Traffic Message Channel

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The TMC service logo

About T raffic M essage C hannel ( TMC ) information about traffic disturbances in the inaudible range of the FM broadcast signal in digital form. Navigation systems can receive traffic jam reports via TMC and thus create routes to bypass traffic jams and obstructions (dynamic route guidance).

To use TMC, a TMC-capable radio receiver is required. These are typically found in vehicle navigation systems. There are also car radios that extract TMC data via an interface (TMC-out) without decoding them themselves. This data can then be processed further in a connected (e.g. portable) navigation system.

As a rule, TMC services can be received free of charge (freeTMC). In some countries, however, there are also TMC services (payTMC) that are subject to a charge and promise better quality of traffic reports. PayTMC is either broadcast encrypted or uses its own "Location Table" ("LT", see below).

Due to the system, TMC can only roughly narrow down where there is a traffic jam, since it can only be referenced to the junctions of motorways and federal highways. It is not possible to specify where the traffic jam is between the junctions, but the length can.

Working principle

TMC information from the navigation system in the Alfa Romeo 147

Each traffic disruption is sent as a separate TMC message. A TMC message consists of an event code and a position code, possibly an additional time limit (expiry time). After a malfunction has ceased, this malfunction message is canceled by another TMC message. If this is not received (e.g. because the recipient has meanwhile moved out of the receiving area of ​​the transmitter), the fault message is alternatively deleted by the recipient when the expiry time is reached.

RDS- TMC messages are transmitted at about 60 bit / s, which corresponds to about 10 messages per minute.

The message is coded according to the Alert-C standard ( ISO 14819 ). This contains a list of approximately 1460 events. With the help of this list, the message can be converted into a form that the user can understand.

Position codes

A location code is assigned to a geographical location using lists (Location Table, LT). These are not subject to any international administration. Each country assigns the position codes for individual road sections itself. In some countries there are even several such lists from different providers in parallel. Because of the maximum data length, only 64,000 positions can be encoded, which makes TMC relatively imprecise. This is why it is not possible in Germany to code all road sections or intersections.

swell

The sources for the traffic information are typically the police , traffic cameras, fixed measurement cross-sections ( inductive loops , IR / radar sensors) or floating car data .

TMC forum

The TMC-Forum was a non-commercial organization whose membership consists of service providers, device manufacturers, automobile and card manufacturers, public institutions, broadcasters and other organizations. The TMC forum sees itself on the one hand as a discussion platform on the subject of traffic information in general, on the other hand it maintains the TMC standard (ISO 14819). On November 11, 2007 the TMC-Forum was merged with the TPEG-Forum in the Traveler Information Services Association , TISA for short. The tasks of the TMC forum will be continued by TISA. While TMC describes a protocol, the Transport Protocol Experts Group (TPEG) deals with the specification of protocol families. The TISA certifies the location tables (LT) submitted by the federal states after testing based on clearly defined test rules.

safety

The TMC protocol does not contain any encryption methods of its own, as the effects of an attack were classified as rather insignificant. The manipulation described by Heise Security requires a mobile transmitter that can broadcast manipulated TMC messages within a small radius (up to 1 km). The operation of such a transmitter is illegal in most countries and the technical and financial costs are high.

Countries with TMC services

The following is an overview of the TMC activities in various countries.

Belgium

A free TMC service, TIC-VL, is available in the Flanders area . Offered by Verkeerscentrum Antwerp and broadcast on Radio 2 by VRT .

A free TMC service is being tested in the southern part of Belgium , Wallonia. Broadcast by RTBF on Classic 21 . The service is a service provided by Center PEREX of the Ministère de l'Équipement et des Transports (MET) in collaboration with TMC4U.

Since 2009 there has also been a nationwide CA-TMC provider (Be-Mobile).

Tritel creates the LT on the instructions of regional municipalities. Since mid-2007 the TMC messages have been broadcast according to LT version 2.1a, the N streets are included in the LT. An LT version 2.2 is already certified.

China

There are two TMC services in Beijing since 2008. Receivable at least within the 5th ring road.

CenNavi sends with PI code C000 (frequency = 91.5, PS name = "106.1")

AutoNavi sends with PI code C001 (frequency = 90.0, PS name = "BJ90.0")

Audi released its Gen 3 navigation systems for the AutoNavi services on September 12th.

Both providers plan to cover China first but the coastal metropolis. The aim is to be able to offer Shanghai by 2010.

Traffic information based on GPS movement data from 17,000 taxis has been available in Guangzhou since 2008. The system - built and operated by Siemens - reaches road users via SMS and other routes via China Mobile. Other cities and regions are in preparation.

Denmark

A free TMC service, DK-TMC, is operated in Denmark by Vejdirektoratet or DRD (Danish Road Directorate). Broadcast on Danmarks Radio's P3 and P4 channels .

It is also responsible for the LT. The LT, which is downward compatible with the previous version, has been sent with version 8.0 since spring 2007.

Germany

Free TMC services are available in Germany and the commercial service Navteq Traffic (formerly TMCpro FM) has been available since January 2005 . The free TMC service can be received via several radio stations of the ARD broadcasting chain and the FM broadcasting of Deutschlandradio ( Deutschlandfunk ). Navteq Traffic uses many private and local radio stations .

The Federal Highway Research Institute (BASt) publishes the LT (= Location Table, also known as the "Location Code List" or LCL), which is compiled by the individual state authorities and organizations. The LCL is updated annually in Germany. Since April 9, 2013, LCL 12.0 has been the valid version of the Location Code List (LCL) and 4.01 has been the valid version of the Event Code List (ECL). Compared to the previous version, 2,508 changes were made, 656 locations added and 126 deleted, so that 46,395 locations are now included. The previous version 11.0 was valid from April 17, 2012 to April 7, 2013.

The location code list is made up of area codes (e.g. cities), linear locations (linear codes; e.g. streets) and point locations (e.g. parking lots, junctions). While all relevant points are mapped in the LCL on motorways and many federal highways, there are still large gaps between the recorded points in the downstream road network. A comprehensive coverage of all junctions, even on less important roads, is not possible due to technical restrictions.

When the version changes, all broadcasters, reporting offices and other organizations switch to the new LCL and ECL at the same time as possible. In principle, all recipients would have to be updated at the same time. In practice, however, this often takes months. The information content can be (slightly) falsified in receivers that have not yet been converted.

State broadcasters of ARD in Germany

German TMC transmitter

German Navteq traffic transmitter

The stations of the Navteq Traffic service (formerly TMCpro FM) can be found in the article of the same name.

Finland

A free TMC service was mainly available in southern Finland until 2007. Like the LT, the service was administered by FINNRA, the Finnish National Road Administration. Since 2007 there is only one commercial service, VTRAFFIC. This is broadcast on YLE Suomi and is encrypted. The LT continues to come from FINNRA; the current version is 2.6 (July 2018).

France

In France there are both one free and two commercial services.

The free service is sent by the road operators, it includes reporting on their toll roads. The road operators are AREA, ASF, ATMB, Cofiroute, ESCOTA, SANEF, SAPN, SAPRR, SFTRF and SMTPC. The TMC service is broadcast nationwide along the motorways on the frequency 107.7 MHz, so it can only be received along the toll roads.

The commercial service V-Trafic is operated by Mediamobile. It's a partnership between TDF, Renault, Trafficmaster, and Cofiroute. The service, which replaces the previous Visionaute service, is broadcast on France Inter's frequencies and can be received nationally. It contains information from the motorways with an accumulation in the Paris area. At first this service was also free, but it was later converted into a commercial service. The service is not encrypted, but uses its own LT to restrict the group of users. This method is called a transition encryption system. The commercial service has approximately 60,000 customers.

There is also a PayTMC service from ViaMichelin . It is broadcast almost everywhere on the stations NRJ and NOSTALGIE. This service is also unencrypted, but uses its own LT.

The LT is published by SETRA and has 21450 locations. The current version is 6.1 and covers the road network both in the metropolitan areas and on the trunk roads. Version 8.0 was certified by TISA in spring 2008.

Great Britain

The private company ITIS Holding broadcasts a commercial TMC service, the iTMC, in the UK. It is broadcast on the FM station. The fee for the service can be included in the price of the vehicle or the navigation system.

In addition to this service, there is another service, RAC Live, operated by RAC Trafficmaster Telematics (RTT), a 50-50 joint venture between RAC Motoring Services and Trafficmaster. This uses 3 private radio stations, GWR, Capital radio and Chrysalis. This guarantees nationwide supply.

Both services use their own LT, which are not compatible with each other. ITIS is currently broadcasting in version 5.1. Trafficmaster is currently using version 3.1.

Italy

A TMC service is also available in Italy . The CCISS makes the data available. The TMC signal is broadcast via the RAI network on station Radio 1. The TMC service mainly covers main roads in the north of the country, especially the West-East Autostrada.

The LT currently manages Mizar Mediaservice in version 1.1. A newer version 2.1 is already certified.

A non-free TMC service from infoblu is broadcast on the RTL 102.5 broadcasting chain , with 80% area coverage.

Netherlands

The service provider TMC4U delivers the data in the Netherlands. The service is currently free, but a local notification service is being planned. TMC4U is a collaboration between Siemens and ANWB. It is broadcast on Sky Radio, Radio Veronica, Radio 1 and 3FM. Radio 2 also broadcasts TMC messages.

A second TMC service, operator Vialis, uses the channels Q-Music, BNR Nieuwsradio and Radio 538.

The LT are the responsibility of the AVV Transport Research Center and are drawn up by TIC Nederland. The current version is 6.1.

Norway

A TMC service is also available in Norway . It is currently available in the Østfold, Akershus and Oslo area. The service is currently being expanded to include larger parts of the country. Statens vegvesen , the Norwegian Public Roads Administration (NPRA) publishes the LT. The current version is 2.0. "Destia" send this data encrypted by the Norwegian radio station P4. NRK has an unencrypted service broadcast on its radio channel NRK P1 .

Austria

In Austria the ORF broadcasts the free TMC service through the broadcasters Ö1 , Ö3 , FM4 and the regional state studios , supported by the Federal Ministry for Transport, Innovation and Technology (BMVIT). The Autobahn and Schnellstraßen-Finanz-Aktiengesellschaft (ASFINAG) is responsible for the LT in Austria . Version 3.2 is currently used.

ORF and ASFINAG Maut Service GmbH started a new, improved TMC service (TMC PLUS) for Austria on June 24, 2009.

Poland

In Poland , the commercial TMC service started on May 1, 2010 on the private radio station RMF FM . The service was provided by Destia Traffic after a two-year test phase and was initially only available to Garmin and Navigon users, but TomTom devices should follow soon. Another commercial service is broadcast on Radio ZET.

Sweden

A free TMC service is available in Sweden. The Trafikverket (Swedish Transport Administration) is responsible for the free service as well as for the LT. Version 2.0 is currently in use. Version 3.0 was certified by the TMC Forum in December 2007. The broadcast is divided into eight broadcasting zones. In the areas, only the messages that fall geographically in this area are broadcast. The reports contain information about accidents, road works and weather reports on European roads, motorways and expressways. The radio program Sveriges Radio P3 is used for broadcasting and reaches 98% of the population of Sweden.

Switzerland

In Switzerland, traffic information is provided by the Viasuisse traffic information center. The TMC signal is broadcast throughout Switzerland by SRG SSR idée suisse on the stations of the first and third FM station chain. The Federal Roads Office is responsible for the LT . Version 6.5 has been in use since April 2016.

Spain

In Spain, the TMC service is operated by the following organizations:

  • SCT in Catalonia
  • DT in the Basque Country
  • DGT (Traffic General Directorate) in the rest of the country

The service includes the motorways and national roads as well as "First Order Roads" belonging to the autonomous areas of Spain. The LT is currently creating the DGT, Dirección General de Tráfico , version 2.1.

Czech Republic

Until 2004 there was no regular TMC service in the Czech Republic. A test run, coordinated by CEDA, was broadcast in 2003. The start of regular operations was planned for mid-2005. The TMC service should initially include downtown Prague and some main streets around Prague. ATT (Transport Telematics Association) organizes ITS activities, the planned service provider of the free local service is TSK (Communication Technical Administration).
A free TMC service is broadcast via the two state broadcasters CR1 and CR3, which covers the motorways (as of 1/2009).

The CEDA is responsible for the LT, 2004 current version was 2.41.

United States

In the USA, the satellite radio operator Sirius has been busy broadcasting the TMC service throughout the country for several years. Clear Channel has also been in the market for some time.

Clear Channel and Navteq now broadcast almost everywhere via FM. A variant of the RDS standard is used in the USA: RBDS (Radio Broadcast Data System)

Clear Channel is z. B. used by BMW, Navteq was able to win Daimler and Chrysler as original equipment manufacturers. Navteq also sends the TMC data via XM and SIRIUS, but Clear Channel has more terrestrial transmitters.

Other countries

TMC in planning

A TMC system is being planned for Portugal.

Luxembourg has submitted a TMC table for certification to TISA for the first time.

Israel has developed a first TMC table.

No TMC service planned

  • Ireland (however there were tests in Dublin in 2008)

TMC in test phase

  • A first LT was published in Dubai. TMC was already receivable in 2008.
  • Hungary introduced TMC as part of the CONNECT project. Since August 1st, 2008 TMC can be received in Hungary as a Pay-TMC service.
  • TMC is currently being tested in Singapore. One LT is already certified by the TMC forum. The introduction of a commercial service is planned for 2008.
  • TMC is currently being investigated in Australia. Test broadcasts can be received from time to time in Melbourne.

See also

Web links

Individual evidence

  1. ^ Heise Security article from April 22, 2007
  2. ↑ German Location Table of the Federal Highway Research Institute ( Memento from February 1, 2014 in the Internet Archive )
  3. ↑ Viasuisse