John Cioffi
Encyclopedia
John Cioffi is an American electrical engineer, educator and prolific inventor who has made contributions in telecommunication system theory, specifically in coding theory and information theory. Best known as “the father of DSL,” Cioffi’s pioneering research was instrumental in making digital subscriber line (DSL)
technology practical and has led to over 400 publications and more than 100 pending or issued patents, many of which are licensed.
. He earned a B.S.E.E. degree from the University of Illinois at Urbana–Champaign in 1978.
From 1978 to 1982, Cioffi worked as a modem designer at Bell Laboratories in New Jersey. While at Bell Laboratories, he also attended Stanford University
, where he earned a Ph.D. degree in Electrical Engineering in 1984.
In 1984, Cioffi left Bell Labs to work at IBM
as a hard disk drive read channel researcher.
In 1986, Cioffi began his teaching career as an assistant professor of electrical engineering at Stanford University. Cioffi supervised the Ph.D. programs of more than 70 students over the course of more than two decades. His and his students’ research into discrete multitone modulation (DMT) became widely-adopted in digital subscriber line
(DSL) technology, used commonly for Internet access
.
In 1991, at the age of 35, Cioffi took a leave of absence from Stanford to found Amati Communications Corporation. His vision was to build DSL modems based on his and his students’ research. Many of Cioffi's former and present students followed him to Amati, where they built the Prelude modem, a DSL modem that could transmit 6+ megabits per second over 9,000 feet of telephone line
. The Prelude modem would go on to win what has become known as the “Bellcore ADSL Olympics” in 1993 by performing significantly better than modems using single-carrier modulation techniques, such as quadrature amplitude modulation
(QAM) and carrierless amplitude phase modulation
(CAP), including modems from AT&T
and Bellcore. Hundreds of millions of people now use DSL based on Amati’s innovations.
In 1993, Cioffi returned to Stanford, although he remained involved with Amati as an officer and director until its 1998 acquisition by Texas Instruments
. Cioffi’s research interests then turned to dynamic spectrum management (DSM)
, an improvement on DSL that mitigates service interruptions and allows DSL lines to run with higher and more reliable data rates.
In 2003, Cioffi founded Adaptive Spectrum and Signal Alignment, Inc. (ASSIA) to help service providers realize improvements in the performance and profitability of their DSL networks. Today ASSIA’s customers collectively provide DSL service to more than 27 million subscribers worldwide.
In 2009, Cioffi assumed emeritus
status at Stanford, as the Hitachi Professor Emeritus of Engineering. He is now CEO and Chairman of ASSIA.
Digital Subscriber Line
Digital subscriber line is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop. In telecommunications marketing, the term DSL is widely understood to mean Asymmetric Digital Subscriber Line ,...
technology practical and has led to over 400 publications and more than 100 pending or issued patents, many of which are licensed.
Biography
John Cioffi was born and raised in IllinoisIllinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
. He earned a B.S.E.E. degree from the University of Illinois at Urbana–Champaign in 1978.
From 1978 to 1982, Cioffi worked as a modem designer at Bell Laboratories in New Jersey. While at Bell Laboratories, he also attended Stanford University
Stanford University
The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...
, where he earned a Ph.D. degree in Electrical Engineering in 1984.
In 1984, Cioffi left Bell Labs to work at IBM
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
as a hard disk drive read channel researcher.
In 1986, Cioffi began his teaching career as an assistant professor of electrical engineering at Stanford University. Cioffi supervised the Ph.D. programs of more than 70 students over the course of more than two decades. His and his students’ research into discrete multitone modulation (DMT) became widely-adopted in digital subscriber line
Digital Subscriber Line
Digital subscriber line is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop. In telecommunications marketing, the term DSL is widely understood to mean Asymmetric Digital Subscriber Line ,...
(DSL) technology, used commonly for Internet access
Internet access
Many technologies and service plans for Internet access allow customers to connect to the Internet.Consumer use first became popular through dial-up connections in the 20th century....
.
In 1991, at the age of 35, Cioffi took a leave of absence from Stanford to found Amati Communications Corporation. His vision was to build DSL modems based on his and his students’ research. Many of Cioffi's former and present students followed him to Amati, where they built the Prelude modem, a DSL modem that could transmit 6+ megabits per second over 9,000 feet of telephone line
Telephone line
A telephone line or telephone circuit is a single-user circuit on a telephone communication system...
. The Prelude modem would go on to win what has become known as the “Bellcore ADSL Olympics” in 1993 by performing significantly better than modems using single-carrier modulation techniques, such as quadrature amplitude modulation
Quadrature amplitude modulation
Quadrature amplitude modulation is both an analog and a digital modulation scheme. It conveys two analog message signals, or two digital bit streams, by changing the amplitudes of two carrier waves, using the amplitude-shift keying digital modulation scheme or amplitude modulation analog...
(QAM) and carrierless amplitude phase modulation
Carrierless Amplitude Phase Modulation
Carrierless amplitude phase modulation is a variant of quadrature amplitude modulation . Instead of modulating the amplitude of two carrier waves, CAP generates QAM signal by combining two PAM signals filtered through two filters designed so that their impulse responses form a Hilbert pair.CAP...
(CAP), including modems from AT&T
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
and Bellcore. Hundreds of millions of people now use DSL based on Amati’s innovations.
In 1993, Cioffi returned to Stanford, although he remained involved with Amati as an officer and director until its 1998 acquisition by Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
. Cioffi’s research interests then turned to dynamic spectrum management (DSM)
Dynamic Spectrum Management
Dynamic spectrum management , also referred to as dynamic spectrum access , is a set of techniques based on theoretical concepts in network information theory and game theory that is being researched and developed to improve the performance of a communication network as a whole...
, an improvement on DSL that mitigates service interruptions and allows DSL lines to run with higher and more reliable data rates.
In 2003, Cioffi founded Adaptive Spectrum and Signal Alignment, Inc. (ASSIA) to help service providers realize improvements in the performance and profitability of their DSL networks. Today ASSIA’s customers collectively provide DSL service to more than 27 million subscribers worldwide.
In 2009, Cioffi assumed emeritus
Emeritus
Emeritus is a post-positive adjective that is used to designate a retired professor, bishop, or other professional or as a title. The female equivalent emerita is also sometimes used.-History:...
status at Stanford, as the Hitachi Professor Emeritus of Engineering. He is now CEO and Chairman of ASSIA.
Honors and awards
Cioffi has received numerous awards and honors. Among them are:- IEEE Alexander Graham Bell MedalIEEE Alexander Graham Bell MedalThe IEEE Alexander Graham Bell Medal is an award honoring "exceptional contributions to the advancement of communications sciences and engineering" in the field of telecommunications...
(2010) - Honorary Doctorate, Edinburgh University (2010)
- International Fellow Royal Society of Engineering (UK) (2009)
- Marconi Fellow (2006)
- Member National Academy of EngineeringNational Academy of EngineeringThe National Academy of Engineering is a government-created non-profit institution in the United States, that was founded in 1964 under the same congressional act that led to the founding of the National Academy of Sciences...
(2001) - IEEE Koji Kobayashi Computers and Communications AwardIEEE Koji Kobayashi Computers and Communications AwardThe IEEE Koji Kobayashi Computers and Communications Award is a Technical Field Award of the IEEE established in 1986. This award has been presented annually since 1988 for outstanding contributions to the integration of computers and communications....
(2001) - IEEE Third Millennium Medal (2000)
- IEE J. J. Thomson Medal (2000)
- University of Illinois Outstanding Alumni Awards (Electrical Engineering 1999 and School of Engineering 2010)
- IEEE Fellow (1996)
- Outstanding Achievement Award, American National Standards InstituteAmerican National Standards InstituteThe American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organization also coordinates U.S. standards with international...
for contributions to ADSL (1995) - The Economist Innovation Award – Computing and Telecommunications (2010)
Selected publications
- T. Starr, M. Sorbora, J.M. Cioffi, and P.J. Silverman, DSL Advances, Prentice Hall, 2003.
- T. Starr, J.M. Cioffi, and P.J. Silverman, Understanding Digital Subscriber Line Technology, Prentice Hall, 1999.
- J.M. Cioffi, Chapter 4, “Generalized Decision-Feedback Equalization for Packet Transmission with ISI and Gaussian Noise” of Communications, Computation, Control and Signal Processing, a Tribute to Thomas Kailath, editors A. Paulraj, V. Roychowdhury, and C.D. Schaper, Kluwer Academic Publishers, 1997.
- J.M. Cioffi, Chapter 34, “Asymmetric Digital Subscriber Lines” of the Communications Handbook, Editor-in-Chief, J.D. Gibson, CRC Press in cooperation with IEEE Press, 1997.
- J.M. Cioffi, Chapter 15, “Adaptive Filtering” of the Digital Signal Processing Handbook, editors S.K. Mitra and J.F. Kaiser, Van Nostrand Reinhold, 1988.