Today is World Radio Day. Unesco has declared February 13 a day to celebrate radio, especially broadcast radio in all its forms.
Radio remains the medium that reaches the widest audience worldwide. It’s my favorite medium. There’s an immediacy and intimacy of radio, unlike television or the internet. The subtle psychology of a mike just inches from mouth. Oh, the humanity…
- Along with radios, mobile phones are one of the most accessible forms of technology, covering over 70% of the world’s population.
- At least 75% of households in developing countries have access to a radio.
- There are about 44,000 radio stations worldwide.
- AM/FM radio counts for 86% of the total time adults aged 25-54 spend listening to three main audio platforms. Adults listen to eight times more AM/FM radio than satellite radio and seventeen times more than internet audio streaming.
The History of radio began as “wireless telegraphy” during the first three decades of radio (1887 to 1920). In 1901, Guglielmo Marconi conducted the first successful transatlantic experimental radio communications. In 1904, The U.S. Patent Office reversed its decision, awarding Marconi a patent for the invention of radio, possibly influenced by Marconi’s financial backers in the States.
When radio was first introduced in the 1930s, many predicted the end of records. Radio was a free medium for the public to hear music for which they would normally pay. Many companies had their major stars sign agreements that they would not appear on radio.
Worldwide, three main technologies are used for digital radio broadcasts: HD Radio, the “DAB Family” and Digital Radio Mondiale. They share some aspects, such as COFDM, but each also has unique characteristics driven by spectrum and regulatory constraints.
- HD Radio is designed to work within the FM band. Digital sidebands are broadcast within the authorized spectrum mask of a 200-MHz channel alongside an analog FM signal, enabling backward compatibility with analog receivers. A variant for AM broadcasting delivers roughly half of the FM system’s data throughput within a much smaller 30 kHz occupied bandwidth.
- The “DAB Family” includes the original DAB, DAB+ and DMB variants. Designed for deployment on VHF Band III (174–216 MHz, occupied by TV Channels 7–13 in the U.S.) or L-Band frequencies (1450–1500 MHz) for terrestrial use, all three systems package several individual services into a single 1.5-MHz “ensemble,” or multiplex. DAB uses MPEG-1 Layer 2 audio coding, DAB+ uses more efficient HE-AAC coding, and DMB supports AVC (MPEG-4) mobile video in addition to audio services.
- Digital Radio Mondiale is currently used for shortwave and can fit more channels into a given amount of bandwidth, using various MPEG-4 codecs. Now called DRM30, it operates on SW and MW bands in standard 9- or 10 kHz channels or in wider 18 or 20 kHz allocations for increased data rate or robustness. A newer variant of the system called DRM+ offers a significantly higher data rate on 100-kHz VHF channels