Oral-History:Francesco Carassa
About Francesco Carassa
Born in Naples in 1922, Francesco Carassa spent most of his childhood in Piedmonte, Italy, where he developed strong interests in engineering and in literature. Carassa studied electronic engineering at Polytechnic of Torino, graduating in 1946. Professor Francesco Vecchiacchi, Director of the Central Radio Laboratory of the Magneti Marelli factory and a professor of radio communication at Polytechnic of Torino, invited Carassa to join Magneti Marelli, the leading Italian radio communications company. At Magneti Marelli, Carassa played significant roles in radio relay development and experimentation, and he directed the company's research laboratory. After fifteen years of employment at Magneti Marelli, Carassa became Chair for Radios and Relays at Polytechnic of Milano in 1962. There, he initiated a research group that focused largely on satellite communications, and he developed the phase-lock demodulator. In 1967, the research group began development of a satellite for orbit and undertook range frequencies testing for satellite communications as part of the Sirio project. With its launch in 1977, Sirio became the first European communication satellite, and it operated successfully for five years. The Sirio satellite enabled testing of video compressed digital communication, and bandwidth compression for digital television became Carassa's next major project.
In this interview, Carassa traces the stages of his career. Early in the interview, he describes the engineering curricula at Polytechnic of Torino. He then details the Magneti Marelli company's experimental development of a radio relay system with time-division multiplexing during the 1930s and 1940s. He analyzes the evolution of Italian radio and television broadcasting for its influence on Magneti Marelli development projects, such as radio links connecting Milano, Rome, and Torino, as well as microwave frequency connection to the island of Sardinia. Implementation of these projects in 1957 enabled multiple channels for television broadcasting. Narrating his transition from industry to academia, Carassa describes the ascendance of telecommunications and satellite communications as research fields. He details the Sirio project's experiments, funding, efforts to obtain international research partners, collaboration with Italian industry, and satellite construction. Carassa explains the reasons for his interest in digital video technology as early as 1967, including interest in developing video telephone technology.
In the concluding section of the interview, Carassa details his other teaching and research activities, including his service as Chancellor of the Polytechnic of Milano from 1969-1972. Carassa describes the evolution of Italian engineering education. He then considers his work's place in the history of invention and in Italian society.
About the Interview
FRANCESCO CARASSA: An Interview Conducted by Frederik Nebeker, IEEE History Center, 7 July 2004
Interview #446 for the IEEE History Center, The Institute of Electrical and Electronics Engineering, Inc.
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It is recommended that this oral history be cited as follows:
FRANCESCO CARASSA, an oral history conducted in 2004 by Frederik Nebeker, IEEE History Center, Piscataway, NJ, USA.
Interview
INTERVIEW: Francesco Carassa
ALSO PRESENT: Professor Guido Tartara
INTERVIEWER: Frederik Nebeker
DATE: 7 July 2004
PLACE: Milan
Childhood, family, and education
Nebeker:
I know that you were born in Naples in 1922. Was your family living in Naples?
Carassa:
No, no, my family was living in Naples for a very short time. I returned back at the age of two years to Piedmonte, near Alexandria. There I had the elementary school and the secondary school. Then after that when I was teaching at the university, I went to Torino.
Nebeker:
Were you always interested in science and technical things?
Carassa:
I must say that, indeed, when one asked of me what I wanted to do, I had two alternatives: one was engineering, and the other was literature.
Nebeker:
Have you continued your interest in literature?
Carassa:
Until a few years ago I had the pleasure of translating the lyrics of [unintelligible]. On the other hand, this book, for example, ...
Nebeker:
Yes, this is a literary achievement.
Carassa:
Then I went to the Polytechnic of Torino, and I graduated in 1946.
Nebeker:
Were the war years difficult for you and your family?
Carassa:
I had no great difficulties. I was in this little place on the water. I was in the Navy. People there asked me if, in case of need, I was available for going in the war. I replied, no.
Nebeker:
But you were in the Navy, yourself?
Carassa:
I was in the Navy before. Then on the 8th of September I came home.
Nebeker:
I see. You left the navy.
Carassa:
Yes, I was an official of the Navy, but not in career.
Nebeker:
As a young man in Italy, did one have to do military service? Did you have to do Army or Navy or something in those days?
Carassa:
Yes. Well, when it was the time to decide, I asked to be in the Navy because I have always been interested in the sea. I am a sailor. I always enjoyed that.
Nebeker:
I see. So you went to the Polytechnic in Torino during the war, and graduated in 1946. Is that correct?
Carassa:
Yes, because I went to Torino just before the beginning of the war. I went to Torino not continuously.
Nebeker:
So you were away for a year or two?
Carassa:
Yes. I succeeded in coming to Torino to give exams. But because they are very bad to take.
Nebeker:
Were you studying electrical engineering?
Carassa:
Electrical engineering.
Nebeker:
Was there communications engineering as a choice at that time?
Carassa:
No. There was only electrical engineering, in which you have the possibility of selecting something more than that. We at Torino had a course on radio communication, which was a very technical course, because in one year we had to do everything. But there was no program in communications. This came much later; it opened the up in 1957.
Tartara:
I was one of the first in the second year. Polytechnic was in the year ‘56 around that. I entered here in 1956 as a freshman.
Nebeker:
That was the first class of a separate program?
Tartara:
Yes. Ten people for nuclear engineering and ten people for the electronic engineering.
Nebeker:
I see. So “electronic engineering” was what it was called?
Carassa:
When we started that, there were ten of them. [Unintelligible] that I was one of them.
Nebeker:
Is that right?
Carassa:
Yes. I was told by the dean of the department that this was the decision and that I have to receive the honor of being one of the teachers, and I say, “Look, I thank you very much, but I have to remark that, in front of the missile industry, ten people was a very little number.” And he replied to me, “Well, but [Unintelligible] was a tradition. We cannot make mistakes. So in selecting ten people, we are sure to select the best people.” And this you know, the best people go on to be a professor or nothing at all.” [Unintelligible] you don’t. He presented me to shake hands. [laughter]
Nebeker:
Were you pleased with your education at Torino? The education you had for the engineering degree, was that a good training?
Carassa:
Yes, I think so. Torino was good and in addition I had the good luck to meet in Torino, Prof. Vecchiacchi. Vecchiacchi was Professor of Radio Communication, and at the same time was Director of the Central Radio Laboratory of the Magneti Marelli factory. He went to Torino because he needed to have some young engineers. And I was the one he asked to go to Milano.
Magneti Marelli
Radio relay
Nebeker:
So that was the research laboratory for magnetic materials?
Carassa:
It was a factory whose name was Magneti Marelli.
Tartara:
It is in communication. Magneti Marelli is a proper name, an historical name in communication.
Nebeker:
It was a telecommunications company?
Tartara:
Yes, Magneti Marelli was only telecommunications. Mainly radio communications. The first radio links in Italy. Also I think, I don’t know the position in the world, but it was the national leader in radios.
Nebeker:
He invited you to come join that?
Carassa:
Yes. I went there, and it was very interesting to me to see that when I arrived at this laboratory they were engaged in developing a radio relay system with time-division multiplexing, which was a very interesting theory at that time. Time-division, as you can understand, is based on control switches, and control switches at the time were only [Unintelligible] of two. So to make an equipment that is equal today is in a box of matches.
Nebeker:
This was an experimental system of time-division?
Carassa:
This was an experiment.
Nebeker:
Was it put into use in any system?
Carassa:
Well, it was put into use also experimentally, but it was put into use because Vecchiacchi started in 1937 with the idea of developing a radio relay system. In ’37 it is just the year of the death of Marconi.
Nebeker:
That’s interesting. Now this radio relay system, was that for telephone channels?
Carassa:
Telephone channels. And the maximum allowed is twenty-four channels. Twenty-four channels—at the moment there is the public need for hundreds, you know.
Nebeker:
Yes, it sounds funny today to say twenty-four telephone channels.
Carassa:
Anyway, I remember that when you have a multiplexing system from the signal multiplexing, you have to drop a group of channels. This is quite common, because you need perfect servility. But if there’s FM monitors needed to build an equipment, we’ll do that. And they’re young, Carassa will ask you to do that. That’s the first thing.
Nebeker:
That was your first project?
Carassa:
And this was impossible to accept because at the time it was not sufficient to do something commercially of interest. So at that time the microwave radio relay system made by the best system in northern Italy, the TV II system, was made with frequency modulation and frequency division multiplex. And those of Vecchiacchi was compared to change and past the frequency modulation of frequencies they use in multiplexing.
Television transmission relays
Carassa:
From the moment we were engaged in developing this radio link, Vecchiacchi was maybe interested in using the broadband system for television.
Nebeker:
Had television broadcasting started in Italy at that time?
Carassa:
It started the radio broadcasting in Torino and Milano and Rome. But the first idea was a link between Torino and Milano and a different programming site in Rome. We assisted the other link by radio.
Nebeker:
So you wanted to link all three cities?
Carassa:
Yes, but after many difficulties we arrived to a single network for radio relay system covering all of Italy, including the islands. And this has been the first radio relay, I think, in Europe of this dimension, because we had twenty repeater stations.
Nebeker:
Was this for television transmission relays?
Carassa:
We had also a part for connecting the island of Sardinia, and this was a very complicated thing because it was a rough path over the sea.
Nebeker:
So you had a link across the sea to Sardinia?
Carassa:
Yes. At this moment, unfortunately, Vecchiacchi died, and I was asked to take the responsibility of this thing. For example, the link to Sardinia was successfully obtained using the same frequencies in the rest of the Italian network, but using site diversity in essentially two places, selecting from time to time the best one.
Nebeker:
I see, because the distance was greater than usual, is that right?
Carassa:
Yes. So the multi-parted factors were bigger.
Nebeker:
Were these in the microwave frequency ranges?
Carassa:
Yes, in the microwave frequency, around 1 GHz.
Nebeker:
That was quite a responsibility for a young man to take over this television…
Carassa:
It was intended, you see, becoming old for a young man. [laughter]
Nebeker:
And how did that work go? Was it very difficult?
Carassa:
Well, of course when you are thinking to have a signal with those meters, with twenty sites.
Nebeker:
So you had twenty stations all around Italy?
Carassa:
Yes. I have here a couple of photographs. These are the experiments in Sardinia. So you see from Milano to Palermo you have twenty options, then these variations on to Sardinia.
Nebeker:
And this was completed in the mid-’50s?
Carassa:
In ’57.
Nebeker:
And was it put into use immediately?
Carassa:
Immediately.
Cultural functions of Italian television
Nebeker:
So that must have been very good for Italian television to suddenly have all of these channels.
Carassa:
This year will the fiftieth anniversary of this creation of television in Italy. And during this ceremony it was remembered that when Italy was made by the Savoyan kings, it was said by the historians, “Italy is made. Now we have to make the Italians.” And then the television had a great role in this.
Nebeker:
Well, I know Italy had a great variety of local cultures and local dialects.
Carassa:
Yes. This was this idea: Italy is very direct to make the Italians.
Nebeker:
So you’re saying that television was very important in making a single country?
Carassa:
Yes. In the sense that it applied to the question what is the impact of what you have done on the society? I think that this is important.
Nebeker:
Absolutely. So all of Italy was able to see the same television programs?
Carassa:
Yes.
Nebeker:
I’m curious, has there been a big change in language, for example, over these fifty years?
Carassa:
Yes. The people were used to a single dialect. It was so much received information, because it evolved, and not information only local.
Nebeker:
That’s right. Was this television a state operation in Italy? It was state broadcasting?
Carassa:
Yes.
Nebeker:
The whole network worked well?
Carassa:
Yes. Very well.
Nebeker:
That’s quite an achievement.
Carassa:
But of course when we say this was a very long system, we have to take into account that at this time it was it was being realized there was a longer system. It was coast to coast in the United States.
Nebeker:
Well, there was more money in the United States, though.
Carassa:
Yes.
Radio relay systems experimentation, 1961-1962
Carassa:
So after that I had the opportunity to do some contributions in the field of radio relay systems.
Nebeker:
This was at the Magneti Marelli Laboratories?
Carassa:
Yes. This was the demonstration of the feasibility of radio relay systems of 2,700 channels. Now at this time the capacity was increasing everywhere, in Italy included. First it was possible that we realized a radio relay system with broader band. We had the capacity. The CCIR, the Consultative Committee of International Radio, decided to put a question, what the limitation to the capacity of radio relay systems, and what can we do to overcome this. I proposed to make history in that. Indeed I remember that when I read to put this proposal to my factory, I said that I was interested at realization of radio relay systems for 1,800 telephone channels. And I said I want also to make this capacity. But the result dropped. I was thinking about 2,700, and we succeeded in realizing 2,700, and the international recommendation made by CCIR was approved.
Nebeker:
At 2,700?
Carassa:
Yes.
Nebeker:
What years did you do this?
Carassa:
This experiment was done in ’61. We discussed it at CCIR in ’62.
Nebeker:
I see. This was the telephone system with 2,700 channels. That must have been very pleasing that that was approved by the CCIR. And it was implemented in Italy and elsewhere?
Carassa:
The first to use it commercially was the Japanese. And then everybody. In any case, we had at this point make an important statement.
Directing the research laboratory
Carassa:
In ’62 I left the industry for university, and I went here to Polytechnic. My life was just that: fifteen years in the industry and thirty-five in the university.
Nebeker:
I see that you were director of this research laboratory at the Magneti Marelli. How large a group was that?
Carassa:
A small group. Twenty persons or so. [Shows photo]
Nebeker:
Was that company successful in those years?
Carassa:
Yes, it was a successful because the main production was in equipment for automobiles. Magneti Marelli equipment for automobiles, spark plugs—anything that is an accessory for automobiles. And they made the money from that, and they spend the money on research for that! [laughs]
Polytechnic of Milano
Chair for Radios and Relays
Nebeker:
So in 1962 you were offered a position at the Polytechnic here?
Carassa:
Yes, I was already coming here three years on courses for Magneti Marelli. At this I won the competition for the Chair for Radios and Relays.
Nebeker:
I see. Was that a new chair?
Carassa:
I was the Chair; it was first the Chair of Professor Vecchiacchi. That was the chair he started.
Nebeker:
So it was just the three of you who have occupied that chair?
Tartara:
Now there are more Chairs.
Carassa:
Yes, now in Telecommunications.
Tartara:
Yes, now.
Carassa:
There were only three then.
Tartara:
At our time, Carassa was the only Chair in Telecommunications. Now in Telecommunications we have six or seven Chairs.
Nebeker:
A much bigger program now.
Telecommunications, satellite communications
Carassa:
Now this has more or less a similar tendency on the scene as telecommunication appeared a new dramatis persona . Now you have to put yourself in the shoes of people who spent their lives sending microwaves from the mountains to other [unintelligible]. He came on the scene and said, “Let me do everything.” You can throw out all your equipment on the mountains, including the intercontinental. Well, Don Vecchiacchi with enthusiasm, had taken into consideration the radio relay through the Bering Strait.
Nebeker:
That’s interesting. That would have been possible with…?
Carassa:
No, he said that it is practically impossible to make through the Strait of Bering
Nebeker:
An interesting idea.
Carassa:
Well, this mess that the last war I had at the laboratory at Magneti Marelli was the experimental agreement for participation to the Test [Unintelligible] Center.
Nebeker:
Oh, they had some involvement with or interest in that work?
Carassa:
Yes. The agreement for participation in the experiment in ’61, ’62. Then when I arrived here, I formed a new research group mainly devoted to satellite communication.
Nebeker:
I see. So you were convinced already in 1962 that that was a very important area of work.
Carassa:
Well, if you have the patience of reading this book, there is an interesting episode in there. The [unintelligible] asked me (I don’t remember when exactly it was; it was perhaps ’60) an opinion about the satellite communication, and I said in this book that never in my life I expressed an opinion, so it might be mistake. Because I said satellite communication is very important, will be very important, but I think that the first time will be realized with passive balloons.
Nebeker:
Yes, like the Echo satellite, and active repeaters.
Carassa:
Especially I expressed this opinion three years after I had already realized the agreement for [Unintelligible]
Satellite communications research group; phase-lock demodulator
Nebeker:
So you came here and started this research group.
Carassa:
Yes.
Nebeker:
How did that go?
Carassa:
First of all, we have to go see that here we had the possibility of doing some research, not with a very large experiment. But anyway, I was able to develop a new frequency demodulator that was capable of extracting the signal from the mixture of signal to noise.
Nebeker:
So you had to design a new demodulator?
Carassa:
It was the phase-lock demodulator.
Nebeker:
And that was because there was a lower signal-to-noise ratio for these?
Carassa:
It was able to work in [unintelligible] situations.
Nebeker:
And so your research group, or you yourself, worked on that demodulator?
Carassa:
Yes, the research group.
Nebeker:
And it was successful?
Carassa:
It was successful because after that was passed to the industry it was produced for serial route stations, etc.
Sirio project
Nebeker:
I see. What other projects did your research group take on?
Carassa:
Well, I must say that the big projects we started in 1967 was the Sirio and this took a great part of our efforts.
Nebeker:
I’m sure. And the idea there was to test a new range of frequencies for satellite communications?
Carassa:
The situation was the following. Europe had in mind establishing a good space program with the idea, or really the possibility, of increasing the knowledge of this field, and to participate in the international competition. It was at that time that there was a program called the Organization ELDO (European Launch Development Organization). This program was launched in three stages. One provided by France, one provided by Italy, and one provided by Germany. Italy was charged to build a test satellite to prove the viability of this and to put into orbit a satellite of the dimension more or less common at this time.
Nebeker:
This was a geostationary orbit? That was the plan?
Carassa:
Yes. This test satellite was equipped with everything you need to have a satellite in orbit: the system for telemetry, the system for tele-command, the power supply. Everything.
Nebeker:
Did it have those solar cells for electric power?
Carassa:
Solar cells, yes, everything. But it does not contain all the telecommunications. Instead of containing all the telecommunications, there was provided a piece of metal.
Nebeker:
Oh, just to fill the space or to have the same weight?
Carassa:
Yes. To me and to the people at the National Research Council it appeared that this was a solution, because we had already some great expense, and we had to see if there was a possibility to establish a program.
Nebeker:
So with this test you wanted to put up a satellite that actually worked. Is that right?
Carassa:
Yes, worked. Although there was some risk because the Russian was an experimental one. But instead of putting nothing in orbit, we tried to put something in operation, and I said it would be important to have in orbit a satellite airborne to do something advanced, not something that’s already done. What was something new, I said at the time, new is indicated by the history of the radio communications, because the history of radio communications has be a continuous run towards ISV.
Nebeker:
That’s right, up the spectrum.
Carassa:
Research on new space available for communications. This was accepted, and they decided to include this inventory. But in ’69 the ELDO PANELISTS (the name of the satellite was ELDO PAS) was canceled for financial reasons. Italy decided to retire from ELDO and transform this ELDO PAS into a national program whose named for Sirio. Sirio was expected.
Nebeker:
Yes, but without, of course, the launch capability, but you’re going to continue to develop the satellite.
Carassa:
That capability we had to apply to the United States, where it was being done.
Nebeker:
Okay, so the Italian government decided to fund this Project Sirio?
Carassa:
Yes. At the time I had no experience on deciding the program
Nebeker:
So were you very involved yourself in convincing the legislature to fund this project?
Carassa:
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Yes. I was involved many times. First of all, I will say that when Italy decided to [unintelligible] material, I began to open a discussion with possible participants with the experiment from other places. In the beginning we had a meeting with the potential international participants. There were at least twelve bodies in Europe willing to participate. We had provided three Italian stations for Sirio. Two big stations: one in Fucino and the other in Lareo, which are the places of the two big stations of tele-sponsor, which you know in Lareo. And there’s no station here at the Polytechnic, although the responsibility of the proper experiment was here at the Polytechnic. From this end, it was created here with agreement between the Polytechnic and the Russia Research Council Center, called Center di Estudio Telecommunique Especiale whose director was Tartara. I was the president of the Scientific Committee. This activity was including propagation studies. We tried to investigate all the rain in Italy, the precipitation effect.
Nebeker:
So the purpose of this satellite was to explore these new bands of frequencies and find out how well they would work for satellite communications?
Carassa:
Yes.
Nebeker:
And you were particularly concerned with the effect of rain on transmission at these frequencies?
Carassa:
That’s right.
Nebeker:
Is that because terrestrial experience had shown that rain could be a problem there, or theoretical arguments?
Carassa:
Theoretical. It was easy to understand that there were problems. It was important to establish the theory from a statistical point of view what were these effects of rain over the propagation.
Nebeker:
So these frequencies were not at that time being used for communication?
Carassa:
At the time we made the proposal, they were not used at all. When we succeeded in it, there was something like ten years of delay. It was the general standard. The lower part of this phase began to be used.
Nebeker:
So you established that Sirio Project here, and you tried to get international partners for it?
Carassa:
Yes, because when you investigate something for research, it is important to have statistical significance. You need statistical samples as large as possible. So the benefit is that it represented an increase in the statistical value.
Nebeker:
Is that because you wanted to have land stations in other countries?
Carassa:
Yes.
Nebeker:
And did you succeed in getting international partners?
Carassa:
Yes. We had partner--which had patience. There was a good participation.
Nebeker:
I see here the countries that were involved, two in England, one in France, two in Germany, one in Finland, one in Holland, and one in the United States. So quite a lot of groups from other countries. The role of these other groups was to establish a land station and then transmit and receive?
Carassa:
They were only a receiving station. In Italy we have a receiving and a transmitting station, because the idea that I had just at the beginning was to use the satellite to establish a network between the engineering schools in Europe. This didn’t happen. Along the way there were causes of delay.
Nebeker:
So what were the main causes of delay? You got initial approval of the project, then it took years, I know.
Carassa:
It was due to the fact that, first of all, it is difficult to fund it. It is rather difficult when you fund this area to do the practical complexity in industry. We thought that when contact with society, and we had a delay from the authorities that decide. They asked if it was still valid.
Nebeker:
So every time there’s a delay, you had to justify the program again and say it’s still valid.
Carassa:
Now at this time it seemed to us a terrible delay, but many other programs are delayed. Sirio remained the first European satellite for communication.
Nebeker:
This was the first European communication satellite?
Carassa:
Yes.
Nebeker:
When did it actually get built?
Carassa:
It was launched in ’77.
Nebeker:
And was it constructed-- was it the industries around here that took part in this?
Carassa:
Italian industries.
Nebeker:
And coordinated here in Milan?
Carassa:
Milano had the responsibility for the experiment. So we had responsibility for all the experiments of communication and propagation. But the construction of the satellite was made by the industry with the responsibility of International Research Council.
Nebeker:
Was that another university that oversaw the construction of it?
Carassa:
No, the university, we were alone the CSETS. It is important to say that, in addition to propagation studies, there were also communication experiments.
Nebeker:
What sort of experiments?
Carassa:
Experiments were made on new things, all experiments in new use of telecommunication. Concerning the first thing, we had the application of this phase-lock demodulator for transmitting television signals. In addition, this possibility of transmitting television was used by our broadcasting company, because, for instance, on Sunday when there are the sport events, they needed an additional television channel between Milan and Rome, and this was useful then. Then there were some experiments of communication data transmission by the Italian Navy. The Italian Navy theory still from the time of Marconi was very keen in doing experiments in data transmission. There was little station of the [unintelligible] of telecommunication for testing new ideas for transmissions. Tartara was the Director of this Center, so I don’t know if you have something else to add.
Tartara:
Oh, yes. We tested video compressed digital communication.
Nebeker:
This was digital video?
Carassa:
This is, I realize, a different story.
Tartara:
And are you speaking only of with Sirio.
Nebeker:
We’re on Sirio right now.
Carassa:
With Sirio, digital television was the following. Before [unintelligible], we requested that the lifetime of the Sirio satellite was two years, assuming that two years was sufficient for any statistical meaning to be provided in space. But Sirio lasted very much more. So if you read the report about the result of Sirio, you may check essentially that there was a group of results after two years. The only ones that we had any great time was five years results, which was the real duration of the satellite.
Nebeker:
So it actually functioned for five years?
Carassa:
Five years. It was a big success.
Nebeker:
Yes.
Carassa:
Both for propagation and telecommunication. When we started with the idea of Sirio in 1967, we started up with a group here in Polytechnic working in digital television in bandwidth compression for television. After three years of life in orbit, I said the following comment: “We are working every week on the digital television transmission, but we are not able to do experiments through Sirio in there, because we will not last sufficiently.” After five years they said…
Nebeker:
What were the limiting factors with Sirio? Were there tubes that didn’t function?
Carassa:
The limiting factor was the auxiliary propellant.
Nebeker:
What’s that, for orientation?
Carassa:
Yes. Orientation and maintaining the position.
Nebeker:
Okay. But the tubes and the power supply were okay?
Carassa:
They were okay.
Digital video;digital television bandwidth compression
Nebeker:
That’s interesting. So at the same time you started this work, you started this work on the digital television, the bandwidth compression?
Carassa:
Yes. And it was sufficient to do the experiment to test digital television compression, so I think that we were the first in doing a demonstration of television under the compression [unintelligible].
Tartara:
We had a group of digital signal processing researchers. Now there are many colleagues that work in this particular field, but the group here which has continued to develop the image processing. The first line of research of this group was just digital video.
Nebeker:
And why were you interested in digital video at that time? That’s very early, and what did you think was important about it?
Tartara:
The digital video was an important line of research. And there’s an application at this time. The first application we were thinking about was teleconference. At this time it was the teleconference, the video telephone—this image of the future.
Nebeker:
You thought going digital would allow you to do it with less capacity?
Tartara:
Yes. At the time it seemed very successful, and very much interest in this line. And this, as you know, raises some variation of the perspective because it was imperfect. At this time the physics element for the video telephone was not successful; it was too costly. Video teleconference was as being a limit of my research. The object was very fascinating, just not travel back to see each other.Yes we know, we like to travel to family.
Nebeker:
Yes, teleconferencing, even today with much better means, is still not very popular.
Tartara:
Yes. Just to say something else. One thing which was interesting is for instance to use teleconferencing for learning, for teaching. And I think that basically the main result practically throughout the area is that if the quality of the video is not excellent, it’s very difficult to make the success of it. And where the very excellent teleconference it is not, in any case, easy and not a technical problem and not a problem of compressing the images, but for many a resource. And so there is a complex of expert of the problem usually. But at this time this was one of the aspects of information theory research, because the focus here that started in information theory was transmitting, coding information, and source coding. The compressed image was the theoretical and system point of view. It was justified it’s basic research, and the first time everyone was convinced of the enormous application.
Nebeker:
What year did you begin that work on the digital video?
Carassa:
’67. But at that time, to show that there were possibilities, subsequently we had to work on a quarter of [unintelligible], not on the full measurement. And in this quarter we were compelled to use as memory. And by [unintelligible] station lied
Tartara:
Yes, it is rudimentary technologies.
Carassa:
But at that time we were learning an important thing, that when the technology is not sufficient to solve the problem, you have to go on that, because it is not able to solve the problem today, but it will be able tomorrow. In fact, all work has been done here with this later technology available, and we realized our goals some years out.
Sirio satellite
Collaborations, launch, and success
Nebeker:
So it took, as you say, ten years to finally get Sirio up in space. It must have been very exciting when that launch took place. Were you here when the satellite was launched?
Carassa:
I was in Cape Canaveral.
Tartara:
[Finds photograph of the launch] This is Sirio, Italia. This is the launch, yes.
Nebeker:
Did you go also?
Tartara:
I went some weeks after just to go to the Space Center. There was some problem.
Carassa:
Now there were some people who went to Cape Canaveral to assist with the launch, and then the rest was performed at the [unintelligible.]
Tartara:
It was some problem of scheduling for this.
Nebeker:
That must have been very exciting.
Carassa:
Oh it was very exciting. You have to understand that those are from the practical point of view. Old people here, young people, were all involved in the Sirio program. Because at any moment I was asking to myself, but I have committed these people to work all of the program. This program is too often worthwhile. In fact, Sirio has been fantastic because from the moment it was put in orbit, everything operated perfectly.
Nebeker:
Well, there’s that side of it, but every now and then it happened in the last year that a satellite has to be destroyed because the launch doesn’t work, and that’s such a tragedy for all the people who worked years and years and years to build the satellite.
Carassa:
I wrote that the program had a certain probability of success. This was calculated in terms of life of the components and everything. If the success does not happen, what can we do? Because a big mission is much more than an estimated space program, we will do that, and if we don’t succeed, we have a the following program to go. But for us it’s a little more [unintelligible]. It was regulative, people were destroyed. It went very well and here the people were very enthusiastic.
Nebeker:
Yes, I’m sure. And then you had this worldwide cooperation, really, with the experiments. How did that go? How did the collaboration with these other centers work?
Carassa:
Well, we had organizing information about all of them, and we had regular meetings that they tell us in a letter. So, for example, [unintelligible] the results, the Sirio of the two years I participated. This is a Carassa interview. Then four papers later you see propagation measurement at the amplitude of the whole thing.
Nebeker:
So this journal, which is Alta Frequensa, Scientific Review in Electronics, had a special issue on Sirio in 1980, with it looks like a dozen or so articles, many of them from these other groups that were using Sirio. And there was a similar thing in 1979, a special issue on Sirio after the first year of the experiment. And in April of ’78, a special issue on Sirio.
Carassa:
And in 1987, this is a special issue on the Sirio program in the tenth year the satellite was up. It was Rafael’s group. This is an interesting story. Now, you understand that Sirio lasted more than two years. It was difficult to have the reports. They asked many times that was lasted, because it was a pity having a satellite in orbit without any experiment, they wanted to go on with the experiment. We obtained at a certain moment a compromise. At a certain moment it happened that the National Research Council was providing only the satellite. The air station in Tigre is funded by TeleSpacio, by Dinelli, by others.
Nebeker:
So you went out and found other sponsors?
Carassa:
Yes. And this was in the fifth year. I did end, though, ’82, if I remember well. Interrogation composed by the Ambassador Telalego which was the president of this delegation, Professor Venieno who was the Director of the Space Plan of Italy.
Collaborations with China
Carassa:
Carassa, Porsoborio and the other professors arrived in Techem with the idea of trying to establish a cooperation in the space field. Just to be brief, at this certain moment the Chinese asked any one of us to give a lecture on what was the activity in this particular area of Italy. So it was for me to illustrate what we were doing here: the experiments we had written, the manner in which we analyzed the data, etc. And this was very well accepted. And it was at this moment the decision was that we’ll try this in China. Went to Milano to participate with our people here to do data production. Seated near me was Professor Venieno, who was the Chief of the Italian Space Program. I said to Venieno, “But why, instead of come the Chinese scientists to Milano, we send the Sirio to China.” Made the different excavation of all the propellants available to Sirio. The answer was, “Yes, you can do that.” You say this and the Chinese are very enthusiastic, and really this was the moment Sirio started to go East moved from the longitude of Italy.
Nebeker:
So you made a big change in longitude there?
Carassa:
Yes. It’s a very interesting situation.
Nebeker:
That is surprising.
Carassa:
And then after one year we were there experimenting technique, the scientists from the East came to Milano.
Nebeker:
Did the satellite then stay at that new longitude for the rest of the time?
Carassa:
Yes. This is one of the things you can put under the heading, “what have you done that surprises you that you do not expect?”
Nebeker:
Yes, this international, or with the Chinese, in particular. That is very, very interesting. That was a very nice story about the Chinese collaboration with the Sirio Project.
Carassa:
Well, I said mainly for a joke to Venieno, “Why we don’t bring the Sirio here?”
Nebeker:
That’s so surprising to me that that was possible.
Technical achievements
Nebeker:
So I can understand, for those ten years—well, even longer, of course, because all the ten years up to the launch of Sirio, and then ten years of active life. What was the active life of it, of the satellite?
Carassa:
From ’77 to…
Nebeker:
I see this special issue in the tenth year. Was it still active in the tenth year?
Carassa:
Yes, not fully usable, but yes. In ’85 Sirio was moved around this new position. In ’85 the Japanese came into the Center for nearly two years.
Nebeker:
When you look back on the Sirio Project as a whole, what were the main technical achievements?
Carassa:
Well, they assumed the data for designing a link to new areas.
Nebeker:
So you had data from many stations in this frequency range, so this was exploration of that frequency range for satellite communications.
Carassa:
Yes. The exploration was attenuation at each frequency. Attenuation because of some rain. And now they say seeing it from a general point of view, you might say, I want to know what power I have to transmit to obtain that declination the rain with not higher than my power margin. This information is my power, I have an interruption of the service. So the question is, how long outage time I must obtain without incurring the power interruption.
Nebeker:
So this information is obviously crucial to planning any communication satellites that are using those frequency ranges. Have those frequencies since been used in communication satellites?
Carassa:
Yes. There is this around 11-12 GHz are currently used today for telephony and for broadcasting.
Nebeker:
So it was very important that these data were gathered.
Carassa:
Oh, yes. If I was yet to have these data, the propagation experiments also involved eighteen years. We have been able to see experimentally how this data increases with the frequencies. We are able to extrapolate our results to higher frequencies.
Nebeker:
So a sort of general understanding of attenuation because of rain.
Carassa:
This is the moment we actually are of service. But what is the possibility of using still higher frequencies? Still I ask this. Trying to answer this question, there is another consideration and the consideration is the fear. If we proceeded the attenuation, which is variable in time because independent of rain, suppose at this moment I have [unintelligible] say that Sirio becomes very [Unintelligible] I can, if transmit power, this is the [unintelligible] operate. But, is it an economic solution or not? The answer is it is not, because to perform the operation in this way, I transmit continuously at high power. Also, it serves only a few things.
Now, in ’79 I have proposed to use two new methods of trying to operate in this way. I explain immediately. First of all, the rain cells that you encounter when you are in an automobile on the highway, the area is a meter in diameter, a meter to overcome this is to use site diversity. There is the satellite there. And you can see two or more [unintelligible]. Now, you can do [unintelligible]. This is an adaptive measure.
Nebeker:
Yes, I see.
Carassa:
I suggested two hundred meters, if one of them is frequency diversity. And frequency diversity was based on the concept that instead of making [unintelligible] at one frequency, I used a very high frequency where the capacity is very high. If you use very high frequency, then the capacity is very high. But when I, not to mention the solar [unintelligible], I switched from this I figured to be roughly when the ... You see, but this wise doctor would always want to know the frequency and that’s all. No, because when I consider the increase of capacity, I have an interest in very high frequencies because we had capacity.
Nebeker:
So you had much greater capacity at those frequencies?
Carassa:
Right. High frequencies, high capacity. But there’s more numerous stations [unintelligible] just receiving this same paper, as I said before is, coordinate. You have a time division system. Suppose that you have a same number of stations which are part of the frame. If you needed three pieces, if one of these stations over here needed more capacity, you [unintelligible], and you can also introduce a recording. But I consider that our research in this respect are all important.
Nebeker:
So these new techniques were overcoming attenuation.
Other teaching and research activities
Nebeker:
So the Sirio Project was I’m sure your main activity from maybe when you proposed it through the ’70s and into the ’80s. Did you turn to some other project at that point?
Carassa:
I was involved in some other research. For example, in the last years I was involved in research on Soliton Optical Fibers.
Nebeker:
I see. By the way, when did you retire from the professorship?
Carassa:
I retired in ’94.
[End of Tape 1, Side B.]
[Tape 2, Side A]
Nebeker:
So in 1997 you retired.
Tartara:
Yes, because in Italy at 70 you retire from teaching, but you can remain for five years. So you are not retired. At 75 you retire from the official point of view.
Carassa:
Now, if you are interested, I can touch on other aspects of things. There is a thing called [unintelligible passage]. We know that you have a satellite transmitting continuously. For us it would be important for the guidance of the devices. I remember that we were near [unintelligible] at Cape Canaveral . Of course we agreed, and at the time, the passage at Tibido was [unintelligible] position of Sirio.
Nebeker:
That’s very interesting. So because the position of Sirio was accurately known…
Carassa:
[Unintelligible] is the fact that there was a possibility of measuring the ionosphere, which allowed us to determine the position of Sirio with accuracy. But it was not the position of Sirio; it was the [unintelligible] which permitted [unintelligible]. And this of course was expected.
Nebeker:
Yes, very nice to have some part in the Voyager missions.
Carassa:
Yes. See, there was only one satellite being developed [unintelligible], thanks to the delay. [laughs]
Nebeker:
[laughs]. It’s nice there’s something good to come out of the delay. I read that you were Chancellor of the Polytechnic here from 1969-1972. If you would tell me a little about that time.
Carassa:
I had here in the Polytechnic, some more students than [unintelligible].
Nebeker:
Oh yes, the student unrest in 1968, yes.
Carassa:
I was to be candidate for this position of Director. And I was not willing to do that just because I had all these commitments already. But Poly insisted and I decided to help with developments to maintain the quality of their studies. Unfortunately, there were big differences between the engineering degree and the school of architecture. Architecture takes much more advanced related easy studies.
Nebeker:
So the architecture students were more involved in the student unrest?
Carassa:
They were more involved. But what happened to me was that I asked to have two [unintelligible passage] to be not alarmed [unintelligible]. Because it was very difficult and the students were asking impossible things. We were in the position of saying that when a student wanted to have easy studies, they did not receive that. The most important reasons for people [unintelligible]. And we tried to explain this to the students. Because it was the poor people who were without other resources.
Nebeker:
So it sounds like those were some difficult years.
Carassa:
There is another thing for you to more understand my reasoning.
Nebeker:
Oh, the dollar sign? [laughter] So those were difficult years to be rector or chancellor, I can imagine.
Carassa:
Yes. We took risks. We took on all these difficulties. It was difficult.
Nebeker:
Yes, I can imagine. So you stopped that in 1972?
Carassa:
Yes, but I was stopped against all of the opinions of the colleagues. I was stopped because I had too much.
Nebeker:
Yeas, you were trying to get the Sirio project going.
Carassa:
The Sirio was itself involved in that it had been delayed allowed me to go to the Director.
Departments, degrees, and disciplines in engineering education
Nebeker:
Yes. How did the Department of the Communications and Electronics program here work? Did the teaching and the undergraduate and graduate programs develop well?
Carassa:
We had [unintelligible] three years ago.
Nebeker:
The university must have been growing in these years.
Carassa:
Yes. In the past we had only one degree; it was five-year degree. Now we had introduced a three-year. There was some feeling that this was more difficult to maintain. Now, we’ve changed it to three years. I must say that I was one of the people who asked to have the degree. Now we have three degrees: Electronics, in Informatics, and Telecommunications
Tartara:
Obviously now. You are speaking of the situation now—not 1968, but now. In short, the situation, the changes in Italy were because of the merging with the international situation. I mean, up until two years ago in Italy we had only one degree, the Laurea, five years, which does not correspond to the bachelor’s, but the master’s. That in engineering it seems to everybody that we need now the other, but for a long time it has been realized that two levels is typical. Typically in Germany students went to different school for a diploma that is something like a bachelor, and more professional, and the other corresponds to an average master’s.
Now we are realizing and implementing the new situation, and now there is a big problem with the university in Italy because every format is the same. This is very much been decided because it is difficult to have the same thing for philosophy and genetics. This is a big theme of discussion. In Italy the situation is the classical organization is centralized, like France. It is not like U.K. or U.S. But now we are changing, type of change toward more autonomy for individual schools. It is a process just beginning, but not completed and under discussion. There has been a general agreement at the European level of the Ministry of Education to have something like recall shortly, three plus two. I mean, two degrees, the first in three years, plus two years. It would be bachelor and master.
Nebeker:
So have you implemented that?
Tartara:
It is time to implement. For some reason there is an lot of discussion now about that. Italy has many opinions: too much, too fast, implementation. Just why not in a European country. We are different situation, but they are implementing, just seeing and implementing slowly the line theoretically decided by this group of ministers. It seems to make some difficulties because we had the system with one degree. Two levels, one more professional. You may understand it’s not easy to have the discussion, and there is a large discussion, and we are just trying to implement strictly a scheme in series, but now there is a reform going on that is just coming back as something, because it’s very difficult to pass easily in this new situation to have after three years an output with some professional doing prejudice to the line. So there is a big discussion now going now.
Nebeker:
I’m also interested in this division of telecommunications, Informatics and Electronics. How far back does that go?
Tartara:
Is another point of discussion, because the classical adhered only one faculty of engineering, two faculties, engineering and architecture. It was a large discussion in the faculty of engineering, more discussion in mechanical engineering. Now there was a coincidence with this new reform. The fact that we split it introduced a management engineering, information engineering, and structural civil engineering. Many faculties visit it at the moment. We think the faculty of information engineering. We have three degree in telecommunications. We are in the same department, so the school is more or less Informatics, which is can also be directional. Electrical engineering, now we have a discussion in which we have a common ground. The first two years are mostly equal information. Then the the first level, and then the master’s which is the second level, and is formally split. Beneath we are in the same department with communication, but this is now a matter of discussion to which degree we could maintain a common.
Nebeker:
Instead of splitting into three separate groups.
Tartara:
Yes. Our logistic common core of discussion, because when I was at school we had those courses in civil structure in Rome for engineering. Now there is a discussion, but practically there is not sufficiently seeing that point of view [unintelligible]. The discussion now is in fact the least Informatics for computer science. From telecommunication and electronics, we stick to the classical scheme of technical engineering. In the information, computer science, there is the possibility to just do only software engineer.
Nebeker:
In the United States there is often a computer science department completely separate from computer engineering department.
Tartara:
There is in Milano a situation, because at the Polytechnic, which is theoretically the Polytechnic commonality, it was the idea. But in the university, the universities where there is a Science, there is also another faculty in information science -- computer science -- which is only computers. The difference was that, before it was okay, but we at the Polytechnic we do engineering. Now this is in discussion because of the competition, the resources, and so on. Our colleagues in information are going because of the competition becoming more similar to that. That’s the problem. To the main and the common core, but this is not popular in some environments at this moment. That I think is thematics which is common to all.
Carassa:
I think that the problem is that in some cases we do not know what the engineer [unintelligible]. Because we have now twice the problem of seeing it. In many newspapers it says that because of the fact that we [unintelligible] number. All that is left to do for the other engineers is now in the factories. This is a question, as I say, that is difficult to answer.
Nebeker:
Yes, that’s right.
Tartara:
- Audio File
- MP3 Audio
(446 - carassa - clip 2.mp3)
Yes, there is a particular problem of what is the right information for the future for an engineer, so the base is strong and large. Everybody agrees on that theoretically. But in practice, you have the problem with employment and so on. For instance, there are some ways common to everywhere, the fact that -- for instance -- the critical technologists in our field, the number of people working in design when I was young was 100%. Back then, an engineer was a design engineer and the leader in the industry. Also, from the other point of view in the 1960s. Now, there is the management and these kinds of things the designer is a more limited percentage, so electronics and so on, that’s the general problem.
In Italy this problem is amplified because this last year a large amount of the [unintelligible] are reduced. For instance, when Carassa was Rector of the Polytechnic, at this time in Milano there was [unintelligible], which is now Alcatel, and another group which is now Ericsson. But all these groups now are not Italian, there is Siemens, Alcatel, and for instance the crisis in the communications and production here, it’s in trouble. Because Alcatel goes to Paris and Siemens to Germany, and these kind of things. In other words, they are larger manufacturing industries.
So Italy’s strong point has been the development of technical expertise with medium and small enterprises. But in our field there are some problems. Many of our students are going to work elsewhere. Two of my students are working in Nokia and SLink. There is this restructuring of the industry. For you in the United States, it is larger, I say Europe it is normal that one has to go to New York, to California. In Europe it was not so common; it was Italy, France, and Germany and so on. But perhaps it’s okay, it’s all right, it’s okay.
Nebeker:
It means the education has to adapt.
Tartara:
Adapt, and this is a process which was being [unintelligible] now Europe has to do this homogenization of qualification. It is a new situation; also our merging of systems.
Carassa:
[Unintelligible] very large number of problems without being more technologies that in the past [were taught] to the engineers. The art of knowing the technologies to produce. Now, we have changed our attitude in our people to solve larger problems using [unintelligible]. For instance, an agreement for [unintelligible] they produce [unintelligible]. But they don’t do original work in the sense of producing a new technology. They do original work.
Nebeker:
It’s more system builders.
Tartara:
Yes, with students with only one [unintelligible] now, we are very important within our technical studies the school of management. Usually the people there are my friends in the school, each of us study here in this department control and system theory and pass it to economic operations with electricity. And the school is gone, and it’s a competition for other schools in Milano which are economic from the origin. And so the school is becoming specifically that important between the polytechnical.
Nebeker:
I know engineering management is a growing field in the United States as well.
Tartara:
And so the organization over this kind of thing, together we could drop three plus two. It’s a big problem, yes.
Collection of Carassa's papers
Nebeker:
Why don’t we see if we have answered those large questions that the Marconi Foundation asked about, just to run through them. So I asked you what things you worked on after the Sirio project, and solitons and fibers with lumped amplifiers with one project. Is this book all of your papers?
Tartara:
Yes, the selected papers of Carassa, from the beginning.
Nebeker:
This is a very impressive, very substantial collection. Let me just put this on the tape that on the occasion of your 70th birthday, your colleagues assembled a very large collection of selected papers, 870 pages, something like that. A paper from 1953 is the first one here, so we have papers from 1953 to 2001. So we have almost 50 years worth of papers here, dozens of papers. Some of them are in English and some are in Italian. A very, very nice collection. The questions the Marconi Foundation had asked us were what are the most significant achievements. And we’ve talked about your TV transmission system that you developed.
Carassa:
It was more important, if you ask me, was the activity because I remember it was [unintelligible] Sirio, because with Sirio we had quite the unusual cooperation between industry, operators, and engineers
Nebeker:
That’s right, that’s right. I understand.
Carassa:
In other words, they say that perhaps we can divide the research activity in two activities. [Unintelligible] stimulating the movement of something new, which I love to do personally. In this case, the television corporation I was convinced always that the [unintelligible passage] processing of signal. But for instance, there is a paper which [unintelligible passage] filters with symmetric attenuation.
Nebeker:
[Looks through papers] So this is an example of a technical concept…
Carassa:
Of original work.
Nebeker:
Though probably not as well known as Sirio.
Carassa:
Right. Although if I remember right, this paper received a comment from [unintelligible]. This was a systematic approach
Influence of inventions on science and society
Nebeker:
I understand that it is difficult to answer a question like that. The next question is how did these contributions fit into the overall development?
Carassa:
[Unintelligible passage].
Nebeker:
Both with these relay stations and with the satellite, yes. The third question was how have these inventions contributed to the general well being.
Carassa:
[Unintelligible] communication everything has developed [unintelligible].
Nebeker:
That’s right, because communications are involved in everything.
Carassa:
Just as an example, I’ve always said that we make Italians.
Nebeker:
Make Italians, yes. [laughs] And all of the satellite communications development has been very important. And it’s made the whole world closer.
Carassa:
It’s fantastic.
Nebeker:
And then the question of have your inventions been used in ways that surprised you? You mentioned, for example, the Voyager missions using Sirio, which was a very nice example. Are there any other you think of?
Carassa:
There was the television operation
Nebeker:
It’s been a pleasure for me to talk to you. And thank you for giving me so much time.
