TIME-DIVISION SWITCHING SYSTEM

摘要

TIME-DIVISION SWITCHING SYSTEM A high-capacity low-blocking time-division switching system including a space-division switching network is disclosed for switching serial digital data words synchronously received on time multiplexed lines in a first code format wherein each data word occupies substantially an entire time multiplexed channel time period. In order to achieve high capacity and low blocking, the space-division switching network is physically large resulting in delays of the digital data words transmitted therethrough, which delays are significant when compared with the time duration of a timedivision multiplex channel and which vary in accordance with the path selected. The communication paths through the stages of the space-division network are reconfigured each time-division multiplex channel time duration, but due to the transmission delays, the effective transmission period is less than the time duration of a channel. Accordingly, data words are converted to a second code format, in which a start code is associated with each data word, and transmitted to the space-division network in a period of time less than the duration of a time multiplexed channel. The start code is utilized to permit asynchronous reception at the network outputs which is necessitated by the variability of time delays through the network. Additionally, the outputs of the space-division network are reconverted to the first code format for synchronous transmission on an output time-division multiplexed line.