Ender Ayanoglu of University of California Irvine EECS/CPCC

Voiceband modems convert a stream of digital symbols into audible signals and transmit them over the Public Switched Telephone Network (PSTN). The first voiceband modem was developed in 1958 and operated at 110 bits/s. Being subject to international standards developed by the International Union of Telecommunications, Telecommunication Standardization Sector (ITU-T), a body of the United Nations, these modems consistently increased their transmission speeds within the next several decades. Every step in the standards process involved a major development in signal processing and communications, such as various forms of adaptive equalization, echo cancellation, and trellis coded modulation. These contributions approximately doubled the transmission speed every step of the standardization process, starting with 300 b/s in 1962 until about 28.8-33.6 kb/s in 1996. Modem designers invoked Shannon's capacity formula and considering quantization noise occurring at the Analog-to-Digital conversion process in the PSTN Central Office as additive white Gaussian noise, decided that the channel capacity for such modems is about 36 kb/s. Yet, towards the end of 1990s, modems that operated at transmission speeds close to 56 kb/s, known generally as 56K modems appeared. This talk will first give a brief history of voiceband modems, and it will describe how it was possible to beat the Shannon capacity formula with the 56K modems. The underlying modeling process and the related mathematics will be described. A history of the development of the 56K modems will be presented and, looking back several decades, the technological, as well as the economic and social impact of these modems, will be discussed.

Biography:

Ender Ayanoglu received the Ph.D. degree from Stanford University, Stanford, CA in 1986, in electrical engineering. He was with the Communications Systems Research Laboratory, part of AT&T Bell Laboratories, Holmdel, NJ until 1996, and Bell Labs, Lucent Technologies until 1999. From 1999 until 2002, he was a Systems |Architect at Cisco Systems, Inc., San Jose, CA. Since 2002, he has been a Professor in the Department of Electrical Engineering and Computer Science, University of California, Irvine, Irvine, CA, where he served as the Director of the Center for Pervasive Communications and Computing and held the Conexant-Broadcom Endowed Chair during 2002-2010. His past accomplishments include invention of the 56K modems, characterization of wavelength conversion gain in Wavelength Division Multiplexed (WDM) systems, and diversity coding, a technique for link failure recovery in communication networks employing erasure coding introduced in 1990, prior to the publication of the first papers on network coding. During 2000-2001, he served as the founding chair of the IEEE-ISTO Broadband Wireless Internet Forum (BWIF), an industry standards organization which developed and built a broadband wireless system employing Orthogonal Frequency Division Multiplexing (OFDM) and a Medium Access Control (MAC) algorithm that provides Quality-of-Service (QoS) guarantees. This system is the precursor of today’s Fourth and Fifth Generation (4G and 5G) cellular Wireless systems. From 1993 until 2014, Dr. Ayanoglu was an Editor, and since January 2014 is a Senior Editor of the IEEE Transactions on Communications. He served as the Editor-in-Chief of the IEEE Transactions on Communications from 2004 to 2008. From January 2015 until December 2016 he served as the Editor-in-Chief of the IEEE Journal on Selected Areas in Communications - Series on Green Communications and Networking. This series published three special issues with record number of papers. He led the efforts to start the IEEE Transactions on Green Communications and Networking and served as its Founding Editor-in-Chief from August 2016 to August 2020. From 1990 to 2002, he served on the Executive Committee of the IEEE Communications Society Communication Theory Committee, and from 1999 to 2002, was its Chair. Dr. Ayanoglu is the recipient of the IEEE Communications Society Stephen O. Rice Prize Paper Award in 1995, the IEEE Communications Society Best Tutorial Paper Award in 1997, the IEEE Communications Society Communication Theory Technical Committee Outstanding Service Award in 2014, and the IEEE Communications Society Joseph LoCicero Award for outstanding contributions to IEEE Communications Society Journals as Editor, Editor-in-Chief (EiC), and the founding EiC in 2023. He has been an IEEE Fellow since 1998. He served as an IEEE Communications Society Distinguished Lecturer in 2022-2023. He is serving a second term as the IEEE Communications Society Distinguished Lecturer in 2024-2025.

Email:

Address:University of California Irvine, , Irvine, CA, United States, 92697-2625