Full-Duplex Data Over the Local Loops

The evolution from the integrated digital network (IDN) into the integrated services digital network (ISDN) which provides fully integrated services through digital connectivity between end users depends on the successful deployment of the digital subscriber loops (DSL). In this paper, the concept and an overview of DSL are introduced. Transmission impairments inherent to the subscriber loops are outlined. They lead to the design considerations of the DSL systems. Each of the essential elements in a DSL system is discussed in some detail, with emphasis on the tradeoffs of various design approaches.