Croatian

Satellite TV

In the next chapter we will introduce you the basics of digital satellite television and show you the differences with analogue satellite television.

Digital TV

Digital TV became a part of everyday-life for most of the Croatian satellite-viewers. Many people thought of it as just a next step in the transmission of TV and radio programs via satellite and that the viewers wouldn’t accept it, since they would have to pay an enormous amount of money, at least in the beginning, to buy a satellite receiver without including the peripherals like modules and cards, which costed a real fortune. Nowadays we can happily say that this has changed, since digital satellite receivers and modules and cards lowered their prices, so that they are affordable for everyone. Digital TV today dominates in the satellite communications and this will last for at least the next ten years till the satellite equipment industry doesn’t come up with something entirely new.
The first satellite transmission in digital technology was performed in June 1993 in Germany. They tested the transmission of ten satellite programs via one transponder. The transmission took place via the Copernicus 2 satellite, which is stationed at 28.5°E.

How digital TV works?

Digital television uses data-compression. Compressed data need less space and is easier distributed via satellite and cable networks. In digital technology the picture and sound data is sent in form of compressed binaries. This means that the data is first transferred into binaries, which means they will be expressed in only zeros and ones. For example 0=0, 1=1, 10=2, 11=3, 100=4, 101=5, 110=6, 111=7, 1000=8, etc. Afterwards this data is compressed and is ready to be sent to the end user.

Data-compression

Why must the data be compressed? This is done for a simple reason: compressed data uses less space than the ordinary analogue sound and picture transmission. In the transmission of satellite and earth programs in analogue technique whole picture slide, 25 frames per second that is, are sent, which delivers a complete picture on the TV. This is the reason why they can transmit only one program via one transponder or available channel on the satellite if the use analogue technique. The second program is transmitted via another transponder, the third program on the next transponder and so on. Expert concluded that this way of transmission uses too much available space. Since frames that are sent are nearly always the same, what means that the sent data of following frames are either totally equal or at least very similar, there is no need to send one frame after another. Via digital transmission and picture and data compression the satellite receiver shows the first picture on the TV set, then it compares it to the next picture, and if it comes up that it deals with the same picture it will simply ignore the second one. Otherwise if the second picture differs only a bit the satellite receiver will only transmit these details and make the necessary changes to the first picture. The receiver will now compare the third picture with the second and will proceed in the described manner. This is how the receiver will compare all following pictures, which it receives via satellite or a ground transmission network that emits digital satellite TV programs. This is the basic of data-compression: the more unnecessary repeating picture-parts you delete the more necessary changing picture-parts you send. This is how all digital programs via satellite and earth are sent today in Europe.
For the ability of sending digital programs in this way there were developed special systems for program transmission. They are called MPEG and they are the standard for digital transmission. Today the only system in use for digital transmission is the MPEG 2 system.
What is the MPEG system?
MPEG means Motion Picture Experts Group. This group is developing systems for digital pictures since the late 80’s. The first system was called MPEG 1 and was overall accepted in November 1994 for the use of digital transmission, but the MPEG 1 system had a picture quality, which is identical to the picture quality of your VCR and that means the system was able to present a horizontal resolution of 250 lines, which is not enough for T transmission. Therefore they started to improve the MPEG 1 system and so a few years later they developed the MPEG 2 system, which fully satisfied the need of digital TV and radio transmission and was therefore recommended as the new world standard. This system is used today in the transmission of digital TV and radio programs whether they are emitted via satellite or via ground networks.

MPEG 1 is used today in the transmission of ADR (Astra Digital Radio) and in the transmission of digital radio programs via ground networks, the so-called DAB (Digital Audio Broadcasting).
In what ways differ these systems? Basically it’s about the signal transmission speed and the audio part. MPEG 2 is capable of data transmission speeds higher than 30Mbit/s. this means that more than 30 million information’s are transferred during one second. MPEG 1 was capable of only 1,5Mbit/s. by the way a MPEG 2 receiver is capable of receiving MPEG 1 signals, but vice versa this not possible.
Another difference is the audio part. MPEG 1 is capable of emitting and receiving only stereo sound, which means it is able to use only two sound channels. MPEG 2 is capable of sending and receiving more-channel surround sound like for example Dolby ProLogic or the newer Dolby Digital. Both systems are sound compatible; therefore MPEG 1 can reproduce MPEG 2 sound but only in stereo sound without the possibility of reproduction with more sound-channels.
In what ways differs analogue satellite TV from digital satellite TV?

The main difference is in the digital program transmission technology itself. The basics are the same. Programs are recorded in a studio with simple cameras, movies are copied with telekinos, afterwards the are translated into digital codes which is given to the TV station, which is sending it to the satellite, which is emitting it so that you can sit at home and receive the program. Your satellite receiver transforms the received digital signals into analogue signals so that they can appear in form of a picture on your TV set. Digital pictures need to be transferred into analogue pictures, since there are no TV sets yet, which would be capable of showing a digital picture without transforming it first.

The main difference is technically that digitally transmitted programs need less space on a transponder, what allows to transmit up to ten (and even more!) programs with one transponder.

If you compare a picture transmitted with digital technology with the same picture transmitted with analogue technology you will see the difference at once. The digital picture is sharper, has good contrast and there are no lines or corns in the picture neither are the colours blurred. In contrast to this the analogue picture is less sharp and has often dull black and white stripes, what is an outcome of a weaker signal or equipment with lower quality.

Digital receivers

These receivers do not differ by their outer appearance from today’s analogue receivers. The main difference is in inside the device; it’s about a newer technology. All digital receivers are small computers, which use memory chips to process the pictures and save data. Today’s satellite receivers have up to 32 MB RAM memory, which is, as you’ll have to admit, equal to memory used in most PC throughout Croatia, even though we are getting used to 64 and 128 MB too!
Some digital receivers include a built-in communication, a modem that is, for the connection to the Internet (only some of them, since most of the receivers with a built-in modem use the modem as a connection between the receiver and the provider, who enables so the ordering of special events- PPV system (Pay per View)) and allows so a fast changing of information.

About the basic characteristics of digital receivers read the chapter about satellite equipment.

Now we’ll only mention that all digital receivers build today have to full-fill the requirements of the DVB group (Digital Video Broadcasting group, which standardizes the digital video transmission).
The possibilities an future of digital TV
Digital TV is a new and big technology, which has a lot to offer in the future. Its possibilities have practically no boundaries. Only digital TV enables real interactive watching of TV programs in the comfort of your home. We will name only a few possibilities.
Internet
We have already mentioned the option of connecting the digital satellite receiver to the Internet. Today’s upper-class models with a built-in modem already have this option. By using such a receiver you have totally new possibilities of communication what is very important today, because it is most important to have the right information in the right time. To use the Internet with such receivers you have to connect to the phone line and configure the connection in the same way as you do it on your PC.
This has to be done, since most of the receivers send queries to the Internet via the phone line and receive data via the satellite network. This way the communication is instant without waiting for results of the Internet-query.
The same never-ending possibilities of communications has the Internet via satellite, which is established by connecting your computer to the digital satellite network in case of which you get your information through the “sky”.
EPG
Digital TV introduced the term EPG, which stands for Electronic Program Guide. This enables us to see anytime, during watching the satellite program, what’s on now and what will be on next. You can also see the content of today’s program and some receivers, like for example the Duo Master 4, allow you to see the program content for the next 4 days. Today there exist special EPG’s, which are emitted by some TV stations, for example the Swedish Viasat emits an interactive EPG, which enables you to get the freshest news, to play games, listen to the radio, to watch the timeline of programs, to watch sport event, to order films, products, merchandise, etc. British Sky emits an interactive EPG with similar options!
Interactive program watching
Digital TVs main attraction is the interactive program watching. Mostly it’s about sport or documentaries. Interactive program watching means that you can interact with your favourite program, which enables you to create your own program. The best example is the transmission of Formula 1 races: you can choose the cameras, change the ankle of view, etc. Such transmission of races are provided by some Italian and German TV stations. A completely different story is the British Sky Sports Extra program, which is a fully interactive program, which enables you to watch nearly all important sport events. Most impressive is the watching of football games, which allows you to change the ankle of view, to choose the camera, to repeat scene from the game and repeat arguable details. At any time you can get the names of all players, statistics, the biography of a player, etc.
Automatic loading of new software for the digital receiver
Automatic loading of new software via satellite is an option exclusively for digital satellite receivers. Since there are today many manufacturers of digital satellite receivers the upgrading has become more important, because even the most luxurious digital receiver won’t be luxury without new software. New software is sent via satellite only for a few receiver types like for example Nokia, Force, Samsung, Humax and others, many other manufacturer don’t offer such a service. Receivers mad by the manufacturer Force recognize by themselves if the new software is installed and if necessary they download and install the software by themselves. After resetting the receiver will be ready to use the new software.
Other manufacturers however enable software upgrading by linking the satellite receiver to a computer via the RS 232 port. Then you have to download the new software from the Internet (mostly on the websites of the manufacturer) and install it in the receiver. Afterwards the receiver will use the new software. If you should have trouble with newly installed software you can always install the old software and afterwards try again installing the new software.
Automatic program search
A digital satellite receiver makes finding programs for you easy, since it downloads all available programs on the satellite, which the antenna is adjusted to, when you use it for the first time and even afterwards during the everyday usage of the receiver. This means you don’t have to enter new frequencies, names and other data. The receiver does it himself if you want him to do it. You can do this everyday or once a week just to see whether there have been made some changes to the frequencies of satellite programs or whether some programs have stopped their transmission or whether there are some new programs. Some receivers like FORCE’s analogue and digital receivers have the option of independent registering of new programs. This means that the receiver by himself enters new and erases old programs every day at a prior given time of day, so you don’t have to think about this at all and you can fully concentrate on watching satellite programs.
Pay per View programs
All film-lovers are cheered by the fact that only in Europe you have over 200 movie-programs, which are all naturally encoded. These programs are emitted as a part of paid packages, a vast number of them are pay per view programs. They are based on the concept of emitting only a few shows with a time delay of approximately 15 minutes. They emit movies and sport events in such ways. If you want to watch a show or movie you just order per phone at what time you want to see it or you can do this by pushing a button on your remote control as it is the case with the British Sky Digital package.
Teletext
Teletext of digital TV programs, which emit this service, can’t be watched on TV like any other ordinary teletext emitted by analogue satellite TV programs, like HTV (Croatian national TV) for example. The digital receiver has the ability to show the teletext emitted by digital programs on your TV set.

The main advantage of digital teletext is its speed. You don’t have to wait to get the information you wanted to see. The basic functions of teletext are: double sized letters, watch, fast text and showing hidden text. It has to be stated that some digital receivers can store up to 3000 pages of teletext.

Now we can say that teletext has reached its purpose by being emitted with digital technology.
Shopping via satellite
Digital technology has made interactive shopping from the comfort of your house become reality, you just have to turn on your TV, tune in a shopping channel, choose the merchandise you want and order it. Some digital packages offer the option that you can buy and pay directly with your satellite receiver. For example the Sky Digital package: The satellite receiver for receiving these programs, the so called Sky DigiBox has not only slot for the inserting of the subscriber card but also a slot for a credit card. If you want to buy something you like you just have to insert your credit card into the credit card slot. The transaction is completed and in a few days you’ll receive the ordered stuff at home. Paying your merchandise like this shopping has just become watching and choosing the products on the shopping channel. This form of payment will certainly attract many customers.
The possibility of watching encoded programs
Digital receivers introduced a new term: CI, which stands for Common Interface, which describes a replaceable module, which is used as an interface to link the receiver to a digital recorder. These decoders are no to be connected through a scart-connector, but through this interface in the front of the receiver. Decoders for digital satellite TV don’t even look-a-like analogue satellite TV decoders, which are independent units, which are not small at all.

More about digital encoding systems and available program-packages can be read in the chapter about encoded programs.

What should I choose? Analogue or digital?

Despite the fact that everyday TV and radio stations are stopping to emit their program in analogue technology, you can still watch nearly 100 TV programs emitted through Astra and HotBird, and you don’t even have to pay a big amount of money for it. Digital satellite receivers are no longer a curiosity in our homes, the reason for that is that their prices are lowering each day. There are more and more receivers, day-by-day newer and more sophisticated models are on the market and therefore older models are becoming cheaper. Now you can buy a digital satellite receiver for just 200€, which is still more than 100€ for an analogue satellite receiver, but it’s a start. Receivers for this amount of money will satisfy any TV viewer, who is not interested in watching encoded TV programs. The more a viewer wants the more he’ll have to pay for such a sophisticated digital satellite receiver, since their prices start at 30kn up to 5000€, as much as costs a SCT Classic (a analogue-digital receiver with decoders) for example. Such a receiver has a lifetime guarantee and many options to upgrade it.

Advice for buyers!

Most of buyers, who aren’t able or who simply don’t want to inform themselves about the capabilities of digital satellite receivers, their prices, options and upgrading simply buy the cheapest available model, which includes an antenna, a receiver and a LNB. After they buy the equipment and it is already installed they simply sit down and watch the program, but soon they are disappointed, since they can’t watch the programs they wanted too. It’s getting worse if they visit a friend with a better receiver, which enables him to watch more programs. The situation is getting even more tense, since they want to watch more programs and start to call everybody they know and ask how to watch these encoded programs and they’ll always end up with the answer: “It’s impossible since your receiver isn’t designed to do this!” Therefore I advise you to inform yourself, since the price isn’t the only issue that matters, but also your wishes and the capabilities of the receiver. So you’ll maybe spend more money in the beginning, but you won’t have to buy a new receiver simply just to be able to see the programs you wanted to see from the beginning on.
Before you are buying a digital satellite receiver inform yourself. Don’t be ashamed to ask questions you will often see that you already know more than some of the people that want to sell you the satellite equipment. The most important thing is to make sure that you can upgrade your receiver so you can later watch encoded programs otherwise you can stick with your analogue receiver.
If you aren’t interested in digital technology or you simply don’t want to spend money to watch TV just stick with your analogue receiver, since he will suit you at least the next 5-6 years.
Signals emitted with digital technology are sent in the form of bits, which is one sign. The more complex a transmitted program is the more it will require a higher transfer rate.