Overview
IEC 62106-2:2021 specifies the message format, coding and definitions of features for the Radio Data System (RDS) used in VHF/FM sound broadcasting in the 64.0 MHz to 108.0 MHz band. This second edition (2021) replaces the 2018 edition and updates group structures, feature coding and introduces the RDS2 file transfer (RFT) mechanism (Annex C) with a CRC‑16 check algorithm (Annex D). The standard defines how RDS groups and data-streams carry programme identifiers, text, alternative frequencies and Open Data Applications (ODAs) to ensure interoperable broadcast and receiver behaviour.
Key Topics
- RDS group structure and message format: Definitions for Group types A, B and C, and their block-level layouts used to encode RDS data.
- Feature definitions and coding: Detailed coding for core RDS features including Programme Identification (PI), Programme Service name (PS / LPS), RadioText (RT / eRT / RT+), Programme Type (PTY / PTYN), Clock Time and date (CT), Alternative Frequencies (AF), Traffic (TP/TA/TMC), Enhanced Other Networks (EON) and Extended Country Code (ECC).
- Open Data Applications (ODAs): Application Identification (AID) and group types for tunnelling ODAs; assignment methods linking channel numbers and AIDs.
- RDS2 File Transfer (RFT): New file transfer function for ODA file delivery (up to 163 kB) with CRC‑16 integrity checks (Annex C & D).
- Coding tables and repetition rates: AF frequency code tables, PI structure and recommended group repetition rates for reliable decoding on data‑stream 0.
- Normative and informative annexes: Methods for linkage information, time/date conversion and CRC-16 calculation examples.
Applications
IEC 62106-2:2021 is used by:
- Broadcasters and network planners to encode consistent RDS services (AF lists, EON links, traffic signalling).
- Receiver and infotainment manufacturers (car radios, portable receivers) to implement correct decoding of PS, RT, PTY, CT and ODAs, and to support automatic retuning via AF and linkage.
- ODM and software developers building RDS middleware, head‑unit software, or ODA-based services (e.g., metadata, file delivery).
- Regulators and test laboratories for compliance testing and interoperability verification of RDS implementations.
Practical outcomes include seamless station switching, displayable programme metadata, traffic alerts, and delivery of small files or metadata via RFT.
Related Standards
- Other parts of the IEC 62106 series (RDS system family) and regional broadcasting recommendations that reference RDS feature sets and frequency planning.
Keywords: IEC 62106-2:2021, Radio Data System, RDS, VHF/FM, message format, RFT, CRC-16, ODAs, Programme Identification, RadioText, Alternative Frequencies.
Open preview (PDF)Radio data system (RDS) - VHF/FM sound broadcasting in the frequency range from 64,0 MHz to 108,0 MHz - Part 2: Message format: coding and definition of RDS features
