a group of six voice bits, two bits from each of the three voice sub-channels, per byte; and a data stream of bytes each having two data bits, from the data sub-channel, per byte; a buffer buffering the content of the data stream, placing a first data bit in a byte from the data stream into a pre-determined data-bit position in a first byte of a retimed data stream of bytes and placing a second data bit in the byte from the data stream into the pre-determined data-bit position in a second byte of the retimed data stream; a shifter shifting the group of six voice bits in a byte from the voice stream into pre-determined voice-bit positions in a byte of an shifted voice stream of bytes; and a summer summing the data bit in a byte from the retimed data stream with the group of six voice bits in a byte from the shifted voice stream to form a byte in the output stream; wherein the clock extractor, the payload splitter, the buffer, the shifter and the summer continuously interoperate to encode the content of successive bytes in the input stream onto successive bytes in the output stream at a rate of 56 kb/s.