The RDS specification was adopted by the EBU, the European Broadcasting Union, and published in 1984. It was also submitted to ITU-R, and the essential characteristics from the EBU specification were transcribed to ITU-R Recommendation 643, updated in 2022.
RDS emerged between 1975 and 1984. Looking back at that ten-year development period, three main requirements shaped the system:
- The desire to universally identify each FM programme, which created the PI and PS features.
- The desire to identify broadcasts for motorists more universally than ARI, which created the TP and TA features.
- The desire to hand over a mobile receiver within a network, which created the AF feature.
There was also a less strong desire to identify programme type, which created the PTY feature. The resulting system was designed for the mobile listener, especially for in-car FM reception where automatic retuning from one transmission coverage area to the next was essential. RDS also emulated the ARI system used in Austria, Germany, Luxembourg and Switzerland. RDS eventually replaced ARI while offering equivalent TP/TA traffic announcement features that still alert drivers today.
RDS was designed for mobile reception
Many other features were proposed and built into the RDS system to be dynamically multiplexed as needed in each transmission. The key mechanisms were designed for mobile reception, using a group/block data format to ensure very fast data synchronisation and decoding of certain features while allowing other features to be conveyed more slowly for general information.
Because the system design was developed by broadcasters working in the well-regulated environment of the 1970s, several features were considered but not fully developed at that time. Future enhancements were expected from the beginning, which allowed RDS to mature over the following years.
In 1985, EUROTECH agreed with the EBU about the general introduction of RDS. On the condition that the EBU supported development of the RDS-TMC feature, EUROTECH promised that the first RDS receivers would be presented at the international consumer electronics show IFA 1987 in Berlin. From 1988, those receivers were marketed in countries where RDS had already been introduced.
Because RDS development was well coordinated by the EBU, broadcasters across Europe were aware of the benefits for listeners. Some said listeners could now surf the radio waves. The European-wide introduction of RDS was fast enough that it was later called the Silent Revolution.
Broadcasters began implementing RDS transmissions using a mixture of self-built RDS encoders and early specialised professional equipment. The first implementations came from large network broadcasters and used only a few RDS features for trials and pre-service activities. Within a couple of years, real-world operation revealed that the original RDS specification needed further development.
First RDS industry standard published in 1990
New RDS features such as EON and ODA were added to the first RDS European standard, issued by CENELEC in 1990. In 1999, RDS became the worldwide IEC standard IEC 62106. Further features including RT+ and eRT were later added, with IEC 62106 Parts 1-6, 9 and 10 updated in 2018-2023.
In the USA, different radio broadcast practices required an adaptation of RDS. In 1997, a subcommittee of the National Radio Systems Committee, in coordination with the EBU, created the RBDS variant. NRSC then issued RBDS as a voluntary industry standard of NAB, the National Association of Broadcasters, and CEA, the Consumer Electronics Association. RBDS became IEC 62106-9 in 2021.
