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Radio Data System (RDS) is a
communications protocol A communication protocol is a system of rules that allows two or more entities of a communications system to transmit information via any kind of variation of a physical quantity. The protocol defines the rules, syntax, semantics and synchr ...
standard for embedding small amounts of
digital information Digital data, in information theory and information systems, is information represented as a string of discrete symbols each of which can take on one of only a finite number of values from some alphabet, such as letters or digit (unit), digits. ...
in conventional FM radio broadcasts. RDS standardizes several types of information transmitted, including
time Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to ...
,
station identification Station identification (ident, network ID or channel ID or bumper) is the practice of radio and television stations and broadcast network, networks identifying themselves on-air, typically by means of a call sign or brand name (sometimes known, ...
and program information. The standard began as a project of the
European Broadcasting Union The European Broadcasting Union (EBU; french: Union européenne de radio-télévision, links=no, UER) is an alliance of Public broadcasting, public service media organisations whose countries are within the European Broadcasting Area or who ar ...
(EBU), but has since become an international standard of the
International Electrotechnical Commission The International Electrotechnical Commission (IEC; in French: ''Commission électrotechnique internationale'') is an international standards organization that prepares and publishes international standards for all electrical, electronic and r ...
(IEC). Radio Broadcast Data System (RBDS) is the official name used for the U.S. version of RDS. The two standards are only slightly different, with receivers able to work with either system and only minor inconsistencies in the displayed data. Both versions carry data at 1,187.5
bits per second In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction w ...
on a 57 
kHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose expression in terms of SI base units is s−1, meaning that on ...
subcarrier A subcarrier is a sideband of a radio frequency carrier wave, which is modulated to send additional information. Examples include the provision of colour in a black and white television system or the provision of stereo in a monophonic radio broa ...
, so there are exactly 48 cycles of subcarrier during every data bit. The RBDS/RDS subcarrier was set to the third
harmonic A harmonic is a wave with a frequency that is a positive integer multiple of the ''fundamental frequency'', the frequency of the original periodic signal, such as a sinusoidal wave. The original signal is also called the ''1st harmonic'', the ...
of the 19 kHz
FM stereo FM broadcasting is a method of radio broadcasting using frequency modulation (FM). Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high fidelity sound over broadcast radio. FM broadcasting is capa ...
pilot tone An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators, because they ar ...
to minimize
interference Interference is the act of interfering, invading, or poaching. Interference may also refer to: Communications * Interference (communication), anything which alters, modifies, or disrupts a message * Adjacent-channel interference, caused by extr ...
and
intermodulation Intermodulation (IM) or intermodulation distortion (IMD) is the amplitude modulation of signals containing two or more different frequencies, caused by nonlinearities or time variance in a system. The intermodulation between frequency compo ...
between the data signal, the stereo pilot and the 38 kHz DSB-SC stereo difference signal. (The stereo difference signal extends up 38 kHz + 15 kHz = 53 kHz, leaving 4 kHz for the lower sideband of the RDS signal.) The data is sent with an
error correction code In computing, telecommunication, information theory, and coding theory, an error correction code, sometimes error correcting code, (ECC) is used for controlling errors in data over unreliable or noisy communication channels. The central idea is ...
, but receivers may choose to use it only for
error detection In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communi ...
purposes. RDS defines many features including how private (in-house) or other undefined features can be "packaged" in unused program groups.


Development

RDS was inspired by the development of the
Autofahrer-Rundfunk-Informationssystem Autofahrer-Rundfunk-Informationssystem (ARI, German language, German for: Automotive-Driver's-Broadcasting-Information) was a system for indicating the presence of traffic information in FM broadcasting, FM broadcasts used by the Germany, German ARD ...
(ARI) in Germany by the
Institut für Rundfunktechnik The Institut für Rundfunktechnik GmbH (IRT) (''Institute for Broadcasting Technology Ltd.'') was a research centre of German broadcasters ( ARD / ZDF / DLR), Austria's broadcaster (ORF) and the Swiss public broadcaster ( SRG / SSR). It was respon ...
(IRT) and the radio manufacturer
Blaupunkt Blaupunkt GmbH () was a German manufacturer of mostly car audio equipment. It was owned by Robert Bosch GmbH from 1933 until 1 March 2009, when it was sold to Aurelius AG of Germany. It filed for bankruptcy in late 2015 with liquidation proceed ...
. ARI used a 57-kHz subcarrier to indicate the presence of traffic information in an FM radio broadcast. The EBU Technical Committee launched a project at its 1974
Paris Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...
meeting to develop a technology with similar purposes to ARI, but which was more flexible and which would enable automated retuning of a receiver where a broadcast network transmitted the same radio programme on a number of different frequencies. The modulation system was based on that used in a Swedish paging system and the baseband coding was a new design, mainly developed by the
British Broadcasting Corporation #REDIRECT BBC Here i going to introduce about the best teacher of my life b BALAJI sir. He is the precious gift that I got befor 2yrs . How has helped and thought all the concept and made my success in the 10th board exam. ...
(BBC) and the IRT. The EBU issued the first RDS specification in 1984. Of the three broadcasting partners of the EBU, the BBC were reportedly pursuing the application of RDS technology most enthusiastically and sought to attract bids from manufacturers to make a "BBC-accredited radio" supporting RDS features. Having received no manufacturer interest, however, the corporation engaged designers at Kinneir Dufort to produce a prototype showcasing these features. This prototype, unveiled in 1989, incorporated a
liquid-crystal display A liquid-crystal display (LCD) is a flat-panel display A flat-panel display (FPD) is an electronic display used to display visual content such as text or images. It is present in consumer, medical, transportation, and industrial equipmen ...
capable of showing images such as weather maps, accompanied by "a light pen with which the radio can be programmed from barcodes", these barcodes encoding programme information, and supported detachable modules, of which a cassette player module and a printer module were developed. Despite reluctance to develop screen-based functionality that might bring RDS into competition with television, the utility of being able to print out information such as weather maps or even advertising was regarded as potentially interesting to both radio and television manufacturers alike. Enhancements to the alternative frequencies functionality were added to the standard and it was subsequently published as a
European Committee for Electrotechnical Standardization CENELEC (french: Comité Européen de Normalisation Électrotechnique; en, European Committee for Electrotechnical Standardization) is responsible for European standardization in the area of electrical engineering. Together with ETSI (telecommun ...
(CENELEC) standard in 1990. In 1992 the U.S.
National Radio Systems Committee The National Radio Systems Committee (NRSC) is an organization sponsored by the Consumer Technology Association (CTA) and the National Association of Broadcasters (NAB). Its main purpose is to set industry technical standards for radio broadcas ...
issued the North American version of the RDS standard, called the Radio Broadcast Data System. The CENELEC standard was updated in 1992 with the addition of Traffic Message Channel and in 1998 with Open Data Applications and, in 2000, RDS was published worldwide as IEC standard 62106.


RDS2

The RDS-Forum (Geneva/CH) decided at its annual meeting (8–9 June 2015) in Glion/Montreux to bring the new standard RDS2 on the way. The standard will be created in close collaboration with U.S. colleagues from NRSC RBDS-Subcommittee and should offer a unified platform for FM broadcasting and data services worldwide. ;Key features: * Seamless support for frequencies from 64 MHz to 108 MHz (AF,
EON Eon or Eons may refer to: Time * Aeon, an indefinite long period of time * Eon (geology), a division of the geologic time scale Arts and entertainment Fictional characters * Eon, in the 2007 film ''Ben 10: Race Against Time'' * Eon, in the ...
) * New character coding:
UTF-8 UTF-8 is a variable-width encoding, variable-length character encoding used for electronic communication. Defined by the Unicode Standard, the name is derived from ''Unicode'' (or ''Universal Coded Character Set'') ''Transformation Format 8-bit'' ...
(old EBU Charset remains for compatibility mode for the old 0A/2A Groups). * New ODA handling, "B" groups are assigned as signalling group to the "A" groups. * Long PS-Name, up to 32 byte with UTF-8 character set. (Indian, Chinese, Arabic, and more) * RadioText (eRT) 128 byte long with UTF-8 character set. * Increased capacity from 11.4 up to 57 "A"-groups per second. (2,109 bit/s. net capacity with the single modulation-type multiple subcarriers (SMMS) technology) * Graphical RadioText – supports HTML/CSS templates (for smartphones, car radios, computers/tablets) * Supports return channel over gRT if the receiver has IP or SMS capability. * Broadcaster's graphical logo – a maximum 4 kilobyte picture (JPEG, PNG, or GIF) * Hybrid Radio feature (partly based on Radio France development)


Content and implementation

The following information fields are normally contained in the RDS data: ;AF ( alternative frequencies list): This provides the receiver with a list of frequencies that allows a receiver to re-tune to a different
frequency Frequency is the number of occurrences of a repeating event per unit of time. It is also occasionally referred to as ''temporal frequency'' for clarity, and is distinct from ''angular frequency''. Frequency is measured in hertz (Hz) which is eq ...
providing the same station when the first signal becomes too weak (e.g., when moving out of range). Before performing the switch, a radio will check for a matching PI code to ensure the AF is the same station. This is often used in car stereo systems, allowing the head unit to automatically tune into the stronger signal on the move, optionally with the same regional code (so that, in the case of national broadcasting stations, the user can keep listening to the original radio program). ;CT (clock time and date): Can synchronize a
clock A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and the ...
in the receiver or the main clock in a car. Due to transmission vagaries, CT can only be accurate to within 100 ms of UTC. CT is not usually transmitted if a broadcaster has no way to regularly synchronise the clock within the RDS encoder. ;EON (
enhanced other networks Enhanced other networks (EON) is a radio system used to deliver traffic information to enabled devices. It is a component of the European Radio Data System Radio Data System (RDS) is a communications protocol standard for embedding small amount ...
information): Informs the receiver about other networks or stations, linked to the one being listened to, for dynamically changing data such as the TA flag turning on for a particular station of the network in a particular moment due to a
traffic Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads) for travel and transportation. Traffic laws govern and regulate traffic, while rules of the road include traffic ...
programme being broadcast, and automatically and temporarily allows the radio to tune into that station. ;PI (
programme identification Programme Identification (PI) is a service provided by radio stations transmitting Radio Data System (RDS) data as part of the FM radio broadcast. The PI code allows the radio to identify the station across different broadcast relay stations. ...
):This is the unique 4 character
hexadecimal In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system representing numbers using 10 symbols, hexa ...
code that identifies the station. Every station in a country should use a unique 3 character code with the correct country prefix character. In the US, PI is determined by applying a formula to the station's
call sign In broadcasting and radio communications, a call sign (also known as a call name or call letters—and historically as a call signal—or abbreviated as a call) is a unique identifier for a transmitter station. A call sign can be formally assigne ...
, or randomly assigned by the NRSC to FM translators (which have a longer call sign, making them incompatible with the formula). The PI code is the most important RDS parameter and the most frequently transmitted within the RDS data structure. The RDS standard for non US use defines country codes for all countries so that no where with common borders has the same code. This removes the need to coordinate codes between different countries. Any transmission that carries the same code is considered by receivers to be the same and can be switched to as an alternative frequency to improve reception (even if it is not specifically listed as an alternative frequency). ;PS (programme service name): This is simply an eight-character static display that represents the call letters or station identity name. Most RDS capable receivers display this information and, if the station is stored in the receiver's presets, will cache this information with the PI code, frequency and other details associated with that preset. In some countries, stations use the PS to dynamically send other information. This is prohibited in some countries and was not its intended use within the RDS system. ;PTY (programme type): This coding of up to 31 pre-defined programme types (e.g., in Europe: PTY1 News, PTY6 Drama, PTY11 Rock music) allows users to find similar programming by genre. PTY31 is reserved for emergency announcements in the event of natural disasters or other major calamities. ;REG (regional): This is mainly used in countries where national broadcasters run "region-specific" programming such as regional opt-outs on some of their transmitters. This functionality allows the user to "lock-down" the set to their current region or let the radio tune into other region-specific programming as they move into the other region. ;RT (radio text): This function allows a radio station to transmit a 64 (or less commonly 32) character free-form text message that can be either static (such as station slogans) or in sync with the programming (such as the title and artist of the currently playing song). ;RT+ (radio text plus): An enhancement of the original RT which allows Artist, Title and some other metadata to be sent to receivers. ;TA, TP (
traffic announcement Traffic announcement (TA) refers to the broadcasting of a specific type of traffic report on the Radio Data System. It is generally used by motorists, to assist with route planning, and for the avoidance of traffic congestion Traffic congest ...
, traffic programme):The receiver can often be set to pay special attention to this flag (taking advantage of the EON linkage if it's available) and, for example, pause a CD or retune to receive a traffic bulletin. The TP flag is used to allow the user to find only those stations that regularly broadcast traffic bulletins whereas the TA flag is used to signal an actual traffic bulletin in progress, with radio units perhaps performing other actions such as pausing a CD/MP3 (so the radio can be heard) or raising the volume during the traffic bulletin. ;TMC ( traffic message channel): Digitally encoded traffic information. Not all RDS equipment supports this, but it is often available for
automotive navigation system An automotive navigation system is part of the automobile controls or a third party add-on used to find direction in an automobile. It typically uses a satellite navigation device to get its position data which is then correlated to a position on ...
s. In many countries only encrypted traffic data is broadcast, and so an appropriate decoder, possibly tied to a subscription service, is required to use the traffic data. The subscription is often paid by the vehicle manufacturer and is therefore transparent to the user. ;US NRSC FM Translator Announcements: The National Radio Systems Committee has introduced a unique Radio Data System Program Identification code for US FM translators. One type of metadata transmitted by RDS subcarrier is the PI code, which is used by the receiver to uniquely identify the audio program being broadcast by the FM station. In the U.S., the PI code has historically been derived from a radio station's call sign, which can become complicated when used in conjunction with FM translators. A new algorithm just for FM translators has been created that assigns a unique PI code to each FM translator. This algorithm has been implemented using a web-based tool and a list of all known PI codes for all FM translators in the US


RDS support

As far as implementation is concerned, most car stereos will support at least AF, EON, REG, PS and TA/TP. * More expensive car stereos will offer Traffic Message Channel, TMC, RT and / or PTY, perhaps with "NEWS" override. * Home systems, especially hi-fi receivers, will mainly support functions like PS, RT and PTY. There are a growing number of RDS implementations in portable audio and navigation devices thanks to lower-priced, small-footprint solutions.


RDS compatibility

The RDS sub-carrier at 57 kHz occupies ±2 kHz of the composite spectrum which in theory keeps it above the upper cutoff of the stereo subcarrier at 53 kHz. However the 53 kHz cutoff is entirely dependent on the performance of the 15 kHz low pass filters used before the stereo encoder. In older equipment, these filters were only designed to protect the 19 kHz pilot and sometimes did not provide sufficient protection to the RDS subcarrier when a significant amount of stereo information was present. In this situation, stereo enhancement devices combined with aggressive audio processing could render the RDS subcarrier unreceivable. Composite clipping systems may also degrade the RDS sub-carrier because of the harmonics created by the clipping. More modern composite clippers include filtering to protect the RDS subcarrier. The RDS subcarrier typically uses 2–4 kHz of carrier deviation. Therefore, the deviation available for the program material is reduced by this amount, assuming the usual 75 kHz deviation limit is not exceeded.


Program types

The following table lists the RDS and RBDS (North American) program type (PTY) codes and their meanings: : The PTY codes have undergone several expansions. The first RDS standard only defined 0–15 and 31. The later RBDS standard implemented in the U.S. assigned the same meanings to codes 0, 1 and 31, but made no attempt to match the rest of the original RDS plan and created its own list for codes 2–22 and 30, including commercially important (in the U.S.)
radio format A radio format or programming format (not to be confused with broadcast programming) describes the overall content broadcast on a radio station. The radio format emerged mainly in the United States in the 1950s, at a time when Radio broadcasting, ...
s such as top 40, religious, country, jazz and R&B which were not in the RDS list. This included mismatched codes for information. sport, and rock. Later RBDS standards added types 23 (College) and 29 (Weather), while the RDS type code list grew to its current size, importing some types (e.g. jazz and country) from the RDBS list. RDBS types 24–26 were added in April 2011. The code mismatches are mainly a problem for people taking
portable radio In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. The ...
s into or out of North America.


RDS technical specification

The RDS standard as specified in EN 50067:1998 is separated into these sections according to the OSI model. (The network and transport layers are excluded, as this is a unidirectional broadcast standard.) #
Data channel A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for informat ...
(Physical layer) # Baseband coding (Data-link layer) # Message format (Session and presentation layer)


Data channel (Physical layer)

The physical layer in the standard describes how the bitstream is retrieved from the radio signal. The RDS hardware first demodulates the 57 kHz RDS subcarrier signal to extract a differential Manchester encoded signal which contains both the bit clock and the differentially encoded bitstream. This allows the RDS decoder to tolerate phase inversion of its input.


Baseband coding (Data-link layer)

At the data link layer, 26 consecutive bits form a "block", consisting of 16 data bits followed by 10 error correction bits. Four blocks make a 104-bit "group". The error correction bits also encode the "offset", or block number within a 4-block group. The error correction is done using a 10-bit
cyclic redundancy check A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. Blocks of data entering these systems get a short ''check value'' attached, based on t ...
, with polynomial . (Neither a preset nor post-invert is used, as they are not necessary with a fixed-size data field.) The CRC is also summed with one of five "offset" words which identify the block: A, B, C, C′, or D. Four consecutive blocks (ABCD or ABC′D) make up a "group" of 104 bits (64 data bits + 40 check bits). There are slightly over 11.4 groups transmitted per second. There is no gap between blocks. The receiver synchronizes to groups and blocks by checking CRCs on each 26 bits until synchronization is achieved. Once synchronized (the offset word is predictable), the code is capable of correcting up to 5-bit
burst error In telecommunication, a burst error or error burst is a contiguous sequence of symbols, received over a communication channel, such that the first and last symbols are in error and there exists no contiguous subsequence of ''m'' correctly receive ...
s. This basic modulation and block structure was originally developed for the "mobile search" protocol, with the difference that MBS (or the North American equivalent MMBS "modified MBS") does not use an offset word. To allow the two systems to interoperate (and to allow FM radio stations to transmit RBDS data while maintaining their pager contracts), the RBDS standard defines a sixth all-zero offset word E. Groups of four E blocks may be mixed with RBDS groups, and ignored by RBDS receivers. (Likewise, the RBS offset words are chosen to appear as uncorrectable errors to MBS receivers.) Data within each block (and group) is transmitted most significant bit first, and thus are numbered from bit 15 (transmitted first) to bit 0 (transmitted last). The most frequently information transmitted is a 16-bit "program identification" code, identifying the transmitting radio station. Blocks A and C′ always include the PI code; offset C is used when the third block contains something else.


Shared structure

Block 1 always contains the 16-bit program identifier. The first 11 bits (bits 15–5) of block 2 are also the same in all groups. The first 4 bits (bits 15–11) of block 2 are the "group type code", which describe the interpretation of the remaining data. Each group type comes "A" and "B" variants, distinguished by the fifth "B" bit (bit 10): If B=0, then the group is 0A through 15A, and contains 5+16+16 = 37 bits of data. If B=1, block 2 contains a PI code (and is encoded with offset word C′), the group is one of 0B through 15B, and contains 21 bits of data. Within Block 1 and Block 2 are structures that will always be present in both group versions, for fast and responsive identifications. The first block of every group, will always be the program identification code. The second block dedicates the first 4 bits for Application/Group Type. Meaning of Block 2 Bits * GTYPE: Group Type * B0: If B0=0 then Message Group Type A else Type B * TP: Traffic Program. Indicates this channel includes periodic
traffic report Traffic reporting is the near real-time distribution of information about road conditions such as traffic congestion, detours, and traffic collisions. The reports help drivers anticipate and avoid traffic problems. Traffic reports, especially in c ...
s. * PTY: Program Type (See .) * ????: Rest of the bits are group type dependent


= Message version A

=


= Message version B

= Block 3 is used for repeating program identification code.


Program identification code (PI code)

This allows for quick identification of radio program type, based on country, coverage area, and program reference number. While the country code is specified by the standard, bit 11 to bit 0 is specified by each country local authorities. Country codes are re-used, but only in geographically distant regions beyond FM broadcast range from each other. For example, country code F is assigned to
France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
,
Norway Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...
,
Belarus Belarus,, , ; alternatively and formerly known as Byelorussia (from Russian ). officially the Republic of Belarus,; rus, Республика Беларусь, Respublika Belarus. is a landlocked country in Eastern Europe. It is bordered by R ...
and
Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Mediter ...
.


Group type

This is a short list of the full group type. Each group type may have a secondary version available


Traffic Program

This can be considered an additional program type bit, and indicates that the station broadcasts periodic
traffic report Traffic reporting is the near real-time distribution of information about road conditions such as traffic congestion, detours, and traffic collisions. The reports help drivers anticipate and avoid traffic problems. Traffic reports, especially in c ...
s. By including it in every group, a receiver can quickly search for a station which includes traffic reports. Another bit, traffic announcement (TA), is sent in block types 0A, 0B and 15B to indicate that such a report is in progress. It is common for otherwise-
simulcast Simulcast (a portmanteau of simultaneous broadcast) is the broadcasting of programmes/programs or events across more than one resolution, bitrate or medium, or more than one service on the same medium, at exactly the same time (that is, simultane ...
transmitters to have periodic local traffic reports which are customized to the individual transmitter. The traffic announcement bit tells a receiver that a transmitter-specific broadcast is in progress, and it should avoid switching frequencies while they are in progress. (There is a different form of traffic announcement bit in block type 14B, which indicates the presence of a traffic announcement on a ''different'' frequency, so that radio receivers can automatically switch.)


RDS message examples

These are non-comprehensive examples that cover just the simple messages likes station name, radio text, and date/time.


Group type 0 – Version B – Station name

As we have already described previous fields above, these dot points below show just the application specific fields. * TA : Traffic Announcement * M/S : Music/Speech The station name and decoder identification code is sent progressively over 4 groups, where the offset is defined by bit C1 and C0.


Group type 2 – Radio text

As we have already described previous fields above, these dot points below show just the application specific fields. * A/B : Text A/B flag is used to detect if a screen clear is requested. * C3 to C0 : Is the text segment offset value The station name and decoder identification code is sent progressively over 4 groups, where the offset is defined by bit C1 and C0.


Group type 4 – Version A – Clock time and data

When group type 4A is used, it shall be transmitted every minute according to EN 50067. The clock time group is inserted so that the minute edge will occur within ±0.1 seconds of the end of the clock time group. Time and date are packed as these: Note: The local time offset is expressed in ''multiples of half hours'' within the range −15.5h to +15.5h. It is expressed in
signed magnitude In computing, signed number representations are required to encode negative numbers in binary number systems. In mathematics, negative numbers in any base are represented by prefixing them with a minus sign ("−"). However, in RAM or CPU regist ...
form, with the most significant bit being the "Local Offset Sign" bit (LOS), 0 = + (east of
Greenwich Greenwich ( , ,) is a town in south-east London, England, within the ceremonial county of Greater London. It is situated east-southeast of Charing Cross. Greenwich is notable for its maritime history and for giving its name to the Greenwich ...
), 1 = −.


Example RDS usage

The following three images illustrate how RDS can be used on an FM radio station; the latter two were taken when the radio was tuned to
Nottingham Nottingham ( , East Midlands English, locally ) is a city status in the United Kingdom, city and Unitary authorities of England, unitary authority area in Nottinghamshire, East Midlands, England. It is located north-west of London, south-east ...
radio station
Trent FM Trent FM was an Independent Local Radio station which broadcast to Nottinghamshire. The station merged with two other East Midlands stations, Leicester Sound and Ram FM to form Capital FM East Midlands (part of Global's Capital FM Network) on M ...
. All the images are of the display on the
Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professional ...
XDR-S1 DAB/FM/MW/LW portable radio.


RDS decoder chipsets

Companies such as
ST Microelectronics STMicroelectronics N.V. commonly referred as ST or STMicro is a Dutch multinational corporation and technology company of French-Italian origin headquartered in Plan-les-Ouates near Geneva, Switzerland and listed on the French stock market. ST ...
,
Silicon Labs Silicon Laboratories, Inc. (Silicon Labs) is a fabless global technology company that designs and manufactures semiconductors, other silicon devices and software, which it sells to electronics design engineers and manufacturers in Internet of Th ...
in
Austin, Texas Austin is the capital city of the U.S. state of Texas, as well as the county seat, seat and largest city of Travis County, Texas, Travis County, with portions extending into Hays County, Texas, Hays and Williamson County, Texas, Williamson co ...
and
NXP Semiconductors NXP Semiconductors N.V. (NXP) is a Dutch semiconductor designer and manufacturer with headquarters in Eindhoven, Netherlands. The company employs approximately 31,000 people in more than 30 countries. NXP reported revenue of $11.06 billion in 2 ...
(formerly
Philips Koninklijke Philips N.V. (), commonly shortened to Philips, is a Dutch multinational conglomerate corporation that was founded in Eindhoven in 1891. Since 1997, it has been mostly headquartered in Amsterdam, though the Benelux headquarters i ...
) offer single-chip solutions that are found in these devices.


See also

;High-level RDS
API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standa ...
s *
Advanced Multimedia Supplements In computing, the Advanced Multimedia Supplements (also JSR-234 or AMMS) is an API specification for the Java ME platform. Practically speaking, it is an extension to JSR 135 Mobile Media API providing new features, such as positional 3D audio p ...
(JSR-234) (in Java programming language) *
OpenMAX AL OpenMAX (Open Media Acceleration), often shortened as "OMX", is a non-proprietary and royalty-free cross-platform set of C-language programming interfaces. It provides abstractions for routines that are especially useful for processing of audio, ...
(in C programming language) ;Related technologies * ALERT FM – RBDS emergency notification system * HEARO – a defunct RBDS emergency notification system *
Data Radio Channel Data Radio Channel (DARC) is a high-rate (16 kbit/s) standard for encoding data in a subcarrier over FM radio broadcasts. It uses a frequency of 76kHz, the fourth harmonic of the FM radio pilot tone. DARC was approved as the All-European standard ...
(DARC) *
DirectBand DirectBand was a North American wireless datacasting, datacast network owned and operated by Microsoft. It used FM radio broadcasts in over 100 cities to constantly transmit data to a variety of devices, including portable GPS devices, wristwatche ...
*
Program and System Information Protocol The Program and System Information Protocol (PSIP) is the MPEG (a video and audio industry group) and privately defined program-specific information originally defined by General Instrument for the DigiCipher 2 system and later extended for the ...
* UECP
protocol Protocol may refer to: Sociology and politics * Protocol (politics), a formal agreement between nation states * Protocol (diplomacy), the etiquette of diplomacy and affairs of state * Etiquette, a code of personal behavior Science and technology ...
(Universal Encoder Communication Protocol)
RDS OF THINGS
– Using RDS in
Smart City A smart city is a technologically modern urban area that uses different types of electronic methods and sensors to collect specific data. Information gained from that data is used to manage assets, resources and services efficiently; in return ...
applications. ;Related topics *
Digital radio Digital radio is the use of digital technology to transmit or receive across the radio spectrum. Digital transmission by radio waves includes digital broadcasting, and especially digital audio radio services. Types In digital broadcasting syst ...
*
Error correction In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communica ...
*
FM broadcasting FM broadcasting is a method of radio broadcasting using frequency modulation (FM). Invented in 1933 by American engineer Edwin Armstrong, wide-band FM is used worldwide to provide high fidelity sound over broadcast radio. FM broadcasting is cap ...
*
Internet radio device An Internet radio device, also called network music player is a hardware device that is capable of receiving and playing streamed media from either Internet radio stations or a home network. Background Streaming media became mainstream with the ...
*
Modem A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by Modulation#Digital modulati ...
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Radio receiver In radio communications, a radio receiver, also known as a receiver, a wireless, or simply a radio, is an electronic device that receives radio waves and converts the information carried by them to a usable form. It is used with an antenna. Th ...
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Teletext A British Ceefax football index page from October 2009, showing the three-digit page numbers for a variety of football news stories Teletext, or broadcast teletext, is a standard for displaying text and rudimentary graphics on suitably equipp ...
– ≈6.5kbit/s data transmission over Analog TV channel


Notes


References

* The Directory of European FM Broadcasting, ''European FM Handbook 2002–2003'', 13th edition, published July 1, 2002, B5 format,

* Dietmar Kopitz, Bev Marks, ''RDS: Radio Data System (Mobile Communications Library)'',

* MSB VMA report

* http://www.interactive-radio-system.com/docs/EN50067_RDS_Standard.pdf * (31 pages)


External links


FARWAY IRFC, TV and Radio Transmission , Radio Data System Encoders


* [https://www.nrscstandards.org/standards-and-guidelines/accept.asp?name=documents/standards/nrsc-4-b.pdf "NRSC-4 National Radio Systems Committee United States RBDS Standard – Specification of the radio broadcast data system (RBDS)"] * Th
RDS Forum
is the professional association of the users of the Radio Data System broadcast technology *

*
RDS Features Serving as Tuning Aids

xRDS "Extending the RDS data transmission capacity"
*


RDSList.com

GR-RDS on Github
– A GNU Radio-based open source implementation of an RDS receiver and transmitter
Decoding RDS TMC program and circuit


– Clifton Laboratories {{Authority control 1984 establishments 1984 introductions British inventions Broadcast engineering Digital radio German inventions Radio technology