14 Jun Digital Radio Mondiale and RRI Successfully Demonstrate DRM for Local Coverage
During the Batam DRM for local coverage (DRM+) demo the DRM signal was inserted into the existing and very crowded FM local spectrum. The existing FM was at 105.1 MHz and DRM was placed at 105.25Mhz. The current analogue transmitter chosen for this has a power of 5kW in analogue. 2.5kW was used for simulcast mode (FM and DRM) and only 0.2KW DRM power was thus utilised. Excellent coverage area was achieved with only 10% of analogue power.
The DRM signal was about 10dB-12dB lower than analogue FM. The mode used was DRM Mode E (DRM+), 4 QAM and the protection level PL-1. The content available during the demo was 2 audio services (16kbit and 17.7 kbit/s) and Journaline service. For mobile reception and predicted coverage area power was calculated with 40 dBuV/m.
Both the indoor and mobile reception were excellent and no interference was noted to the neighbouring FM stations at 105.1Mhz and 105.5Mhz.
During the three days of presentations, practical work, the fruitful questions and answers sessions, participants checked the clear benefits of digital radio for local coverage: excellent audio, multimedia features including Journaline advanced text and images, good coverage and efficient energy use.
RRI is adding the Batam DRM for local coverage successful demo to its conclusive demonstrations of DRM in the AM bands (medium wave) for large-area coverage in Bogor (2015) and in Bali (2016).