DRM and Emergency Warning Tested Successfully on FM in Jakarta – Indonesia
The Indonesian Communications Ministry (Kominfo) and the public broadcaster, Radio Republik Indonesia (RRI), have continued testing DRM FM - started in July in Pelabuhan Ratu, West Java. The excellent audio results recorded in Jakarta doubled by no interference from DRM to existing FM stations and the good functioning of the Emergency Warning Functionality (EWF).
In Jakarta DRM was transmitted in the frequencies of 92.6 MHz and 93 MHz. To check the potential interference with flight frequencies, DRM was transmitted on 107.9 MHz but no spurious DRM was noted within the flight frequencies (108-137 MHz).
The measurement results conclusively showed that there is no interference between DRM radio and the existing FM radio stations placed at 200 kHz distance, at 92.4 MHz, 92.8 MHz, and 93.2 MHz. The DRM audio quality was excellent.
The results of the emergency warning functionality (EWF) test showed that EWF functioned properly. The delay between the activation of the emergency button and the reception on the receiving device was of about 38 seconds, but this can be still optimised to go down to 10 seconds.
The two sets of trials conducted in West Java and Jakarta proved that the field test results are consistent with ITU-R Recommendation BS.1114 and BS.1660. In this case it is possible to implement DRM digital radio in VHF Band II (FM radio band) side by side (co-existence) with analog FM radio using a 200 kHz frequency space from the existing FM radio broadcaster. In addition, for full pure DRM implementation the frequency space can be of 100 kHz between DRM radio broadcasters.
The general conclusion of the Indonesian tests is that DRM on the FM frequency bands can improve the effectiveness and efficiency of the spectrum usage, thus improving the quality and coverage of radio broadcast services used for information, emergency warnings or entertainment.
DRM receivers are expected to be available in the form of car head units, portable receivers, USB dongles, and as embedded modules in smartphones. One of the Ministry Officials (the Director General of SDPPI) will further liaise with the local manufacturing industry and automotive industry in order to get availability of dual-mode analog-digital (AM/FM/DRM) broadcast radio receiver devices.
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