The RDS Forum 2006 decided that the ARI system specification should be deleted from a future version of the RDS standard IEC 62106.
The ARI system was used previously to RDS, which incorporated later its functionality, and the ARI system became thus completely redundant. However, to protect old ARI receivers without RDS, ARI was continued to be broadcast in some countries simultaneously with RDS and in the years 2004/2006 ARI was finally switched off. RDS receivers were designed initially to be compatible with ARI. They used a notch-filter to filter out ARI, before RDS was decoded. Since ARI is no longer used, this notch-filter is thus no longer required which leads to a simplification for many RDS receivers. However, these new RDS receivers are then incompatible with ARI which means that ARI shall now no longer be used.
RT+ is the result of a joint German project development involving the public broadcaster WDR, the broadcast technology research centre IRT and the mobile telephone manufacturer Nokia. RT+ permits a broadcaster to tag specific RadioText elements under a variety of categories, such as title and artiste or interpreter of information and so on, which will then permit new listener friendly functions to be realised. Important traffic incidents can thus also be displayed as text messages, if this is exceptionally required.
RDS Forum Member Dr. Hans-Christoph Quelle (Nokia) explains RT+ as follows:
“RT+ will allow the radio receiver to "understand" the broadcast Radiotext. Understanding means, the radio station can tell the receiver,
The receiver will be able to act accordingly. It may display Title and Artiste nicely, and if it has a built-in back-channel (if it is a phone) the user might call the hotline with one click or the user can get more information from a web-site or from a hotline or even switch to another frequency.”
The new development was first presented to the RDS Forum 2005. First transmission tests were carried out on WDR 2 during 2005 and the new development was also first demonstrated over DVB-S radio at the IFA 2005 in Berlin.
In November 2005 Nokia invited to a Workshop, which had the aim to critically review this interesting new development.
This meeting was well attended by RDS Forum Members and other guests invited by Nokia.
The RT+ test transmissions from WDR 2 were analysed by RDS Forum Member Joop Beunders (Catena), who used his various test records and his RDS signal analyser software.
Rüdiger Malfeld, head of WDR radio programming, explained why RT+ was such an important innovation from the radio programme makers’ point of view. He also told, that all relevant ARD bodies have agreed that ARD radio stations will soon make use of RT+ to enhance the radio listening experience.
Andreas Niendorf (Digineus) showed a first RT+ receiver implementation for DVB-S radio.
Dietmar Kopitz (RDS Forum Office) explained how RT+ worked and compared it with the US alternative proposed by the US NRSC/RBDS committee. He concluded that RT+ was a much superior solution, fully compatible with present RDS receivers, and also easier to implement by the broadcaster. At the same time he raised a number of questions (collected through the RDS Forum) regarding minor improvements to RT+. These questions were discussed in detail and consensus decisions were made to resolve these little problems.
The developer companies IRT/Nokia/WDR declared that they make the specification openly available for free.
The EBU and the NAB (for RBDS) were informed at the end of 2005 by the RDS Forum Office of the decisions taken.
During Spring 2006 additional demonstrations were made within the EBU and also at the NAB Convention in Las Vegas.
In June 2006 the RDS Forum agreed that RT+ should become an integral part of a future edition of the RDS standard (planned IEC submission for 2008).
Some minor enhancements of the specification were agreed during the RDS Forum 2006 to meet requirements of US broadcasters. The aim of the RDS Forum was to harmonize RT+ with the RBDS sub-committee to enable RT+ to be used by both, RDS and RBDS.
The RDS Forum will later also develop appropriate RT+ implementation guidelines for broadcasters, transmission operators and receiver manufacturers. However, there was no priority to undertake this task. Implementation will be easy anyway as RT+ uses the ODA feature which is generally supported by RDS encoders using the UECP.
In July 2006, the EBU Technical Review published an article on RT+.
Download the EBU article R06/044_1
In September 2006 three RDS Forum 2006 participants (Broadcast Electronics, Catena and Kenwood) joined together to give an over-the-air demo of RT+ to the RBDS sub-committee meeting in Seattle (WA), USA.
The final version of the RT+ specification agreed after the RDS Forum 2008 is available here. It includes all the agreed enhancements.