Design Issues in the ISDN U-Interface Transceiver

The design challenges faced in the integrated circuit realization of the basic customer access U-interface transceiver at 144 kbits/s in the integrated services digital network (ISDN) are summarized. Given the cost and performance objectives, this represents a very challenging design problem from an algorithmic and technology point of view. This survey paper describes the alternative design approaches concentrating on algorithmic issues as opposed to circuit design issues, in the context of the echo cancellation (EC) method of full duplex data transmission. Particular emphasis is given to the areas of echo cancellation, equalization, line code selection, and timing recovery.