The not-for-profit International DRM Consortium has recently released the DRM Consumer Radio Receiver Functionality Recommendation (rxspec.drm.org), a guide for radio manufacturers.  The document completes a triad of key documents available from www.drm.org to any manufacturer, broadcaster and regulator interested in implementing DRM.

For a full description of the ITU and ETSI recommended digital audio broadcasting standard the DRM Handbook (handbook.drm.org) remains the fundamental document giving precise technical details for DRM in both the AM and all three VHF bands. A recent update gives more information on the multi-channel option (using one frequency for getting multiple channels and over a dozen audio and data DRM channels on air). The Handbook is available in both English and Chinese.

Addressing more specifically the receiver manufacturers the DRM Consortium also released the Minimum Receiver Requirements for DRM Receivers (mrr.drm.org). The main goal of the document is to provide guidelines to receiver manufacturers for minimum receiver performance and technical features. Following this recommendation will give confidence to broadcasters that their DRM transmission can be received by all receivers in the market. It will also give assistance to regulators and broadcasters to plan their network.

The third piece of the triad is the advisory DRM Consumer Radio Receiver Functionality Recommendation (rxspec.drm.org). This is just a guide for radio manufacturers built on the more technical MRR. It describes and defines the core functional parameters of consumer radio receivers capable of receiving DRM radio broadcasts, so that consumers get a common and consistent DRM digital radio experience. The DRM Consumer Radio Receiver Functionality Recommendation outlines three functionality levels: Essential Radio, Feature Radio, and Advanced Radio.

• The Essential Radio level represents the minimum required functionality, as specified in the DRM Minimum Receiver Requirements (mrr.drm.org). Support for this level is a mandatory prerequisite for using the DRM logo on devices.
• The Feature Radio level collects those additional features that define a well-rounded DRM receiver with all key functionalities supported, while keeping the hardware requirements on practically the same level as an Essential Radio device. It may therefore be considered a starting point to check for new receiver developments.
• The Advanced Radio level proposes features beyond the Feature Radio level, which may be particularly useful for listeners and manufacturers to differentiate their products.

DRM is an open standard and all these documents freely available on drm.org are there to guide and help the development of a sound receiver manufacturing eco-system in line with the parameters set by the national regulators and the ever-evolving content offers of the broadcasters.