The Prelude experimental model represents a complete network which can integrate any bit rate from data to moving pictures by an asynchronous time-division (ATD) technique. To get reliable and full assessment of ATD, the model is made up of a switch, a concentrator, two home networks, and terminals. The project started in 1982 and was completed in the middle of 1987. The success of the experiment proves the feasibility of ATD, which is now agreed on as a possible solution for future ISDN (integrated-services digital network) use. The authors address the results derived from the experiment and analyze the trends that can be expected for the future. First, an outline of Prelude is given to describe the state of the art reached within the experiment. Each element of the system is described with special emphasis on the switching matrix, as its optimized and efficient implementation could lead to short-term industrial developments. Then a thorough assessment of the whole system is given from which future evolutions are most likely to be derived. Possible ATD fields of application are given.
