The term broadcasting means the transmission of radio or video content using radio frequency waves. With the recent advancement in digital technology, radio broadcasting now applies to many different types of content distribution. Today you’ve the choice of tuning in to more types of radio station than ever before.
Analog radio consists of two main types: AM and FM. Analog radio station frequently feeds only one transmitter and referred to as an AM station or an FM station in the U. S. But it is quite possible for a station to feed both transmitter in a similar areas or to feed more than one transmitter covering different areas.
Four standard for digital radio system exist worldwide: IBOC, DAB, ISDB and DRM. All are different from each other in several respect.
a company named iBiquity Digital corporation, with a trademarked name of HD radio, developed IBOC and still continues to manage it. Introduced for a regular use in 2003, it’s now in frequent in the U. S. More than 2,000 u. S. AM and FM station are using the IBOC digital radio services today.
Also known as Eureka 147 in the U. S. And as digital radio in the U. K. DAB comes with a number of advantage similar to IBOC. But it is fundamentally different in its design. Recently, improved version of DAB, known as DAB+ and DAB IP, have been developed.
Specifically developed for Japan in 2003, ISDB TSB is the digital radio system used for multi program services. It is currently using transmission frequencies in the VHF band. A unique features of ISDB TSB is that the digital radio channel are intermingled with ISDB digital TV channels in the similar broadcast.
DRM is a system developed primarily as a direct substitute for AM international broadcasting in the short wave band. DRM uses the similar channel plan as the analog services and with some limitations and changes to the analog service. A DRM broadcast can share the same channel with an analog station. Existing channel allocation DRM is a single audio channel system when used with.
Sirius XM is the combination of two similar but competing satellites radio service: XM satellite radio and Sirius satellite radio. XM and Sirius,which still operate separately at the retail level,are subscription services. They broadcast more than 150 digital audio channel intended for reception by car,portable and fixed receivers. These provide coverage of the complete continental United States,much of Canada and parts of Mexico.