KR100478543B1 - Transportation guide transmission method and receiver used in it - Google Patents

Abstract

The present invention relates to a method for transmitting a traffic announcement via digital audio broadcasting (DAB) using a TMC-code, in which an audio signal can be simply assigned to TMC data. The assignment is established via the data frame of the digital transmitter and by the associated data protocol.

Description

Traffic guide transmission method and receiver used therefor

The present invention relates to a method for transmitting announcements of a traffic information alert service using digital audio broadcasting (DAB) and a receiver for receiving and selectively playing announcements.

Currently, traffic announcements for road users consist of messages broadcast by analog transmitters. More developed is a digital traffic information alert service, i.e. a radio data system (RDS), comprising a traffic message channel (TMC). The structure and coding of digital traffic messages is based on CEN Draft pr. Based on Alert C, proposed in November 1990 by the RDS ATT Alert Consortium. It is specified in ENV / 278/4/1/0011. Important elements of a traffic message are location and event. The information is cataloged. In other words, each traffic-related location and event is assigned a specific code. Linking locations in the location table along existing distances reveals a route. In addition to a general receiver device including a decoder, to use a traffic message channel (TMC), devices are needed for decoding, storing, subsequent processing and outputting a traffic message. Speech conversion is required to decode these digitally coded traffic messages. However, since this is substantially complex, in small population countries or regions where a particular language is spoken, the TMC system is introduced as soon as possible. Can't expect to be However, unlike the traffic messages of the TMC system, traffic messages such as those referred to below as traffic announcements cannot be selected for their geographical assignment.

At the same time, the introduction of digital broadcasting, i.e., digital audio broadcasting (DAB), is expected to increase. Compared to the old analog method, digital broadcasting has the advantage of higher reception reliability and the sound quality comparable to that of a CD. The specification of this digital sound broadcast is specified in ETS 300401, February 1995. In order to transmit TMC messages, a digital sound broadcast protocol is provided with a channel, i.e. a fast information channel (FIC). However, terminal devices currently available for digital sound broadcasting still do not include any decoder for TMC messages. Thus, in the current digital sound broadcast, only traffic messages integrated into the sound broadcast program are output, but this information is also not selectable as in the analog method and cannot be managed in any way.

1 is a diagram showing the basic structure of digital broadcasting;

2 is a diagram showing the structure of a fast information block (FIB);

3 shows the starting point of parallel transmission.

4 illustrates a multimedia object including audio segments.

5 is a block diagram of a receiver.

6 illustrates an example of a set of objects in a receiver memory.

On the contrary, an advantage of the method according to the invention with the features of the independent claims is that the digital transmission of sound broadcasts allows simple assignment of the data of the digital traffic information warning system. Another advantage is that the transmission of TMC data through digital wireless broadcasting is performed better because there is little reception difficulty in the digital method. This method is particularly useful in areas of multipath reception (mountains, high-rises in large cities) and / or areas served by ARI broadcast transmitters at the same time.

The measures set out in the dependent claims enable the implementation and improvement of the method disclosed in the independent claims. In particular, it is desirable to link the TMC messages of the FIC data channel and the traffic announcements of the digital radio by means of data blocks, so-called link objects. In this case the clarity of the assignment is ensured due to the parallelism of the connection and the transmission to the transmitter.

According to this method, it is desirable that the start and end of traffic guidance in a digital radio be signaled by the caller pressing the button. The signaling controls the TMC transmission.

In another preferred embodiment, the traffic guidance data is not transmitted by the actual sound broadcast program, but separately transmitted audio segments are used. This allows the announcements to be sent in different languages, so that the correct language can be selected at the receiver. A preferred embodiment of a receiver that enables traffic guidance reception according to the method of the present invention includes a TMC decoder and associated manager as well as a DAB decoder.

Embodiments of the present invention are illustrated in the drawings and will be described in detail in the following description.

The method according to the invention is used to transmit other optional information such as TMC messages, traffic announcements, and road maps for traffic information messages in a digital sound broadcast. The digital wireless broadcast (DAB) enables parallel transmission of text, audio or video sequences. In each case, the DAB ensemble is broadcast by the DAB transmitter. In FIG. 1 such an ensemble is indicated at level A by the term "north". Individual programs, for example sound broadcast programs, are represented as services. See level B. 1 are services, for example, north1 and FFN. The service may include a plurality of components, that is, service components such as audio, data, video components, and the like. These components are indicated at level C. One of the possible ingredients is TMC. In the level D, i.e. data frame of digital sound broadcast, sub-channels are assigned to individual service components. The specification of digital sound broadcast according to ETS 300 401 defines a special channel (FIC (High Speed Information Channel)) for TMC messages. The various subchannels are integrated into the MSC main service channel. The entire data block is given a frame structure by the transmitter, and the data is also given a sync word Sync. The area of the fast information channel (FIC) related to the digital traffic guidance is divided into a plurality of fast information blocks (FIB). The FIBs are subdivided into a plurality of data types and extensions. The fast information block is shown at level E in FIG. The actual data field contains 30 bytes, while the control field (Cyclic Redundancy Check) contains 2 bytes as an error protection code. The actual data field has a plurality of extensions on level F. Special extensions include headers and extension data; See level G. The structure of level G represents a fast information data channel (FIDC). According to the proposed protocol ETS 300 401, the fast information data channel (FIDC) corresponds to data type 5. According to level H, the header of the FIDC is an identifier of type 5, information about the extension length, Rfu 0 (reserved for future), TCId (Type Component Identifier), as well as Ext as the first extension of the FIB. Contains 1. The actual information comes after the extended data area. It is possible to transmit up to six TMC groups. The groups contain traffic messages encoded in 37 bits. If the FIB is not fully utilized by the extension, the data end marker follows the last extension and the remaining length is filled with padding bytes.

The transmission in the data frame structure defined by the transmitter is performed for the sound broadcast program in the data and stream mode (eg guides) in the packed mode (eg multimedia objects). The multimedia object is composed of a required header having a length of 10 bytes, an optional header having a variable length, and an object body including actual data (see FIG. 3). Special media objects, ie link objects, are used to link the TMC messages in the fast information channel with the traffic announcements in the audio stream. These objects, on the one hand, refer to the part of the audio stream containing the traffic announcement (mandatory header and body), on the other hand, they contain a reference to the TMC message (selection header). In this case, rather than referring to the fast information data channel, a service component of level C from which the TMC message appears is created. Clarity is ensured by the parallel processing of connection and transmission to the service. At the transmitter, the start and end of traffic guidance are signaled by the caller or technician pressing a button. When the start of the traffic announcement is signaled, the corresponding TMC message is sent once on the high speed information data channel. In parallel with this, in the same digital radio data frame, a link object is generated in the following manner. That is, the starting point of the audio stream, i.e. the start of traffic guidance, is referenced and is generated in such a way that a connection to the TMC message is made. When the end of the traffic announcement is signaled, another header is generated in one of the following data frames indicating the end point of the audio stream. At the receiver, the indicated portion of the audio stream is stored with the associated TMC message and can be used for other applications such as selection. In the fast information channel, only TMC messages can be transmitted into the digital radio data frame in which the multimedia object is transmitted. TMC messages of other data frames are not important even when the audio stream is not yet finished, because they are not referenced by the link object. Only the connection of the audio stream with the TMC messages is allowed, since synchronization can only be carried out by one program. In general, multiple services can access one and the same service component, but only one service can determine the content of the service component.

In another preferred embodiment, another link object structure is selected. Here, the TMC message is no longer sent over the FIC channel, and the optional header of the link object contains the TMC message itself. The audio stream is marked as shown in FIG. 3 as described above. At the start of the traffic announcement, the corresponding TMC message enters into the optional header of the link object. In parallel with this, the starting point of the audio stream in the link object, that is, the start of traffic guidance, is referenced. When the end of the traffic announcement is signaled, another header is generated in the data frame indicating the end of the audio stream. Along with the relevant TMC message, the marked portions of the audio stream can be stored at the receiver and used for subsequent application. The above embodiments can provide unique individual traffic directions from which each program can be selected.

In another embodiment a parallel audio stream, ie a sound broadcast program, is not used to transmit traffic announcements, but rather the announcements are assigned to a separately transmitted audio segment. In this regard, it is preferable that one audio segment corresponds to one traffic guidance. By the program the traffic announcements can be used as audio segments and TMC messages. TMC messages are sent according to FIG. 4 in the optional header of the multimedia object. Audio segments are adjusted in the object body area. Optionally, a TMC message may be sent in the object body and the audio segment in an optional header.

In an improvement of this method a plurality of audio segments, video segments and text labels are transmitted in an optional header. In this way, providing traffic directions in different languages makes it possible to graphically display traffic obstructions on a road map, and to textually display the message directly visible to the receiver. A receiving segment operating in accordance with the method of the present invention is shown in FIG. Sound broadcast programs, TMC messages and other data are transmitted from the transmitter 1 via digital radio broadcast. In the DAB decoder 2 of the vehicle itself, the audio and video signals of the executing programs are first decoded, generated and supplied to the reproduction unit 8. In addition, multimedia objects and data channels are decoded. TMC messages are supplied to the TMC decoder 3 and audio and video segments, and text inputs are sent to the manager 4. The TMC decoder decodes the TMC messages and likewise sends them to the manager 4. In the manager 4, objects from the DAB decoder are managed by TMC messages. The correct allocation between the objects and the storage in the memory 5 and the updating of the objects stored in the memory 5 and, if necessary, erasing are controlled by the manager. The user can enter selection criteria, for example highway numbers, via the input device 7. These inputs are compared with the information contained in the TMC messages at 6 and output if necessary. 6 shows a possible configuration of a TMC message for a set of objects, which set includes various audio segments, video segments and text messages. These messages can likewise be selected via selection.

Claims (11)

A traffic guide transmission method for transmitting traffic announcements through digital audio broadcasting (DAB), The data of the message from the digital traffic information warning system is assigned to the guide data of the digital radio by the data frame structure of the transmitter. The method of claim 1, And wherein the digital signals are transmitted in direct time correlation with the digital guidance data. The method according to claim 1 or 2, The messages of the traffic message channel according to the Alert C protocol are used as digital signals. The method according to claim 1 or 2, The digital signals and the announcements are associated by multimedia objects. The method according to claim 1 or 2, And said digital data comprises headers and a data area (body). The method according to claim 1 or 2, The start and end of the traffic guide is characterized by being represented by a link object having a specific header. The method according to claim 1 or 2, The link object comprises a reference to a digital message in an optional header, characterized in that it marks the header and the body in the audio stream at the start of the traffic announcement. The method according to claim 1 or 2, And the multimedia object transmits the digital message itself in the header. The method according to claim 1 or 2, And the multimedia object comprises digital information as well as the traffic guidance as an audio segment itself.  A receiver for receiving and selectively playing announcements received in connection with digital information, the receiver comprising: The receiver comprising a decoder for the digital messages and the traffic announcements.  The method of claim 10, A receiver, characterized in that a management system is provided for adjusting incoming audio and digital information.