WO2004102844A2

WO2004102844A2 - Improvements relating to digital radio

Info

Publication number: WO2004102844A2
Application number: PCT/GB2004/002106
Authority: WO
Inventors: Quentin Howard; Philip Bond; Glyn Jones
Original assignee: Digital One Limited
Priority date: 2003-05-15
Filing date: 2004-05-17
Publication date: 2004-11-25
Also published as: WO2004102844A3; GB0311187D0

Abstract

A digital radio primarily arranged to receive broadcast digital information including audio data related to a radio station and displayable data which is radio station-independent, the radio comprising decoding means for decoding the received digital information; means for generating a sound signal from the decoded station-related audio data of the received digital information to present the same to a listener; and means for displaying the decoded station-independent displayable data of the received digital information at the radio; a memory for storing the decoded audio data and displayable data; wherein the generating means and the displaying means are arranged to operate independently such that the displayable data can be displayed concurrently with, and independently of, the presentation of the audio data related to a particular radio station, wherein the displayable data further comprise content data for populating a template and the radio comprises processing means arranged to populate the template with the content data to create a graphical image.

Description

IMPROVEMENTS RELATING TO DIGITAL RADIO

Field of the Invention

The present invention relates to a digital radio for receiving and decoding broadcast digital information.

Background to the Invention

Digital Audio Broadcasting (DAB) is a radio-based digital audio and data transmission technology capable of delivering high quality digital sound, text and graphic information free from the effects of multipath interference, using non-directional antennas, to fixed, portable and mobile receivers.

The EUREKA- 147 DAB system was developed by a consortium of 12 partners and has now been accepted almost worldwide as the standard for DAB, with the exception of USA and Japan. The DAB transmission signal carries a multiplex of several digital services simultaneously which a digital radio can receive and decode. The ensemble contains audio programmes, data related to the audio programmes and optionally, other data services.

The EUREKA- 147 system works by combining two digital technologies: an audio compression system (MPEG) and COFDM (Coded Orthogonal Frequency Division Multiplexing). The MPEG audio compression system used for sound (radio) services reduces the amount of digital information required to be broadcast by encoding only the signals that the ear can detect and discarding those which it can not. This means that bit rate reduction is achieved by only broadcasting audible information essential to derive a received high quality signal. The audio channel bit rates for the system are typically from 64 k/bits to 384 k/bits at a sampling rate of 48 kHz, or from 8 k/bits to 160 k/bits at a sampling rate of 24 kHz. Several audio channels and optional data channels are coded into a single data stream for transmission. The audio and data channels embody forward error protection data which helps the receiver to recover lost or corrupted information. An additional support data channel is included which carries technical information for use by the receiver tuning and service selection processes. The COFDM system splits the encoded multiplex signal over a thousand different sub-carrier frequencies, each one being QPSK modulated. This group of frequencies, known as a frequency 'block' , occupies around 1.5 MHz of the radio spectrum. As the signal impairment is frequency dependent, only part of the block tends to be corrupted. But since the digital information is spread across a wide group of frequencies, there is normally sufficient data present from other carriers to allow the audio or data channel to be recovered. The Eureka 147 system therefore offers a reliable and robust broadcast which is far superior to analogue technology.

Each multiplex is able to carry stereo and mono sound radio channels (typically between six and eleven) as well as non-radio channels carrying multimedia data (e.g. text and graphic data). Digital radio devices can receive the multiplexed signal and separate the individual digital radio stations and other services from each other.

The ability to reconfigure a multiplex is a central feature of the Eureka 147 system, so the array of services being broadcast may change at any time. Services may be added or removed as required. Similarly, the bit rate of any service may also be changed. This alters the audio quality of sound services, and the speed of delivery of data services.

Stand-alone digital radios act as conventional receivers and are generally designed for audio listening only and so do not allow user interaction with data services. Currently, the standard mobile digital radios i.e. radio-dedicated devices, look like their FM/AM counterparts. AU have buttons for radio station selection and a text display (alphanumeric), rather than a tuning dial and a cursor scale. The text display, which is either a plasma, LED or LCD panel, shows the radio station name, programme type, and/or radio programme-related text, known as 'dynamic labels', for example "Radio XYZ News at One". Typically, the text displays have rows of alpha-numeric characters, allowing the listener to view the textual dynamic labels. The dynamic labels broadcast by the radio station on its radio channel may be up to 128 characters in length which is longer than the capacity of a typical display panel. Therefore, many digital radios show the text as a sideways stepping or scrolling display. The dynamic label feature in DAB is almost identical to the RDS Radio-Text available on FM stations, except that each message may be twice as long as the 64 characters allowed with RDS. These types of digital radios are not able to receive or display non-text data which may be broadcast either as part of the audio channel or in separate data sub-channels.

Currently, improved access to and interactivity with digital displayable data, especially non-text digital displayable data, is provided through general purpose computing devices configured to have a tuner function because of their larger memory and display capability. Typically, one such general purpose device uses a personal computer (PC) with an internal or attached digital radio receiver, in which the displayable data is displayed on the PC monitor and the keyboard and mouse are used to make tuning selections. Audio and graphic data can be stored in the PC's memory. Additionally, web-style data services (e.g. "Digizone" in the UK) can be accessed and viewed using the PC.

However, PC-based digital tuners are general-purpose devices and not dedicated digital radio devices. It will be appreciated that PC-based digital tuners are bulky, cumbersome, not mobile, and normally not portable. Also, additional software must normally be installed to an existing PC in order to receive digital data and to operate the data navigation system which can be both expensive and confusing for a user.

Another type of general purpose computing device which has been configured to have a digital tuner function is a PDA. PDAs offer a more compact solution but as with any PC- based digital tuner, they are expensive and may require the installation of additional software.

It is desired to provide an improved digital radio device which facilitates interactivity with digital data without the use of a return channel.

Summary of the Invention

According to one aspect of the invention there is provided a digital radio primarily arranged to receive broadcast digital information including audio data related to a radio station and displayable data which is radio station-independent, the radio comprising: decoding means for decoding the received digital information; means for generating a sound signal from the decoded station-related audio data of the received digital information to present the same to a listener; and means for displaying the decoded station-independent displayable data of the received digital information at the radio; wherein the generating means and the displaying means are arranged to operate independently such that the displayable data can be displayed concurrently with, and independently of, the presentation of the audio data related to a particular radio station.

By the generating means and the displaying means operating independently in this way, a user may view the displayable data independently of the radio station which is selected for listening. Preferably, the decoding means decodes the audio data and displayable data separately from each other such that the selection and display of the decoded displayable data can be independent of the radio selection. Further, the digital radio comprises at least two distinct storage memories in which the audio data and the displayable data are stored separately.

By audio data it is meant audio programmes and other audio information broadcast by radio stations and other service providers.

By displayable data it is meant graphic data which includes images, pictures and other non-text data, and text. The information content of the displayable data includes, for example, current news headlines and stories, current business and finance news, current sports headlines and stories, travel, weather, lottery results, newspapers, advertisements, and a clock display, all of which are generally not related to the audio programmes. Displayable data may also include radio-programme or radio-station related textual data available within the Fast Information Channel or within the Programme Associated Data (PAD) region of an audio data channel. This includes the radio station name, programme type and Dynamic Labels carried as Dynamic Label Segments (DLS), for example, the name of the DJ, the title of the song being played etc.

Advantageously, the displaying means is arranged to display a selectable portion of the stored displayable at the radio, and preferably, the selection means comprises means for browsing the stored displayable data in order to select the portion of the stored displayable data to be displayed. In this way, the user can interact with the data which has been received and stored by the digital radio by selecting which portion of it to view at any one time.

In a preferred embodiment, the displayable data comprises instruction data, expressed as a mark-up language, defining a displayable template, and content data for populating the template, and the digital radio further comprises processing means for processing the instruction data to create graphical representations on the displaying means. The displayable data is therefore a composite image which is created by the processing means from the broadcast digital content data and the instruction data. In this way, the digital radio can present composite graphical images on the displaying means of the digital radio which are selectable by the user for display.

It is further preferred that the instruction data comprises static data to be displayed unchanged over a relatively long time period, that the content data is dynamic in that it is to be displayed for a relatively short time period and that the radio further comprises means for overwriting the displayed dynamic content data with more recently received broadcast content data. Advantageously, this means that the informative content of the content data displayed on the digital radio is kept up-to-date to avoid the user being presented with out-of-date inforaiation.

Optionally, the displaying means is arranged to display portions of the displayable data sequentially as a slideshow according to a predetermined schedule, which means that the user does not have to interact with the digital radio or the displayable data in order to view the displayable data.

Preferably, the digital radio is both a portable and a mobile device for convenience and transportability.

The present invention also extends to a system of broadcasting, receiving and presenting digital information including audio data related to a radio station and displayable data which is radio station-independent, the system comprising: multiple data channels of digital information; a multiplexer for multiplexing the multiple data channels together into one signal; a transmitter for broadcasting the signal; and a digital radio primarily arranged for receiving and de-multiplexing the broadcast signal into the multiple data channels of digital information, the digital radio comprising a means for generating a sound signal from the received station-related audio data to present the same to a listener, and means for displaying the received station-independent displayable data at the radio, wherein the generating means and the displaying means are arranged to operate independently such that the displayable data can be displayed concurrently with, and independently of, the presentation of the audio data related to a particular radio station.

As the transmitter broadcasts the content data throughout the night and day, and the instruction data during the night, the content data stored in the digital radio is regularly updated to present up-to-date information to the user on the displaying means. Advantageously, the instruction data which is broadcast during the night is transmitted at a higher speed which permits the transmission and receiving of larger data components which can be stored in the memory of the digital radio without affecting the radio's functionality during the day.

The present invention also extends to a method of broadcasting, receiving and presenting digital information including audio data related to a radio station and displayable data which is radio station independent, the method comprising: multiplexing multiple data channels of the digital information together into one transmittable signal; broadcasting the transmittable signal; receiving and de-multiplexing the received signal with a digital radio; generating a sound signal from the de-multiplexed station-related audio data of the received digital information to present the same to a listener, and displaying the decoded station-independent displayable data of the received digital information at the radio, wherein the generating step and the displaying step are arranged to operate independently such that the displayable data can be displayed concurrently with, and independently of, the presentation of the audio data related to a particular radio station.

According to another aspect of the invention there is provided a digital radio primarily arranged to receive broadcast digital information including audio data and displayable data, the digital radio comprising: means for decoding the received digital information; a memory for storing the decoded audio data and displayable data of the received digital information; and means for displaying the stored displayable data, wherein the displaying means is arranged to display a selectable portion of the stored displayable data at the radio. The digital radio of this aspect of the invention allows the user to interact with the stored displayable data by browsing the stored displayable data in order to select the portion of the stored displayable data to be displayed.

Advantageously, the displayable data comprises instruction data defining a displayable template, and content data for populating the template, and the digital radio further comprises processing means for processing the instruction data to create graphical representations on the displaying means. The displayable data is therefore a composite image which is created by the processing means from the broadcast digital content data and the instruction data. In this way, the digital radio can present composite graphical images on the displaying means of the digital radio which are selectable by the user for display.

The present invention also extends to a system of broadcasting, receiving and presenting digital information including audio data and displayable data, the system comprising: multiple data channels of digital information; a multiplexer for multiplexing the multiple data channels together into one signal; a transmitter for broadcasting the signal; and a digital radio primarily arranged for receiving and de-multiplexing the broadcast signal into the multiple data channels of digital information, the digital radio comprising a memory for storing the audio data and the displayable data and displaying means for displaying the stored displayable data, wherein the displaying means is arranged to display a selectable portion of the stored displayable data at the radio.

The present invention also extends to a method of broadcasting, receiving and presenting digital information including audio data and displayable data, the method comprising: multiplexing multiple data channels of the digital information together into one transmittable signal; broadcasting the transmittable signal; and receiving and demultiplexing the received signal with a digital radio; storing the audio data and displayable data in a memory of the digital radio and displaying the stored displayable data at the radio, wherein the displaying step comprises displaying a selectable portion of the stored displayable data. According to a third aspect of the invention, there is provided a digital radio primarily arranged to receive broadcast digital information including audio data and displayable data, the digital radio comprising", decoding means for decoding the received audio data and the received displayable data; and means for displaying the decoded displayable data as a non-text graphical image at the digital radio, wherein the displayable data further comprises content data for populating a template and processing means arranged to populate the template with the content data to create the non-text graphical image.

Preferably, the displayable data comprises instruction data, which is expressed as html mark-up language and defines the displayable template, and the processing means processes the instruction data to create graphical representations on the displaying means. The displayable data is therefore a composite image which is created by the processing means from the broadcast digital content data and the instruction data. This avoids the need for transmitting and receiving complete composite graphical representations. In this way, the digital radio can present composite graphical images on the displaying means of the digital radio which are selectable by the user for display.

The present invention also extends to a system of broadcasting, receiving and presenting digital information including audio data and displayable data, the system comprising: multiple data channels of digital information; a multiplexer for multiplexing the multiple data channels together into one signal; a transmitter for broadcasting the signal; and a digital radio for receiving and de-multiplexing the broadcast signal into the multiple data channels of digital information, the digital radio comprising means for displaying the displayable data of the digital inforaiation as a non-text graphical image at the digital radio, wherein the displayable data further comprises content data for populating a template and processing means arranged to populate the template with the content data to create the non-text graphical image.

The present invention also extends to a method of broadcasting, receiving and presenting digital information including audio data and displayable data, the method comprising: multiplexing multiple data channels of the digital information together into one transmittable signal; broadcasting the transmittable signal; and receiving and demultiplexing the received signal with a digital radio; and displaying the displayable data as a non-text graphical image at the radio, wherein the displayable data further comprises content data for populating a template and processing means arranged to populate the template with the content data to create the non-text graphical image.

The term digital radio is to be considered to apply to dedicated digital broadcast receiving devices that can be relatively inexpensive, if required, due to their receive-only functionality, just as in the case of conventional analogue radios. They are not, for the purposes of the present invention, to be considered to include PC's with integrated digital tuners (often in the form of a plug-in card) or any other general purpose computing device having an added digital radio function.

The optional features described in relation to the first invention are equally applicable to the second and third aspects of the invention described above.

Brief Description of the Drawings

The invention will be described, by way example only, with reference to the accompanying drawings, in which:-

Figure 1 is a diagram of a front face of a digital radio embodying the present invention, including a display;

Figure 2(a), (b) and (c) are displayable data pages presented on the display of the digital radio of Figure 1 when the digital radio is in an Interactive Data mode;

Figure 3(a) to (f) are further examples of displayable data pages on the display of the digital radio of Figure 1 when the digital radio is in the Interactive Data mode;

Figure 4(a) is a representation of a displayable page on the display of the digital radio of Figure 1 when selecting a radio station in a Radio Tuning mode;

Figure 4(b) to (e) are displayable data pages presented on the display of the digital radio of Figure 1 when the digital radio is in the Radio Tuning mode; Figure 5(a) to (d) are displayable data pages presented on the display of the digital radio of Figure 1 when the digital radio is in a Push service mode;

Figure 6 is a displayable data page presented on the display of the digital radio of Figure 1 when the digital radio is off or on a standby mode;

Figure 7 is a schematic diagram of a digital radio broadcasting system embodying the present invention and including the digital radio of Figure 1;

Figure 8 is a schematic diagram showing a part of the schematic diagram of Figure 7 in more detail;

Figure 9 (a) to (f) are examples of the templates of the displayable data pages before they are populated with content data;

Figure 10 is a schematic diagram of a transmission schedule of the graphic data and content data of the system embodying the present invention;

Figure 11 is a table showing the priority of transmission of data items depending on their information content;

Figure 12 is a table showing the coding scheme for data items having different information contents;

Figure 13 is a schematic block diagram of the main components of the digital radio embodying the present invention;

Figure 14 is a schematic block diagram showing the digital radio embodying the present invention in more detail; Figure 15 is a table showing the naming convention of the navigation sub-menu pages presented on the display of the digital radio of the present invention when the digital radio is in the Interactive Data mode;

Figure 16 is a table showing the naming convention of the displayable pages presented on the display of the digital radio of the present invention when the digital radio is in the Interactive Data mode;

Figure 17 is a table showing the naming convention of the displayable pages presented on the display of the digital radio of the present invention when the digital radio in the Push service mode;

Figure 18 is a schematic table showing an example of the naming of the displayable pages of the Push service according to the naming convention of Figure 17;

Figure 19 is a table showing the naming convention of the content data for populating the templates before being presented as displayable pages on the display of the digital radio of the present invention;

Figure 20 is a table showing an example of the naming of content data according to the naming convention of Figure 19;

Figure 21 is a table showing the naming of navigation hyperlinks in the displayable pages presented on the display of the digital radio of the present invention when the digital radio is in the Interactive Data mode;

Figure 22 is a flow diagram showing the creation of the displayable pages by the digital radio embodying the present invention and user access to the displayable pages;

Figure 23 is a schematic diagram showing the creation of the displayable pages to be presented on the display of the digital radio embodying the present invention by populating the templates with the content data; Figure 24 illustrates html code defining a template of a topic menu and forming part of a displayable page of the digital radio of the present invention;

Figure 25 is a schedule of the displayable pages to be presented on the display of the digital radio embodying the present invention when the digital radio is in the Push service mode;

Figure 26 is a schematic diagram of the cycle of data caching by the digital radio, embodying the present invention, from the multiplex; and

Figure 27 is a displayable data page presented on the display of the digital radio embodying the present invention when the Interactive Data service is not available.

Detailed Description of a Preferred Embodiment

A schematic diagram of a front face 10 of the digital radio 12, according to an embodiment of the present invention, is shown in Figure 1. As in a conventional portable stereo digital radio, the front face 10 of the digital radio 12 comprises two speakers 14 for outputting the digital audio data and an audio volume control knob 16 which also doubles up as a standby/on button. Unlike most conventional digital radios, a colour graphic display for viewing the displayable data is also provided on the front face 10 of the digital radio 12, together with control buttons positioned around the display 18 for interacting with the displayable data and facilitating tuning selection. Specifically, six control buttons are provided 20, 22, 24, 26, 28, 30 set out so that there are three control buttons along two sides of the display. The display 18 is a 320 x 240 pixel Thin Film Transistor (TFT) screen.

Three further control buttons 32, 34, 36 are provided on the front face 10, by means of which the user can select an operating mode or service. These modes are 'Interactive Data' mode, 'Radio tuning' mode and 'Rewind radio' mode, and will be described in more detail later. Their corresponding control buttons are the Interactive Data button 32, the Radio tuning button 34 and the Rewind radio button 36. There is also a 'Push' service which activates automatically without interaction from the user and will also be described later. A Light Emitting Diode (LED) is also provided on its front face 10 to indicate when the radio is 'live' i.e. the audio broadcast is live.

The digital radio 12 also has a back face (not shown) on which two audio data output sockets suitable for headphones and connection to external audio equipment, and a mains on/off switch are provided.

The digital radio 12 is mobile in that it is able to be moved easily, and portable in that it is light and small enough to be easily carried or moved. The radio 12 further comprises a telescopic antenna 40 to improve reception quality, where needed. The digital radio 12 is capable of receiving both Band III and L-Band ensembles even though currently in the UK, only Band HI spectrum is used for DAB digital radio. Therefore, the antenna 40 is optimised for Band III reception in the UK.

The services provided in the various operating modes of the digital radio 12 will now be described with reference to Figures 2(a) - (c) and 3(a) - (f). The Interactive Data service provides a user access to relevant and up-to-date information which is presented graphically on the display as pages of displayable data, similar in look and navigability to web pages. As mentioned earlier, the content of the displayable data includes news headlines and stories, business and finance news, sports headlines and stories, travel, weather, lottery results, newspapers, clocks and advertisements. Users can select a certain category of information for viewing or browse through the available pages of information.

At least one page is a menu of the different categories of information that are available (Figure 2(a)), for example, News, Sport, Weather, Business, Entertainment and Lotto. The menu options are arranged on the menu page 42 such that each menu option is adjacent a corresponding control button so that the user can select a menu option by pressing the corresponding adjacent control button. If the News option 44 is selected, for example, a page 46 showing the latest headlines will be displayed (Figure 2(b)). The full news story page 48 can be viewed by selecting a particular headline (Figure 2(c)). In this way, the user can browse and navigate their way through the displayable information pages and select specific pages for viewing on the display. Access to the displayable pages are through sub menus, like a tree structure. If the user does not interact with the radio 12 while in the Interactive Data mode, e.g. by pressing a button, for more than 90 seconds, the radio 12 automatically switches to the Push service (described below). If the Interactive Data control button 32 is pushed within five minutes of this time, the display 18 reverts to the last viewed displayable Interactive Data page. These time periods can be pre-set as something other than ninety seconds and five minutes. Further examples of the displayable pages presented in the Interactive Data service are shown in Figure 3(a) - (f) and include a football results page (Figure 3(a)), a business page 52 (Figure 3(b)), a weather forecast page (Figure 3(c)), a lottery results page 56 (Figure 3(d)) and advertisement pages 58, 60 (Figure 3(e) and (f)). Entertainment pages (not shown) may include film clips, short presentations involving still images, slide-shows, animations and moving images.

The Radio tuning mode allows a user to select a radio station to listen to by presenting a radio tuning menu 62 to the user on the display (Figure 4(a) and (b)). The menu options normally display a choice of five radio stations and a 'more stations' option 64. Selecting 'More stations' displays a further menu 66 containing five or six more radio stations (Figure 4(c)). Once tuned into a radio station, pages 67, 69 showing a station logo and radio programme related text are presented on the display (Figure 4(d) and (e)). After the radio has been used for a while, the first radio station selection menu displays the five most listened to or selected radio stations and indicates these as 'favourites' (not shown).

The Rewind radio mode provides a means of listening to the previous sixty minutes of a broadcast radio programme (audio data) of the selected radio station by using the display 18 and the rewind button 36 to control and monitor the rewind. The radio programme- related text is also replayed as part of this Rewind service and its replay is synchronised with the audio data playback. The audio data and other programme related data is stored in an audio memory of the digital radio 12 and the capacity of the audio memory determines how much audio data and associated other data can be stored and therefore how far back in time the data may be rewound. In this embodiment, one hour of audio data can be stored which means that a radio programme which was broadcast up to an hour ago can be replayed through the Rewind radio service. The Rewind button 36 is a single stepped rotary knob which when rotated anticlockwise regresses the stored audio data in five second increments back to a maximum of sixty minutes. Rewinding the knob 36 more than eight clicks (i.e. a forty second rewind) changes the rewind increment into one minute steps. When the knob 36 is rotated clockwise, the audio skips forward in five second increments. As soon as the Rewind knob 36 is activated, visual feedback is provided to the user to indicate how far back the data has been re- wound.

In the present embodiment, a timeline is presented graphically on the display 12 which shows where the listening point is in the last sixty minutes. The timeline is displayed for fifteen seconds before the display 12 reverts to the Push service (see below). The LED 38 is not lit while in the rewind radio mode to indicate that the radio is not 'live'. Alternatively, instead of a rewind knob 36 for controlling the rewind, the digital radio 12 may be provided with a display menu for selection with the control buttons around the display of options such as rewind, fast forward, play, pause and resume live radio listening.

The Push service is an automated display service which automatically activates when the user has not interacted with the digital radio 12 for fifteen seconds or any other predetermined time interval, for example if the radio 12 is not re-tuned or is left tuned to an audio service but the Interactive Data service is not accessed. In the Push service, pages of information are automatically and sequentially presented on the display, like a slide show. The display sequence is not defined by the user but is set by the service provider according to a predetermined schedule. In the present embodiment, the sequence comprises: advertisement pages 72 (Figure 5(a)), information pages 74 e.g. news, headlines, sport, weather etc. presented graphically (Figure 5(b)), pages displaying the dynamic label broadcasts but displayed in a different, stylish font (not shown). Some of the displayable pages in the Push service may use some of the information content of the Interactive Data service such as news, sport and financial headlines. Some of the displayed pages 76, 78 may offer prompts for further information (e.g. 'more details' and 'return') that the user can select by a control button adjacent the option if they are interested in finding out more information (Figure 5(c) and (d)). Figure 6 shows the presentation 80 on display 18 of the digital radio 12 when the radio 12 is off or on standby showing a digital clock 82 with the current time together with the date 84. This page can also be selected for display through the Interactive Data mode and can also be viewed through the Push service.

Referring now to Figure 7, in digital radio broadcasting systems 90, digital information streams from different service and information providers are multiplexed together and transmitted over a single frequency. Put another way, data associated with a number of radio stations is broadcast over a common channel, together with other data. In the present example, the Multimedia Object Transfer (MOT) protocol in combination with the Broadcast Website (BWS) application are used, both of which are supplementary specifications for the application of data services using the Eureka 147 system. The service providers 92, 94, 96 are UK-based radio stations (A: Virgin radio; B: Talk radio; C: Capital radio) and an information provider 98 (D: Digital One). The digital information streams 100, 102, 104 of the service providers 92, 94, 96 (A to C) comprise audio data of the radio programmes and may also include dynamic labels or PAD such as the radio station logo or the name of the song that is being played. The digital data stream 106 of the service provider 98 (D) comprises displayable data which is not radio-station or radio- programme related and is transmitted by service provider 98 (D), before being multiplexed, using one component within a packet-mode data sub-channel which is separate from the other service providers 92, 94, 96 (A to C).

Existing digital radio devices 108 can receive and decode the data transmitted from the service providers 92, 94, 96 (A to C) but are not able to receive and decode data stream 106 (D) from service provider 98 (D). The digital radio 12 of the present invention can decode the data stream 106 transmitted from service provider 98 (D) and display this data at the same time as playing the radio programmes from a different service provider. For this to happen, the service providers 92, 94, 96, 98 must all be on the same multiplex. The presentation of the displayable data is in the form of the displayable pages through the Interactive Data and the Push services, described earlier.

The digital radio 12 plugs into the mains and can be turned on and off by the on/off switch. Once it is turned on, the radio 12 starts an automatic scan of DAB frequencies and at the same time the display 18 presents welcome messages explaining that in a couple of minutes the radio 12 will be ready to use. Once it has found the multiplex that the service provider 98 is on, the digital radio 12 automatically tunes into one of the radio stations available on that multiplex.

A more detailed schematic of the digital radio broadcasting system of Figure 7 is shown in Figure 8. The displayable data stream 106 (D) comprises content data 110 and graphic data 112 which is stored in a content database 114 of the service provider 98 (D). The contents of the content database 114 are ordered by a transmission manager 116 according to a transmission schedule 118 which is devised by the service provider 98 (D). The ordered content data 110 and graphic data 112 is then formatted for transmission, added to a dedicated data carousel 120, multiplexed at a transmission centre 122 with the other digital streams 100, 102, 104 from the other service providers 92, 94, 96 (A to C), and transmitted on the national terrestrial digital radio multiplex. The transmission manager 116 operates in real-time, checking the transmission schedule 118 and controlling the broadcast data carousel 120.

The content data 114 is normally real-time information from a news and information content provider e.g. The Press Association. The real-time information from the content provider is obtained and formatted by the service provider 98 (D) before being stored in the content database 114 of the service provider 98 (D). Where automated data capture techniques are used to obtain the information, the operation of any filter programs must be reliable and regularly reviewed to ensure data sanity. It is preferable to have a well maintained information content for the content data rather than capturing the data from other page formats. Part of the reformatting may involve extracting the raw information only without any formatting information. To improve the speed of delivery of the content data, the content data comprises text (e.g. ASCII text code) and is sent in the form of small identifiable packages of ASCII code which have a specific association with a template page.

The graphic data 112 comprises backgrounds or templates into which the digital radio 12 slots the content data 114 in order to create the composite displayable pages which are displayed as part of the Push service and Interactive Data service. It is to be appreciated that the radio 12 itself combines or assembles the content data 110 and the graphic data 112 together to make the composite displayable pages. The backgrounds are expressed in the form of instruction data defining the displayable template such as html as a mark-up language. Some examples of the displayable background templates 126, 128, 130, 132, . 134 defined by the graphic data are shown in Figure 9(a) to (e). These files are 320x240 pixel JPEG format files which are nominally 17 kilobytes in size. The menu background template 136 (Figure 9(f)) is in the form of a six cell table and is arranged so that content data 114 can occupy five of the cells and a graphic image of 'more stations' is in the sixth cell. The menu templates are produced using HTML editors such as Macromedia® Dreamweaver, whilst the image content is created and edited using standard graphics software such as Adobe® Photoshop or JASC PaintShopPro®.

The graphic data 112 also includes formatting support images or graphics for example, cloud and sun symbols for use on weather maps, logos of all radio stations on air in the UK for use on the radio channel selection mode, advertisements. These overlay the backgrounds and are contained within tables. Small dynamic images such as arrows or headline backgrounds are broadcast during the day and night.

The graphic data 112 further comprises a series of schedules denning the pages to be presented in the Push service, the content of which is defined by the service provider 98 (D). The schedules are in the form of a list of data items, the time at which they are to be displayed and how long they are to be displayed for, and are normally broadcast a day ahead of when they are needed. The schedules can also relate to sequences of images related to particular audio channels, but the images are transmitted in a separate data stream from the audio channel data stream.

The speed of transmission of the data stream 106 (D) depends on the time of day and the data being transmitted (i.e. content data or graphic data), and is shown schematically in

Figure 10. The content data 110 is broadcast during the day (6 am to midnight) and during the night (from midnight to 6 am) at a rate of 8 kbit/sec. Transmission of the content data

110 is continuous and repetitious to ensure that users of the digital radio 12 receive the latest information. The graphic data 112 is broadcast at night only (from midnight to 6 am) at a rate of 64 kbit/sec. The transmission of this data is repeated several times throughout the night, together with the content data 110. Occasionally non-textual time critical images such as weather maps may be transmitted with the content data. It is assumed that the digital radio 12 will not usually be used for radio listening but will be on standby during the night which means that it continues to receive the data transmissions.

If the user uses the mains plug to switch the digital radio 12 off, the Interactive Data service and the Push service will eventually stop working as the digital radio 12 cannot switch itself on in the night to download the displayable data. Therefore to discourage users from switching off the radio 12, the digital radio 12 has a built-in start-up presentation which is shown on the display 18 as soon as the digital radio 12 is switched on at the mains. The re-boot process informs the user of the initialisation procedures with warnings about the consequences of disconnecting the power.

The content data 110 is transmitted using plain ASCII files which are of a smaller size than the graphic data 112 which are JPEG or PNG compression files. If the content data files were delivered at the same time as the bulky graphic data files, the content data delivery time would be slowed down. Broadcasting of content data 110 during the day saves considerable capacity in the digital radio 12 and ensures a rapid delivery time of real-time information. At night, it is still possible to maintain similar performance of the digital radio 12 while the graphic data 112 is being received by the digital radio 12. This system also means that the transmission of the content data 110 can be set to repeat very rapidly, allowing new listeners to access the up-to-date content data without undue delay.

If too much content data 110 is transmitted, the user of the digital radio 12 receiving this data will encounter a delay. Therefore, it is possible to control the data carousel 120 so that the transmission time can be adjusted on a content data file by content data file basis.

For example, news and finance are given the highest priority which means that content data 110 on news and finance are transmitted more regularly because this type of information tends to get updated more often. An example of the priority within the transmitted content data and graphic data is shown in the table 140 in Figure 11. The data of Figure 11 is based on a trial service run by the applicant using a carousel manager utility to prioritise the data within the transmission. The digital radio 12 creates the displayable pages of information from the graphic/instruction data 112 and content data 110 by populating the displayable templates with the content data 114, the exact mechanism of which will be described later. Placeholders in the instruction and graphic data identify where the content data should be placed.

The content data 110 is handled as files but can also be treated as data objects i.e. blocks of data bytes with a name or a Unique Identifier code (UID). The chunks of the content data are identifiable by coding which is included within the object name which means that there is no need to add any identifying references within the data itself. The coding within the object name includes a reference to the target template and a unique and appropriate identification pattern (text) which includes the topic to which the content data relates. The content can be divided into any number of topics such as news headlines and stories, business and finance, sports headlines and stories, entertainment, weather, lottery results, newspapers, advertisements, and radio service related, and coded appropriately. The topic coding scheme of the sub-divided content data and the digital radio services in which each topic appears is shown in a table 142 in Figure 12.

The main components of the digital radio 12, according to an embodiment of the present invention, are shown in Figure 13 and include a tuner 144 for receiving a broadcast digital signal, an audio data decoder 146 for decoding the received digital audio data and generating an output signal, a displayable data decoder 148 for decoding the displayable data, the audio data memory 150 for storing the received digital audio data, a displayable data memory 152 for storing the displayable digital data (content data and graphic data), processing means 154 for processing the digital displayable data and controlling means

156 for implementing the commands of the user through the control buttons by communicating with the audio decoder 146 and the displayable data decoder 148. The processing means 154 constantly examines all data objects and creates displayable pages for the Interactive Data and Push services from data files stored in the displayable data memory 152.

The digital radio 12 can receive digital signals of both band HI and L-Band ensembles and has an RF sensitivity of at least -95dBm, exclusive of any gain achieved through the antenna 40. The digital radio 12 decodes separately the received audio data and the displayable data. The displayable data decoder 148 is of a type suited to the service, such as Multimedia Object Transfer (MOT) protocol. In the present embodiment, the audio data decoder 146 and the displayable data decoder 148 can receive and decode one data sub-channel and one audio sub-channel, respectively, on the same multiplex simultaneously. The audio data decoder 146 decodes the broadcast audio data (ISO-DAB frames) using MPEG 1 Layer II up to 256 kbit/sec, and low sample frequency using MPEG 2 Layer II coding.

The components of the digital radio 12 are shown in further detail in Figure 14. As can be seen, the digital radio 12 comprises both a non- volatile Random Access Memory (RAM) 158 and a Read Only Memory (ROM) 160. The displayable data is stored within subdivisions of the displayable data memory on the RAM which are Radio Station List memory 162, Radio Station Logo memory 164, Content Menu memory 166, Composite Displayable Pages memory 168, Content Data memory 170, Graphic Data memory 172, Instruction Data memory 174, Push Pages memory 176, Push Page Images memory 178, and Push Service Schedule memory 180. All data is time stamped by the carousel 120 before DAB transmission.

The Radio Station List memory 162 stores a list of the names of all the radio stations available on the digital radio system and the Radio Station Logo memory 164 stores their corresponding logos. The Content Menu memory 166 stores the displayable menu pages of the Interactive Data service. The Composite Displayable Page memory 168 stores the displayable pages created by the digital radio 12 when the graphic data defined templates are populated with the content data 110. The Content Data memory 170 stores the received displayable content data 110. The Graphic Data memory 172 stores the formatting support images and graphics images for the templates and backgrounds of the displayable information pages. The Instruction Data memory 174 stores the instruction data defining the templates of the displayable pages. The Push Pages memory 176 stores the created displayable push pages for the Push service. The Push Page images 178 store the graphic data for use in the Push service displayable pages and the Push Schedule memory 180 stores the schedule for the Push service. The ROM 160 stores pre-prepared images and templates, as well as some pre-prepared pages of user help instructions. In this embodiment, the ROM 160 memory has a capacity of 13,184,000 bytes and the RAM 158 memory has a capacity of 25,033,944 bytes.

Also provided within the digital radio 12 is an HTML Interpreter and Rendering Engine (file browser) 182, a DAB Radio User Interface (UI) 184, a Interactive Data Service UI 186, a Push Service UI 188, and a Rewind Radio UI 190.

The DAB Radio UI 184 scans the DAB Receiver Band, allows tuning and DAB service selection. The DAB Radio UI 184 also creates and manages a store of available ensembles and services and presents service names, tuning icons, dynamic labels and graphics on the display.

The Interactive Data Service UI 186 activates the HTML (file) browser 182 when the user presses the Interactive Data button 32 to access the Interactive Data Service, presents the first main menu file to the browser and passes navigation responses from the display buttons to the browser 182.

The Push Service UI 188 activates the HTML (file) browser 182 if there is no action from the radio 12 after one minute (or any chosen time period) and passes navigational responses, e.g. "More" or "Back", from the display buttons to the browser 182.

The Rewind Radio UI 190 responds to the Rewind radio button 36 and controls the live/rewind MPEG decoder 192 switching. If the user is listening to a 'live' programme, the Rewind Radio UI 190 switches to replay the previous five minutes. If the user is already in rewind mode, it reverts to the live mode and instructs the DAB Radio UI 184 to present the dynamic labels to the display 18.

A Live/Rewind Switching component 194 manages the audio data memory 150 as a 'ring buffer' first-in-first-out for audio frames and routes the current ISO-DAB audio frames to the MPEG decoder 192, live or from the audio data memory 150. A 5 watt amplifier 196 drives the speakers 198 and/ or headphones 200. The digital radio 12 also comprises a Push Page Display Controller 202 for controlling the display of the pages for the Push service. The Push Page Display Controller 202 constantly checks the CPU real-time clock, reads the Push Service schedule, passes Push Service page files to the HTML Browser 182 and checks with the Push Service UI 188 to see if 'More Info' is requested.

A control button hardware interface 204 reads the button interface electronics, identifies the button actions and passes 'press' events to a main processes 206 control programs.

A real-time operating system 208 provides the important programmable environment with interfaces for peripheral hardware such as buttons and display drivers 210, and forms the basis for the core receiver processes. The peripheral hardware includes object storage management which is similar to a filing system, interface to video device drivers for the display, memory management, interface for input/output (e.g. control button hardware chips, and audio Digital Signal Processing capability).

The Main Processes component 206 monitors all operational controls, responds to the user control buttons, senses switching user modes, activates the separate sub tasks depending on the mode selected, checks for long term tuning delays and task failures, purges the memory of old or corrupt data and pipes the MPEG audio frames into a ring buffer in RAM. Sub processes includes a key scanning interface which signals to the main process when any user button is depressed. Depending on the digital radio mode, the button responses are passed to the relevant GUI control programs. For example, if the user is choosing a new radio service, the buttons control the digital radio. Instructional text labels or icons associated with the screen navigation buttons change depending on the mode of the receiver.

The digital radio 12 synchronises its clock and locale to the Fast Information Channel (FIC) of an audio data stream of the multiplex. However, if the digital radio 12 is in standby mode, its clock is synchronised from the FIC of the displayable data stream of service provider 98 (D). The content data 110 and graphic data 112 naming convention in the present embodiment was devised to ensure ease of navigating the various pages of information displayed on the digital radio 12. The essence of the naming convention is that a specific name label is used for each data type and each data package.

Top Level Menu naming

As mentioned earlier, all of the six control buttons may be used to access the various topic menus. If more than six topics are made available, the top level menus are reduced to show four item choices, with navigation to other top level topic menus using two buttons marked 'MORE' and 'PREVIOUS'. All top level menu screen defining graphic data are given the names: MENU_l.htm. The first and subsequent top-level topic menu displayed on the Interactive Data service is named: MENU_2.htm, MENU_3.htm etc.

The menu's appearance is defined by the graphic data, not with text. These full page images are given names relating to the menu page. i.e. MENU_lg.jpg, MENU_2g.jpg etc.

Sub Menu naming

Sub menus comprise background images with overlaying navigation labels. The position of the label text signifies to the user which button should be pressed to view the full content page. For News, Sport and Business topics, menu labels are filled with dynamic data. Certain categories do not use sub-menus, instead the first page is accessed using a 'MORE' button.

All navigation sub-menu pages used in the Interactive Data service are named according to a table 220 shown in Figure 15. Like main menus, the graphical images for the backgrounds retain the same name, except that a lower case 'g' appears before the period, and the file extension will be either JPG or PNG. For example:

TMS 1.htm - Text Menu for Sport - Menu Number 1 - html page code.

TMB2.htm - Text Menu for Business - Menu Number 2 - html page code.

Interactive Data Page naming

Created information pages are formed with letter codes that relate to the application and topic, plus two or three digits, h the case of Interactive Data pages that are accessible from a sub menu, the first digit indicates the previous level menu number. The second digit indicates the page number within the group, up to a value of four. Topic page groups not accessible from a sub-menu may have higher page numbers, subsequent pages being accessible using the 'MORE' or 'NEXT' buttons.

Some pages of the Push Service include a 'MORE' option to allow the user to navigate to additional sub-pages of information that are not seen in the presentation sequence. This feature allows the user to find out more information about products or services advertised, so additional numeric codes are added. The naming conventions of the Interactive Data Pages are shown in a table 222 in Figure 16. Examples:

TB24.htm - Text Business number 24 If a Business section Menu is implemented, this page may be accessed from

Business sub-menu 2, page number 4

TW12.htm - Text page, accessed from Weather sub-menu 1, page number 2 If the page is not accessed through sub-menu, 'MORE' or 'NEXT' button labels may be shown that allow the user to navigate to the next page in the section, where available. In this example, the NEXT button would cause page TW13 to be displayed.

All content pages include a 'MENU' button label to allow the user to return to the previous selection level. Pages of the Push Service showing supplemental information include a ' MORE' and 'PREVIOUS' button labels that allow the user to navigate through the content.

To help the management and organisation of the service, the background graphic images for each page may be named as per the content page appended with a lower case 'g' prior to the file extension. In the above example, content page TW12.htm would use a full screen graphic named TW12g.JPG. This approach is not mandatory.

Push Service Page Naming

The Push Service pages require minimal navigation, so the naming scheme is more flexible. Some advertisements may comprise several pages, to allow the user to find out more information about a product or service. Access to the supporting screens is possible through 'MORE INFO', 'FIND OUT MORE' button labels shown on the screen (see Figure 5(c) and (d)). The navigation instructions for the HTML Browser are included within the page code. All Push service pages comprise full screen images, formatted using HTML. Topic codes may be used, with additional numbers to help. The page naming convention used for Push service pages is shown in table 224 in Figure 17.

The content set number is arbitrary. A two-digit ID code of '00' is given to the page presented in the display sequence. If this is an Interactive Data service page, subsequent pages accessible through the 'MORE' button label are LD code digits higher than 00. This should correspond to the access sequence. If a Push Service page with ID code digits 00 was found to have button hyperlinks within the code, the following page name would be identified as 01. This technique is shown in the example in table 226 in Figure 18.

Background graphic data for each Push service page named may be identified using the associated page file name, with a lower case 'g' added prior to the file extension. In practice, this need not be so rigid, especially if an image is used in more than one page.

Content Data Naming

The broadcast content data is named, in part, according to the template pages that will contain the content data. To aid the production of the template pages, the text patterns are distinguished from other page text, and HTML tags '~' (Tilde) symbols. There may be more than one text object used on a template page, so additional characters can be freely added. An example of a page data, text data object name is shown in tables 228 and 230 in Figures 19 and 20, respectively. The point of including the part of the corresponding page content name is intended to simplify the page update and production process within the receiver. Note that the processing means 154 checks for the presence of a template page number within the Push Service content, checking the template code for the marker text and producing a Push Service page automatically. This allows the same data to be deployed in both Push Service pages and Interactive Data service pages. The data may also contain HTML code fragments although this departs from the general principle of the data delivery. Examples:

~TN1 lhead~.dat - Text data for primarily used in the creation of page TNI 1.htm ~TB22textl2~.dat - Text data used in the creation of page TB22.htm Graphic Template Naming

All template files/data start with an upper case 'X' e.g. XTN11.htm, XPB 11.htm.

Defining Navigation Hyperlinks in Content Pages As mentioned earlier, six dynamically assignable buttons provide the facility to navigate through the- Interactive Data pages. Special HTML text in the page code is included to instruct the processing means about which pages appear on the display 18 in response to the button pressed. Since the displayable pages are 'browsed' using an HTML interpreter 182, normal hyperlinks can provide this mechanism, set to point to other named file objects rather than using HTTP -based URLs. In the present system, the HTML page code is scanned by the processing means to look for the hyperlinks, and the button associated with each one. This requires that when navigation is required, the code must follow a consistent structure. The fact that the hyperlinks are read by the digital radio software and associated with user buttons is a key feature of the HTML browser software. The button names are shown in table 232 in Figure 21, along with an HTML code fragment that must be included.

In the example of a News sub-menu 1, the upper four buttons link to other pages, whilst the lower buttons are intended to move to the main top level menu (MENU_l.htm) or to the next News sub menu (TMN2.htm). Example of navigation hyperlink: -

In some case just one or both of the lower buttons would be required. In these cases, only the relevant button text definitions need be included. The button definition code must be placed so that it falls outside the receiver's 320 x 480 pixel display otherwise the text may be visible on the display. This is useful at the content and template preparation stage as the page navigation may be tested on a normal web browser. The way in which the digital radio provides the Interactive Data service is described with reference to Figure 22. At step 200, the digital radio receives the displayable data. At step 202, the Displayable Data Decoder decodes the displayable data. All displayable data is encrypted before it is transmitted so that only digital radios primarily arranged to receive such displayable data, as in the present invention, are able to decode the displayable data. An MOT decoder reconstitutes the displayable data into the data objects that were multiplexed. A file cache manager reads all the MOT carousel data objects received, checks their date, replacing outdated ones as soon as they are received and stores them as 'real' file objects in the relevant memory (not using HTTP), at step 204. For example, content data is directed to the Content Data memory and Instruction data to the Instruction Data memory. At step 206, the displayable data objects are received into the displayable data memory, the processing means reads the displayable data and automatically creates a new displayable page using the associated instruction data or template data and content data. The created displayable page is then stored in the Displayable Pages memory 168. At step 208, the processing means 154 also looks at the file name of the content data object as it is received into the Content data memory 170 and opens all the templates that use that content data. At step 210, if the recently received content data objects are newer than those stored previously, the processing means 154 replaces the previously stored data objects with the recently received ones and a new displayable page based on the newly received content data is created and stored in the displayable page menu 168, at step 212. When the user presses the Interactive Data button 32 at step 214, the HTML Interpreter and Rendering Engine 182 is activated which accesses the first Interactive Data main menu file from the Content Menus memory 166 and presents it to the browser which then presents the page on the display 18. At step 216, if the identified position on the template for the received content data is empty, the processing means inserts the content data into position in the template to create the displayable page.

The way in which the processing means 154 creates the displayable pages will now be described with reference to Figure 23. As mentioned earlier, content data is broadcast as packages/objects of plain ASCII code. Each data object 230 is identified with a code 232 which is related to the target template background 234. Each target template/background

234 contains defined text patterns 236, such as HTML code, which indicates where each content data object 230 should be placed. The processing means 154 substitutes the marker pattern text 236 in the template with the ASCII code 232 of the content data object 230. The resulting displayable page is stored in the memory 168 under an identifying file name for access by the user through the display 18.

An example 240 of instruction data defining a template of a topic menu is shown in Figure 24, and a Push Service content schedule 242 in Figure 25.

If the user chooses to listen to a radio station but not through the multiplex broadcasting the Data stream 106 (D), the digital radio 12 cannot simultaneously receive the Data Stream 106 (D) from service provider 98 (D). The impact of this is minimised by arranging for the radio 12 to re-cache the data stream 106 when the radio 12 is not being used, i the off-state the digital radio 12 automatically tunes to the Data stream 106 and continues to update the content cache. This is entirely transparent to the user. If the user switches on the digital radio 12 while this process is happening, and the last chosen station is not on the Data stream 106 multiplex, the digital radio 12 stops caching and refreshing the data and immediately re-tunes to the appropriate multiplex, assigning its audio decoder 146 to the required radio station. If the last chosen radio station is being broadcast on the Data stream 106 multiplex, the data decoding process continues. Figure 26 demonstrates the cycle of data caching from the Data stream D 106 multiplex.

This means that the user can receive the Push service and the Interactive Data service. However, the content of both services will be displayed from the radio's memory. The advertisements, radio text and DLS screens within the Push service are not affected provided the content has been received during the previous night. However, the news/sport/business-based pages within the Push service are potentially affected as these pages cannot be updated. For the first hour this is unlikely to be a problem i.e. in this context, displaying information which may have changed is not a major problem, but after one hour, or any other predetermined time interval, the Push service would cease showing news/sport/business pages. The weather pages, and any other less time sensitive pages would continue to be displayed.

For the Interactive Data service, as it may not be acceptable for the user to be shown cached and potentially out of date information, the display presents a message to indicate that this service is only available when the consumer is listening to particular services i.e. the radio stations being broadcast on the same multiplex as the Data D multiplex (Figure 27). If the user does nothing then their radio 12 also does nothing i.e. the radio will not automatically retime. However, if the user selects a station from the same multiplex as Data stream 106 (D), the Data D will be decoded. If the user presses the Interactive Data button immediately after selecting the station, a non-Interactive Data banner page 250 will be presented for about five minutes warning that the content is currently updating and may change in the next few minutes.

Having described a particularly preferred embodiment of the present invention, it is to be appreciated that the embodiment in question is exemplary only and that variations and modifications such as will occur to those possessed of the appropriate knowledge and skills may be made without departure from the spirit and scope of the invention as set forth in the appended claims. For example, the display can be a touch screen so that user interaction with the displayable data is possible by the user touching the screen rather than through buttons. The present embodiment has not incorporated a touch screen display because they are more expensive option at the time of writing. The invention need not be limited to the Eureka 147 DAB system. The LED may also be a series of LEDs of different colours whereby each colour LED, when it is lit, represents the current 'live' mode of the digital radio.

Claims

1. A digital radio primarily arranged to receive broadcast digital information including audio data related to a radio station and displayable data which is radio station- independent, the radio comprising: decoding means for decoding the received digital information; means for generating a sound signal from the decoded station-related audio data of the received digital information to present the same to a listener; and means for displaying the decoded station-independent displayable data of the received digital information at the radio; wherein the generating means and the displaying means are arranged to operate independently such that the displayable data can be displayed concurrently with, and independently of, the presentation of the audio data related to a particular radio station.

2. A digital radio according to Claim 1, further comprising a memory for storing the received and decoded station-related audio data and the received and decoded station- independent displayable data wherein the displaying means is arranged to display a selectable portion of the stored displayable data at the radio.

3. A digital radio according to Claim 3, wherein the selection means comprises means for browsing the stored displayable data in order to select the portion of the stored displayable data to be displayed.

4. A digital radio according to Claim 3 or Claim 4, wherein the selection means comprises a touch screen.

5. A digital radio according to any preceding claim, wherein the displaying means comprises a graphical display and the displayable data comprises graphic data which is displayable as a non-text image on the graphical display.

6. A digital radio according to any preceding claim, further comprising at least two distinct storage memories in which the audio data and the displayable data are stored separately.

7. A digital radio according to any preceding claim, wherein the displayable data comprises content data for populating a template and processing means arranged to populate the template with the content data.

8. A digital radio according to Claim 7, wherein the displayable data further comprises instruction data defining the displayable template and the processing means processes the instruction data.

9. A digital radio according to Claim 8, wherein, the memory further comprises pre-stored instruction data.

10. A digital radio according to Claim 8 or Claim 9, wherein the instruction data is expressed as a mark-up language and the processing means is arranged to use the mark-up language instructions to create graphical representations on the displaying means.

11. A digital radio according to Claim 10, wherein the mark-up language is html.

12. A digital radio according to any of Claims 8 to 11, wherein the instruction data comprises static data to be displayed unchanged over a relatively long time period.

13. A digital radio according to any of Claims 7 to 12, wherein the content data is dynamic in that it is to be displayed for a relatively short time period and the radio further comprises means for overwriting the displayed dynamic content data with more recently received broadcast content data.

14. A digital radio according to any preceding claim, wherein the audio data is related to two or more radio stations and the radio further comprises radio station selecting means for user selection of one of the two or more radio stations to be listened to.

15. A digital radio according to Claim 14, wherein the decoding means decodes the audio data and displayable data separately from each other such that the selection and display of the decoded displayable data can be independent of the radio station selection.

16. A digital radio according to any preceding claim, wherein the displaying means is arranged to display portions of the displayable data sequentially as a slideshow according to a predetermined schedule.

17. A digital radio according to Claim 16, wherein the displaying means is arranged to initiate the slideshow automatically when there has been no user interaction with the digital radio for a predetermined time period.

18. A digital radio according to any preceding claim, wherein the radio is a portable device.

19. A digital radio according to any preceding claim, wherein the radio is a mobile device.

20. A_. system of broadcasting, receiving and presenting digital information including audio data related to a radio station and displayable data which is radio station- independent, the system comprising: multiple data channels of digital information; a multiplexer for multiplexing the multiple data channels together into one signal; a transmitter for broadcasting the signal; and a digital radio primarily arranged for receiving and de-multiplexing the broadcast signal into the multiple data channels of digital information, the digital radio comprising a means for generating a sound signal from the received station-related audio data to present the same to a listener, and means for displaying the received station-independent displayable data at the radio, wherein the generating means and the displaying means are arranged to operate independently such that the displayable data can be displayed concurrently with, and independently of, the presentation of the audio data related to a particular radio station.

21. A system according to Claim 20, the system further comprising coding means for coding the digital information of the multiple data channels before the multiple data channels are multiplexed and wherein the digital radio further comprises decoding means for decoding the received and de-multiplexed multiple data channels of digital information.

22. A system according to Claim 20 or Claim 21, wherein the transmitter broadcasts the displayable data at different rates during the day depending on the size of the data to be broadcast.

23. A system according to Claim 22, wherein the transmitter broadcasts the displayable data at a higher speed during the night than during the day.

24. A system according to any of Claims 20 to 23, wherein the broadcast displayable data comprises instruction data defining a template displayable on the digital radio displaying means and content data for populating the template.

25. A system according to Claim 24, wherein the transmitter broadcasts the content data throughout the night and day, and the instruction data at night.

26. A system according to Claim 25, wherein the transmitter broadcasts the instruction data at a higher speed than the content data.

27. A system according to any of Claims 20 to 26, wherein the audio data is related to two or more radio stations, at least one of the data channels comprising the audio data related to one radio station.

28. A system according to Claim 27, wherein the radio station-independent displayable data is in a separate data channel to the radio station-related data channels.

29. A method of broadcasting, receiving and presenting digital information including audio data related to a radio station and displayable data which is radio station independent, the method comprising: multiplexing multiple data channels of the digital information together into one transmittable signal; broadcasting the transmittable signal; receiving and de-multiplexing the received signal with a digital radio; generating a sound signal from the de-multiplexed station-related audio data of the received digital information to present the same to a listener, and displaying the decoded station-independent displayable data of the received digital information at the radio, wherein the generating step and the displaying step are arranged to operate independently such that the displayable data can be displayed concurrently with, and independently of, the presentation of the audio data related to a particular radio station.

30. A digital radio primarily arranged to receive broadcast digital information including audio data and displayable data, the digital radio comprising: means for decoding the received digital information; a memory for storing the decoded audio data and displayable data of the received digital information; and means for displaying the stored displayable data, wherein the displaying means is arranged to display a selectable portion of the stored displayable data at the radio.

31. A digital radio according to Claim 30, wherein the selection means comprises means for browsing the stored displayable data in order to select the portion of the stored displayable data to be displayed.

32. A digital radio according to Claim 30 or Claim 31, wherein the selection means comprises a touch screen.

33. A digital radio according to any one of Claims 30 to 32, wherein the stored displayable data comprises content data for populating a template and processing means arranged to populate the template with the content data.

34. A digital radio according to Claim 33, wherein the stored displayable data comprises instruction data defining the displayable template and the processing means processes the instruction data.

35. A system of broadcasting, receiving and presenting digital information including audio data and displayable data, the system comprising: multiple data channels of digital information; a multiplexer for multiplexing the multiple data channels together into one signal; a transmitter for broadcasting the signal; and a digital radio primarily arranged for receiving and de-multiplexing the broadcast signal into the multiple data channels of digital information, the digital radio comprising a memory for storing the audio data and the displayable data and displaying means for displaying the stored displayable data, wherein the displaying means is arranged to display a selectable portion of the stored displayable data at the radio.

36. A method of broadcasting, receiving and presenting digital information including audio data and displayable data, the method comprising: multiplexing multiple data channels of the digital information together into one transmittable signal; broadcasting the transmittable signal; and receiving and de-multiplexing the received signal with a digital radio; storing the audio data and displayable data in a memory of the digital radio and displaying the stored displayable data at the radio, wherein the displaying step comprises displaying a selectable portion of the stored displayable data.

37. A digital radio primarily arranged to receive broadcast digital information including audio data and displayable data, the digital radio comprising: decoding means for decoding the received audio data and the received displayable data; and means for displaying the decoded displayable data as a non-text graphical image at the digital radio, wherein the displayable data further comprises content data for populating a template and processing means arranged to populate the template with the content data to create the non-text graphical image.

38. A digital radio according to Claim 37, wherein the displayable data comprises instruction data defining the displayable template and the processing means processes the instruction data.

39. A digital radio according to Claim 38, wherein the memory further comprises pre- stored instruction data.

40. A digital radio according to Claim 38 or 39, wherein the instruction data is expressed as a mark-up language and the processing means is arranged to use the mark-up language instructions to create graphical representations on the displaying means.

41. A digital radio according to Claim 40, wherein the mark-up language is html.

42. A digital radio according to any of Claims 38 to 41, wherein the instruction data comprises static data to be displayed unchanged over a relatively long time period.

43. A digital radio according to any of Claims 37 to 42, wherein the content data is dynamic in that it is to be displayed for a relatively short time period and the radio further comprises means for overwriting the displayed dynamic content data with more recently received broadcast content data.

44. A system of broadcasting, receiving and presenting digital information including audio data and displayable data, the system comprising: multiple data channels of digital information; a multiplexer for multiplexing the multiple data channels together into one signal; a transmitter for broadcasting the signal; and a digital radio for receiving and de-multiplexing the broadcast signal into the multiple data channels of digital information, the digital radio comprising means for displaying the displayable data of the digital information as a non-text graphical image at the digital radio, wherein the displayable data further comprises content data for populating a template and processing means arranged to populate the template with the content data to create the non-text graphical image.

45. A method of broadcasting, receiving and presenting digital information including audio data and displayable data, the method comprising: multiplexing multiple data channels of the digital information together into one transmittable signal; broadcasting the transmittable signal; and receiving and de-multiplexing the received signal with a digital radio; and displaying the displayable data as a non-text graphical image at the radio, wherein the displayable data further comprises content data for populating a template and processing means arranged to populate the template with the content data to create the non-text graphical image.