As World Radio Day, which marks the anniversary of the first broadcast by UN Radio in 1946, is celebrated every 13 February, the IEC, involved in technical developments of radio broadcasting since 1926, is working with other organizations to secure the future of this medium by developing new audio technologies.
Optimizing spectrum resources
The radio frequency spectrum is a valuable and limited resource, seeking to make optimum use of it and to benefit from other advantages, such as the possibility of increasing the number of programmes in a given bandwidth, improving audio quality and reducing transmission power, led manufacturers, regulators and broadcasters to work on developing digital radio broadcasting.
This technology requires audio signals to be digitized and compressed before being transmitted.
Developing digital compression
Digital audio compression has been developed by MPEG (Moving Picture Experts Group) a working group of experts formed by IEC and ISO (International Organization for Standardization) to set Standards for audio and video compression and transmission.
The four international digital radio systems recognized by ITU (International Telecommunication Union), namely DAB/DAB+ (Digital Audio Broadcasting), DMB (Digital Multimedia Broadcasting), DRM (Digital Radio Mondiale) and IBOC (in-band on-channel), rely on digital audio compression Standards developed by MPEG.
They include MPEG-1 Audio Layer II or MPEG-2 Audio Layer II (or MP2), defined by ISO/IEC 11172-3:1993, various codecs based on MPEG-4 Audio profile, such as HE-AAC (High-Efficiency Advanced Audio Coding) defined by ISO/IEC 14496-3:2009.
IEC work across equipment and audio compression to secure the future of radio
With its standardization work in the fields of radio equipment, prevention of radio interference and digital audio compression, the IEC has been at the forefront of developments in radio broadcasting for nearly 90 years. It will continue to prove central to the vitality of the sector for the greater benefit of listeners, broadcasters and manufacturers around the world.