Early experiments with asynchronous time division networks

Asynchronous time division multiplexing (ATDM) is a technique for sharing a transmission line by carrying user data in small fixed-size cells, usually no larger than 64 bytes. The technique is attractive because it can simultaneously support voice, video, and data communications at a variety of transmission speeds and using many protocols. A retrospective account of three experimental ATDM networks that were developed during the period 1969 through 1984 is presented. Spider was an initial exploration of asynchronous time division multiplexing as a foundation for data communications. Lessons drawn from that experience were built into Datakit, an experiment that eventually became an AT&T product and Incon, an experiment which put wall sockets in offices and in people´s homes.<>