Note: Descriptions are shown in the official language in which they were submitted.
219295
~E~E; RJ~-~i Ti i;;3 ~.;.:~'.~J~...
''.'RAP:~~AT!~rJ
A Method for-Transmitting Digital Data and Digital Complementary
Data, and a Method for Playing Back Digital Data and Digital
Complementary Data
Prior Art _
The present invention relates to a method for transmitting
digital data and digital complementary data-as set out in the
principalpatentclaim. Itis known from thearticie "Digital
Audio Broadcasting, Radiohoren in CD-Qualitat [Digital Audio
Broadcasting: CD-quality Radio Reception] that appeared in
Funkschau, No. 16, 1992, that digital data in the form of audio
data and digital complementary data that applies, for example, to
the traffic or traffic management system can be transmitted. The
complementary data are stored independently of the data and are
output as desired, independently of the data.
"The MPEG Systems Coding Specification," (G. McInnes, Signal
1
_ _. __ _
219298
Processing Image Communication,.Volume 4,~ No. 2, pp.,.155, 259,
states that theflow of,digitaldata that_are__to be transmitted
be divided into"vi~lao presentation units" or "audio presentation
units." The presentation units result from association of an
internal time marker in,the system encoder. The assignment of
time markers to the units is necessary in order to ensure that
the image and audio data are,played_back_in_parallel to each
other _ _ ___ ___-__..-_ ___ __ __ ___.. __ _
over time. -
EP 0 577 329 A2describes an arrangement for.Asynchronous
Transfer Mode (ATM-). networks that makes_it possible to derive a
system clock pulse from=an asynchronously transmitted
multiplexed audio and video signal, so that synchronization of
the asynchronously transmitted useful data is achieved. The
arrangement serves to reestablish the sypchgonicity of the data,
lost because of asynchronous transmission.
(DE 43 35 271 Al) describes a data demultiplexer to which
multiplexed audio and video data arepassed from a storage
medium, time markersfor.-identifying the start points of the
audio and video_packetsbeing assigned to the multiplexed
signal.
2
2192958
Advantages of the Present Invention
In contrast to the foregoing, the method according to the present
invention, having the features as set out in Patent Claim 1,
S entails the advantage that the digital complementary data, for
example, image data, text data, or speech-data, are divided up
into fixed data groups as units.
As an example, a unit can contain an image or a part of an image,
a song or a part of a song, or a page of text or a section of a
text. A unit identifier and a control character for the unit are
transmitted for-each unit and when the unit is being selected
these inform the receiver as to the time the playback or output
of the unit begins, and how long the playback or the output of
the unit lasts. This means that complementary data are available
for data such as audio data, and these are output in the
receiver, synchronized over time, by way of an appropriate
selection. It is left up to the user of the receiver to call up
the complementary data from the complementary data that is
offered and which the user may have output. A multimedia data
transfer method is made possible-in this way.
In contrast to the foregoing, the method according to the present
invention, with the features set out in Claim II, entails the
3
2:9295$
advantage that digital data, for example, audio data and digital
complementary data such as image data and/or text-data and/or
speech data can be selected for_output and the output of the data
and the complementary data is effected in a format that is
synchronized over time. In this manner, the user of a receiuer
that is operated in accordance with the method described can
select information that is of particular interest to him from a
large quantity of data andcomplementary data, and-then having
this output individually.
Interactive and multimedia use of the receiver is achieved by
this means.
Advantageous developments and improvements of the method
described in Claim 1-are made possible by the measures set out in
the secondary claims. An improvement to the method is achieved in
that a storage time ox a.storage interval-is transmitted for each
unit, and this indicates how long the unit is stored in a
receiver. By this means, it is possible to match the requirement
for storage space to the demand. This results in a saving of
storage space. If a plurality of transmission channels are used,
it is particularly useful to transmit a channel word for each
unit, this-word indicating the transmission channel that is used.
In this way, the transmission channel ofthe particular unit will
4
219298
be found rapidly. Additionally, after selection of the units, it
is thereby possible-to restrict reception to the appropriate
transmission channel.It.is particularly advantageous that,
because pf this, a plurality of available transmission channels
can be used-to transmit the units, depending on the workload:
this leads to moreefficient utilization of the transmission
capacities af.the transmission channels -.
It is also useful to-transmit the beginning of the transmission
of each unit and the number of the data bits that make up the
unit. This informs the receiver of the time period within which a
unit is transmitted, so that the receiver can make the storage -
space required-to store the unit available on a timely basis.
This results in a saving of storage space. The method described
is improved in that a number of-repetitions of the transmission
of the unit is also transmitted. In this way, the receiver knows
whether or not or how frequently the unit is repeated. This
offers the advantage that in the event of incorrect transmission
of the unit, the receiver receives the unit again during the next
transmission of the unit. and stores it. This results in increased
reliability of the transmission of the data.
The flexibility with which the complementary data are
represented is increased in that playback attributes for the
5
21929~~
representation or the=output-of the units is transmitted. Thus,
it is possible, to vary the representation or the output over
time without retranam;tting the units. In this way, more
interesting representation or output of the data is made possible
without additional, major transmission costs.
The use of a check sum for the transmission of the units makes
it possible to carry-out error checking of the transmission. This
increases the reliability of tha transmission method.
The use of the tran.am;-scion method is further improved in that a
plurality of units are combined to form components, and a
plurality of components are combined to form a program. Thus, the
user has the possibility of selecting the components of a program
so that the units that are elements of-the components can be
output.
Various types of data, such as images, music,--speech, and text,
or different data-contents such as political information, sports
information, and stock-exchange-information, can be used as
components. This provides the advantage that not every unit has
to be specially selected; rather, a number of units is determined
by the selection of a component. This increases convenience when
the transmission method is used.
6
~
219298
The use of designators or names for the units and components that
are represented or output with a receiver simplifies selection
for the user of the receiver since it is more canvenient to
select designators ~or_names instead of incomprehensible code
words. This also increases convenience when the transmission
method is used..
The method that has-been described is particularly suitable for
the transmission of a.-digital radio program, the data
representing audio data, for example, and the complementary data
representing image data,andJor audio data andlor text data. This
permitsa multimedia-interactive radio program that offers a
greater information content, and the possibility of putting
together an individual program.
The measures set out in the secondary claims are useful
developments and improvements of the method described in Claim
11. In an advantageous manner, the method is improved in that for
each unit a storage time that indicates how long a unit has being
stored in a stozage device is also stored_ This means that the
receiver has the-possibility of optimal allocation of the storage
space that is to be kept available. In this way, the amount of
storage space that is to. be kept available can be reduced to a
minimum.
7
219298
The method that has beendescribed is further improved in that a
channel word that is transmitted with every unit is also stored:
this indicates the transmission channel by which the unit is
transmitted. Thus, if a plurality of transmission channels is
used, it is possiblefor::the receiver to locate the units and
only store the selected units_
It is particularly useful to store playback attributes for each
unit. This will mean that the receiver will play back the data of
a unit as a function of the stored playback attributes,
differentiated over time. In this way, the functions of the
method that has been described can be expanded without any major
additional data costs. The playback of the units can thus be made
more interesting, and this also increases convenience.
The method that has beendescribed is particularly well suited
for operating a digital radio broadcast receiver. The
functionality of the-method is expanded in that a plurality of
units are combined to form a component, and a plurality of
components are combined to form a program:- In this way, an
individual program can be assembled by a selection of components,
without the need to select each individual unit. This increases
convenience when the receiver is used.
8
CA 02192958 2001-07-23
22386-2646
It is particularly useful to erase the complementary
data held in storage after expiry of the storage time that is
transmitted with this complementary data, or else overwrite
such complementary data with new complementary data that has
been received. In this manner, it is possible to make better
use of available storage space. Furthermore, it is an advantage
that after the input of a selection of units and/or a
components, only the selected units are put. into intermediate
storage in the receiver. This minimizes the amount of storage
space that is required.
In accordance with the present invention, there is
provided a method for the radio-broadcasting transmission of a
unit of digital audio data or of digital additional data
representing pictures, text, or announcements. The method
comprises the steps of: transmitting information data;
transmitting a unit identifier containing a name of the unit,
by which a user can select the unit; and transmitting a
plurality of control characters. The control characters
include: a validity period, being a period of time over which
the unit is to be stored in a receiver; a time at which the
unit is to be presented at the receiver in the event that a
user selects the unit with reference to the name of the unit;
and a period of time over which the unit is to be displayed at
the receiver.
Drawings
One embodiment of the present invention is shown in
the drawings appended hereto, and this will be described in
greater detail below. The drawings show the following:
9
CA 02192958 2001-07-23
22386-2646
Figure l: a transmission frame;
Figure 2: a fast-information group
Figure 3: a Type 2 field; and
Figure 4: a second Type 2 field;
9a
2192958
Figure 5 a thirdType 2 field;
Figure 6: a Type 1 field;
Figure 7: a program field;
Figure 8: a-component indicator;
Figure 9: a digWal receiver.
Description of the exemplary embodiment
The transmission of the data, the classification. of the
transmission channels, the manner in which the data are
transmitted, and synchronization of the data are controlled from
a superior frame protocol that is not explicitly described.
However, the overall..-transmission method is described by P.
Ratliff, "EUREKA 147 Digital Audio Broadcasting - The System for
Mobile, Portable, and Fixed Receivers," Second International
Symposium on Digital Audio Broadcasting, Toronto, Canada, March
1994, p. 294 et seq: -
219295
Other detailed explanations are contained in Pommier, "High
quality digital soundbroadcasting to mobile, portable and fixed
receivers," IEEE International Broadcasting Conference, No. 293,
Brighton, September, 1988; in ETSI, "Radio Broadcasting System;
Digital Audio Broadcasting (DAB) to mobile portable and fixed
receivers," European Telecommunications Standard Draft
prETS300401, Sophia Antipolis, January 1994; in Chambers,
J.P.,"DAB system multiplex organization," Proc. First
International Symposium on DAB, EHU, Mon~reuX;-Tune 1992, pp.
111-120; and in Le Floch, "Channel coding and modulation for
DAB," Proc. First International Symposium on DAB, EBU, Montreux,
June, 1992, pp. 99-110. ,
In this embodiment, all that will be described are the data
formats that are needed to transmit the control data. Figure 1
shows a transmission frame 1 that is used for transmitting the
data in digital radio broadcast transmission (digital audio
broadcasting, DAB). The transmission frame 1 consists of a
synchronization channel 2, a fast information channel 3, and a
main service channel 4. The transmission frame 1 consists of a
fixed number of databits. The fast information channel 3 is, in
its turn, divided into fast information blocks 5. A number of
fixed data bits are arranged in the synchronization channel and
these are used for synchronizing the transmission frame 1.
11
i, 21929J8
Information-data in the form of data frames (common interleaved
frame, CIF) 6 are transmitted in the main service channel 4.
Information data is understood to be the digital otata such as
audio-data and the digital complementary data such as image data,
audio data, or text data: The data of the=main service channel 4
are time-interleaved. The data frames 6 are individually fold
coded, with identical or different,error protection being used.
The fast information channel 3 is used to transmit information
rapidly to a receiver. In particular, the multiplex arrangement
of the main service channel 4 is transmitted by way of the fast
information channel. Additionally, the data required for
controlling the complementary data are transmitted on the fast
information-channel 3. These data are understood to include those
needed to represent the complementary data. This takes place in
the form of the fast information blocks 5. The fast information
channel 3 is not time-interleaved, and it incorporates fixed
error pratection.
The synchronization channel 2 is used within the transmission
system for basis demodulation functions, such as the
synchronization of the transmission frame 1, automatic frequency
control, channel status assessment, and for identification of the
12
~
2192g~~
sender. Each fast information block is divided into fast
information groups.
Figure 2 shows afirsf fast information group 7-that represents a
fast information-group of Type 2. The first fast information
group 7 has a header 8 that consists of a first data word 10 and
a second data word 11. The first data word 10 indicates the type
of the fast information group, in this case, Type 2. The data bit
sequence 010 is used for;this.
The fast information group 7 also has a data field 9. The second
data word 11 indicates the length of this data field 9. The data
field 9 is divided into a first data word 13, an extension field
14, and a Type 2 field The third data field 13 has a length of 4
bits and-is free for use for future applications. The extension
field 14 is 4 hits long and makes it possible to assign a
specific value to the Type 2 field.
Figure 3 shows a--first Type 2 field 12 with the extension 0,
which is to say that the character 0 is stored in the extension
field 14. The first Type 2 field 12 is divided into a program
identifier field 15, a unit identifier field 16, a first and a
second start field 17, 18; a validity field 19, a free data field
20, a transmission route field 21, and a transmission field 22.
13
212958
The program identifier field 15 indicates the program with which
the unit is associated. -The unit identifier field 16 provides an
identifier number for the unit with which the unit for which the
first Type 2 field-12is, transmitted is-uniquely characterized. A
specific bit sequence is° used as the identifier number. The first
start field 17 indicates the beginning -of the validity period of
the unit in the form of the modified Julian date. The second
start field 18 indicates the beginning of the validity period of
the unit in Coordinated Universal Time Code (UTC).
The modified. Julian date and the Coordinated Universal Time Code
are fixed and established time calculations that are described,
for example,-in "Specification of the Radio Data System (RDS),"
European Standard, EN 50067, Geneva, April 1992, Chapter 8.1.3.
It is, of course, possible to use other time calculations. The
validity field--I9 indicates the duration of the validity period
of the unit in hours,-minutes, and-seconds, calculated from the
beginning of the validity period, coded in Coordinated Universal
Time Cods (UTC). The validity period indicates how long a unit is
kept in storage: The free data field 20 remains free and
available for future. use: As a channel word, the transmission
identifier field 21 indicates the transmission channel by which
the unit is transmitted.-When this is done, for example, the data
14
2192958
bits 00 indicate a continuous data flow [stream mode) as the
transmission channel; the data bits 01 indicate a data flow that
is divided into data packets (packet mode) as the transmission
channel; 10 indicates a data flow in the form that is closely
connected with the audio: data (program associated data), and this
is transmitted in an ancillary data field based on ISO standard
1117213-as-the-~ransmissiori cTiarineI~--
The transport field 22 indicates where in the corresponding
transmission channel the particular unit is to be found. The
first Type 2 field 12 thus indicates the start time, the duration
of representation of a unit, and the transmission channel by
which the unit is transmitted.
Figure 4 shows a second Type 2 field 25 with the extension 1 that
incorporates a program field 15, a unit identifier field 16, a
third start field 23, and an attribute word 24. The program
identifier field 15 has 16 bits and indicates the program with
which the unit is associated. The unit identifier field 16 also
has 16-bits and indicates the identifier of the unit. The third
start field 23-has eight bits and provides a CIF count from which
the appropriateunitls played back or the playback of the
appropriate unit is ended. The CIF count is a counter pulse that
~1929J8
is emitted from the._.sender,and synchronized with that of the
receiver-. -:---,- _ _
The CIF count permits exact synchronization of the playback, or
the ending of the playback or a change in-the manner of playback -
of the units. The attribute word 24 also has eight bits, and by
way of playback attributes indicat~s,how the output or
representation pf the-_units_is to be-effected.-when this is done,
for example, eight null bits indicates that the playback of the
unit is ended, when a playback apparatus is set to the status
that applied to-the playback apparatus prior-to the start of
playback.
A string of seven null bits and a one bit indicates that playback
is beginning in-the form, that is optimal for the playback
apparatus. Use of the third start field 23 fixes-the time from
which a change in the type of playback is effected, and the
manner of the change-of playback of the unit is fixed by way of
the attribute word 24. _"._,
Figure 5 shows- a third Type 2 field.26 with the extension 2. The
third Type 2 fieldindicates the beginning of transmission of a
unit. The third Type 2 unit 26 has a unit identifier field 16, a
third start field 23, a length field 27, a repetition field 28, a
16
219298
free data field 20, a CRC flag 29, and a CRC field 13. The unit
identifier field 16 indicates the identifier of the unit for
which the third. Type 2 field 26 is determined. The unit
identifier field 16 has 16 bits. The third start field 23 is
eight bits long and indicates the CIF count from which the
transmission of the unit begins. The length field 27 is 32 bits
long and indicates the number of data bytes in the unit.
As an example, a free data field 20 has a length of 3 bits and is
available forfuture use: At present, for example, null bits are
transmitted in a free data field 20. The CRC flag 29 is one bit
long and indicates whether a check sum is transmitted. If a zero
bit is stored inthe CRC flag, no check sum is used. A 1 bit
indicates that a check sum is transmitted. In-this instance, for
example, a 16 bit long check sum is used and-this is based on the
following polynomial:-
G (x) = x16 + x12 + x5 + 1
ao
The check sum (cyclic redundancy check word) is stored in the CRC
field 30.
17
~
219298
A first, second, and third Type 2 field 12, 25, 26 is transmitted
for each unit. -
Figure 6 shows a Type 2 field 31 with the extension 3. The Type 2
field has a-16 bit long unit identifier field 16.-In addition,
there is a 16.~_O..bi~,long character field 32 and a 16 bit long
character flag field33. The character field-~2contains a
f
designator or a=n~me.for_. the units. designated by the unit
identifier-field lb_-~he:character.flagf~.eld 33_ contains a short
form of_the designator or of the name.
A name of a unit is transmitted with the help of the Type 2 field
31. The name--of.the unit is clearly associated with a unit by way
of the unit identifier field 16. The name can be displayed in a
receiver on a display or else enunciated through a loud speaker,
so that a user of the receiver can select the unit with the help
of the name. If only a small number of characters or letters are
available to .represent the designation, the short form that is
stored in characterflag-field 33 is displayed. A Type 2 field 31
is transmitted for.every unit.
Figure 7 shows a program field 39 that is divided into a program
identifier field 16, a number field 60, a first, a second, and a
third component field. 61., 62, and 63. The program identifier
18
2192958
field l5.indicates-~he_program; the number field 60 is 4 bits
long and indicates the number of components associated with the
program, in this instance, three. The first component group 61 is
16 bits long and contains. an identifier that clearly indicates
S the components, a designation, or a name for the component and
information to the effect that this is an~image component, i.e.,
all units that belong to..the first component 61._contain image
data.
The second component~ieLd 62 is 16 bits long and contains an
identifier that clearly shows the components, a designator, or a
name for the components, and the fact that these components are
audio data. All unitsthat belong tothe second component 62
represent audio data..
The third component field 63 is 16 bits long and contains an
identifier that clearly indicates a designator or a name for the
component and the fact that this component involves text data.
This establishes that-all units that belong to this component
contain text,datasA ,programfield 59 is transmitted for each
program. -
Figure 8 shows a coiuponeiit indicator 64 that is 24 bits long and
indicates the components to which.a unit belongs.. To this end,
19
219298
the component indicator 64 has a unit identifier field 16 that
indicates-the unit and a component date 65 that indicates the
identifier of the component to which the unit belongs. A
component indicator 64 is transmittedfor-each unit so that for
each unit it isknown to which component it belongs. This also
makes clear what type of data, e.g.,-=image data, audio data, or
text data, the units contain.
Figure 9 is a diagrammatic representation of the digital
broadcast receiver (DAB receiver). The data that is transmitted
passes from an antenna 44 to a front end 58 and from the front
end 58 to a channel decoder 32. The channel decoder 32 is
connected-by data lines 66 to a fast information decoder 33, a
data decoder 34, a PAD decoder 55, a memory 37, and to a first
audio decoder 36. An output of the fast information decoder 33 is
connected.to.a system controller 38. An output of the data
decodsr_34..is cahnected to the memory 37. In the same way, an
output of the PAD decoder 35 is cannectedto the memory 37. The
memory 37 is connected via data outputs 56 to a second audio
decoder-14, a video decoder 41, and a text decoder 42.
An output of the second audio decoder 40, an output of the video
decoder 41, an output of the text decoder 42 and an output of the
first audio decoder 36 are connected with inputs of a multimedia
219298
terminal 43. The system controller 38 is connected by a first
control line 49 to the channel decoder.32, through a second
control line 45 to the fast information decoder 33, through a
third control line 46 to the data decoder..34, through a fourth
control line 47 with the PAD decoder 35, and through a fifth
control line 48 with the first audio decoder 36.
In addition, the system controller 38 is connected by a seventh
control line 51 with the second audio decoder 40, by an eighth
control line 52 to the video decoder41, and by a ninth control
line 53 to the text decoder 42. In addition, a control and data
connection 54 runs from the system control-ler 38 to the
multimedia terminal-43. Control-and data signals are exchanged
between the system controller 38 and the multimedia terminal 43
by way of the control and data line 54. The system controller 30
is connected through a tenth control line 55 with the memory 37.
The method for transmitting digital data and digital
complementary data will be described below using the transmission
of a digital radiobroadcast program as an example. This method
can also be used for other digital data transmission systems such
as television transmission. In the digital radio broadcast
program that is-described, audio datais transmitted as digital
data and images and/or audio dataand/or text or any other forms
21
219298
of data are transmitted as digital complementary data, the data
formats shown in Figure 1 to Figure 8 being used for transmission
of the data. Other data formats can also be used, depending on
the particular transmission method.
The transmission of the-data and of the complementary data is
effected in the transmission frame d . When this is done, the data
and the complementary data itself are transmitted in the main
service channel 4 that is divided into the data frames 6 (CIF).
The control data that are required to represent the complementary
data are transmitted in the fast information channel 3, which is
divided into fast information blocks 5. The control data are the
control data that are shown in Figure 2 to Figure 8.
A program that is transmitted consists of various components that
are divided into time and/or content units. The components are
represented by music; images, or text units. The components are
divided into units in accordance with preset time intervals.
Thus, it is possible that a program consist of a music components
that in its turn is divided into a plurality of music units, a
music unit representing a time section of a piece of music, for
example. In addition, the same program has an image component
that is also diuided into a plurality of image units that
represent one and the same image in different forms, or different
22
~~~~958
images. In-addition, a third component, a text component, is an
element of the program, and this is also divided into text units.
The text units can represent different texts or parts of a text,
for example.
S
The division of-the components can also be used to distinguish
between complementary data with respect to content; as an
example, news can be divided into political news, sports news, or
economic-news segments which are, in each instance, associated
with different components.
In the simplest case, an identifier for the unit is transmitted
for each unit that is transmitted. This means that each unit can
be unmistakablyidentified. In addition, the CIF count is
transmitted for every unit, and this indicates when the unit is
output. The transmission 'of a designator for the unit is
necessary in order to inform a user of a sender which units can
be selected.
In an impraved method, for every unit there is an indication as
to the time at which the validity period of the unit begins. In
addition, the duration of the validity period is also transmitted
at the beginning-of the validity period. The validity period
23
2192 i8
indicates the point in time at which the units is stored in the
memory 37 of a receiusr:-
A further addition during the transmission of the unit provides
information as to the transmission channel by which the unit is
transmitted, and where within the transmission channel the data
for the units are--to be found
The first Type 2 field 12 shown in Figure-3 is used to transmit
the program identifier, the identifier of the unit, the beginning
and the data of the validity period, the transmission channel,
and the location in which the unit is transmitted within the
transmission channel.
In addition, the beginning and the end of the playback of a unit
within the validity period is transmitted in the second Type 2
field 25 that is shown in Figure 4. To this end, the program
identifier, the identifier of the unit, and the CIF count that
indicates the time from which the playback is to begin or end,
and the playback attributes are also transmitted.
In this way, a receiver is kept informed by the playback
attributes as to whether the playback is to begin or end, and how
the playback is to be effected. When this is done, the beginning
24
2192958
of a playback or the end-of-the playback is indicated by the CIF
count. The manner in which the playback is to be effected is
established by the playback attributes. For example, in the case
of images, the size of the image section, the resolution, the
selected colour err, in the case of text output, for example, the
size of-the text, or-in the case of speech output, the volume,
can be established, for example.
In addition to the information described above, other information
with respect to the transmission of a unit is transmitted. This
is done in the third Type 2 field 26, as is shown in Figure 9. By
providing the identifier.of the-unit and the CIF count, the
length of the unit, the number of repetitions of the transmission
of the unit, and information as to whether a check sum is also
transmitted, as well as the check sum itself, are transmitted.
In this way, a receiver obtains information as to when the
transmission of the corresponding unit begins (CIF count), the
length of the unit data field, whether and how many repetitions
of the transmissions of the unit follow, and whether or not a
check sum, and which check sum, has been transmitted. In this
way, a receiver has the possibility of filtering out the
transmission of the unit or, in the case bf an incorrect
transmission, receiving the repetition-of-the transmission of the
~1~~958
unit and evaluating the check sum to check for error-free
transmission by evaluating the check sum.
In addition to the data described above, a designator or a name
for every unit is also transmitted. This is effected by way of
the Type 2 field 31 that is shown in Figure 6. The name or an
abbreviation for the name of the unit is transmitted with the
help of an alphabetic field 32 and an alphabetic flag field 33,-
when quoting the identifier of the unit.
The data that are shown in Figure 2 to Figure 8 are transmitted
on the fast information channel 3.The data of the unit itself
are transmitted on the main service channel 4, within the data
frame 6. The transmission is so configured that the control data
that belong to the units.of the data that are transmitted on the
fast information channel 3 are transmitted prior to transmission
of the data of the units and are thus available to a receiver in
a timely manner.
In order to provide for more convenient use of the receiver, a
plurality of units are combined to form a component. This is
effected by the transmission of a component indicator 64 for each
unit; this provides information as to the component to which the
unit belongs. In addition, a plurality of-components are combined
26
2192958
to form a program and a program field is-transmitted, this
indicating which components belong to the program and which type
of data the units of the components contain. Since an indicator
for every component is transmitted with the component field, both
the components and the units can be displayed in the receiver, by
displaying the designator of the components or of the unit for
selection.
The method of playing back digital data and digital complementary
data will be described below on the basis of the digital radio
broadcast receiver that is shown diagrammatically in Figure 9.
The method that is described can-also be used for any digital
receiver_ A receiver as 'shown in Figure 9 receives channel-coded
data and complementary data by way of an antenna 44. The data and
complementary data are converted by a front end 58 into digital
data and digital complementary data. Then the data and the
complementary data are passed to a channel decoder 32. The
channel decoder32 decodes the control data that is stored in the
fast information channel 3 and sends this to the fast information
decoder 33. The-fast-information decoder 53 decodes this control
data and passes it onto the system controller 38. Thus, the
system controller 38is informed of an identifier for the unit,
the program to which-theunit is associated, the validity period,
and the transmission channel for each unit. In addition, the
27
~
219295
system controller is alsb informed as to the CIF count from which
the playback of-the-unit--isto begin-or-end. In addition, the
system controller is-informed by way of the playback attributes
as to how the unit is to be represented by way of the playback
attributes.
In addition, there is information as to when the transmission of
the unit begins, the length of the-unit, whether or not there
will be a repetition of the transmission of the unit and whether
or not or which check sum is transmitted. In addition, a name for
each unit is passed to the system controller 38.-In addition, the
system controller 38 also receives information as to which
components are combined to form a program, which type of data is
contained in the components, and which units belong to which
components. In addition, a designator or a name is received for
each component. The-system controller compilers a table in which
the control data required to receive and/or select and/or output
the units or components are stored.
The channel decoder 32 decodes the transmission channel by which
the digital data are transmitted in the form of audio data and
passes this to the first audio decoder 36.
28
219295
In this embodiment, three different transmission channels are
used to transmit the complementary data in the form of units.
However, other and more or fewer transmission channels can be
used. In the first instance, the data are transmitted in the form
of a serial data flow; in the second inst-ance, the data are
transmitted in packets; and in the third-instance, the data are
transmitted in-the form of data 1 that are closely linked with
the audiodata (program associated data) and which are
transmitted in an ancillary data field based on ISO-standard
11172/3. Further details are described in P. Ratliff, "EUREKA 147
Digital Audio Broadcasting - The System for Mobile, Portable and
Fixed Receivers," Second International Symposium on Digital Audio
Broadcasting, Toronto, Canada, March 1994, pp.294 et seq.
Three decoders for the three different types of transmission are
arranged within the receiver. The channel decoder 32 for the
serial data, the data decoder 34 for the data that is transmitted
in packets, and the PAD decoder 35 for the data that are
transmitted in the ancillary data field. The decoders 32, 34, 35
can be controlled from the system controller 38. The decoders 32,
33, 34, -and 35 are so configured that the data of the
corresponding transmission-channels are decoded.
29
2192958
Since the system controller 38 has the information as to the
particular transmissiom.~channel by which the units are to be
transmitted and at whicnli time, the system controller 38 switches
the channel decoder 32 to the appropriate channel, so that the
channel decoder_32 then reads the channel decoded complementary
data either to the data decoder 34 or to the PAD decoder 35 or
decodes it directly and reads it into the memory 37. The channel
coded-control data are passed on after triggering from the system
controller 38 from the channel decoder 32 to the FIC decoder 33.
The data decoder 34 and the PAD decoder 35 decode the
complementary data aid read the decoded complementary data into
the memory 37. The system controller-38 is connected by the tenth
control line 55 to the memory 37, so that read-in of the decoded
complementary data from the system can additionally be controlled
by the system controller via a write line.
The system controller 38 compiles the table which contains
information as to which units belong to which components and
which components belong to which programs. In addition, the
designators for-each unit and for each component of also stored
in the table. In addition, the table also contains the validity
periods of the units, so that storage of the complementary data
that represent the data of the units in the memory 37 is only
219958
effected for the validity period. After the expiration of the
validity period, the unit is erased on a selective basis, or the
unit is overwritten with-data of a new unit once the validity
period has expired. -
The system controller 38 indicates the designator or names of the
units and/or the components by way of the multimedia terminal 43.
The multimedia terminal has an optical and/or acoustic display
and also has akeyboard for inputting numbers and/or letters
and/or a name or a designator by way of a speech computer for
acoustic input.
A user of the receiver selects which components or units of a
program are to be output by inputting the designator or the name
using the multimedia terminal 43. This information is passed on
to the system controller 38. According to the data supplied by
the user, the system controller 38 reads the selected units out
from the memory 37 and, depending on the type of unit data of the
unit, i.e.;-whether it is audio data, video data, or text data,
passes it onto the second audio decoder 40, to the video decoder
41, or to the text decoder 42. The audio decoder 40, the video
decoder 41, and the text decoder 42 are controlled in the
appropriate manner from the system controller 38 and convert the
digital complementary data into analog signals.
31
2192958
The data of the units or-of the components are passed on to the
multimedia terminal 43. The multimedia terminal 43 is similarly
controlled from the system controller 38. Playback of the data of
the units or components in the form of audio data and/or video
data and/or text data is. effected with the help of the multimedia
terminal 43. The units are output in keeping with the control
data that is also transmitted.
The multimedia terminal 43 passes information to the system
controller 38 on the control and data line 54 and this data
indicates which playback, e.g., image, speech, or text, is
possible, so that the system controller 3-8 only passes on the
units that can also- be output to the multimedia terminal.
The digital data that have been transmitted, in this case, the
audio data decoded by the first audio decoder 36, are always
received or are received limited by time depending on the
triggering of the system cantroller 38, and are output by way of
the multimedia terminal 43.
-
The method that hasbeen proposed makes it possible to designate
all components of a program, for example,-and output other
components during each playback.
32
