DEVA SmartGen 6.0, Инструкция по техническому обслуживанию и эксплуатации

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APPENDIX A
RDS: EUROPE VS AMERICA
The European Broadcasting Union (EBU) and its member countries originated the concept of
“Radio Data” transmission. The European RDS specification, CENELEC Standard EN50067, was
first published in 1984. It was revised in 1986, 1990, 1991 and 1992.
European RDS has grown in use following initial adoption of the Standard. RDS is nearly
universal throughout Europe; it is almost impossible to find a European FM broadcasting station
that does not carry a radio data subcarrier.
The popularity of RDS in Europe is very much in contrast with initial reluctance on the part
of US broadcasters to embrace this technology. This can be ascribed to material differences in
broadcasting practices.
Almost without exception, FM broadcasting in the United States is ‘detached’ and independent
- each station originates its own programming. America’s National Public Radio might be
considered as an exception, though for most of the broadcast day even NPR stations originate, or
at least schedule, their own programs.
Most of European broadcasting is similar to the concept of network radio that was common in
the US prior to the 1950s. In Europe, a central program originator may have many transmitting
facilities of modest power situated throughout the country, at several different frequencies to
blanket a designated service area. The European disposition, toward lower-power transmitters can
be found on the “local radio” level, as well.
The European concept of a service area equates to the US broadcaster’s market. The subtle
difference between these designations further characterizes broadcasting practices and ethics.
RDS benefits the European broadcaster through almost an altruistic endeavor to be of service to
his listeners. The US broadcaster is marketing his programming and is primarily interested in how
he can create additional revenue from RDS.
THE RDS SYSTEM
RDS is a digital data channel, transmitted as a low-level subcarrier above the range of the
composite stereo program signal in the FM baseband. The data transmission (baud) rate is
comparatively low, yet it is quite robust because of data redundancy and effective error correction.
It is not within the scope of this Manual to cover the details of RDS subcarrier coding and
modulation. For this, the reader is directed to the Specification appropriate to his location either
the CENELEC EN50067 Specification for Europe or the United States NRSC Specification. Since
the Manual will deal with specific implication of RDS implemented with the SmartGen 6.0, it is
assumed that the user is familiar with the RDS concept.