Guest editorial twisted pair transmission-ever increasing performances on ancient telephone wires

Digital subscriber line (DSL) technology for high-speed data transmission over the local-loop telephone twisted pairs was advanced in the labs of several research institutions during the late 1980’s and early 1990’s. Researchers began to develop and experiment with new transmission ideas and to realize high-speed modems in prototype form. As technology matured and standards evolved, these modems came to be known collectively as “xDSL” modems. The ISDN basic-rate interface, which was developed during the early 1980’s and operated at a “mere” 160 kb/s, today is often cited as being the archetype of this technology.