DE19710863A1 - Method and receiver for the 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 who (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 announcements and the location list are in CEN pr ENV12313-1 and pr ENV / 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 reports 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 traffic-relevant events is. The chaining of the locations along the location table 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, further 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. A 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 and route codes can be entered directly, which is longer Journeys but is too inflexible and cumbersome. A Coupling 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.

In the method according to the invention, this object 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 to receivers who 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: 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 are dependent and may be different Transmission media, e.g. B. DAB, AMDS, are transmitted.

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 below - can be sent by the recipient can be used directly as a selection criterion, since all for the coding and decoding of the messages Places 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. Because 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 configuration 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 Embodiment 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 Coordinates and radii can also be transferred 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 several channels with it overlapping selection information the intersection the selection information received for selection is used.

Embodiments of the invention are in the drawing represented with several figures and in the following Description explained in more detail. It shows:

Fig. 1 is a block diagram of a receiver according to the invention,

Fig. 2 shows a schematic representation of data blocks containing selection information,

Fig. 3 is a schematic representation of the travel of a vehicle by a plurality of coverage areas and TMC-areas,

Fig. 4 is a flowchart for the evaluation of the received selection information, and

Fig. 5 is a flowchart for selection of messages based on the received selection information.

The receiver shown in FIG. 1 has an antenna 1 , a receiver 2 , a stereo decoder 4 , an LF amplifier 5 and power amplifiers 6 , 7 and loudspeakers 8 , 9 in a manner known per se. In addition to the stereo decoder 4 , the stereo multiplex signal emitted by the receiving part 2 is fed to an RDS decoder 3 , the output of which is connected to a microcomputer 13 . In addition to controlling the receiver, the microcomputer 13 is used for decoding, management, preparation for the reproduction and selection of the TMC messages. A keyboard 14 and a display device (display) 15 are connected to the microcomputer 13 . The selected TMC messages can be output either via the display 15 or as a voice output, for which purpose the microcomputer 13 is connected to an input 10 of the LF amplifier 5 via a speech synthesizer 16 .

FIGS. 2a and 2b show, respectively, system messages of two blocks C and D in accordance with the TMC specifications, in which the first two bits are set to 00, which is intended to mean, in the embodiment, that these system messages are used for transmitting the selection information. For this purpose, 30 bits are initially available in block C. The 6 bits following 00 represent a location table number LTN (location list number), since according to TMC specifications different location lists are possible and 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. B. 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) 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  indicate 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.

If the selection information is transmitted in the form of geographic coordinates and the range, the bit CID (= coordinate-ID) is set to 1 according to FIG. 2b. 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, the X coordinate and Y coordinate are transmitted with 8 bits each. The area covered by the location list is thus divided into 256 × 256 fields. These can then be addressed individually using the X and Y coordinates.

Fig. 3, the drive schematically shows a vehicle from a point A to a point B. The vehicle is thereby in the range of the transmitter x, y, z and passes through besides, the areas G1 to G7. After the start of the journey, the vehicle first comes into the transmission range of transmitter x. Its transmission area is covered by the area codes G1 to G6, so that all messages from this area are selected. At point B, the receiver switches to transmitter y, which is now more receivable. This indicates areas G2, G3, G5 and G6 as transmission areas. By comparing with the areas of the still receivable transmitter x, the receiver can now narrow the selection to the areas G2 and G3 and only outputs messages for these areas.

At point C the vehicle leaves the area of the transmitter y, but now finds the transmitter z. Although it is weaker to receive than the transmitter x, the receiver chooses this transmitter because the target point E is in area 7 and only the transmitter z references this area. The selection then only takes into account the messages from areas G3 and G4, which corresponds to the intersection of the areas specified by transmitters x and z. From point D, additional messages from the target area are selected, since the transmitter x can no longer be received and the intersection is therefore no longer required.

FIG. 4 shows a flowchart for evaluating received selection information, which will also be called selection codes in the following. After starting at 21 , an 8A group is fetched and decoded by the communication unit in the program part 22 . At 23 there is a branch depending on whether it is a group of selection codes SC. If this is not the case, ie if there is a normal TMC message, it is decoded at 24 and selected at 25 according to the selection table currently in memory. This selection table is the result of selection codes received previously.

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

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

After 29 or 31 , the program branches at 32 depending on whether the notification stock M is 0. If this is not the case, ie if there are still messages in the memory, the selection is carried out at 25 using the updated selection table. If there is no longer a message, branch 26 follows.

Fig. 5 shows a flow chart for the selection of messages based on the received selection code. After starting at 41 , an error-corrected and verified 8A group is called at 42 . The program is then branched at 43 depending on whether a selection is active, that is, whether a user has set a selection. If this is not the case, the message - like any other - is marked as selected at 44 . The program is then ended at 45 . However, if the selection is active at branch 43 , a check is made at 46 as to whether the selection table contains coordinates. If this is not the case, it is then checked at 47 whether the selection table contains area codes AC. If this is the case, it is checked at 48 whether the location code LC contained in the respective processed message is referenced to area codes AC. If this is the case, the message is marked as selected at 44 . If this is not the case, the message at 49 is marked as not selected.

If it is determined at 46 that the selection table contains coordinates, the coordinates COORD belonging to the respective location code LC are determined at 50 . The program is then branched at 51 depending on whether the location L is outside the area A, which is defined by the coordinates contained in the selection table. If the location is not outside of this area, the program continues at 47 . However, if the location is outside the area, the message is marked as not selected at 49 .

Claims (12)

1. A method for the 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 transmit selection information which characterizes their respective transmission area, that are compared in the receiver with the location information contained in the messages. 2. The method according to claim 1, characterized in that the selection information of location codes for coding and decoding the messages are defined areas, that fall at least partially in the transmission range. 3. The method according to claim 1, characterized in that the selection information coordinates and radii of the Are transmission ranges. 4. The method according to any one of the preceding claims, characterized in that each of a group of Same selection information is broadcast on transmitters.   5. The method according to any one of the preceding claims, characterized 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. 6. The method according to claim 5, characterized in that transmit the following information in a first data block are: a label that selection information are transmitted, the number one for decoding the Messages in the required list of locations and Information about the type of selection information. 7. The method according to claim 6, characterized in that in the first data block also the information about the type of Selection information is transmitted by a bit that states whether the selection information from location codes of Areas or coordinates and radii exist. 8. The method according to claim 7, characterized in that how many is also transmitted in the first data block Follow location codes of areas. 9. The method according to any one of claims 6 to 8, characterized characterized in that in at least one further data block a location code of an area is transmitted. 10. The method according to any one of claims 6 to 8, characterized characterized in that in the first data block the radius and in the coordinates are transferred to another data block. 11. Recipients with a facility for selecting digitally encoded messages from multiple transmitters be broadcast, contain location information and in Recipient according to the position of the recipient dependent selection information is selected,  characterized in that the recipient further a Device for receiving selection information from Broadcasters are broadcast and the range of the identify each station, and a facility for Comparison of the selection information with that in the Contains messages containing location information. 12. Receiver according to claim 11, characterized in that when receiving multiple channels with overlapping Selection information the intersection of the received Selection information is used for selection.