Satellite radio systems are actually part of a larger group of broadcasting mediums, which specialists refer to as Digital Multimedia Broadcasting or DMB. This digital transmission system is used in order to send data to different receivers such as radios, television sets or mobile phones and PDAs. There are two different ways of using digital multimedia broadcasting – S-DMB which is broadcasting via a satellite or T-DMB which uses terrestrial emitters. The complexity of the entire digital multimedia broadcasting field is huge. Out of all the features and characteristics digital broadcasting offers, satellite radio is probably the most spectacular as it generated immense interest and triggered an intense competition between the two main satellite radio broadcasters, Sirius and XM Radio. The development of satellite radio and other forms of digital broadcasting is spectacular because it offers two main qualities that terrestrial emitters are deficient in: quality and coverage. In the case of satellite radio, for example, the sound quality from a satellite broadcast is much higher than AM or FM broadcasts, as the hissing noises and transmission disturbances are eliminated.

Technical features of digital multimedia broadcasting – overview

Whether it refers to television, satellite radio or cell phone transmissions, digital multimedia broadcasting is based on the Eureka 147 DAB standard. Digital television uses the T-DMB which is made for transmissions on frequency bands III (VHF) and L (SHF). T-DMB is an ETSI standard (TS 102 427 and TS 102 428).
T-DMB uses MPEG-4 Part 10 (H264) for the video and MPEG-4 Part 3 BSAC or HE-AAC V2 for the audio. When it comes to satellite radio, there were a few issues to be resolved by the main satellite radio broadcasters. The satellite radio receiver needs to be in the line of sight of the satellite to receive the transmission ? and there is the problem of having different landscaping objects block the direct transmission. Land based devices were installed in order to eliminate the lack of direct satellite transmission. Since the wider spectrum of broadcasts has to be covered, digital multimedia broadcasting uses OFDM-4DPSK modulation and a chip of T-DMB receiver is also provided by MPEG-2 Transport Stream De-multiplexer. This helps reduce the negative effects of shadowing and fading, present in many digital transmissions.

The future of digital multimedia broadcasting

The transfer from the analog world to the digital one is obvious in all fields of work. Since digital multimedia broadcasting is developing so quickly, there is a silent battle going on between the new age digital technology and the classic analog one. OF course, many compare the transition from the analog to the completely digital era with the way audio cassettes were replaced by CDs and later on even DVDs. However, the development of digital multimedia broadcasting is slower since it happens on so many levels at the same time. Digital television is taking us into new spaces that are basically hybrids of the features of regular TV and characteristics of the Internet. Satellite radio is also taking huge leaps forward, with more and more programs having satellite radio exclusivity. There are even discussion of moving events like the MLB exclusively on satellite radio, which would provide one of the first deadly strikes against terrestrial radio broadcasting. Digital data transmission is fast and accurate, and so far reality proves that the satellites used in order to facilitate broadcasting and reliable. Most digital multimedia broadcasting companies that own satellites also have backup ones ready to go in orbit and replace a defective one. Some other benefits of digital multimedia broadcasting recommend it as a next step in the development of broadcasting. From the consumer?s point of view, the quality and interactivity options of digital TV or satellite radio broadcasts are important features. Although most digital multimedia broadcasting channels and technologies are still complex and sometimes expensive, the evolution of digital broadcasting seems to be here to stay.

Satellite radio is often considered one of the biggest improvements in broadcasting since the introduction of the FM band. Satellite radio is also called subscription radio or pay-radio because it is only available trough subscription to one of the satellite radio providing companies. Satellite radio follows a concept similar to cable television by providing a very wide range of programs which are not available in the traditional FM or AM format for a fee.

Satellite radio uses satellites to deliver radio programs to subscribers. The radio signal is broadcasted from Earth based stations to communicational satellites, which then redirect the signal to satellite radio receivers. The radio signal is broadcasted by communication satellites to a much larger area than traditional terrestrial radio antennas. For example, satellite radio is available al across the continental area of the United States. Satellite radio is available now in most parts of the world trough services provided by companies like WorldSpace (in Europe, Asia and Africa), Sirius and XM Radio (in North America). The radio signal you receive using satellite radio is digital, which means that it is always clear and static-free, which is one of the great advantages of satellite radio. Another great thing about satellite radio is that it is almost completely commercial-free.

To begin listening to satellite radio you will need the actual satellite radio (also known as tuner or receiver), a satellite radio antenna (which is often incorporated in the satellite radio) and a subscription to the service you choose. There are several types of satellite radio from which you can choose. One of them is the dedicated car or home radio, which play trough your car or home stereo. A second option is the plug-and-play radio, which can be used in your car, as well as in your home by paying a single subscription. Your third option is the portable radio, which has rechargeable battery, a built-in antenna and you can listen to it wherever you go using headphones. The radio signals offered by different satellite radio companies are proprietary, which means that you will need different hardware for receiving, decoding and playback, depending on your subscription. Each satellite radio receiver has its own serial number called Radio ID. When you get your subscription, you will also get an activation code for your receiver. Besides the actual radio programs, satellite radio transmits metadata that contains the name of the artist, the title of the song or program, as well as the name of the channel. This makes it easier for you to decide which channel to listen to and which program to choose.

Satellite radio services provide the subscriber with more than 100 programs that vary in content from rock and jazz to rap and classical music. But satellite radio?s utility reaches far beyond listening to your favorite music without the interruption of those annoying commercials. Satellite radio also offers exclusive sports programs, cultural and educational shows, news and talk-shows. Some of the celebrities that have moved their shows from free radio to satellite radio include Howard Stern, Opie and Anthony, Bob Edwards and Martha Stewart. Unlike terrestrial radio, satellite radio is not affected by bad weather or even calamities.

At first, many people wondered why they should pay for radio if they can get it free. However, satellite radio attracts more and more people every year due to its great advantages: no commercials, extensive reach, theme programs and exceptional quality of sound.

There are two important characteristics that recommend satellite radio as a service most people would like to have in their vehicles or homes: quality and content. When talking about quality we mostly refer to how clear the sound output is from satellite radio when compare to terrestrial radio broadcasts. Content, on the other hand, refers to the quality of the transited material. This is where the two giants in the satellite radio industry ? Sirius and XM Radio ? battle it out. The quality of the receivers and the technologies they both use are similar, but the difference can be made when it comes to exclusive high quality content. Let?s have a look at both the satellite radio quality and content characteristics:

Broadcasting quality

The broadcast quality is, when put in numbers, of 128kb/s 44.1khz for both digital radio service providers. This is the equivalent of CD quality. Although the coverage of satellite radio, which is far superior to what any terrestrial radio station can deliver, is an important factor, the quality of the sound is what brought Sirius and XM Radio more subscribers. There are many similarities to the way digital television worked or how cable TV has over 80% of the US population as subscribers, although they can receive free programming using UHF and VHF antennas. It?s the same with satellite radio ? although one can get free terrestrial radio, satellite radio comes at an affordable price and offer a broadcasting quality that is superior to analog radio. Also keep in mind that satellite radio is commercial free ? and this is huge selling point.
The high analog-to-digital conversion quality means that there will be no sound interferences, hissing sounds and other audio disturbances characteristic to FM and AM transmissions. This is mostly obvious when listening to music on your satellite radio system. The bass is much stronger and accurate, while the high sound levels are crystal clear. There is also a stronger mid range of sounds that you will consider to be more robust and accurate than what terrestrial radio produces. Although someone with a trained ear will tell you the music quality is not exactly as good as CD quality, it is extremely close and for the largest majority of users this difference is not even noticeable.

Content

So now that we know how good the technological side of satellite radio really is, let?s have a look at how broadcasters are trying to improve the quality of the content they provide. One of the most interesting approaches was to fight for obtaining exclusivity over some transmissions. For example, negotiations have been carried out between XM Radio and MLB in order for the satellite radio provider to obtain exclusivity rights to broadcast all MLB games. In an interview to WSJ, Edison Media Research’s President Larry Rosin declared that “it is probably inevitable that baseball radio broadcasts will go to a 100% subscription model… It will happen because there’s too much money in it not to do it.” Today, around 23% of XM subscribers are signed up to receive the MLB transmissions, so there is real potential in such a venture. Of course, this would be a terrific blow against terrestrial radio and the two sides are engaged in combat while you are reading this. Of course, content quality can also be increased by having the best people in the industry work with satellite radio. Both Sirius and XM Radio know that someone who pays $300 for a receiver and $10 – $12 each month for a radio service wants to get the best content out there. Surprisingly, when it comes to music channels, the difference in content quality between satellite radio and terrestrial radio is made in one main topic ? commercials (or rather, lack of commercials on satellite radio). Since most of XM Radio and Sirius channels are in-house productions and only a small percentage are retransmits of terrestrial radio, this becomes an interesting aspect to consider.