The “DRM30’ modes DRM can deliver FM-comparable sound quality and are specifically designed to utilise the AM broadcast bands below 30MHz (Long Wave, medium Wave and Short Wave) which allow for very-long-distance signal propagation.
The system allows the new digital transmissions to co-exist with the current analogue broadcasts, and a significant amount of work has been undertaken to quantify the operating parameters that assure mutual analogue and digital compatibility. Hence the changeover from analogue to digital broadcasting can be phased over a period of time, which in turn allows existing broadcasters to spread the required investment to meet any budgetary constraints. Furthermore, unlike some other digital systems, the DRM system has been designed to allow suitable analogue transmitters to be modified to switch easily between digital and analogue broadcasts. This can significantly reduce the initial investment cost for a broadcaster. An additional budgetary benefit is the reduction of transmission energy costs.
DRM exploits the unique propagation properties of the AM bands. The introduction of DRM30 services allows a broadcaster to provide listeners with significantly improved audio quality and service reliability. As a result, international broadcasters can provide services on SW and MW that are comparable to local FM services, whilst enhancing the listener experience with easier tuning and added data services. National and local LF and MF broadcasters will derive similar benefits.
You can also consult a summary of the Features and Key Benefits of DRM for the listeners, manufacturers, broadcasters and regulators.