Satellite Radio: what is satellite radio? and how does a satellite radio work?

In 1971, I was a simple radio listener who had never thought that radio would become his profession. That year, in my hometown Medellín, a rock event called Festival de Ancón was held, which was intended to emulate the Woodstock Festival, held 2 years ago in the United States.

At 17 years old, I did not want to miss a moment of what was happening in that series of concerts, not only because of the music but because of the way in which the young people of that very conservative city behaved during that weekend.

Because I was immersed in another activity, I was unable to attend the festival, but I was able to follow what was happening step by step thanks to two radio stations that broadcast the entire event live: Radio 15 and the voice of music.

Radio 15 belonged to the Caracol network, so it had all the necessary equipment to broadcast its signal from there, surely including its mobile units, but La Voz de la Música was an independent station, which stayed on the air more out of a passion for the radio and the love for the music of its owner than for its commercial situation, which was very precarious.

The Voice of Music, at that time, was my favorite station. Its programming was destined 100% for rock, at a time of great changes in music and, by coincidence, its owner, Aurelio “El Grillo” Toro, decided to move with his station just a couple of blocks from my house, so We ended up becoming good friends.

That’s why, after the event, I went to talk to him to ask me how he had found the festival, how the broadcast had gone, and how he had managed to carry his signal.

The site of the event, known as the southern ancón of the Aburrá Valley, was very complicated at that time for transmission of this nature. Not only was he out in the open, with no telephone lines close at hand, but there was a large hill that made it impossible to send the signal from there directly to his studios.

Not having repeater units, “El Grillo,” told me that when doing his first tests he found a rock wall on the side of a mountain and calculated that by sending the signal of his FM link towards it, it would bounce and reach the studios where I could capture it.

At that time, the only thing I knew about the radio was turning on the device and changing stations on the dial, but I still didn’t buy the story. The idea, although with some logic, did not seem viable to me. I couldn’t imagine a radio signal bouncing off a rock to be picked up later.

Only in 2006, 35 years later, on a visit to the transmitters of the Grupo Latino de Radiodifusión stations in Costa Rica, did I understand what “El Grillo” had told me.

Luis Rodríguez, the company’s technician, took me to Cerro Chayote, in the province of Alajuela, where the transmission equipment was located. There, in the middle of a pasture and on the top of a mountain, he showed me a metal structure that, he told me, had been used for a long time as a “mirror” for some stations to broadcast their signal to other places.

It was a kind of elongated metal pyramid. It looked like a modern, rusty, semi-abandoned sculpture, but apparently, it was still doing its job thanks to radio signals “bouncing” off its walls and continuing on its journey.

There I understood perfectly what the owner of La Voz de la Música de Medellín had explained to me.

And what does this story have to do with satellite radio?

Well, that principle is basically the same.

One of the main concerns of radio has been to carry its signal as far as possible to achieve a long-range. However, this is not so easy.

Beyond the power output, the topography factor greatly influences the advancement of the signal, and if you work in a country like Colombia, which is crossed by 3 large mountain ranges or branches of the Andes, the situation is even complicated. more.

When radio networks began to emerge, the method used to link their signals was short wave transmission. Although this allowed the signal to be sent from one place and reached almost anywhere on the planet, the sound quality was not the best and even less so to be retransmitted.

Then came the microwave links that connected the cities. For this, relay points were installed on the highest and most inhospitable hills of the Colombian geography, so that there were no geographical obstacles that could interfere with the signal.

It is easy to understand that, although it was a very logical solution, at the same time it was expensive and difficult to handle. Maintenance at those sites was very difficult. Many times, vehicles did not even arrive there and it was necessary to use beasts of burden to carry equipment, spare parts and even the technicians themselves.

The broadcasters lived there in very precarious conditions. They were far from civilization. They had to stay there for long periods of time, enduring the inclement weather. Transportation to get food and basic necessities were very complicated.

The services were very unstable and there were regular blackouts. In addition, the same meteorological conditions threatened the instability of the equipment. All this without counting that, later on, some of these broadcasting stations became the target of the guerrilla groups.

Despite all of the above, the large networks created powerful FM networks with which they covered practically the entire country. In this way, about 95% of the Colombian territory had access to the radio.

Until the satellites arrived.

The concept of a communications satellite was first proposed by Arthur C. Clarke, together with Mikhail Tikhonravov and Sergey Korolev based on the work of Konstantin Tsiolkovsky. In October 1945, Clarke published an article entitled “Alien Relays” in the British magazine Wireless World.

The article described the fundamentals behind the deployment of artificial satellites in geostationary orbits for the purpose of transmitting radio signals. For this reason, Arthur C. Clarke is referred to as the inventor of the concept of communications satellites, as well as the term “Clarke Belt” used to describe the orbit in which these satellites are found.

The idea, similar to the rock against which the signal was sent during the Ancón festival or to the metallic structure of the Chayote hill in Costa Rica, was the same: to have a kind of “mirror” that would allow the radio waves to be reflected, but now from space, avoiding geographic obstacles.

The first artificial terrestrial satellite was Sputnik 1, put into orbit by the Soviet Union on October 4, 1957, which was equipped with an onboard radio transmitter.

The satellite was not put into orbit for the purpose of sending data from one point on earth to another but to study the properties of the distribution of radio waves throughout the ionosphere.

The launch of Sputnik 1 was an important step in space exploration and rocket development and ushered in the so-called Space Age.

Then, on July 10, 1962, AT&T Bell Telephone Laboratories and NASA launched Telstar 1, the first communications satellite. For the first time, live television broadcasts and telephone signals could be transmitted between the US and Europe via this satellite.

The size and weight of the satellite were limited by the capacity of the rockets that could put it into orbit. For this reason, it was only about 80 centimeters in diameter and weighed approximately 77 kilos.

Inside it carried some of the most complex electronic components known to mankind until then. It had 3,600 solar cells for power and a traveling wave tube to amplify radio signals.

The key task of Telstar 1 was to receive signals transmitted from the US, amplify them 10 billion times, and relay them to live audiences in Europe and vice versa.

Telstar 1 circled the planet every two and a half hours. It was only in the correct position to broadcast between the US and Europe for 20 minutes in each orbit before losing contact.

To achieve continuous transmission and achieve the “mirror” effect, later satellites were created that were located in the so-called geostationary orbits. In them, a satellite travels at a speed synchronized with the earth and seems to always stay at the same point.

A geostationary orbit circles the Earth about 36,000 kilometers from the Earth’s equator and synchronously follows the direction of our planet’s rotation.An object in this orbit has an orbital period equal to the period of rotation of the Earth, that is, one day, so it seems to an observer on the ground that it is immobile, in a fixed position in the sky.

Being 36,000 kilometers from the earth, the signal has a delay of almost half a second to return. Recall that the signal travels at the speed of light, which is approximately 300,000 kilometers per second.

On its up and down journey, this signal has to travel approximately 72,000 kilometers. The above without counting the latency that occurs at the time of compressing the digital signal.

For this reason, and although it seems like a very short delay, those of us who have done satellite transmissions have had to get used to handling that signal delay that, at first, made us gag when trying to hear ourselves through the headphones.

The geostationary orbit concept was also popularized by science fiction writer Arthur C. Clarke in the 1940s as a way to revolutionize telecommunications. The first satellite to be placed in this type of orbit was launched in 1963.

The use of the satellite in Colombia

Despite these technological advances of the 60s, only 30 years later could they be used commercially in Colombia by private companies. Colombian legislation had slowed down the incorporation of these and other new technologies for the media.

However, as of 1991, an opening process began that authorized them to use the satellite for data transmission, thereby gaining immediacy and quality, not only for radio but also for other media, including newspapers. .

With the use of satellites, the two large radio networks, Caracol and RCN, stopped using the services of Telecom, the state communications company, to connect all the stations of the chain and take their signal to places as far away as San Andrés, near Nicaragua; Leticia, in the Amazon or Arauca, on the border with Venezuela.

In this way, Telecom served as an intermediary to sign the agreements with the owners of the satellites, and the transmitting and receiving antennas were located at their headquarters and not in the town of Chocontá, where Telecom had its satellite broadcast and reception center.

Caracol began using the private satellite PanAm Sat and RCN opted for that of the International Organization for Satellite Communications, Intelsat, which was the one used by Telecom.

In my personal case, this was an extraordinary advance for the growth of the music station network that I directed, Radioactive de Caracol. Thanks to this new technology, we were able to connect 16 stations across the country to broadcast some of our programs live.

In this way, the young people of the country were able to meet and share their tastes and lifestyle. Broadcasters in the cities had live participation in these programs and thanks to them, excellent talents emerged that, without the satellite, would probably not have been able to make themselves known nationally.

Satellite transmission also had its drawbacks. Although it was initially a great novelty, companies began to take advantage of it to reduce their personnel costs based on economies of scale.

Now the idea was to broadcast from the capital of the country a single signal in a uniform way for the other cities.

At a time when the country began to suffer from the economic crisis of the late 90s, the satellite appeared as a saving table. After all, examples such as those of the chain Los 40 Principales de España showed that it was feasible to broadcast unified content via satellite for the entire country.

The same thing happened in Chile: the capital’s stations began to broadcast their signals to the rest of their territory without their audiences being affected.

Radioactiva collapse, however, in the case of Colombia, the opposite happened: for being a country with a clash of cultures very marked by the different regions, when the local flavor was lost, d and was on the verge of disappearing, and even had to change its format. Today only 2 stations remain Bogotá and Medellín.

However, although the signal was transmitted via satellite, this radio cannot be considered “Satellite Radio”.

So what is “Satellite Radio”?

It is one thing to link the stations through the use of satellites so that what is produced from the matrix of a station in one city can be received from the satellite and put on the air by another station in a different city. After all, what you hear on the radio is the traditional AM or FM signal.

Another thing is that one can pick up the radio signal directly from a satellite.

In 1992, the FCC in the United States approved radio transmission to be picked up directly from a satellite, but it took companies years to raise the money, build a system, and launch the satellites.

Around this time, two companies interested in this new technology appeared: XM Satellite Radio and Sirius Satellite Radio. The first began its commercial service in 2001 and the second the following year. In 2008, the two companies merged to form SiriusXM Radio.

Satellite radio differs from traditional radio not only in that its signal is received directly from a satellite, but it also uses digital technology, offering high-quality sound, free of static and interference.

Plus, it has great coverage. You could drive your car from Miami to Los Angeles in the United States listening to the same station all the time, many times without commercials.

Likewise, the service offers more than 300 channels for varied tastes, with specialized formats in different genres and ‘curated’ or supervised by renowned artists or celebrities. And there is not only music programming: there are also channels specialized in sports, news, traffic, weather, and comedy.

The downside is that the user has to pay a monthly fee to listen to it. It currently ranges between $ 13 and $ 17 a month. Also, if the user’s radio is not configured for satellite reception, they will also need to purchase compatible hardware, which can be relatively expensive and may not provide CD-quality music.

And although the service has national coverage, the satellite signal can be blocked by tunnels, overpasses, large buildings, mountains, and even trees, causing some potholes in the programming.

To address this problem, content is broadcast simultaneously from two satellites, each at a different location in the sky. In addition, SiriusXM uses a network of terrestrial repeaters to receive the signals and retransmit them. Most repeaters are found in large cities with tall buildings.

Today, most automakers include satellite radios as factory equipment in the United States, but receivers are also available for use in the home or office, including optional outdoor antenna kits to better receive the signal.

Additionally, SiriusXM makes your content available online and through its Apple iPad, iPhone and iPod touch app, as well as for Android smartphones and other connected devices.

Satellite Radio in North America