Statistical voice/high-speed data multiplexing on a 64 kbit/s channel

The authors describe a method for the immediate recognition of signal transitions in voice/data multiplexing which allows effective transmission of high-speed data during silences in a telephone conversation. In particular the authors define the procedures through which synchronization can be recovered in the occurrence of false or undetected transitions between the two signal types. A statistical multiplexer based on this method is presented which can be used at source by a single user of a 64 kb/s pulse-code-modulation (PCM) telephone channel. The multiplexer efficiency has been enhanced by using a speech detector whose threshold values are dynamically adapted to the background noise and to amount of data queued for transmission. The design of such a multiplexer is assessed by simulations whose major results are presented