The LT-1 Connector - A Conventional Transmultiplexer

The LT-1 connector has been designed to provide an economical means of terminating analog transmission facilities on the No. 4ESS, a digital toll switching machine. It performs a bilateral conversion between two 12-channel analog group signals in the 60-108-kHz band and a 24-channel digital digroup at 1.544 Mbits/s. In addition, signaling information in the form of a 2600-Hz tone must be converted to the digital format. The connector has been implemented with conventional per-circuit technology but achieves significant savings compared to back-to-back channel banks. This is accomplished by eliminating redundant circuitry and using a number of custom designed silicon integrated circuits. This paper gives a description of the design and some typical performance data.