Digital Audio Broadcasting (DAB); Multimedia Object Transfer (MOT) protocol

Specification of the DAB Multimedia Object Transfer (MOT) protocol.

Digitalna zvokovna radiodifuzija (DAB) - Protokol za prenos multimedijskih objektov (MOT)

General Information

Status
Published
Publication Date
30-Jun-2005
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Jul-2005
Due Date
01-Jul-2005
Completion Date
01-Jul-2005
Mandate

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SLOVENSKI STANDARD
SIST EN 301 234 V1.1.1:2005
01-julij-2005
Digitalna zvokovna radiodifuzija (DAB) - Protokol za prenos multimedijskih
objektov (MOT)
Digital Audio Broadcasting (DAB); Multimedia Object Transfer (MOT) protocol
Ta slovenski standard je istoveten z: EN 301 234 Version 1.1.1
ICS:
33.170 Televizijska in radijska Television and radio
difuzija broadcasting
SIST EN 301 234 V1.1.1:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 301 234 V1.1.1:2005

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SIST EN 301 234 V1.1.1:2005
EN 301 234 V1.1.1 (1998-01)
European Standard (Telecommunications series)
Digital Audio Broadcasting (DAB);
Multimedia Object Transfer (MOT) protocol
European Broadcasting Union Union Européenne de Radio-Télévision
EBU
UER
European Telecommunications Standards Institute

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SIST EN 301 234 V1.1.1:2005
2 EN 301 234 V1.1.1 (1998-01)
Reference
DEN/JTC-DAB-MOT (bfc00ico.PDF)
Keywords
DAB, digital, audio, broadcasting, multimedia,
protocol
ETSI Secretariat
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Copyright Notification
No part may be reproduced except as authorized by written permission.
The copyright and the foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1998.
© European Broadcasting Union 1998.
All rights reserved.

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SIST EN 301 234 V1.1.1:2005
3 EN 301 234 V1.1.1 (1998-01)
Contents
Intellectual Property Rights.4
Foreword .4
1 Scope.5
2 Normative references .5
3 Definitions and abbreviations .7
3.1 Definitions . 7
3.2 Abbreviations. 8
4 General description of the MOT protocol.9
4.1 Requirements of Multimedia services. 9
4.2 Problems MOT is attempting to solve . 9
4.3 Receiver architecture reference model. 10
5 Object description .11
5.1 Header core. 11
5.2 Header extension. 12
5.2.1 Structure of the header extension . 13
5.2.2 Future expansion of the parameter data field . 14
5.2.3 Parameters of the header extension . 14
5.3 Object body. 16
6 Object transport mechanisms.17
6.1 Segmentation of objects - transport level. 18
6.1.1 Segmentation header . 19
6.1.2 Transport of header segments. 19
6.1.3 Transport of body segments . 19
6.2 Packetizing segments - network level . 20
6.2.1 Packet mode . 20
6.2.2 X-PAD . 20
6.2.2.1 Indication of the Data Group Length. 20
6.3 Different methods of transferring MOT objects. 22
6.3.1 Repetition on object level. 22
6.3.2 Insertion of additional header information . 23
6.3.3 Interleaving objects in one MOT stream . 23
6.3.4 Repetition of Data Groups/segments. 24
7 Updating.24
7.1 Object update. 24
7.2 Updating header information/triggering objects . 24
7.2.1 Triggering an object . 25
7.2.2 Deletion of an object . 25
History.26

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SIST EN 301 234 V1.1.1:2005
4 EN 301 234 V1.1.1 (1998-01)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETR 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in respect of
ETSI standards", which is available free of charge from the ETSI Secretariat. Latest updates are available on the ETSI
Web server (http://www.etsi.fr/ipr).
Pursuant to the ETSI Interim IPR Policy, no investigation, including IPR searches, has been carried out by ETSI.
No guarantee can be given as to the existence of other IPRs not referenced in ETR 314 (or the updates on
http://www.etsi.fr/ipr) which are, or may be, or may become, essential to the present document.
Foreword
This European Standard (Telecommunications series) has been produced by the Joint Technical Committee (JTC) of the
European Broadcasting Union (EBU), Comité Européen de Normalisation ELECtrotechnique (CENELEC) and the
European Telecommunications Standards Institute (ETSI).
NOTE 1: The EBU/ETSI JTC was established in 1990 to co-ordinate the drafting of standards in the specific field
of broadcasting and related fields. Since 1995 the JTC became a tripartite body by including in the
Memorandum of Understanding also CENELEC, which is responsible for the standardization of radio and
television receivers. The EBU is a professional association of broadcasting organizations whose work
includes the co-ordination of its members' activities in the technical, legal, programme-making and
programme-exchange domains. The EBU has active members in about 60 countries in the European
broadcasting area; its headquarters is in Geneva *.
* European Broadcasting Union
CH-1218 GRAND SACONNEX (Geneva)
Switzerland
Tel: +41 22 717 21 11
Fax: +41 22 717 24 81
The DAB system is a novel sound broadcasting system intended to supersede the existing analogue amplitude and
frequency modulation systems. It is a rugged, yet highly spectrum and power efficient sound and data broadcasting
system. It has been designed for terrestrial and satellite as well as for hybrid and mixed delivery. The DAB system has
been publicly demonstrated on a number of occasions during its development. It has been subject to extensive field tests
and computer simulations in Europe and elsewhere. In 1995, the European DAB forum (EuroDab) was established to
pursue the introduction of DAB services in a concerted manner world-wide, and it became the World DAB forum
(World DAB) in 1997.
NOTE 2: DAB is a registered trademark owned by one of the Eureka 147 partners.
National transposition dates
Date of adoption of this EN: 5 December 1997
Date of latest announcement of this EN (doa): 30 April 1998
Date of latest publication of new National Standard
or endorsement of this EN (dop/e): 31 October 1998
Date of withdrawal of any conflicting National Standard (dow): 31 October 1998

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SIST EN 301 234 V1.1.1:2005
5 EN 301 234 V1.1.1 (1998-01)
1 Scope
The present document specifies a transmission protocol, which allows to broadcast various kinds of data using the
Digital Audio Broadcasting (DAB) system. It is tailored to the needs of Multimedia services and the specific constraints
given by the broadcasting characteristics of the DAB system. After reception this data can be processed and presented to
the user.
The present document defines the transport specific encoding for data types not specified in ETS 300 401 [1] according
to the transport mechanisms provided by DAB. It allows a flexible utilization of the data channels incorporated in the
DAB system, as well as methods to manage and maintain a reliable transmission in a uni-directional broadcast
environment. Provisions are also made for the creation and presentation of advanced Multimedia services using formats
such as Hyper Text Markup Language (HTML) (see RFC 1866 [3]) or Multimedia and Hypermedia information coding
Experts Group (MHEG) (see ISO/IEC CD 13522 [4]).
The present document describes the core transport protocol. Subsequent parts or revisions of the present document will
describe backwards compatible extensions.
Aspects related to the further decoding and processing of the data objects carried are outside the scope of the present
document. Hardware or software implementation considerations are not covered.
2 Normative references
References may be made to:
a) specific versions of publications (identified by date of publication, edition number, version number, etc.), in
which case, subsequent revisions to the referenced document do not apply; or
b) all versions up to and including the identified version (identified by "up to and including" before the version
identity); or
c) all versions subsequent to and including the identified version (identified by "onwards" following the version
identity); or
d) publications without mention of a specific version, in which case the latest version applies.
A non-specific reference to an ETS shall also be taken to refer to later versions published as an EN with the same
number.
[1] ETS 300 401: "Radio broadcasting systems; Digital Audio Broadcasting (DAB) to mobile,
portable and fixed receivers".
[2] Sun Microsystems (1994, 1995): "The Java Language: A White Paper". Called "Java" in the
present document.
[3] RFC 1866 (November 1995): "Hyper Text Markup Language (HTML) Specification-2.0",
T. Berners-Lee, D. Connolly; MIT/LCS onwards.
[4] ISO/IEC CD 13522: "Information Technology - Coding of Multimedia and Hypermedia
Information", ISO/IEC JTC1/SC29 - Multimedia and Hypermedia information coding Experts
Group (MHEG).
[5] ISO DIS 10918: "Digital Compression and Coding of Continuous-tone Still Images", Joint
Photographers Experts Group (JPEG).
[6] ISO-8859-1 (1987): "International Standard; Information Processing; 8-bit Single-Byte Coded
Graphic Character Sets; Part 1: Latin alphabet No. 1".
[7] ISO-8859-2 (1987): "International Standard; Information Processing; 8-bit Single-Byte Coded
Graphic Character Sets; Part 2: Latin alphabet No. 2".

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SIST EN 301 234 V1.1.1:2005
6 EN 301 234 V1.1.1 (1998-01)
[8] RFC 1521 (September 1993): "MIME (Multipurpose Internet Mail Extensions)
Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies",
N. Borenstein, N. Freed.
[9] RFC 1945 (May 1996): "Hypertext Transfer Protocol – HTTP/1.0", T. Berners-Lee, R. Fielding,
H. Nielsen.
rd
[10] ISO/IEC 646, 3 edition (1991): "Information Technology - ISO 7-bit coded character set for
information interchange".
[11] © CompuServe, Incorporated (June 15, 1987): "GIF ™, Graphics Interchange Format ™":
A standard defining a mechanism for the storage and transmission of raster-based graphics
information".
[12] BMP: "Device-independent bitmap format used as default graphics file format for Microsoft
Windows".
[13] ISO/IEC 11172-3 (March 1993): "Coding of Moving Pictures and Associated Audio for Digital
Storage Media at up to 1,5 Mbit/s - Audio Part".
[14] ISO/IEC 13818-3 (November 1994): Generic coding of moving pictures and associated audio -
Audio part".
[15] ITU-T Recommendation G.711: "Pulse Code Modulation (PCM) of voice frequencies".
[16] Apple Computer, Incorporated: "Audio Interchange File Format (AIFF): A Standard for Samples
Sound Files".
[17] Sony: "Adaptive Transform Acoustic Coding".
[18] Sony: "Adaptive Transform Acoustic Coding II".
[19] ISO/IEC 14496-3 (Working Draft): "Very Low Bitrate Audio-Visual Coding".
[20] ISO/IEC 11172-2 (March 1993): "Coding of Moving Pictures and Associated Audio for Digital
Storage Media at up to 1,5 Mbit/s - Video Part".
[21] ISO/IEC 13818-2 (November 1994): Generic coding of moving pictures and associated audio -
Video part". It is also standardised by ITU-T as Recommendation H.262.
[22] ISO/IEC 14496-2 (Working Draft): "Very Low Bitrate Audio-Visual Coding".
[23] ITU-T Recommendation H.263: "Video Coding for Low Bitrate Communication".
[24] ISO 7498 (1984): "Open Systems Interconnection (OSI) Basic Reference Model".
[25] EN 50067: "Specification of the Radio Data System (RDS) for VHF/FM broadcasting in the
frequency range from 87,5 to 108,0 MHz".

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SIST EN 301 234 V1.1.1:2005
7 EN 301 234 V1.1.1 (1998-01)
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following definitions apply:
body: The body carries any kind of data, where structure and content of the data are described in the header.
byte ordering: All numeric values using more than one byte have to be coded in Big Endian Format (most significant
byte first). In all schematics the bits are ordered with the most significant bit of a byte ("b7") at the left end and least
significant bit ("b0") at the right end of the drawing.
Conditional Access (CA): A mechanism by which user access to service components can be restricted.
DAB receiver: The Multimedia Object Transfer (MOT) specific definition of a DAB receiver includes decoding of the
DAB signal and resolving the multiplex structure of the main service channel.
data channels: The data channels in DAB (packet mode, X-PAD) provide the functionality on the transport layer in
order to convey the objects.
data decoder: The data decoder processes the MOT data stream and applies both packet mode/X-PAD specific
decoding and then MOT decoding.
ensemble: The transmitted signal, comprising a set of regularly and closely-spaced orthogonal carriers. The ensemble is
the entity which is received and processed. In general, it contains programme and data services.
eXtended Programme Associated Data (X-PAD): The extended part of the PAD carried towards the end of the DAB
audio frame, immediately before the scale factor Cyclic Redundancy Check (CRC). It is used to transport information
together with an audio stream which is related or synchronized to the X-PAD. No provisions for error detection are
included in X-PAD so that additional protocols are required for some applications.
Fast Information Channel (FIC): A part of the transmission frame, comprising the Fast Information Blocks (FIB),
which contains the multiplex configuration information together with optional service information and data service
components.
header: The header consists of the header core and the header extension.
header core: The header core contains information about the size and the content of the object, so that the receiver can
determine whether it has system resources to decode and present the object or not.
header extension: The header extension includes additional information about the body.
Main Service Channel (MSC): A channel which occupies the major part of the transmission frame and which carries
all the digital audio service components, together with possible supporting and additional data service components.
MOT data service: A data service comprises information which is intended to be presented to a user, i.e. text, pictures,
video or audio sequences. An application decoder is required to gain access to the data. This might be a viewer which
decodes text and pictures and displays them on a screen. It might also be a Multimedia engine which manages various
inputs and outputs a number of different audio-visual media synchronously. In terms of MOT a data services consists of
one or an ordered collection of several objects. It is not in the scope of MOT to deal with the content of the object, but
to carry information to support both presentation and handling of these objects.
MOT object: A MOT object is used to transfer data in DAB, the object contains a header and a body carrying the
payload.
MOT stream: One stream of MOT objects is transferred in an individual service component (packet mode) or as part of
the X-PAD of a programme service, where several MOT objects might be conveyed in parallel by interleaving.

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SIST EN 301 234 V1.1.1:2005
8 EN 301 234 V1.1.1 (1998-01)
packet mode: The mode of data transmission in which data are carried in addressable blocks called packets. Packets are
used to convey MSC Data Groups within a sub-channel. The packet mode carries the load in packets of a certain size,
separating different streams of packets by specific addresses. Error detection and repetition are already covered by
packet mode and thus allow a reliable and flexible data transmission.
Programme Associated Data (PAD): Information which is related to the audio data in terms of content and
synchronization. The PAD field is located at the end of the DAB audio frame.
service: The user-selectable output which can be either a programme service or a data service.
service component: A part of a service which carries either audio (including PAD) or data. The service components of
a given service are linked together by the Multiplex Configuration Information (MCI). Each service component is
carried either in a sub-channel or in the Fast Information Data Channel (FIDC).
service label: Alphanumeric characters associated with a particular service and intended for display in a receiver.
transportId: This 16-bit field shall uniquely identify one data object (file and header information) from a stream of
such objects. It shall be used to indicate the object to which the information carried in the segment belongs or relates. It
is valid only during the transport time of the object.
transport time: The transport time is the entire duration which is needed to transfer a MOT object completely
(including all repetitions), i.e. the time during which a particular TransportId is valid for one MOT object.
X-PAD Data Group: A package of data for carrying one segment of an MOT object in the Extended Programme
Associated Data (X-PAD).
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
AIFF Audio Interchange File Format
ASCII American Standard Code for Information Interchange
ATRAC Adaptive Transform Acoustic Coding
BMP Windows Bitmap
CA Conditional Access
CRC Cyclic Redundancy Check
DAB Digital Audio Broadcasting
ECM Entitlement Checking Message
EMM Entitlement Management Message
ETS European Telecommunication Standard
FFT Fast Fourier Transform
FIB Fast Information Block
FIC Fast Information Channel
FIDC Fast Information Data Channel
GIF Graphics Interchange Format
HF High Frequency
HTML Hyper Text Markup Language
HTTP Hyper Text Transfer Protocol
JFIF JPEG File Interchange Format
JPEG Joint Photographic Experts Group
MCI Multiplex Configuration Information
MHEG Multimedia and Hypermedia information coding Experts Group
MIME Multipurpose Internet Mail Extensions
MJD Modified Julian Date
MOT Multimedia Object Transfer
MPEG Moving Pictures Expert Group
MSC Main Service Channel
PAD Programme Associated Data
PCM Pulse Code Modulation
PLI Parameter Length Indicator
Rfa Reserved for future addition
Rfu Reserved for future use

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SIST EN 301 234 V1.1.1:2005
9 EN 301 234 V1.1.1 (1998-01)
UTC Universal Time Co-ordinated
X-PAD Extended Programme Associated Data
4 General description of the MOT protocol
4.1 Requirements of Multimedia services
Multimedia in general can be referred to as information and its presentation in various formats (visible, audible, etc.)
and forms (text, pictures, video, etc.). The material is often structured and packaged into a number of containers or files
which shall be either completely available before the presentation or are delivered on request of the user.
Multimedia services require to control the presentation (e.g. the arrangement of visible information on a screen) and
therefore direct access to both hardware and software resources of the receiver/terminal is essential. The appropriate
time shall also be considered for the presentation. Thus it is required to synchronize the various elements (e.g. video
together with the sound), i.e. some kind of a runtime environment is necessary.
4.2 Problems MOT is attempting to solve
The MOT protocol is a data transport protocol specified to provide facilities for the transportation of Multimedia objects
in the DAB system. These objects can consist of:
- self-contained Multimedia objects, such as:
- MHEG (see ISO/IEC CD 13522 [4]); and
- Java [2]; or
- actual files containing for example:
- JPEG pictures (see ISO DIS 10918 [5]);
- American Standard Code for Information Interchange (ASCII) text;
- Moving Pictures Expert Group (MPEG) video or audio sequences.
For transmission of Multimedia objects, the protocol provides the means to use the following data channels of the DAB
system:
- PAD; and
- Packet Mode.
Session layer
Transport layer Packet Mode/X-PAD
Network layer Packets/X-PAD subfields
Figure 1: Target for the MOT protocol
MOT interconnects the closed and well defined world of DAB to the open world of Multimedia services with its large
variety of systems and data formats. It comprises functionality to carry information to the terminal, respectively the user.
MOT does not cover issues specific to runtime environments to control Multimedia services, i.e. the interpretation and
execution of object code, pseudo code or script languages. This shall be included in the particular application.

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SIST EN 301 234 V1.1.1:2005
10 EN 301 234 V1.1.1 (1998-01)
4.3 Receiver architecture reference model
An example decoding process for MOT objects is shown in figure 2 (data flow top-down).
ETS 300 401
HF Part
FFT, Demux,
Channel Decoder
PAD stripping
XPAD subfield Packet
PAD Decoder Packet Mode Decoder
Data Group Data Group
MOT Decoder
Object data Additional information
Audio Decoder
Application
Multimedia
terminal
speaker
Figure 2: Example scheme for the data decoding part of a DAB receiver
Additional information: Additional information is carried in the MOT header. It is decoded by the MOT decoder and
forwarded.
Object data: Object data is carried in the MOT body.
Parts within the grey background (HF part, FFT/demux/channel decoder, PAD stripping, PAD decoder, packet mode
decoder and audio decoder) are defined in ETS 300 401 [1]).
Interface to the MOT decoder: Communication between PAD/packet mode decoder and MOT decoder uses complete
Main Service Channel (MSC) Data Groups (see ETS 300 401 [1]). The session header of a Data Group cannot be
omitted, although it is optional in the DAB specification, since it carries the TransportId, which is necessary to
reassemble the MOT objects.
Presentation Decoding process

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SIST EN 301 234 V1.1.1:2005
11 EN 301 234 V1.1.1 (1998-01)
5 Object description
An object consists of an ordered collection of the following three parts (see figure 3):
header core: The header core contains information about the size and the content of the object, so that the receiver can
determine whether it has system resources to decode and present the object or not.
header extension: The header extension includes information that supports the handling of the objects (e.g. memory
handling) and provides additional information that can support an application.
body: The body carries any kind of data, where structure and content of the data is described in the header core and the
header extension.
For transportation the object is split into several segments, at least one header segment and, if present, one body
segment. Each segment is mapped into one Data Group as described in clause 6.
The header is separated from the body during transportation in order to:
- have the possibility to repeat the header several times before and during the transmission of the body (which is
useful when transmitting long objects);
- send the header in advance in order to give the receiver the opportunity to "be prepared in advance" to the data
that is going to be received;
- send the header unscrambled when the body is scrambled.
7 bytes variable variable
header core header extension object body
Figure 3: General object structure
The header shall be sent at least once preceding the body of the object.
5.1 Header core
The header core shall be coded as shown in figure 4:
28 bits 13 bits 6 bits 9 bits
body size header size content type content subtype
b b b b b b b b
55 28 27 15 14 9 8 0
Figure 4: Structure of the header core
body size: This 28-bit field, coded as an unsigned binary number, indicates the total size of the body in bytes. The body
size all ones "FFFFFFF" (hexadecimal notation) indicates unknown size (at the beginning of the transmission).
header size: This 13-bit field, coded as an unsigned binary number, indicates the total size of the header in bytes.
content type: This 6-bit field indicates the main category of the body's content (see table 1). All other codes are
reserved for future use.
content subtype: This 9-bit field indicates the exact type of the body's content depending on the value of the field
ContentType (see table 1). All other codes are reserved for future use.

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SIST EN 301 234 V1.1.1:2005
12 EN 301 234 V1.1.1 (1998-01)
Table 1: Content types and content subtypes
content type interpretation content subtype interpretation
b b b b
14 9 8 0
000000 general data 000000000 Object Transfer
000000001 MIME/HTTP [8], [9]
000001 text 000000000 Text (US ASCII) [10]
000000001 Text (see ISO Latin 1) [6]
000000010 HTML [3]
000010 image 000000000 GIF [11]
000000001 JFIF [5]
000000010 BMP [12]
000011 audio 000000000 MPEG I audio Layer I [13]
000000001 MPEG I audio Layer II [13]
000000010 MPEG I audio Layer III [13]
000000011 MPEG II audio Layer I [14]
000000100 MPEG II audio Layer II [14]
000000101 MPEG II audio Layer III [14]
...

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