John M. Cioffi | |
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Born | Illinois, U.S. | November 7, 1956
Alma mater | Stanford University (PhD) University of Illinois at Urbana–Champaign (BSEE) |
Known for | Digital subscriber line |
Awards | Marconi Prize (2006) IEEE Alexander Graham Bell Medal (2010) IET J J Thomson Medal (2000) FREng NAE |
Scientific career | |
Fields | Digital communications Coding theory |
Institutions | Stanford University |
Doctoral advisor | Thomas Kailath |
Doctoral students | Peter Sienpin Chow Inkyu Lee |
John Mathew Cioffi (born November 7, 1956) is an American electrical engineer, educator and inventor who has made contributions in telecommunication system theory, specifically in coding theory and information theory. Best known as "the father of DSL," [1] 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.
John Cioffi was born and raised in Illinois. 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, under the supervision of Thomas Kailath.
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. [2] 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 then-current and former students followed him to Amati, where they built the Prelude modem, a DSL modem that could transmit 6+ megabits per second over 9,000 ft (2,700 m) 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. [3] 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. [4] 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 2001, Cioffi was elected as a member into the National Academy of Engineering for contributions to the theory and practice of high-speed digital communications.
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 70 million subscribers worldwide. [5]
In 2009, Cioffi assumed emeritus status at Stanford, as the Hitachi Professor Emeritus of Engineering. [2] He is now CEO and Chairman of ASSIA.
Cioffi has received numerous awards and honors. Among them are:
Integrated Services Digital Network (ISDN) is a set of communication standards for simultaneous digital transmission of voice, video, data, and other network services over the digitalised circuits of the public switched telephone network. Work on the standard began in 1980 at Bell Labs and was formally standardized in 1988 in the CCITT "Red Book". By the time the standard was released, newer networking systems with much greater speeds were available, and ISDN saw relatively little uptake in the wider market. One estimate suggests ISDN use peaked at a worldwide total of 25 million subscribers at a time when 1.3 billion analog lines were in use. ISDN has largely been replaced with digital subscriber line (DSL) systems of much higher performance.
Digital subscriber line is a family of technologies that are used to transmit digital data over telephone lines. In telecommunications marketing, the term DSL is widely understood to mean asymmetric digital subscriber line (ADSL), the most commonly installed DSL technology, for Internet access.
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Thomas Kailath is an Indian born American electrical engineer, information theorist, control engineer, entrepreneur and the Hitachi America Professor of Engineering emeritus at Stanford University. Professor Kailath has authored several books, including the well-known book Linear Systems, which ranks as one of the most referenced books in the field of linear systems.
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Asymmetric digital subscriber line (ADSL) is a type of digital subscriber line (DSL) technology, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. ADSL differs from the less common symmetric digital subscriber line (SDSL). In ADSL, bandwidth and bit rate are said to be asymmetric, meaning greater toward the customer premises (downstream) than the reverse (upstream). Providers usually market ADSL as an Internet access service primarily for downloading content from the Internet, but not for serving content accessed by others.
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Richard D. Gitlin is an electrical engineer, inventor, research executive, and academic whose principal places of employment were Bell Labs and the University of South Florida (USF). He is known for his work on digital subscriber line (DSL), multi-code CDMA, and smart MIMO antenna technology all while at Bell Labs.
Björn Ottersten is a Swedish educator, researcher, and electrical engineer who is the co-inventor of Space/Spatial Division Multiple Access (SDMA) technology. He has made contributions in array signal processing and wireless communications and has received many notable awards in these areas. Currently, he is a Professor of Signal Processing at Royal Institute of Technology (KTH), Stockholm, Sweden, and the founding director of the Interdisciplinary Centre for Security, Reliability and Trust, at University of Luxembourg, Luxembourg.
Peter Sienpin Chow is an American electrical engineer. A Ph.D. student of John Cioffi at Stanford University, he is best known for his contributions to the development of discrete multi-tone modulation and its application to digital subscriber line services.
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Victor B. Lawrence is a Ghanaian-American engineer credited with seminal contributions in digital signal processing for multimedia communications. During his 30-plus-year tenure at Bell Laboratories, Lawrence made extensive and fundamental personal contributions to voice, data, audio and video communications. He led numerous projects that significantly improved or enhanced every phase in the evolution of early low-speed and today's high-speed data communications. He is a Research Professor and Director of the Center for Intelligent Networked Systems (iNetS) at Stevens Institute of Technology, where he also served as Associate Dean. He was inducted into the National Inventors Hall of Fame in 2016. He is a Member of the National Academy of Engineering, a Fellow of the IEEE for contributions to the understanding of quantization effects in digital signal processors and the applications of digital signal processing to data communications, a Fellow of AT&T Bell Labs, and a Charter Fellow of the National Academy of Inventors.
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