Calling it the first commercial-grade DRM+ live transmission system, three organizations are cooperating to produce a live signal at the NAB Show.
Fraunhofer’s DRM+ ContentServer, RFmondial’s DRM+ Modulator and Nautel’s DRM+ Exciter will be combined in the demo, which include a real-time encoded audio program with surround option, DRM text messages, a textual information service called Journaline and DRM+ signaling.
To be seen in the Nautel booth are Fraunhofer DRM+ ContentServer, a broadcast encoder system that provides stereo and MPEG Surround audio encoding, data application handling including Journaline, electronic program guide and Slideshow support along with broadcast automation and security features. The output format is the standardized MDI multiplex signal.
The RFmondial DRM+ Modulator uses the MDI-delivered radio content to produce a modulated and RF-transformed radio signal for DRM+. For low-power transmitters a linear amplifier is provided with the modulator; for higher-power transmitters an external linear amplifier can be used via an AES interface, and other interfaces are available on request.
Completing the system is the Nautel NV5 FM transmitter, which receives digital I and Q signals via an AES interface from the DRM+ Modulator and generates the DRM+ RF signal. All Nautel NV Series transmitters support DRM+ transmission.
DRM+, like the established DRM standard, provides audio coding, data services, multiplexing and signaling schemes. But where DRM is aimed at short-, medium- and long-wave up to 30 MHz; DRM+ operates in frequencies between 30 and 174 MHz, including the broadcasting bands Band I and Band II.
“Spectrum usage parameters are determined from internationally agreed norms in the FM band of 88 to 108 MHz; the service’s occupied bandwidth is 95 kHz with a frequency grid of 100 kHz,” the proponents note. “This signal bandwidth guarantees worldwide compatibility with existing FM channel assignments, flexible positioning of digital operation anywhere in the spectrum with individual power levels and supports service linking for seamless DRM/FM/AM/DAB service switching.”
The DRM Consortium has completed technical development of DRM+ and the technology enhancement to the DRM system specification is in the ETSI standardization process.