Digital radio has a number of significant advantages over conventional analog broadcasting, including improved frequency economy and the availability of additional digital services such as traffic information, weather news, insertion of artists and music titles, and much more. The more efficient use of frequencies is achieved through the use of audio codecs. Another important aspect is the sound quality and the reception quality. Both are not always guaranteed with analog transmission.
If you take a look at the amplitude modulated transmissions on longwave, mediumwave and shortwave that have been available up to now, you can certainly not speak of a sound experience. The transmission in these frequency bands is characterized by intermodulation, noise, hissing and crackling.
The different transmissions for digital radio
Digital radio can be transmitted via existing terrestrial broadcasting stations, but also via the Internet, broadband cable and satellite. The receiving equipment can be stationary and located in a building or apartment, but it can also be mobile and located in a motor vehicle, on a ship or in a train. Terrestrial transmission can be used to reach both stationary and mobile reception facilities (digital radios). Accordingly, most digital radio methods are geared to terrestrial reception. Mobile reception of Internet radio is more difficult.
This technology is supported by modern mobile networks and smartphone browsers, but can also be received via WLANs. The problem is different for mobile satellite radio. Since the GEO satellites can only radiate a limited amount of power, some methods combine satellite transmission with terrestrial transmission. Mobile reception of digital radio via broadband cable is completely out of the question.
DAB and other technologies
In Europe, one of the best-known digital radio techniques is DigitalAudio Broadcast( DAB), which is broadcast via terrestrial radio transmitters, among others. Since the upper frequency band at 1.5 GHz can also be used for satellite transmission, a distinction is made between T-DAB for terrestrial transmission and Satellite DAB( S-DAB), for satellite-based transmission. Satellite radio also includes DARS radio (Digital Audio Radio Service) and DVB-S radio.
DRM radio takes a different approach, relying on the very neglected frequency bands of longwave, mediumwave and shortwave and transmitting digital broadcasting on these frequencies.
In the U.S., terrestrial broadcasting is focused on HD radio, which is intended to provide a smooth migration from analog frequency-modulated broadcasting to digital broadcasting. HD radio broadcasts both signals, analog and digital, simultaneously on the same frequencies. In addition to terrestrial HD radio, there are also satellite-based digital broadcasting systems in the USA, such as XM Satellite Radio or Sirius Satellite Radio.