As the worlds of telecommunications and data communications merge, the re-use of ordinary phone lines to transmit megabits per second of digital bandwidth, in addition to Plain Old Telephone Service (POTS) has emerged as a strong alternative for the delivery of digital services.
This talk enumerates some of the advantages and disadvantages of the use of existing twisted pairs for high-speed digital subscriber access with respect to other media such as coax or wireless. In finding the economic and time advantages of the re-use of existing phone lines, the challenging problem of transmission at high speeds over this non-ideal medium is exposed. The worldwide standardized and validated solution Discrete MultiTone (DMT) solution is then described as the solution for twisted pairs. Worldwide efforts in deploymenets and developments are then reviewed in the area of ADSL, VDSL, and xDSL
John M. Cioffi is an associate professor at Stanford and the founder, in 1991, of Amati Communications Corporation, where he is now Chief Technical Officer. After receiving his Ph.D. in Electrical Engineering at Stanford, he worked as a modem designer at Bell Laboratories and as a disk read-channel researcher at IBM. He has been on the faculty at Stanford since 1986.