FI99185C - Program file in a digital broadcast radio system - Google Patents

Description

• 99185

The present invention relates to the processing of program information of service programs in a digital broadcasting system, which enables the transmission of audio and data services and the selective reception of these services. The information transmitted on the transmission channel can be either a continuous audio or data stream or in packet form.

In the digital radio system DAB (Digital Audio Broadcasting) developed for efficient use of frequency bands, the transmission path is fully 10 digital. DAB defines a multi-carrier digital radio channel suitable for transmitting both audio and data services. The transmission channel can be either a continuous data stream or a packet channel. The DAB system for transmission, transmission and reception is described in detail in ETSI (European Telecommunication Standards Institute) 15 standard ETS 300 401, February 1995.

From the user's point of view, the DAB system has the highest level of abstraction called ensemble, Figure 1. It contains all the services that are in a certain single frequency band. The ensemble is changed by tuning to another frequency band. : Just like channel selection in current FM radio reception. The ensemble 20 is divided into services, in the figure Alpha Radio 1, Beta Radio and Alpha: Radio 2 as an example. In addition, there may be data services, although they are not shown in the figure. Each service is further subdivided into service components. Each service component is either an audio channel or a data channel. For comparison, t § An FM radio has only one service and one service component (audio / speech) • · · • «· 25 on each channel. At the lowest level is a transmission frame consisting of three • ·

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• ‘• j / parts that are consecutive in time. The first is the synchronization channel, • f **: * ', which does not contain service information. Next is a fast information channel. i ’FIC (Fast Information Channel), which is a fixed length for each mode. It contains general information SI (Service 30 Information) for audio and data services, which facilitates the user to select the desired service, multiplexing configuration information MCI (Multiplex Configuration Information) 2 99185, i.e. information on the number, size and location of subchannels in the frame. The last is the MSC (Main Service Channel) which contains all the subchannels. The location, size, and number of subchannels within the MSC may vary, but the size of the MSC is fixed. The MSC contains up to 63 different audio and / or data-5 subchannels. The subchannels are numbered so-called. Based on Subchannel ID from 0 to 62. In addition, the MSC may have an Auxiliary Information Channel (AIC) with a fixed channel number 63. The AIC may contain the same type of information as the FIC.

At the receiving end, the information channel FIC and the channel MSC containing audio and data services are separated from each other, and subchannels are separated from the MSC channel, which are then routed for further processing. The subscriber gets to know from the received FIC channel what all the services of the received ensemble contain and can choose the desired service or services accordingly. By combining the service components of the subchannels such as audio / speech, continuous video and packet data-15 according to the application program, multimedia services, hypermedia service, file-based service and hypertext are formed. The generated services are then exported. to the user's display device or for further processing.

:: To make it easier for the user to make a service selection, generate

• '· receiver service information channel SI and information backup channel AIC

: 20 information utilizing a user interface, which can be character::: based or graphical. For example, the user interface could contain text that * · t reads “This Ensemble has services ALPHA RADIO 1, BETA RADIO, .. ALPHA RADIO 2”, followed by the prompt “select service.” Then • ♦ «« «" ... the user selects the desired service, after which the application program block • · · 25 instructs the information channel processing block to distinguish from the subchannels • ♦ · the desired channels to form the program.

• · • · * 1 * The problem with this type of selection is that the application program processing block has to operate in a service hierarchy and on the rather scarce program content information that is obtained from the prior art service information channel SI and the information backup channel AIC. In the prior art system, the information transmitted to the user on the FIC channel 3 99185 is only the name of the service represented by a 16-character “service label”. Names are transmitted as a 6-bit encoded binary number.

As a general solution to the problem, the applicant has proposed in his earlier, currently still secret patent application FI-954753, filed on 5 October 1995, a special electronic program guide that is graphical, easy to use, informative and interactive and allows the user to launch the desired program directly. That application proposes that each service provider draw up its own service guide using the same uniform format. A particularly preferred format is HTML (Hypertext Markup Language), which is a simple data format for creating hypertext documents and producing documents that can be transferred from one hardware to another.

The following is a brief description of the content of the HTML concept. HTML documents are SGML documents and their general meaning theory enables 15 to present different types of information. The source material of the service provider, which may be text, images or combinations of text and image, or structured graphics. documents containing fics are converted to HTML-v: using HTML. The document is sent via the transmission network. The received document is processed and displayed on the screen in exactly the layout specified. 20 in the document. SGML is defined in ISO 8879: 1986, Information Processing Text and Office Systems Standard Generalized Markup Channel (SMGL). One well-known application is the World Wide Web, which is a hypertext-based distributed information system developed by CERN.

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Its use is especially known for its Internet connection.

• · · • _ 25 The term HTML is commonly used to refer to both the document type and its events. Events refer to changes in elements in a • · • · ’· * document, such as the beginning and end of a title, the beginning and end of a paragraph, •’ ·. images, hyperlinks, etc. Markups are syntax delimiters added to document data to describe its structure. The most common markup is a tag called 30 used to separate elements, including the start tag, which is the <> character, and the end tag, which is the </> character. Tags can also be used to give instructions to the receiver's program, eg the element 'TITLE' with a start tag of <TITLE> indicates that the next text is a title, which in turn ends with a end tag </TITLE>. An important element for this invention is anchor A. It defines a hyperlink, which is the relationship between two anchors, one of which is called the head and the other the tail. The anchors can be in the same or different documents. This is what makes Internet surfing familiar to Internet users possible. In order for a user to move from an anchor over a hyperlink to another anchor, a Uniform Resource Identifier (URI) must be defined, which is used to uniquely identify hyperlink anchors. In practice, the URI consists of a URL (Uniform Resource Locator) and a Relative URL. The link can refer either directly to the target (head Anchor) using a URI or indirectly using a URL.

Referring to Figure 2, each DAB service provider creates an HTML format guide file associated with its service, comprising one or more pages. The file may contain text sections and images. One page can have. an overview of the service, a more detailed presentation of the day's program with presentation times on one page and a weekly program on the other pages. Some pages may have lyrics about the lyrics of the songs being played. In addition, there may be pictorial ·.:. 20 files with still images. The page may have several links that point to certain points on other pages of the same file or to an image file, ie the link • · · is associated with the URL of the head.

.. The DAB operator compiles HTML program files from different service providers • · ·] ·: ·. and possibly add your own hyperlinks to them. In addition, the operator makes its own • · ·. *. 25 files presenting the possible different ensembles and listing their • · · • · · services and adding hyperlinks to the service provider files. Hyperlinks can be added to the page of the service provider's program file, which is an overview of the services, to link the pages to pages of other service providers or other services of the same provider, and to link the pages to 30 ensembles. In this way, the DAB operator generates a combined program guide that contains multiple HTML file pages.

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An excerpt from the service provider's program guide could look like this, for example:

Alpha Radio: This service consists mainly of music with occasional news. The programs today are.

5 8:00 - 9:00 Light music to start the working day. This is a multimedia program. You may view the program with all the multimedia features by clicking here or you may choose to only listen to the program with lyrics or without lyrics.

9:00 - 9:10 News 10

If you want to preview the Alpha Radio programs Tomorrow clickHere.

The sections in bold in the above section are hyperlinks. In HTML, their paragraph begins with the tag <A> and ends with the tag 15 </A>. When a user clicks on such an item, the application program retrieves the anchor address of the other end of the link and performs a jump to the file and item provided by it,. and a new page will appear on the screen.

• j 'Bold text Alpha Radios / oi can be a link to the list of Ensemble services, which can be a link to the list of other ensembles. In the previous 20 cases, by clicking on the desired service, the user sees the supply of channels:: in this service. A program guide made up of consecutive HTML files is placed in a DAB multiplex and sent. At least a portion, .. most preferably the landing page, is placed in the AIC channel (Auxiliary Information • · • · ·

Channel). Other files can be placed on either the AIC channel or one of the · · · 25 packet channels.

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The electronic program guide must contain up-to-date • • • · * · * information. Therefore, hyperlinks to programs that have already ended must be • \ inactive or deleted, as must the associated text.

Similarly, the program guide needs to be complemented by future programs. In this case, according to 30 DAB file transfers, the version number of the file that makes up the program guide must be increased by one each time a change is made.

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It is not necessary to synchronize the exact moment of changing the file contents of the guide to a possible change in the multiplex configuration. If the structure of the services changes during reconfiguration, it may also require changes in the program file. On the other hand, the program file changes much more often than the DAB multiplex due to the start and end of programs 5, and the program file can change even before a program ends, as there should be no reason to allow the user to select a program that ends after a few seconds. For these reasons, a program file retransmission frequency of less than once per second is sufficient. In addition, large portions of the 10 program files, such as image and audio files, may be transmitted outside the AIC channel and may have a different playback frequency than the portions transmitted on the AIC channel.

The application program in the receiver generates HTML pages from the received files and generates for the user a graphical user interface defined by them, in which the hyperlinks are visible. They allow the user to switch to the desired service. When the user activates the hyperlink, the application program block searches for the link anchor based on the address and displays the v file containing the anchor. Files are downloaded and launched immediately in response to user intervention.

20 However, the program file mechanism disclosed in patent application FI-954753 has some shortcomings. One drawback is that the proposed program file implemented as hypertext »• · · 'is mainly suitable for the PC screen, as there are many alphanumeric characters and images to be displayed. However, the display of DAB receivers can be • · «any of the 8 characters of a modest level receiver • 0 ·. ·. From 25 monitors to a VGA-level monitor on a general-purpose PC. There is no mechanism for the receiver to operate when only part of the text to be displayed fits on the screen and no images can be displayed at all.

The present invention provides a system which does not have the above disadvantages.

The system is characterized by what is stated in claim 1. The receiver for the system is defined in claim 7.

7 99185

According to the invention, a new element related to the display type of the receiver and its attributes are defined in the writing language of the program file. The element indicates the type of display for which the information between the start tag and the end tag is intended. Correspondingly, 5 different types of monitors are divided into display categories. The display class attribute associated with the element informs the receiver that the information specifically intended for it is included in the program file. The nature and source of the information are mentioned by their own attributes and the information may be audio information, reduced text information or a combination thereof. From the 10 program files received, the receiver detects an element related to the display type and searches its display class attribute to see if it contains the display type in question. information related to the receiver display. If they are found, the receiver operates according to the attributes indicating the nature of the information, displaying the reduced text and / or reproducing the audio information.

The invention will now be described with reference to the accompanying figures, in which Figure 1 shows the hierarchical levels of a DAB system, Figure 2 is a schematic representation of the basic idea of a program guide, Figure 3 is a schematic representation of a program fragment, Figure 4 is a modified program fragment, and Figure 5 is a modified program fragment. is another modified program fragment.

‘* The display of DAB receivers can be anything from a modest 8-character display to a PC VGA-level display on a general-purpose computer.

• ·! *: *. A program file implemented as hypertext contains alphanumeric characters. ·. 25 sets to be displayed at once, making it ideal for • · · • · · PC screens. If the display is only 8 or 16 characters, the receiver's * · * "application program must decide what is displayed. The natural solution would be to compromise 'intelligibility and show only the beginning of the text or scroll the text.

8 99185

According to the invention, different screens are already taken into account when creating a program file by setting the element DISPLAY in the language of the program file and assigning attributes to it.

The DISPLAY element is used only in the BODY 5 part of an HTML document, which is known to contain a document text stream with titles, chapters, lists, etc. The element in the program file text indicates very short segments intended to be displayed on the receiver attribute class such as a modest 8 character receiver. These segments can be the same as the 10 main hyperlinks in the file. Less important hyperlinks such as links to images are omitted. Segmentation changes the text displayed on the minimum screen to a hierarchical menu structure, allowing the user to scroll the screen line by line.

The attributes proposed for the DISPLAY element are described below.

15 Attributes are set according to the element structure of the HTML language and are: ID, CLASS, ALT, and VAT.

The attribute ID is an SGML identifier and is used as a hypertext link: object or in style lists related to naming specific elements.

Tags are NAME characters and must be 20 unique within the document.

The CLASS attribute is used to classify the types of display devices. Pre-

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* for <DISPLAY CLASS = MINIMAL> could specify an 8 or 16 character display.

.. By convention, “class” names are interpreted hierarchically by the most common class • · · /: ·. being the leftmost and the most specific being the rightmost.

• · ·. ·. 25 Category names can be separated by a space. The receiver application program • · · • · · recognizes the DISPLAY element and its CLASS attribute and then displays * ”on the screen only the characters intended for the displays of the class that that receiver has.

The ALT (Alternate text) attribute refers to optional text that can be displayed as an alternative to graphics for a PC-level display or long 99185 g of text. Optional text can contain hyperlinks (anchors) but no hidden DISPLAY elements.

The VAT (Alternative voice) attribute refers to an audio file that can be presented instead of or as an add-on to the marked part. The use of this attribute is particularly convenient because, when used in conjunction with marked short text segments, a user interface for narrow-screen receivers is obtained with a menu menu and each menu item has an explanatory audio message. The audio file can be transmitted on a packet channel, by setting the application type parameter to 10 16 or 17 in the PAD field of the audio frame, or the audio file can be a marked clip from a continuous audio stream. The advantage of the latter option is that the audio file does not need to be stored in memory but is played as soon as it is received. This helps to make a cheaper and simpler receiver.

The following examples illustrate the use of the element and attributes according to the invention.

Assume that the program file fragment contains the text: 8:00 to 8:30 Music Magazine. This is mainly music with some discussion;.:: On actual topics in between. The language is French.

• · ’In HTML format without the element of the invention, the text would be as follows: 20 8:00 - 8:30 <A HREF="dab://5/23:16/4:A"> Music Magazine. </A> This is mainly music with some discussion on actual topics in between. The

t t I

• * language is French.

Schematically, this is shown in Figure 3, which is read from left to right.

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First comes a text with the times. This will be followed by a hyperlink • · ·. 25 anchor start tag that includes an address reference to the dab audio service. This • · · • · · is followed by a piece of text in Music Magazine, which, when clicked, activates the • · *** hyperlink, followed by the hyperlink end tag. The piece of text is marked in the figure as “long text.” The program file then continues with the text, only the parts of the text are visible to the user.

10 99185 Using the DISPLAY element according to the invention, the text to be displayed on the display of a receiver with a minimum display can be indicated in the hyperlink, in which case the above HTML format would be as follows: 8:00 - 8:30 <DISPLAY CLASS = minimum VAT- "dab: // 5/23 : 16/5: D / 5 musmag.mpg: N "> <A HREF="dab://5/23:16/4:A"> Music magazine ne. </A> </DISPLAY> This is mainly music with some discussion on actual topics in between. The language is French.

The receiver recognizes the DISPLAY element of the start tag, knowing that the anchor contains information about the type of display. From the information of the CLASS attribute 10 minimal, it recognizes that the receivers with the minimum display can receive the information indicated by the VAT attribute, i.e. decode the mpeg-encoded audio file from the continuous audio stream. Only after this start tag comes the same start tag as in the example without the DISPLAY element, i.e. the same hyperlink text “Music Magazine” 15 with its anchors is still the same and this text is displayed on the screen of the receiver with the better display.

• If the receiver is unable to display the hyperlinked text ‘Music v’ · Magazine ”in bold or otherwise distinguish it from other text, or if

If the character display only contains the above text, the receiver can play VAT

20 audio file referenced in the attribute, which in the example is placed in the Ensemble 5 * »· service 23 (servicejd = 23) and more precisely in the packet mode (identifier D) Γι ': * service component 5 with the filename musmag.mpg. In this case, a description of the music magazine is given as audio information.

• · · * · ♦ ·. Fig. 4 schematically shows a program snippet according to Fig. 3. ·. 25 with an element and an attribute according to the invention. The addition is a start tag • i i11 / DISPLAY with the attributes CLASS and VAT, of which the VAT attribute indicates where the audio file is available. This is followed by the ‘hyperlink’ as shown in Figure 3 and finally the DISPLAY end tag. The original hyperlink is thus between the DISPLAY start and end tags.

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The ALT attribute for alternate text can be used to refer to text intended for receivers with a minimum display. In this case, the original HTML format mentioned above could be as follows: 8:00 - 8:30 <DISPLAY CLASS = minimum ALT = "8:00 <A HREF = 5" dab: // 5/23: 16/4: A "> Mus Mag "</A>> <A HREF= "dab://5/23:16/ 4:A ">

Music Magazine. </A> </DISPLAY> This is mainly music with some discussion on actual topics in between. The language is French.

The original hyperlink is preserved, and in addition, the ALT attribute brings to this hyperlink hidden alternative text “8.00 Mus. Mag. " The receiver can thus 10 display the text "Music Magazine" or the text "8.00 Mus. Mag." and clicking both texts activates the same hyperlink.

Figure 5 schematically illustrates this option. The ALT attribute that follows the DISPLAY start tag is associated with the short text Mus.Mag. anchor with address. The address is the same as in the long text (Fig. 3), whereby the activation triggers exactly the same receiver functions in both. This is followed by the original • ·. hyperlink and finally DISPLAY end tag.

v: The use of the VAT and ALT attributes has been described separately above, but it is of course possible to use both attributes simultaneously with the DISPLAY element. The CLASS attribute can be used to conveniently divide the screens t * * into the desired categories and then use the VAT and ALT attributes to indicate only the information intended for the receivers of these t * · • · · categories. However, the receiver can

; ·. always decide whether to use the original format or take DISPLAY into account

• · · element parameters.

. \ 25 The proposed new element attached to the program file with its attributes allows • · · ** ··, 'to allow receivers of different levels of display to receive ·. maximize the benefits of the program file.

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Claims (10)

1. Digital broadcast radio system in which a transmission frame comprises time multiplexed: a fast information channel comprising general information about a service whole, i.e. ensembles, audio and data services, a channel consisting of multiple subchannels and which provides an ensemble's audio and data services, one of the subchannels being a backup channel intended for information, characterized by one of several distinct unexplored hypertext-type composite programs whose files the user contains invisible data which controls the function of a receiver, is transmitted in transmission frames, whereby the user can activate at least part of the functions, to which the data invisible to the user belongs an element which indicates the recipient's display type and which has attributes, and with this element has in the uncovered files such functions are defined separately which are intended to be performed in a receiver whose display belongs to the class determined by the class name of the class attribute of the element. v The system according to claim 1, characterized in that the ': separate uncovered file is a program file of HTLM (Hypertext Markup Language) -:, the type that the producer of each individual service has created and which relates to: the own service, and that the person maintaining the system adds their own in ':'; 25 files. System according to claim 2, characterized in that the element: ·. is a new element (DISPLAY) that is appended to the HTML element group. 4. A system according to claim 2, characterized in that the class attribute (CLASS) is followed by several class names and the recipient interprets • ·: 30 the class names hierarchically and performs the functions for which the class display belongs. System according to claim 2, characterized in that the element additionally has an attribute (ALT) which determines the alternative text and which specifies the format that indicates the alternative text, the format highlighting the alternative text on the display as it is started in the receiver instead of a graphic or text segment intended for a full-size display. ib 99185 The system according to claim 2, characterized in that the element additionally has an attribute (ALV) which determines the alternative sound and which specifies the format that indicates the sound file, the format producing sound information when it is started in the receiver instead of a graphic or text segment. 7. Receivers in a digital broadcast radio system, in which audio and data services are transmitted in subchannels in a transmission frame, and a hypertext-type program composed of several different underexposed files, which files contain for the user invisible data controlling the function of the receiver, is received as a receiver. service, wherein the user can activate at least some of the functions, characterized in that the receiver belongs to a certain class which is determined on the basis of the display type, the receiver separates an element belonging to the data invisible to the user and which indicates the display type, and its attributes from the program and performs the functions that have been communicated with said attributes. Receiver according to claim 7, characterized in response to the attribute (ALT), which determines the alternative text and which specifies the format that indicates the alternative text, the receiver 20 highlights the alternative text on the display instead of a graphic or text segment which : is intended for a full size display. ': 1': Receiver according to claim 7, characterized by: - / response to the attribute (ALV), which determines the alternative sound and which states the format which indicates the sound file, produces the receiver sound information in j 'i'; 25 instead of a graphic or text segment. Receiver according to claim 9, characterized in that: ·. the attribute (ALV), which determines the alternative sound, specifies in which subchannel • · · in the transmission frame the audio information is transmitted. • · · • · 4 · * ♦ «♦. «· · ··