EP0900432B1 - Method and receiver for geographical selection of digitally coded messages - Google Patents

Abstract

The invention relates to a method and to a receiver for geographical selection of digitally coded messages which are sent by several transmitters and contain local data which is compared in receivers with selection data according to the respective positions of the receivers so that the transmitters can also send selection data characterizing their respective transmitter range. Said data is compared in receivers with local data contained in the messages.

Description

The invention relates to a method for geographic Selection of digitally coded messages by several Stations are broadcast and contain location information, which in receivers with the respective position of the Comparison of recipient-dependent selection information be, and a receiver with a facility for Selection of digitally coded messages.

To inform motorists have been around for a long time Spoken traffic announcements known. These are with various disadvantages, for example with Delays and inaccuracies caused by manual and thus also subjective acceptance and transmission of the Information is connected. For example, it happens before a driver gets stuck in a traffic jam that (still) was not announced, or that despite the traffic jam warning relevant road when it arrives at the designated Can drive relatively smoothly.

A more precise recording and faster transmission has become known with the help of the Systems for the transmission of digitally coded traffic reports become possible. The structure and coding of these Traffic reports and the list of places are in CEN pr ENV12313-1 and pr EMV / 278/7/3/0004 specified on the Standard proposal ALERT C, June 1996, published by RDS ATT ALERT Consortium. The essential elements of a Traffic announcements are the location of the event and the event. This information is cataloged that means that every traffic-relevant place and everyone assigned a unique code to a traffic-relevant event is. The concatenation of the places in the place table along existing roads reflect the course. Except the usual facilities of a receiving device with a RDS decoders are used to use the traffic information channel TMC (Traffic Message Channel) Decoding devices for Storage, processing and output of the Traffic announcements required.

Digitally coded traffic reports - also in the following Called TMC messages - can with the radio data system (RDS), which is an additional and inaudible Transmission of digital data in parallel with Broadcast programs in a data channel. Specifications of the radio data system for FM radio are among others in the publication Tech. 3244-E, March 1984 of the European Runfunk Union (EBU). Radio receivers with suitable RDS decoders can transmitted data in addition to audio reception with the Record and decode the same receiver.

With an introduction of the TMC system is with a very large number of TMC messages, of which the only a small part of the respective driver is interested. On essential quality feature of future recipients for digitally coded messages will therefore be from the large number of messages received for the driver filter or select relevant messages and to protect the driver from information overload. A position-based selection is advantageous however requires knowledge of the position of the recipient, so the vehicle.

To determine the position - if necessary also one approximate position - various methods are known. For example, the position can be set manually via area and Route codes can be entered directly, which is longer Journeys but is too inflexible and cumbersome. A Coupling of the RDS / TMC receiver with a navigation system - for example GPS - requires additional technical Effort and therefore more costs.

The object of the present invention is a position-based selection without additional operating effort and with as little technical effort as possible enable.

From US-A-5 438 687 a method is known in which an approximate position based on the frequency of the transmitter of the vehicle is determined in order to select messages.

In the method according to the invention, this task solved in that the transmitter also their respective Selection information characterizing the send area broadcast in the receiver with in the messages contained location information can be compared.

The inventive method uses only that for Decoding of the messages already present in the receiver Data. The accuracy achieved is less than that with a navigation system, for the selection of Messages, however, quite high enough. A change of Frequency or one or the program information codes several transmitters is for the inventive method irrelevant as long as those emitted by the transmitter Selection information is retained.

The method is particularly advantageous with such Applicable, which automatically search for stations and according to reception conditions on the strongest station the desired program. It can inventive method also in so-called A tuner devices can be applied since none Perform field strength measurements on other frequencies are.

For devices with dedicated TMC tuners, the result is as further advantage that when receiving several TMC transmitters a selection of the service based on the Selection information, especially the area codes, can be carried out. For example, if the system The destination of the trip is known, so it can be the TMC service select, whose area code contains the target point, because so is ensured, all relevant for the route To select messages. The procedure is also not up certain RDS details depend on and may be on others Transmission media, e.g. DAB, AMDS.

In a first embodiment of the invention The method provides that the selection information Location codes from for coding and decoding the Messages are defined areas that are at least partially fall within the coverage area. These location codes - in also called area codes - can be sent by the recipient can be used directly as a selection criterion, since all for the coding and decoding of the messages Locations are referenced to such area codes. That is: only those messages pass the filter, their primary or secondary location itself within the by the Area code defined area is located.

A second embodiment of the method according to the invention is that the selection information coordinates and radii of the transmission ranges. The radius is here simplifying the range of the respective transmitter. Around this selection information is to be used in the recipient the location coordinates for each location code in the location list save. As this is also a requirement for a graphic Representing the traffic situation, such data is often already included in the list of locations and can for The inventive method can also be used.

This is particularly the case with transmitters with long ranges second embodiment may be cheaper, since the Dispersion area either by specifying a large one Area (federal state) only imprecise or with many small ones Areas could be described in detail. Since each code is 16 Bit transmission capacity is then used Often when deciding on the transmitter side for the imprecise solution.

Will be in front of each individual station for him applicable selection information is the Greatest accuracy. However, it is according to another Design of the method according to the invention is also possible that the same from a group of transmitters Selection information will be broadcast.

There is a further development of the method according to the invention in that the selection information and Reference information for the selection information in System messages one of the digitally coded messages contained data stream are transmitted. Especially that TMC signal according to ALERTC contains four system messages, which are determined by the first two bits of block C be distinguished. The first of these variants with the Code 00 can be used for this training for transmission the selection information is used. It is preferably provided that in a first data block the following information is transmitted: a Identification that selection information is transferred be the number one for decoding the messages in the Required location list and information about recipients the type of selection information.

Ultimately, should both the transmission of area codes the transfer of coordinates and radii is also possible be in an advantageous embodiment of this Training provided that in the first data block further information about the type of selection information is transmitted by a bit that indicates whether the Selection information from location codes of areas or Coordinates and radii exist. In case of transfer of area codes, it is advantageous if in the first Data block is also transmitted how many location codes from Areas to follow. This can be done in at least one other Data block a location code of an area are transmitted.

For one consisting of radius and coordinates Selection information can be the further training of the inventive method be designed such that in first data block the radius and in another Data block the coordinates are transmitted.

In a receiver according to the invention with one device for the selection of digitally coded messages from several stations are broadcast, location information included and in the recipient according to the position selection information dependent on the recipient are achieved, the object of the invention is achieved that the receiver also has a device for receiving Selection information that is broadcast by stations and mark the transmission range of the respective transmitter, and a facility for comparing the Selection information with the information contained in the messages Has location information.

According to a development of the receiver according to the invention can reduce the size of the selection area be that when receiving multiple channels with it overlapping selection information the intersection the selection information received for selection is used.

Fig. 1

ein Blockschaltbild eines erfindungsgemäßen Empfängers,

Fig. 2

schematische Darstellung von Datenblöcken, welche Selektionsinformationen enthalten,

Fig. 3

die schematische Darstellung der Fahrt eines Fahrzeugs durch mehrere Sendegebiete und TMC-Gebiete,

Fig. 4

ein Ablaufdiagramm zur Auswertung von empfangenen Selektionsinformationen und

Fig. 5

ein Ablaufdiagramm zur Selektion von Meldungen basierend auf empfangenen Selektionsinformationen.

Exemplary embodiments of the invention are shown in the drawing using several figures and are explained in more detail in the following description. It shows:

Fig. 1

2 shows a block diagram of a receiver according to the invention,

Fig. 2

schematic representation of data blocks which contain selection information,

Fig. 3

the schematic representation of the journey of a vehicle through several transmission areas and TMC areas,

Fig. 4

a flowchart for evaluating received selection information and

Fig. 5

a flow chart for the selection of messages based on received selection information.

The receiver shown in Fig. 1 has in itself known manner an antenna 1, a receiving part 2, a Stereo decoder 4, a NF amplifier 5 as well Power amplifiers 6, 7 and speakers 8, 9. That from the stereo multiplex signal delivered to the receiving part 2 in addition to the stereo decoder 4 fed to an RDS decoder 3, the output of which is connected to a microcomputer 13. The Microcomputer 13 is used in addition to the control of the receiver for decoding, management, preparation for playback and selection of the TMC messages. To the microcomputer 13 a keyboard 14 and a display device (display) 15 connected. The output of the selected TMC messages can either be via the display 15 or as a voice output take place, for which the microcomputer 13 via a Speech synthesizer 16 with an input 10 of the LF amplifier 5 is connected.

Figures 2a and 2b each show system messages two blocks C and D according to the TMC specifications, at which have the first two bits set to 00, which is the case with the embodiment should mean that this System messages for the transmission of the Selection information can be used. To do this, first of all available in block C 30 bits. The 6th after 00 Bits represent a location table number LTN (Location list number), since according to TMC specifications different place lists are possible and that The method according to the invention takes this into account.

This is followed by three bits as Extended Service Characteristics, the enable a more detailed description of the service, e.g. certain operating conditions or a description of the Message content. If there are currently one or more messages are sent out, the following bit (ntr = nothing to report) is set to 0, while a 1 indicates that none There are reports of malfunctions. The next bit defines the type of selection information. Here means a 0, the following 19 bits an index and a Area code included. A 1 indicates that the following 19 bit geographic coordinates and a radius contain. Finally, 3 bits of IDX are provided identify how many of up to eight different ones Area codes are transmitted.

In the following data block D of 16 bits one Area code transmitted, namely the location code of one in the area listed in the LTN.

The selection information is in the form of geographic Coordinates and the range are transmitted according to 2b the bit CID (= coordinate-ID) is set to 1. Then the bits IDX are used to transmit the radius, for example in 30 km steps with 000 = 30 km to 111 = 240 km. In the second data block D with 8 bit transfer the X coordinate and Y coordinate. That from The area covered area list is thus in 256x256 fields divided. These can then be individually via the X and Y coordinates can be addressed.

Fig. 3 shows schematically the travel of a vehicle from a point A to a point B. The vehicle comes within range of the transmitters x, y, z and drives through the areas G1 to G7. That comes after the start of the journey Vehicle first in the range of transmitter x. Whose The transmission range is defined by the area codes G1 to G6 covered so that all messages from this area be selected. At point B the receiver switches on the now more receivable transmitter y. This gives the Areas G2, G3, G5 and G6 as transmission areas. By Comparison with the areas of the still receivable Sender x can now select the recipient on the Restrict areas G2 and G3 and only give messages for these areas.

At point C, the vehicle leaves the area of the transmitter y, but now finds the transmitter z. Although this is weaker to receive than the transmitter x, chooses Receiver this transmitter because the destination point E in area 7 lies and only the transmitter z references this area. The After that, selection only takes into account the messages the areas G3 and G4, which is the intersection of those of the Transmitters x and z corresponds to the specified areas. From point D additional messages from the target area are selected, since the transmitter x is no longer receivable and therefore the Intersection is not necessary.

4 shows a flow chart for evaluating received selection information, also in the following Selection codes are called. After starting at 21 in program part 22 an 8A group from the Communication unit picked up and decoded. Done at 23 a branch depending on whether it is a Group selection codes SC. Isn't that the If there is a normal TMC message, it will decoded at 24 and at 25 after the current one in Selection table in memory selected. This Selection table is based on previously received selection codes emerged.

Then it is checked at 26 whether there are any more 8A groups available. If this is not the case, the program ended at 27.

However, if there are still 8A groups, program part 22 picked up an 8A group from the communication unit and decoded and then checked again at 23 whether it is is a group of selection codes SC. If so, it is checked at 28 whether the bit CID (FIG. 2) is 0 or 1 is set. If the bit CID is 0, they contain Selection codes location codes with which the 29 Selection table is updated. Become 1 at CID in the same 8A group coordinates as selection codes received so that at 31 the selection table with the received coordinates is updated.

After 29 or 31, the program becomes dependent on 32 branches off whether the reporting stock M is 0. is if this is not the case, there are still messages in the memory at 25, the selection is updated with the updated one Selection table carried out. Is no longer a message branch 26 follows.

5 shows a flow chart for the selection of messages based on received selection codes. After a start at 41 an error corrected and verified 8A group called at 42. Then the program at 43 depending on whether a selection is active is, that is, whether a user set a selection Has. If this is not the case, the message - like any other others too - marked as selected at 44. After that the program ends at 45. However, is with the If branch 43 has the selection active, it is checked at 46 whether the selection table contains coordinates. Isn't this the case, it is then checked at 47 whether the Selection table contains area codes AC. Is this the Case, it is checked at 48 whether the in each case processed message contained location code LC on area codes AC is referenced. If this is the case, the will be at 44 Message marked as selected. Isn't that the Case, the message is not selected at 49 characterized.

It is found at 46 that the selection table Contains coordinates, at 50 those for each Coordinates of location LC belonging to COORD determined. Then at 51 the program becomes dependent on it branches whether the location L is outside the area A, the by the coordinates contained in the selection table is defined. If the place is not outside of this area, the program continues at 47. However, the place is outside the area, at 49 the message is considered not selected marked.

Claims (12)

1. Method for geographical selection of digitally coded messages which are broadcast by a plurality of transmitters and contain location information which is compared in receivers with selection information which is dependent on the respective position of the receivers, characterized in that the transmitters also broadcast selection information which characterizes their respective transmission zone and is compared in the receiver with location information contained in the messages.
2. Method according to Claim 1, characterized in that the selection information is location codes of areas which are defined for the coding and decoding of the messages and are located at least to a certain extent in the transmission zone.
3. Method according to Claim 1, characterized in that the selection information is coordinates and radii of the transmission zones.
4. Method according to one of the preceding claims, characterized in that identical selection information is broadcast in each case by a group of transmitters.
5. Method according to one of the preceding claims, characterized in that the selection information and reference information is transmitted to the selection information in system messages of a data stream which contains the digitally coded messages.
6. Method according to Claim 5, characterized in that the following information is transmitted in a first data block: an identifier indicating that selection information is transmitted, the number of a location list which is necessary for decoding the messages in the receiver and information on the type of selection information.
7. Method according to Claim 6, characterized in that the information on the type of selection information is transmitted in the first data block by means of a bit which indicates whether the selection information is composed of location codes of areas or coordinates and radii.
8. Method according to Claim 7, characterized in that information indicating how many location codes of areas follow is also transmitted in the first data block.
9. Method according to one of Claims 6 to 8, characterized in that a location code of an area is transmitted in at least one further data block.
10. Method according to one of Claims 6 to 8, characterized in that the radius is transmitted in the first data block and the coordinates are transmitted in a further data block.
11. Receiver having a device for selecting digitally coded messages which are broadcast by a plurality of transmitters, contain location information and are selected in the receiver in accordance with selection information which is dependent on the respective position of the receiver, characterized in that the receiver also has a device for receiving selection information which is broadcast by transmitters and characterizes the transmission zone of the respective transmitter, and a device for comparing the selection information with the location information contained in the messages.
12. Receiver according to Claim 11, characterized in that when a plurality of transmitters with overlapping selection information are received, the intersection set of the received selection information is used for the selection.

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