ISDN SUBSCRIBER LOOP TRANSMISSION SYSTEM BASED ON A TWO-CHIP APPROACH.

A 144-kb/s digital subscriber loop (DSL) transmission system has been developed using two CMOS LSIs, a programmable multiplexing processor, and an echo canceler. The system uses AMI (automatic mark inversion) line code and a unique frame format for stable timing extraction. Experiments have shown that the system is capable of error-free bidirectional transmission over more than 6 km on a 0. 5-mm-diameter cable at 160 kb/s. The features of the multiplexer-processor and the echo-canceller LSIs, the DSL functions, and some performance characteristics of the system are discussed.