@prefix edm: . @prefix dcterms: . @prefix dc: . @prefix skos: . edm:dataProvider "CONTENTdm"@en ; dcterms:isReferencedBy "http://resolve.library.ubc.ca/cgi-bin/catsearch?bid=3191655"@en ; dcterms:isPartOf "University Publications"@en ; dcterms:issued "2015-08-26"@en, "1990"@en ; edm:aggregatedCHO "https://open.library.ubc.ca/collections/focus/items/1.0115134/source.json"@en ; dc:format "application/pdf"@en ; skos:note """ *### 19 15-1990 ANNIVERSARY Vol. 1, No. 2 Fall 1990 CENTRE FOR MEGRA1ED COMPUTER SYSTEMS RESEARCH • C *I • C • S • R - THE UNIVERSITY OF BRITISH COLUMBIA FOCUS COMMUNICATING IN THE FUTURE CICSR researchers are developing techniques that will be used in the communications networks of the 21st century. ■ People have come to rely on their communications systems as an everyday part of their business and personal lives. For most people, this communications system is the telephone. In the future, people will have their own personal communications systems that will enable others to reach them at any time, anywhere in the world. „ ... continued on page 2 CICSR researchers Samir Kallel and Cyril Leung are working on ways to reduce error in transmission of information over mobile radio channels. The techniques they are developing could be used to improve data transmission over communications networks such as the MDI system for public safety forces (right). Photo: Mobile Data International (MDI) Director's statement Dr. James Varah More on CICSR researchers and their work in communications technology page 2 Norm Hutchinson joins CICSR and UBC Department of Computer Science page 3 CICSR Calendar page 4 Director's Statement This is our second CICSR newsletter, meant to cover the events of Fall, 1990. As you can see, we are highlighting the area of Communications in this issue, to coincide with our Distinguished Lecture Series for 1990/91. This approach also serves to bring your attention to the excellent research in communications and related areas presently in progress at UBC. For example, these CICSR researchers form an important node in the Institute for Telecommunications Research, the Federal Network of Centres of Drs. Peter Lawrence and James Varah Excellence in Telecommunications. The members are well-represented in both the Departments of Computer Science and Electrical Engineering. I would also like to take this opportunity to inform you that I will be on leave for the first six months of 1991. During my absence, Professor Peter Lawrence from the Department of Electrical Engineering will be Acting Director. Peter is well-known for his research in telerobotics, and has always been a strong advocate of the CICSR concept. ■ UBC Dept. of Electrical Engineering professors Victor Leung and Takis Mathiopoulos.. COMMUNICATIONS ... continued from front demodulator even for a digital signal. Dr. James Varah Professor Takis Mathiopoulos in the UBC Department of Electrical Engineering has a keen interest in the communications systems of the future. He is working on an important aspect of the global communications network of the future: digital cellular, the next evolution of cellular technology. Currently, cellular transmissions are analog. There are about two million users of cellular technology in North America, and Mathiopoulos estimates that in a few years, there will be ten million users. Already, cellular networks are operating at near-capacity in many large cities. Mathiopoulos is working on a new approach to digital cellular that will allow five users in the same 30 kilohertz bandwidth where there is now one. He is also working to improve system efficiency to allow up to ten users per channel. Mathiopoulos is also concerned with minimizing what he calls "spectrum pollution," a phrase that carries a lot of weight in these days of environmental awareness. "The spectrum is a very precious resource," says Mathiopoulos. "We have to ensure we don't take up too much of the spectrum and that we don't create interference." Digital cellular communications will be introduced by the end of the year, but there will be a five-year transition period before analog systems will become obsolete. In the meantime, users will need hybrid systems. Mathiopoulos is working on such systems which can use an FM (analog) Mathiopoulos is especially interested in cellular because of the large market out there for the technology. "My group's research is applied. We always try to adapt our research to industry's needs." Mathiopoulos' group consists of himself and four graduate students.'Tm so excited about our research, I'm working 12 hours a day," said Mathiopoulos. "It's an exciting field, so we have the drive. We feel we can contribute a lot to the area of personal communications." Samir Kallel is another communications specialist in the UBC Department of Electrical Engineering. His main area of research is in controlling error in communications systems. One way to reduce error is to increase transmitted power, but in some situations, this isn't possible. Kallel is developing error control coding that requires less power but still extracts good performance from communications systems. Kallel says there are two ways to control error in digital communications. One is to send an automatic repeater request to each information bit and add parity bits to detect errors in transmission. If there are errors, the transmitter sends the information packet again until it is received correctly. Another alternative is to incorporate redundancy bits into each block of data for the purpose of error correction. The more redundancy bits the better the error- correction performance, but less information is transmitted. Kallel's research involves developing a system that will adapt the number of redundancy bits transmitted according to channel variations: the more noise on the channel, the more redundancy bits will be sent. Kallel plans to adapt this technology to data transmission through mobile communications networks. Kallel believes adaptive error control techniques will be applied in the next generation of cellular telephones. Kallel likens the systems he is working on to the way people communicate when they're talking to each other. "If you feel the person is not understanding you correctly, you add more information, and you repeat what you're saying. I That's basically what this system does — it repeats itself until the message is received correctly." Cyril Leung, a faculty member in the UBC Department of Electrical Engineering is conducting some research very similar to Kallel's: reducing error in data communication over mobile radio channels. He is working on error-correction coding, adding redundant bits to reduce the effects of transmission errors and in automatic repeat request (ARQ) technology. With an ARQ system, if an error is detected, the receiver sends an automatic request to retransmit the information packet. Leung is developing a system where the faulty information packet is not automatically discarded. Instead, if the system receives a number of these erroneous copies, they could be combined to deduce a correct copy. Another area of interest for Leung is in overcoming the problem of signal fading due to distance and obstacles. "Fading greatly complicates data communication over mobile radio channels," says Leung. One solution which Leung is investigating is called orthogonal frequency division multiplexing (OFDM). In conventional modulation schemes, information bits are transmitted serially over the communication line. Using OFDM, a block of bits is transmitted simultaneously, each bit occupying a narrow frequency band. "Since the time duration of each bit is now much longer than if one used the conventional serial scheme, signal fades will affect each bit only slightly," said Leung. Leung is also working to solve the multiple access problem encountered by users of mobile communications networks. A typical system will have one fixed base and a number of mobile terminals. When there are several terminals transmitting to the fixed base at once, which is often the case, there are severe contention problems which greatly degrade system performance. "One of my objectives," said Leung, "is to design a good multiple access system to minimize the contention problem." Cyril's namesake, Victor Leung, is also interested in mobile communications, but those based on satellite, not terrestrial, networks. The bulk of Leung's research land-based systems. He is looking at the design of multiple access protocols in frequency division multiplex for fibreop- tics. Currently, fibreoptics offer tremendous bandwidth with far more capacity (in the terrabits-per-second range) than electronic transmitters and receivers can keep up with. "To overcome the electronic bottleneck, you divide the band into channels of lower capacity," said Leung. This is called multiplexing. Leung is working on a protocol to ensure users efficient access to the different channels. He says it's much like controlling access to and from a multiple-lane superhighway. ■ Dr. Cyril Leung Dr. Norm Hutchinson involves network design for the mobile satellite system (MSS) to be launched in North America within five years. Leung's work uses the Demand Assignment Multiple Access (DAMA) scheme which he says is "like a switch in the sky being controlled on the ground." The scheme allows the system to determine available capacity for a call, monitor the call, recoup capacity and re-assign it. A future application of satellite networks that interests Leung is mobile radio communication applied to satellite. Satellites have an advantage over terrestrial-based networks in their wide area of coverage. Three satellites can easily cover the entire planet. Land-based systems rely on numerous transmitter towers and are not economical in sparsely-populated areas. Still, it takes a lot of engineering money to launch satellites, and the use of them is expensive. Leung is involved in the design of a communications protocol for data messaging via satellite. The goal is to use satellite channels as efficiently as possible. In his research, Leung has not ignored UBC welcomes Norm Hutchinson Beginning in January, the UBC Department of Computer Science and CICSR will have a new member. Norman Hutchinson, currently assistant professor in the Department of Computer Science at the University of Arizona will take on a similar position at UBC. After teaching in Arizona for almost four years, and taking his Masters and PhD degrees in Computer Science at the University of Washington, Hutchinson said he was anxious to return home to Canada. He chose UBC because "the university seems really committed to building a strong department." Hutchinson is interested in two main research areas, communication protocol and distributed programming languages. He is working with the x-kernel to define operating system abstractions that make it easier to implement network protocols. H Passing notes Building update We are continuing detailed planning of the CICSR/CS Building; we expect to complete the planning phase by the end of the year. Construction is expected to begin in the Summer of 1991 and be completed by the Summer of 1992. Model of the CICSR/CS Building. Lecture reviews Dr. Mike Brady, Professor and Chair of Engineering Science at Oxford, visited UBC in May as a Distinguished Lecturer. His talk covered major recent advances in intelligent robotics, with emphasis on mobile robotics and active perception, especially vision. He also outlined his views to the overflow crowd on the current research agenda. In Brady's visits to the CICSR robotics groups, old friendships were renewed, and common problems discussed. His illustrated talk, and reprints of his recent Oxford papers, are available from the CICSR office. A five-day intensive course on the Cambridge HOL system, was held here June 4-8. The course was sponsored by CICSR and the UBC Centre for Continuing Education, and organized by Jeffrey Joyce of the Computer Science Dept. The Cambridge HOL system is an interactive environment for machine- assisted theorem-proving in mathematical logic. The system can be used to construct formal proofs about the correctness of computer hardware or software with respect to a formal description of system requirements. The five-day course consisted of both lectures and hands-on laboratory sessions. It attracted local and international participants, including representatives from British Telecom, IBM (France), Mitsubishi, Boeing Aircraft and Unisys. It will likely be offered again in June 1991. For those interested in knowing more about CICSR, drop by our office and Susan Perley or Gale Ross will be happy to assist you. If you like, ask them \\ to add your name to our CICSR FOCUS mailing list. ■ C-A-L-E-N-D-A-R Distinguished Lecturer Dr. Mike Brady spoke to a full house on advances in intelligent robotics. CICSR Distinguished Lecture Series: Window on Digital Communications October 18, 1990 Crytography in the Computer Age Dr. James L. Massey, Member, the Swiss Academy of Engineering Sciences. Growing computer interconnection to sensitive data bases sharpens the need for privacy and authenticity of messages. In the first lecture of the 1990/91 season, Dr. Massey will discuss relevant and recent cryptographic techniques. November 1, 1990 A Trot Through the Future World of Gigabit Networks - Can We Get There From Here? Dr. David J. Farber, Director of the Distributed Systems Laboratory, University of Pennsylvania. Lectures run from 1:00 p.m. to 2:30 p.m., Room 100, November 22, 1990 Formal Specifications for Testing Designs and Implementations: Applications to OSI Protocol Testing Dr. Gregor V. Bochmann, holder of the IDACOM-NSERC-CWARC chair of industrial research on communication protocols, University of Montreal. December 13, 1990 Forward Error-Control as a Central Design Concept for Digital Communications Systems Dr. Andrew J. Viterbi, Vice Chairman and Chief Technical Officer,Qualcomm Inc.; Professor of Electrical Engineering, UCSD. February 7, 1991 The Limits of Layering in Network Protocols Dr. David Clark, Senior Research Scientist, MIT Computer Science Lab. March 7, 1991 The Opening Up of Communications - Towards Wideband Telecommunications Dr. Robert Lucky, Executive Director, AT&T Communication Sciences Research. April 4, 1991 Networks in the Nineties Dr. Leonard Kleinrock, Professor of Computer Science and Chairman of TTI, UCLA. SCARFE Building. Guests welcome at no charge. CICSR: The UBC Centre for Integrated Computer Systems Research (CICSR) is an interdepartmental research organization made up of computer- related research faculty members in the Departments of Computer Science, Electrical Engineering and Mechanical Engineering. Currently there are more than 50 CICSR researchers who direct over 100 graduate students and collaborate with dozens of industrial firms in areas such as robotics, artificial intelligence, communications, VLSI design and industrial automation. CICSR FOCUS is published twice a year. EDITOR: Leslie Ellis DESIGN: Rob Bishop Office: 2053 - 2324 Main Mall, Vancouver, B.C. V6T1W5 Tel: (604)228-6894,fax: (604)228-7006 Contact: Susan Perley 19 15-1990 ANNIVERSARY THE UNIVERSITY OF BRITISH COLUMBIA"""@en, "Titled \"Focus\" from 1990 to 2010, and \"Innovations\" from 2010 onward."@en ; edm:hasType "Periodicals"@en ; dcterms:spatial "Vancouver (B.C.)"@en ; dcterms:identifier "QA75.5 .F628"@en, "QA75_5_F628_1990-09-01"@en ; edm:isShownAt "10.14288/1.0115134"@en ; dcterms:language "English"@en ; edm:provider "Vancouver : University of British Columbia Library"@en ; dcterms:publisher "Vancouver : University of British Columbia Centre for Integrated Computer Systems Research (CICSR)"@en ; dcterms:rights "Images provided for research and reference use only. Permission to publish, copy, or otherwise use these images must be obtained from The University of British Columbia Institute for Computing, Information and Cognitive Systems (ICICS): http://www.icics.ubc.ca/index.php"@en ; dcterms:source "Original Format: University of British Columbia. Archives"@en ; dcterms:subject "University of British Columbia"@en, "Computer systems"@en ; dcterms:title "Focus"@en ; dcterms:type "Text"@en ; dcterms:description ""@en .