Digital loop switch for controlling data information having differing

Abstract

There is disclosed a digital loop for interconnecting a number of data interchangers, each data interchanger connectable over a single high speed communication link to a remote station controller. The high speed link is arranged to bidirectionally transfer both bursty and continuous data to and from the data interchanger. A central controller is serially inserted in the digital loop and serves to assign time slots in a frame for information exchange between the various programmable data interchangers. Each frame contains a first field for data interchange between the data interchangers and the central controller; a second field having time slots assignable under control of the controller to a specific set of data interchangers for transferring information from the continuous data inputs; and a third field having time slots assignable under control of each data interchanger for transferring information from the bursty data input. The controller in cooperation with the data interchangers varies the size of the fields of each frame such that the portion of the field associated with continuous communication expands and contracts as traffic flow changes thereby increasing or decreasing the number of time slots available for the transfer of bursty data.