A Compatible Multiplexing Technique for Anisochronous and Isochronous Digital Data Traffic

This concise paper reports the result of a study on a multiplexing scheme for digital data transmission and switching which can handle both anisochronous and isochronous data traffic of various mix, mainly in one digital channel of PCM primary multiplex level (e.g., 1544 kbits/s) and corresponding time-division switch (TDSW) of data-switching equipment. The study aims to determine a unified scheme which is economical and flexible for intercity heavy-traffic data links, to accommodate a wide range of data speeds. The paper describes various multiplexing schemes and analyzes their features in terms of frame structure, synchronization time, error-correction capability, compatibility with signaling, hardware complexity, etc. A bit-interleaved multiplexing scheme is chosen as suitable and is applied in a laboratory model of a digital data switching system, the DDX-1 System.