“ALOHA to the Web”
Dr. Norman Abramson, Professor Emeritus, University of Hawaii
Thursday, April 14, 2016
Hughes Electrical Engineering Center (EEB)
Reception 3:00pm (EEB Courtyard)
Lecture 4:00pm (EEB 132)
Wireless access to the Internet today is provided predominantly by random access ALOHA channels connecting a wide variety of user devices. ALOHA channels were first analyzed, implemented and demonstrated in the ALOHA network at the University of Hawaii in June, 1971. Information Theory has provided a constant guide for the design of more efficient channels and network architectures for ALOHA access to the web.
In this talk we examine the architecture of networks using ALOHA channels and the statistics of traffic within these channels. That traffic is composed of user and app oriented information augmented by protocol information inserted for the benefit of network operation. A simple application of basic Information Theory can provide a surprising guide to the amount of protocol information required for typical web applications.
We contrast this theoretical guide of the amount of protocol information required with measurements of protocol generated information taken on real network traffic. Wireless access to the web is not as efficient as you might guess.
Norman Abramson received an A.B. in physics from Harvard College in 1953, an M.A. in physics from UCLA in 1955, and a Ph.D. in Electrical Engineering from Stanford in 1958.
He was an assistant professor and associate professor of electrical engineering at Stanford from 1958 to 1965. From 1967 to 1995 he was Professor of Electrical Engineering, Professor of Information and Computer Science, Chairman of the Department of Information and Computer Science, and Director of the ALOHA System at the University of Hawaii in Honolulu. He is now Professor Emeritus of Electrical Engineering at the University of Hawaii. He has held visiting appointments at Berkeley (1965), Harvard (1966) and MIT (1980).
Abramson is the recipient of several major awards for his work on random access channels and the ALOHA Network, the first wireless data network. The ALOHA Network went into operation in Hawaii in June, 1971. Among these awards are the Eduard Rhein Foundation Technology Award (Munich, 2000), the IEEE Alexander Graham Bell Medal (Philadelphia, 2007) and the NEC C&C Foundation Award (Tokyo, 2011).
“Fundamental Limits on Information Security and Privacy”
H. Vincent Poor, Ph.D.
Dean of the School of Engineering and Applied Science
Michael Henry Strater University Professor
- Ph.D., Princeton University, 1977
- M.A., in Electrical Engineering, Princeton University, 1976
- M.S., in Electrical Engineering, Auburn University, 1974
- B.E.E., with Highest Honor, Auburn University, 1972
Tuesday, March 24, 2015
Hughes Electrical Engineering Center (EEB) 132
As has become quite clear from recent headlines, the ubiquity of technologies such as wireless communications and on-line data repositories has created new challenges in information security and privacy. Information theory provides fundamental limits that can guide the development of methods for addressing these challenges. After a brief historical account of the use of information theory to characterize secrecy, this talk will review two areas to which these ideas have been applied successfully: wireless physical layer security, which examines the ability of the physical properties of the radio channel to provide confidentiality in data transmission; and utility-privacy tradeoffs of data sources, which quantify the balance between the protection of private information contained in such sources and the provision of measurable benefits to legitimate users of them. Several potential applications of these ideas will also be discussed.
H. Vincent Poor (Ph.D., Princeton 1977) is Dean of the School of Engineering and Applied Science at Princeton University, where he is also the Michael Henry Strater University Professor. From 1977 until he joined the Princeton faculty in 1990, he was a faculty member at the University of Illinois at Urbana-Champaign. He has also held visiting appointments at a number of other universities, including most recently at Stanford and Imperial College. His research interests are primarily in the areas of information theory and signal processing, with applications in wireless networks and related fields. Among his publications in these areas is the recent book Principles of Cognitive Radio (Cambridge University Press, 2013). At Princeton he has developed and taught several courses designed to bring technological subject matter to general audiences, including “The Wireless Revolution” (in which Andrew Viterbi was one of the first guest speakers) and “Six Degrees of Separation: Small World Networks in Science, Technology and Society.”
Dr. Poor is a member of the National Academy of Engineering and the National Academy of Sciences, and is a foreign member of the Royal Society. He is a former President of the IEEE Information Theory Society, and a former Editor-in-Chief of the IEEE Transactions on Information Theory. He currently serves as a director of the Corporation for National Research Initiatives and of the IEEE Foundation, and as a member of the Council of the National Academy of Engineering. Recent recognition of his work includes the 2014 URSI Booker Gold Medal, and honorary doctorates from several universities in Asia and Europe.
USC’s Viterbi School of Engineering has provided the following abstract for the talk:
Entropy, introduced by Shannon in 1948, arises naturally as a universal measure of information in single-source compression, randomness extraction, and random number generation. In distributed systems, such as communication networks, multiprocessors, distributed storage, and sensor networks, there are multiple correlated sources to be processed jointly. The information that is common between these sources can be utilized, for example, to reduce the amount of communication needed for compression, computing, simulation, and secret key generation. My talk will focus on the question of how such common information should be measured. While our understanding of common information is far from complete, I will aim to demonstrate the richness of this question through the lens of network information theory. I will show that, depending on the distributed information processing task considered, there can be several well-motivated measures of common information. Along the way, I will present some of the key models, ideas, and tools of information theory, which invite further investigation into this intriguing subject. Some parts of this talk are based on recent joint work with Gowtham Kumar and Cheuk Ting Li and on discussions with Young-Han Kim.
Biography: Abbas El Gamal is the Hitachi America Professor in the School of Engineering and Chair of the Department of Electrical Engineering at Stanford University. He received his Ph.D. degree in electrical engineering from Stanford University in 1978. He was an Assistant Professor in the Department of Electrical Engineering at the University of Southern California (USC) from 1978 to 1980. His research interests and contributions have spanned the areas of information theory, wireless networks, CMOS imaging sensors and systems, and integrated circuit design and design automation. He has authored or coauthored over 200 papers and 30 patents in these areas. He is coauthor of the book Network Information Theory (Cambridge Press 2011). He has won several honors and awards, including the 2012 Claude E. Shannon Award, and the 2004 Infocom best paper award. He is a member of the National Academy of Engineering and a Fellow of the IEEE. He has been active in several IEEE societies, including serving on the Board on Governors of the IT society where he is currently its President. He cofounded and/or served in various leadership roles at several semiconductor, EDA, and biotechnology companies.
Audiences: Everyone Is Invited
"Adventures in Coding Theory"
Professor Elwyn Berlekamp
University of California, Berkeley
Gerontology Auditorium, Thursday, March 3, 4:30 to 5:30 p.m.
The inventors of error-correcting codes were initially motivated by problems in communications engineering. But coding theory has since also influenced several other fields, including memory technology, theoretical computer science, game theory, portfolio theory, and symbolic manipulation. This talk will recall some forays into these subjects.--via viterbi.usc.edu