Numerical radio

The radio numerical indicates commonly the Radiodiffusion Numérique, i.e. the diffusion of programs of radio by numerical way.

Principle

Contrary to the Analogical radio such as one meets it with the diffusion in AM or FM where the electrical signal translating the sound module directly the wave Porteuse, numerical broadcasting converts initially the sound into binary data (generally compressed to reduce the flow of it) and transmits them by processes specific to technologies used (satellite, Internet, terrestrial VHF, terrestrial HF, cable, etc).

Advantages

The advantage of the numerical radio rests on a quality of its close relation of that of a CD, the possibility of putting in pause an emission then to take it again (Time shifting) and the reception of additional details (posting of the name of the station and artists, small pockets of albums, titles of the topicality, etc).

Its arrival should also relieve of the bands FM increasingly saturated.

Deployment

Already launched to the the United States, in Asia and in European countries like the Germany or the England, the numerical radio should experience a development comparable with that of TNT for television.

In France, the decree project of the government chose the standard of diffusion T-DMB (Terrestrial DIGITAL Multimedia Broadcasting), derived from technology DIGITAL Audio Broadcasting as well as the DRM (DIGITAL Radio World) and supported by the majority of the operators (Radio France, Lagardere Active, NRJ, RTL, etc). The T-DMB makes it possible to diffuse video associated with the audio. The DAB+, new version of the DAB, are a standard retained in many European countries and will be can be added to the T-DMB and the DRM to make French numerical radio a multichannel, pluralist and various radio. An experimentation is in hand in Paris in 2007, and the numerical radio should start to emit in 2008.

Standards

There exist several processes of numerical diffusion of radio. Some are the fruit of work of collaboration between manufacturers, research centres and diffusers and are opened, those are generally standardized by organizations of Standardization like the International union of telecommunications (UIT) or ETSI. Others are developed by companies and are thus owners. One also distinguishes from the differences between country and continents.

Some open standards :

DAB (Audio DIGITAL Broadcasting). European standard for the radio diffusion in the ultra-short waves (VHF, UHF) and microwaves (SHF). It gave rise to alternatives, like the T-DMB (Terrestrial DIGITAL Multimedia Broadcasting).
DRM (DIGITAL Radio World). World standard for the numerical diffusion in Short waves, average and long (<30MHz).
DVB ( Digital Video Broadcasting ). Standard at the base for the Television but which includes the radio diffusion. It is declined in a version intended for the diffusion by satellite: DVB-S, it is currently most current, with the terrestrial diffusion: DVB-T, with the terrestrial diffusion towards the mobile : DVB-H and with the diffusion by cable: DVB-C.
SDR: standard for the radio diffusion by satellite, standardized for Europe by the ETSI since November 2006

Some standards owners or partially open :

IBOC, American system also met under the term of HD Radio.

Owner systems of diffusion per satellite :

XM Satellite radio, diffused by satellite and ground network in North America.
Sirius Satellite Radio, also.
Worldspace, diffused by satellite on each continent.

Some abandoned systems or in the process of disappearance :

ADR, Astra Radio DIGITAL, system of diffusion per satellite.
DSR, Radio Super DIGITAL, system of diffusion per cable and satellite. The sound is not compressed and thus the band-width occupied on the transmission channel is large.

Equipment

The numerical radio can be collected in the car, on a final of pocket or at the house with a Récepteur radio operator compatible. Remain that the listener must acquire a station compatible with the standard of diffusion adopted by the stations of his country.

To harmonize the offer in this field, to the organizations endeavor to encourage the industrialists to develop joint receivers. For example, the WorldDAB consortium, which gathers the interests of the DAB, made in 2003 an agreement with consortium DRM for the development in the future of receivers DAB/DRM.

Another hope of convergence lies in the evolution of the software Radio (radio operator software) . Association for the Numerical Radio DR. militates for the multichannel numerical radio, whose first receivers (compatible DRM/DAB/AM/FM/MP3) are currently in test.

A common label was created for the promotion of the numerical radio in France and Belgium/Luxembourg.

See too

DIGITAL Radio World

Random links: