Commission C – Signals and Systems
by Ernst Bonek August 24, 1999
Business Meetings
The Commission held open business meetings on 16, 18, and 20/8/99. The following persons were present at least at one meeting, but mostly at several:
At the opening of the first meeting attendees introduced themselves. The Chair welcomed everyone to the meeting and noted that there were 13 young scientists selected in Commission "C".
Chair report and setting the scene
The Chair explained his personal view of what URSI is all about:
The all important General Assembly is a an opportunity to learn and also meet convivially. We need to have a program which will continue to attract the very best people in the world at what we do.
The Chair noted that during the last three years while he had the responsibility of getting ready for the Toronto General Assembly he found it difficult to get reactions from many of the national "C" representatives. Of course there were notable exceptions.
The whole URSI organization is working hard to make its links with the ITU work really well. This will provide opportunities for URSI people to tap in to the huge and important work which is handled by ITU's study groups and to provide scientific input to ITU-R.
Election of the next Vice - Chair.
Commission C had a single candidate : Masami AKAIKE, Japan
Nevertheless, it was deemed fit to make a formal election by the national representatives present. No votes had been cast prior to the GA.
The result was 15 Yes, 1 No, so the candidate was elected.
Review of the Terms of Reference
The existing Terms of Reference were considered to be very broad. While it was felt that we can’t drop anything, a focus on radio communication systems was considered necessary. A GA cannot compete with the numerous specialized conferences in the area of signals and systems, so the ToR should make clear to scientists in these areas that their work for radio science and mobile communications is welcome. As Commission C provides enabling technologies for many other commissions´ work, collaboration with other commissions is also essential.
The new version of the ToR, later approved by Council, now read:
The Commission promotes Research and Development in:
in the areas of radio science and radio communications.
The design of effective telecommunication systems must include scientific, engineering and economic considerations. This Commission emphasizes research into the scientific aspects, and provides enabling technologies to other areas of radio science.
In order to find a way to activate national representatives to contribute to the work of the Commission with ideas, with their desires what do they want to see done, what will attract them to come to the GA and contribute, the Chair presented a "job description" for the National Representatives:
This was met with approval.
Particularly for researcher active in the areas of Commission C, the non-referenceable one-page abstracts in the Book of Abstracts were a deterrent in the past. For URSI GA Proceedings to become archival from now on will requires summaries to be at least four (4) pages in length. This will certainly greatly assist in assessing and improving the quality, make submissions much more attractive to potential contributors, but will require significantly more reviewing effort. The idea was welcomed.
As concerns topics for the next GA, Ernst Bonek compiled a provisional list of possible topics, which was enlarged and refined during the business meetings. It was agreed to circulate this list nationally and to other commissions, and to iteratively reduce it to the topics of widest interest. Each proposer of a new topic should say with three sentences what the topic is to include and to suggest a list of invited speakers, both highly recognized and willing to speak.
As of August 21, 1999, this list reads:
Possible topics together with other commissions include WDM for fiber optics, Application of secondary standards in telecommunications, Synchronization between satellites and ground, Clock synchronization for High-Speed Digital, Channel sounding in mobile radio (Commission A), Interference mitigation for passive radio science, High data rates in real-time systems, Software radio technologies and their application to radio astronomy, Photonics in radio astronomy, Wideband array technologies and systems (Commission J).
Editor for RRS
As in previous trienna, it was decided to charge the incoming Vice-Chair, Masami Akaike, with this task. He accepted.
Associate Editor for the Radio Science Bulletin
It was decided to charge Robin Braun from Australia with this task, who accepted.
Other business.
Paul Delogne described developments in Council to redefine the Scientific Committee for Telecommunications (SCT) and ongoing efforts with "Commsphere".
Robin Braun, stressing the international idea in URSI observed the difficulty non-native speakers have with English. He suggested mentoring by senior persons, eg practice sessions before the next GA.
Scientific Report
The enormous progress in applied and fundamental research in digital signal processing, stochastic and non-linear methods, in multicarrier transmission, in combined source and channel coding and modulation, in smart antenna technologies, radio over optical fiber, low-power radio circuit design have found their way into many contributions presented and discussed at the Toronto General Assembly.
Spectrum utilization and the avoidance of intersystem interference played an important role in the GA, and an inter-commission workshop was devoted specifically to spectrum congestion.
The topics of "Signals and Systems" and the underlying methods cut across the work of several commissions. The importance of Commission C-related-topics for URSI in general showed in the great number of joint sessions with other Commissions, i.e.
In mobile radio, signals are transmitted via electromagnetic waves, terrestrial and satellite mobile radio systems are the most complex telecommunications systems ever devised, not the least because of the difficulties radio multipath propagation presents. So, many aspects of mobile communications have become a major theme at this GA. This fact bore out in a number of sessions within commissions,
as well as the joint sessions
The General Lecture of Prof. Bach Andersen on " Scientific Trends in Personal Communications " was a sweeping success. Presently cellular subscribers outnumber internet subscribers 300 vs. 200 million worldwide. Cellular radio will overtake fixed-line subscribers by 2010, also worldwide. This already has happened in some European countries, an outflow of the overwhelming success of GSM.
For the future, Prof. Bach Andersen expects different technologies, not a single system, to fill different application pockets. Among them "Blue Tooth ", a very short range cable cutting technology in many devices (dish washer, washing machine, ...), wireless broadband access for stationary customers, and aircraft carrying piggyback transponders for wide area broadband coverage. The multiple access method for 3rd generation mobile communications systems will be Code Division Multiple Access. Prof. Bach Andersen pointed out that there exists a trade-off between spectral and power efficiency, spectrum being more valuable. However, power consumption drains handset batteries and power is related to range. One way of getting around the range problem are adaptive antennas. In a scattering environment, adaptive antennas make possible multiple independent channels, so "the bad channel is the good channel". Signal processing, "blind" ( i. e. without reference data) also, will solve many problems in multi-user detection and in estimating/predicting the channel (a wavelength ahead is already possible now). Software radio will adapt to local system and channel situations, but is presently limited by power-hungry analog-digital conversion. An interesting new development is a purely stochastic approach to urban propagation. Biological effects - not hazards - are still a potential problem, setting a power limit near the head.