144 kbit/s second-generation ISDN: Transmission equipment for distribution network

The article presents the transmission system for second generation 144 kbit/s ISDN subscriber line. As for the first generation system, this system uses as a transmission medium the existing distribution network of metal cables. In comparison with the first generation, the second is basically distinguished by the following points: optimisation of costs by use of the elaborate integration techniques making the price of the digital link very attractive, reduction in the volume of equipment by benefitting from these new techniques, optimisation of the operation and maintenance aspects taking into consideration the experiences of the first generation. The article provides a description of the corresponding accomplishments as well as the principal methods of implementation.