Standards Australia – CT2/A Project No. CT2/002-0210

Standards Australia – CT2/A Project No. CT2/002-0210
Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
DRAFT
Guideline Requirements for
Digital Television Receivers
to Operate with Australian
VHF/UHF DVB-T Transmissions
Including Interoperability Considerations for
Cable and Satellite DTV Services
Contents
Objectives
Scope
Overview
Table of Requirements
Annex-A: Notional Receiver
Annex-B: References
Annex-C: Glossary and Abbreviations
Annex-E: Typical Receiver Block Diagram
Annex-F: Reception Quality OSD Meter
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Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
Objective
This document is a set of essential requirements for Australian DVB-T receivers and includes high definition
video, AC3 audio and other options and recommended implementations. Interoperability guidelines for satellite
and cable operation are also included.
Scope
The reception equipment will be considered in a range of forms and classes.
Low cost
Limited Facility
Premium
Full facility
Modular Equipment
Units1
Integrated Receiver
with Display
Typically: Low cost, may
operate with existing
4:3PAL TV; single tuner,
S-Video, PAL b/band &
RF o/p; Mono or stereo
audio output; CA Card
Small TVs for kitchen etc,
Portable TVs; single tuner;
may have 16:9 display;
HD may be displayed in
SD; single or dual
speakers;
CA Card
Range é ê
range é ê
May have RGB, HD out
may feed hi-quality 16:9
display; internal storage
Data & IEEE-1394A port;
CA Card(s); Modem
may have inbuilt DVD
Typically
Hi-quality 16:9 display;
HD display & may have
line doubling for SD
input; PIP; Digital & PAL
tuner;
Data & IEEE-1394 port;
CA Card(s); Modem
The table above serves to illustrate the range of facilities that a manufacturer may choose to include in
various models to satisfy various market needs.
1
Modular equipment may be Set-top box style Integrated-Receiver-Decoders or plug-in PC card tunerdecoders.
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Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
Overview
Digital terrestrial television broadcasting (DTTB) based on the DVB-T system has been adopted for Australia.
Previous implementations of digital television systems around the world operated on pay satellite and cable
systems where compatibility between transmission and reception equipment is generally under the control of a
single system operator.
With no single operator in control, there will be multiple free-to-air services and multiple receiver/decoder
manufacturers. Consumers will expect a choice of reception equipment from many manufacturers and this
equipment will be expected to satisfactorily receive broadcasts from a choice of multiple broadcasters, (each
probably using different brand of encoding and transmission equipment).
The international ETSI, IEC/ISO, ITU-R and DVB documents, and Australian Standards (see list attached,)
detail the various specifications for the Australian implementation of the DVB-T digital television broadcasting
system. These documents give the general operating parameters for receiving equipment.
However there are Australian specific details and unique items about which manufacturers and suppliers need
to be aware.
In general, it will be the manufacturer’s choice of how their receiver operates over a variety of conditions and
their interface through the on-screen display and remote control. These could be in reaction to SI data present
in the received transport stream or the action of changing channels.
Nevertheless it should prove valuable to list some of these conditions and note the expected operation of the
receiver to clarify the intent of the standards or provide guidance where no clear standard applies.
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Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
Table of Guidelines for Operation of DTV Reception Equipment
The details listed in the tables below are based on the Australian adaption of the DVB-T standards for digital television terrestrial transmissions and are for the guidance of
manufacturers and suppliers of Australian DTTB consumer equipment. The Cable and Sat(ellite) columns are shown in the interest of interoperability.
Readers are advised that Section 1 is an overview and that reference should be made to the sections following for more complete detail.
LC-STB:
FF-STB:
Low cost Modular Equipment
Full facility Modular Equipment
LC-Rx:
FF-Rx:
Low cost integrated receiver
Full facility integrated receiver
ITEM
1.0
NA
O
R
E
Not Applicable
Optional
DTTB
Recommended (should be available)
Essential to operate on all services
Cable
COFDM
Cable QAM
Sat QPSK
Digital terrestrial TV broadcast
Note: This is not a DVB standard and is
included for comment only.
Per DVB-C
Per DVB-S
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
Cable
C
Cable
Sat
OFDM QAM QPSK
Broadcasts can be assumed to be DVB compliant within the
Australian context including video MP@HL and audio AC3
additions.
Basic Features
Further detail can be found in
following sections.
1.10
RF to Transport Stream
E
E
E
E To DVB-T standard with basic Australian requirements
1.21
Digital Tuner VHF-UHF
E
E
E
E Input per AS/NZ standard
1.22
Receive capability for Analogue PAL
O
O
O
R For integrated receivers operating in areas where PAL services not
yet duplicated on digital
1.23
Digital Receiver Noise Figure2
R
R
R
R VHF / UHF Bands III, IV & V; better than 6dB, 7dB & 8dB
respectively
1.24
Australian tuning table3
E
E
E
E Tuning to cover VHF and UHF; also S-Channels
TR 101 190
E
E
R
AS (TBA) See
Note
E
2
Receiver noise figures are those of a “notional receiver”. The noise figure performance is measured at the receiver’s aerial RF input socket and takes into account the effect if
more than one digital and/or analogue tuners are fitted internally. The figure is used for coverage planning –(see http://www.aba.gov.au/what/digital/spec_aba.htm
dttbaba.pdf). Other parameters for defining the Australian DTTB “notional receiver” are under consideration. The Notional Receiver information is detailed in Annex A
3
Note: Capability to tune to the S (cable) channels is recommended to enable access to channel shift in MATV systems. Refer SA Consumer Television Interfaces Part1 PAL
RF Appendix A Tables A1 & A2. Ability to tune to offset transmissions may be required.
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E
Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
LC- FF- LC- FF- Remarks
STB STB Rx Rx
ITEM
Reference
Standards
1.30
Transmission Parameter Signaling4
E
E
E
E Transmissions set to 7MHz channel . Clock 64/8=8MHz
1.31
IF Bandwidth – 7MHz (refer note 4)
E
E
E
E Primary standard
1.32
No. of Carriers –2K & 8K
E
E
E
E Both modes will be used
1.33
COFDM Symbol Rate range
E
E
E
E QPSK, 16QAM, 64QAM
1.34
Transport Stream
E
E
E
E
EN 300 744 §4
Cable
C
Cable
Sat
OFDM QAM QPSK
E
E
EN 300 744 §4
NA
E
E
The transport stream may include multiple program streams as well ISO/IEC13818-1
E
E
E
E
E
E
as private data and some PIDs may have conditional access applied.
1.35
Max Transport Stream Capacity
E
E
E
E 27.71Mb/s payload in a 7MHz channel
EN 300 744 AnnexE (Aus)
1.36
OFDM Hierarchical reception
R
R
R
R Capability to receive OFDM hierarchical mode.
Data-rate tables are under revision
EN 300 744
§4.6.2.6
1.37
Performance
E
E
E
E The unit must be capable of simultaneously decoding from the
transport stream, a video stream up to 1920x1080x50i MP@HL, an
associated audio stream up to (AC3) 5.1channel and either a teletext
or subtitle caption and present the decoded (and scaled if necessary)
information in time synced manner to a display device.
1.4
MPEG-2 Decoding MP@HL5
E
E
E
E HDTV Services may include 25 and 50 frame/s progressive and
50field interlace formats up to and including
1920pixels/1080lines/50field/s interlaced.
(For Line rates refer to Item 7.1 an 7.2 below)
ISO/IEC 13818-2
EN 300 468
O
O
O
1.41
MPEG-2 Decoding MP@ML
E
E
E
E Services may include 25 frame/s progressive and 50field/s interlace ISO/IEC 13818-2
formats up to and including 720pixels/576lines/50field/s interlaced. EN 300 468
E
E
E
1.42
MPEG-1 Video decoding
E
E
E
E MPEG-1 formats at 25 frame/s
ISO/IEC 11172-2
E
E
E
E Various implementations are possible which are detailed below.
ISO/IEC 11172-3
E
E
E
1.51
6
Audio Decoding MPEG-1, LayerII
E
E
E
4
Use of a 6MHz channel mode for Australian Channels 9A & 27 in some locations is being considered but not confirmed.
8MHz operation may be required for interoperability
5
Note: MP@HL is specified as “must have” as Government requires a proportion of broadcasters’ programs to be in a high definition format.
6
Both MPEG-1 Layer II and AC3 decoders are required as transmissions may have either or both.
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Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
LC- FF- LC- FF- Remarks
STB STB Rx Rx
ITEM
1.52
Audio Decoding MPEG-2, Layer II
R
R
R
Reference
Standards
R Backward compatible for interoperability purposes
ISO/IEC 13818-3
Cable
C
Cable
Sat
OFDM QAM QPSK
R
R
R
AC3 carried as “Private Data” Various implementations are possible ITU-R Rec.
BS.1196
O
O
O
1.53
Audio Decoding AC3
E
E
E
E
1.61
Teletext display7,
R
R
R
R Closed captions may be available as teletext Page801 etc
EN 300 472
R
R
R
1.62
,8
Subtitle display
R
R
R
R Closed captions and other information may be available
ETS 300 743
O
O
O
1.7
Service Information
-
-
-
-
1.71
9
Conditional Access
R
E
R
E One or two slots for Smartcard with Software Implementation under
consideration
E
E
E
1.72
Parental Guidance10
E
E
E
E Control of access to programs per Australian regulatory
requirements
1.73
Receiver Embedded Identification
R
R
R
R Identify model, software release etc. (eg. for software upgrades,
loading APIs)
1.81
Data Interface
R
E
R
E 2 way data connection. See details below
E
E
E
1.82
Modem Connection
R
E
R
E Internal or capability for external
E
E
E
1.83
Memory requirements
E
E
E
E To requirements of APIs operating system and upgrades;
decoding of program material including MP@HL pictures;
decoding and display of OSDs and captions;
Storage of 5 station minimum EPGs;
“house keeping” items such as storage of tuning tables;
Program interactive applications
Cross carriage of SI between TV Networks is not expected.
ACA-TS 2???
7
Broadcasts with Closed Captions may be in teletext format and/or in bitmapped subtitle format.
8
Closed Caption decoding and display may become mandatory requirements in integrated receivers, and is pending in Australian Government legislation.
9
Range of use and type of Conditional Access system subject to outcome of Government, Broadcasters and Industry discussions.
10
Receiver Parental Guidance requirement currently under discussion
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Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
ITEM
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
1.9
Regulatory Safety Requirements
E
E
E
E
1.91
Stand-by Scan mode
O
R
O
R Scan for stations’ extended program information for EPG use.
1.92
Stand-by Low Power mode
R
R
R
R Energy sving mode
2.0
Power on Operations
2.1
1st time operation initialization
R
R
R
R Request through on screen set-up menu to enter region for time
offset
2.2
Subsequent switch-on
R
R
R
R Return to previous set-up and previous channel (main service if
previous program stream selected not available – eg change from
multiprogram streams to high definition)
2.3
Identifying new services
R
R
R
R Behavior when new services are introduced - for example identifying
a new translator
2.4
Portable or Relocation Operation
R
R
R
R Behavior when activated at new location
3.0
User Operation
3.1
Operating System (API)
-
-
-
-
3.2
Hardware Reset
R
R
R
R Recommended to be easily accessible
3.3
Signal Quality Monitor
E
E
E
3.41
Change channel acquisition lock
R
R
3.42
On channel change
R
3.5
Loss of signal
3.6
Rescan tuning tables
Printed 01/29/99
Australian Electrical Mains –240V AC 50Hz EMC EMI
Cable
C
Cable
Sat
OFDM QAM QPSK
ASNZS/3250 –3260
AS 1053 CISPR/E
13
ETR 162
R
R
R
R
R
R
E Combination of signal strength and bit-error-rate, essential in setting
up receiving antenna (Numerical readout desirable) See Annex – F
Informative “Reception Quality OSD Meter”.
E
E
E
R
R Less than 1 second for stable picture
R
R
R
R
R
R Go to main service –display program table, Viewer advised of all
programs on newly selected service.
R
R
R
R
R
R
R Display “Loss of signal”
R
R
R
E
E
E
E Must be either after full “power-on” or from easily accessible menu
function
E
E
E
17076.CDR.DOC
Manufacturer’s choice
Page 7 of 29
Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
ITEM
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
4.0
COFDM Demodulation and
Channel decoding
4.1
COFDM Spectrum polarity
E
E
E
E Tuner local oscillator frequency is center frequency of selected
transmission plus the IF frequency
4.2
Acquisition of Signal. Reference lock
decoding
E
E
E
E Refer to Australian variations to EN 300 744
4.2
Reception of hierarchical transmission
R
R
R
R Some transmissions may operate in hierarchical mode. The receiver EN 300 744
§4.6.2.6
shall be capable of identifying hierarchical transmission and
decoding high or low priority bit streams within the range of the
receiver’s operational carrier to noise ratio. See Item 1.36
4.3
Marginal Signal operation
-
-
-
-
4.4
Interference Immunity
4.41
Impulse Noise Rejection
R
R
R
R Impulse noise can be more severe in the VHF bands, as used in
Australia. Ability to reject impulse noise may be affected by receiver
AGC performance.
5.0
Multiplex and Transport
Stream
5.2
Minimum number of PIDs recognised
E
E
E
E 32 – may affect memory requirement
6.0
Service Information (SI)
Processing
6.1
SI variations for Australia
E
E
E
E Refer to Australian amendment table
“Standards Australia CT2/C Doc501”
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17076.CDR.DOC
EN 300 744 §4.2 –
4.8 & Annex E Aust
Message of poor signal See Items 3.3 and 3.5 above
Page 8 of 29
EN 300 468;
ETR211
Cable
C
Cable
Sat
OFDM QAM QPSK
Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
LC- FF- LC- FF- Remarks
STB STB Rx Rx
ITEM
6.2
E
E
Reference
Standards
Cable
C
Cable
Sat
OFDM QAM QPSK
ETR 211 §4
Interpretation of MPEG-2, DVB
mandatory and DVB optional tables
E
E
6.3
Interpretation of Time and Date and
Time Offset Tables
E
E
E
E
EN 300 468 §4 – 5
ETR 211 §5
6.4
Interpretation of Descriptors
E
E
E
E
ETR 211 §5
EN 300 468 §4 - 5
EN 300 468 §6
E
E
E To provide minimum EPG display – See Annex xx
EN 300 468
E
E
E
E MPEG-1 formats at 25 frame/s, 352 x 288 (SIF);
ISO/IEC 11172-2
E
E
E
E
E
E
E 1) Pixel x lines @ 25frame/s progressive scan or 50field/s interlaced
720 x 576; 544 x 576; 480 x 576; 352 x 576; or.
2) 50 frame/s progressive formats
544 x 576; 480 x 576; 352 x 576; 352 x 288
ISO/IEC 13818-2
E
E
E
6.5
EITs & Present/Following (Now/Next) E
7.0
Video Decode and Display
7.1
MPEG Video decoding
7.10
MPEG-1 Video decoding
7.11
Decode MP@ML video formats
1112
EN 300 468 table16
ETR154 §5 &
Annex A
11
Broadcasters will only use active-lines-in-pictures formats of 1080, 576 and 576/2. This may benefit the interest of lower cost receivers, as a single frequency horizontal line
scan systems can be used. (eg. nominally (2 x 15.625kHz) 31.25kHz for HD displays with 576 line pictures scaled up by 2, and 15.625kHz for ED/SD displays where HD
pictures are scaled down by 2.) Broadcasters have advised that 720 line formats will not be used.
12
The MP @ HL decoder must also be able to decode lower MPEG levels such as MP @ LL .For interoperability, 704 pixels x 576 line formats may be used.
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Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
ITEM
7.12
Decode MP@HL video formats 10
LC- FF- LC- FF- Remarks
STB STB Rx Rx
E
E
E
Reference
Standards
E 1) Pixel x lines at 25frame/s progressive scan or 50 field/s interlace
1920 x 1080 line (both “p” at 25frame/s, “i” at 50field/s.)
Use of 1280x720line format not expected.
Note: 960 x 1080; 1280x1080; 1440 x1080line formats currently
under consideration by DVB and will possibly be used.
1035 and 1152 line formats will not be used. 1080 line formats are
preferred by Australian DTTB broadcasters.
2) 50 frame/s progressive formats
720 x 576line “p”. Use of 1280x720p not expected.
SI-DAT
ETR154 §5 & Table
4
O
O
O
E
E
E
O
O
O
O
O
O
TM
EN 300 468 table16
ETR 154 §5 &
Annex A
7.2
Reproduction of 25frame/s Progressive E
Formats13
E
E
E For reproduction on interlaced displays including standard 625line
displays, 25frame/s Progressive Formats (presumably from film
sources) will need to be output in 50field/s interlaced format
7.3
Video Scaling, up and down
O
O
O
O Preferred values typically are 0.5, 1.0 and 2.0 also 3/2, 4/3, 2/3
7.4
Video Stills
E
E
E
E Part of the DVB MPEG system
7.5
Multiview display
O
R
O
R In MP@HL decoder, SIF concurrent decoding recommended
7.6
Mosaic display
O
O
O
O Displayed from a single program stream
7.7
On-Screen display (OSD)
7.8
Aspect Ratio
7.81
Use of Active Format Descriptor
O
R
O
R Use of AFD indication of picture “area of interest” is optional
ETR 154 AnnexB
7.82
Identification of 4:3 and 16:9 pictures
E
E
E
E Broadcasts may have 4:3 or 16:9 pictures as identified by the 4-bit
integer aspect_ratio_information `0010’ or `0011’ respectively.
Use of 2.21:1 is not expected
ISO/IEC 13818-2
§6.3.12
13
Cable
C
Cable
Sat
OFDM QAM QPSK
ISO/IEC 13818-1
2.1.48
ETR 211 §5
EN 300 468
§6.2.13
See Section 10 for recommendations
ETR 154 §5.1.3
Video 25frame/s progressive scan formats may be used because of better MPEG encoding with current equipment. 24 or 23.98frame/s formats will not be broadcast in the
Australian 50Hz paradigm.
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Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
ITEM
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
7.83
14:9 Pictures
O
O
O
O Some broadcasts may use this ratio
7.84
Correct display of 4:3 and 16:9
pictures
E
E
E
E 16:9 pictures should be capable of being displayed on a 4:3 display. ISO/IEC 13818-2
This could be a viewer’s choice as letterbox or cutout following pan §6.3.12
offsets included in the MPEG program stream (refer to 7.84 below).
Manufacturers may also choose to provide overscan and stretch
modes for 4:3 pictures on wide-screen displays.
ISO/IEC 13818-2
§6.3.12
7.85
On 4:3 displays, show full height 4:3
pictures cut from a 16:9 video
program stream by use of MPEG-2
Pan & Scan vectors.
(This applies to set-top-boxes feeding
existing 4:3 display TV sets or
integrated digital receivers with 4:3
displays.
R
E
R
E Horizontal (Pan) offset may be available in the program stream.
The (16-bit signed) interger frame_centre_horizontal_offset will be
included in the video bitstream semantics. If this element is absent
from the bitstream then a zero offset (ie. Centred) is assumed.
Vertical (scan) offsets (per ETR-154) will not be used.
In the case of HD 16:9 program video that is being fed to a SD 4:3
display, the received line structure should be scaled appropriately.
7.86
Frame accuracy of use of Scan offset
E
E
E
E Shift of picture should be frame accurate with reception of
frame_centre_horizontal_offset information.
7.9
Picture Colorimetry
7.91
Chroma_format
E
E
E
E Chroma decoding to 4:2:0 format
chroma_format will be 01
ISO/IEC 13818-2
§6.1.1.8
§6.3.5; Table 6-5
7.92
Colorimetry
R
R
R
R SD and EDTV to EBU/ITU-R Report 624-4;
HD to Rec. ITU-R BT. 709-3. Transmitted pictures will be colour
ISO/IEC 13818-2
§6.3.6; Table 6-7
ETR154 §5
balanced to D6500.
Manufacturers may choose to alter the display colour temperature.
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17076.CDR.DOC
Page 11 of 29
Cable
C
Cable
Sat
OFDM QAM QPSK
Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
ITEM
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
Lower cost units may operate with a single loudspeaker and in such
cases multichannel program audio including stereo will be converted
to monaural. Broadcasters may use either MPEG or AC3.
8.0
Audio – Detail
8.1
MPEG Audio
8.10
Audio stream using MPEG-1 Layer II
E
E
E
E Services may be MPEG-1 layer II in single (mono) or dual or joint
stereo or stereo modes. Multiple services may be present to support
other languages. User should be able to select
8.11
MPEG-1 Layer II sampling rates
E
E
E
E Broadcasts may use either 32, 44.1 or 48kHz sampling rates –
All audio frames have same bit rate
8.12
MPEG-2 Layer II
R
R
R
R Backward compatible basic stereo information should be decodable
ISO/IEC 11172-3
E
E
E
E
ETR154 §6.1
R
R
R
O
O
O
O
O
O
8.13
MPEG-2 (discrete 5.1 channel)
O
O
O
O Also known as MPEG Multichannel (backward compatible) sound.
ISO/IEC 13818-
8.2
AC3
E
E
E
E Included in the DVB TS as “private data”. AC3 may be used for
mono, stereo, stereo with ProLogic© surround sound or discrete 5.1
channel surround sound.
ITU-R Rec.
BS.1196, ATSC
A/52
Other features of AC3 follow:
8.21
AC3- Number of channels -As many
as required (for multiple languages)
Complete Main services each 1 to 5.1
channels plus associated services
8.22
AC3 Karaoke mode
8.23
Dual AC3 decoders
Printed 01/29/99
Cable
C
Cable
Sat
OFDM QAM QPSK
?
?
?
?
A/53 §6
Each CM service can have a complete mix or only Music Effects
which could be mixed in the receiver with
Dialogue; Visually Impaired; Hearing Impaired
Additionally the following have over-ride capability
Commentary; Voice Over & Emergency
Not all AC-3 decoders may have ME & D decode & mix capability.
C & VO services operate assuming a “ducking” capability which
receivers may not have.
A/52
NA NA NA NA
O
R
O
17076.CDR.DOC
Dolby
R
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Standards Australia – CT2/A
Project No. CT2/002-0210 DRAFT
DTV Receiver Guideline requirements - 27th Jan 1999
ITEM
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
8.24
Decodable AC3 Sampling Frequency
Range
E
E
E
E Receiver Sampling frequency Range
Digital audio sampled at a frequency of 32 kHz, 44.1 kHz or 48 kHz,
locked to the 27 MHz system clock. The 48 kHz audio sampling
clock is defined as:
48 kHz audio sample rate = ( 2 ÷1125 ) × ( 27 MHz system clock )
Refer Aust change
to ATSC A53
Clause 5.2
Sampling
Frequency
8.25
Decodable AC3 Bitrate range
E
E
E
E Receiver Decodable Bit rate
A main audio service, or an associated audio service which is a
complete service (containing all necessary program elements) shall
be encoded at a bit rate less than or equal to 640 kbps. A single
channel associated service containing a single program element shall
be encoded at a bit rate less than or equal to 128 kbps. A two
channel associated service containing only dialogue shall be encoded
at a bit rate less than or equal to 256 kbps. The combined bit rate of
a main service and an associated service which are intended to be
decoded simultaneously shall be less than or equal to 768 kbps.
Refer Aust change
ATSC A53
Clause 5.3 Bit
rate]
8.26
Recognition of AC3 in MPEG-2
Transport Stream
E
E
E
E AC3 audio streams will be identified as a private_stream_1). Note:
there may be other AC3 streams and/or other private data streams
such as sub-title data with the same stream_id also present.
ETR 154 AUST
The stream_id will be 0xBD (private_stream_1)
The stream_type will be 0x81 (user private)
The private_data_specifier will be 0xD0 (Dolby Private)
For the component_descriptor : The stream_content is 0x02 (audio)
and component_tag is 0xBD
ITU-R BS.1196
Other changes refer to Australian Submissions to DVB
8.3
Audio Identification & Control
8.31
Identifying which audio stream
present
E
E
E
E OSD should briefly display choice when present
8.42
Multiple Audio streams
E
E
E
E If several audio streams present in either MPEG-1 layer II and/or
AC3
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ITEM
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
8.43
Receiver auto-switch when program
audio changes from MPEG to AC3 or
vice versa
?
?
?
?
If a program stream changes its audio delivery from MPEG-1 layer
II to AC3 or vice-versa, Switch should be automatic and muted
8.44
Reception of Dolby ProLogic™
O
R
O
R To ensure satisfactory decoding, audio phase response must be
maintained on stereo output with decoded MPEG or AC3
This applies to audio streams ≥ 224kbps
8.45
Audio commentary channel
?
?
?
?
8.46
Audio Reference Level -20dBfs
R
R
R
R To maintain perception of same volume from different sources
For visually impaired
MPEG: ETR154 §6
AC3: A/52
8.47
Audio Dynamic Range Control
O
R
O
R Ability for user to set through OSD menu.
8.48
Maximum Picture-Sound misalignment (Lip Sync) ± 20mSec
R
R
R
R
9.0
Operating Software
9.1
API
?
?
?
?
BHTML; Java; MHEG-5
?
?
?
?
No comment
O
R
O
R Interactive material may be present in broadcasts
E
E
E
E Minimum of two video planes supported (video & OSD). The OSD
shall be provided as solid, translucent or clear. (Refer Sect ?
10.0 Interactivity and On Screen
Display
10.1
Remote Control
10.12 Capability to operate interactively
10.2
OSD
10.21 Video Planes – Two (video & OSD)
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ITEM
10.3
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Teletext
Reference
Standards
There may be more than one Teletext data stream in a Transport
Stream and more than one stream in a Packetised Elementary
Stream.
The PMT teletext_descriptor tag value is 0x56
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EN 300 468
§6. Table 12
EN 300 472
10.31 Decoding of teletext information
O
R
O
R If fitted, OSD must indicate to viewer what teletext streams are
available in a service.
PIDs as identified in PMT of the PSI.
stream_type is 0x06 (private data).
Each stream identified by different data_identifier
EN 300 468
§6.2.32
EN 300 472 and
revisions
O
O
O
10.32 Minimum equivalent lines decoded –
16 per 20mS field period.
R
R
R
R If fitted, essential that equivalent line21 and 334 be decoded for
closed captions
EN 300 742 §1.
O
O
O
10.33 User Access to teletext via re-insertion
on analogue SD or ED 625 line
output.
R
R
EN 300 742 §1.
ITU-R BT.653-2
EBU SPB 492
O
O
O
10.34 Display on 4:3 and 16:9 pictures
E
E
E
E If fitted, in teletext assigned colour and positioned according to row
number.
10.35 Time accuracy of display ± 40mS
E
E
E
E Accuracy of Closed captions with picture
10.36 Access to Closed Captions for Hearing
Impaired14
E
E
E
ETR 211 §4.2.6.4
E Australian Closed Captions for Hearing Impaired are normally on
page 801. Broadcasts containing only this information as Teletext in
the DVB data Transport Stream may not have complete information
but should be able to be decoded for display.
10.4
NA NA If fitted, Teletext should be reinserted on VBI lines of video output
for display on teletext capable TVs connected to the STB/IRD.
Bit-Mapped Subtitles
Subtitles, logos and other graphical elements may be coded and
carried in DVB bitstreams.This format could also include Closed
Captions for the Hearing Impaired
10.41 Decoding of Bit-mapped information
O
R
O
R See note
10.42 Features of Display Minimum number
of Colours -16
E
E
E
E 256 colour recommended but at manufacturer’s choice dependent on
memory allocation
14
Refer previous footnote 8 – Requirement for decoding and display of closed captions is under consideration by Industry and Government.
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EN 300 742 §1.
EN 300 743
EN 300 468
§6. Table 12 &
6.2.30
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LC- FF- LC- FF- Remarks
STB STB Rx Rx
ITEM
10.43 Display on 4:3 and 16:9 pictures
Reference
Standards
E
E
E
E
E
E
E
E
E
E
E
E If bit-mapped captions provided
10.51 General
-
-
-
-
Australian DTTB broadcasters will only transmit their own SI and
EPGs. Cross carriage of SI between TV Networks is not
expected. Receiver manufacturers will need to make their own
decisions on memory size and allocation for viewers convenience in
referring to previously captured EPG data.
10.52 Use of EPG Flush
-
-
-
-
Broadcasters will not use EPG Flush function if this erases EPGs of
other broadcasters
10.53 Broadcaster Generated EPGs
?
?
?
?
Under discussion with broadcasters
10.54 Receiver Generated EPGs
?
?
?
?
Under discussion with broadcasters
10.55 Use of Now/Next (present/following)
E
E
E
E Required for basic navigation in digital supplied by EIT
10.56 Use of Extended program information
?
?
?
?
10.57 Use of Running status Table
R
R
R
R Needed to identify changed program duration – User choice, selected
by OSD menu.
10.44 Closed Caption Display
14
10.45 Time accuracy of display of CC
±40mS
10.5
EPG
EN 300 468
§6.2.6 –7
EN 301 192
11.0 Data Broadcasting
11.1
Access to data Service
O
E
O
E There may be more than one Data Broadcast stream in a Transport
Stream.
11.2
Data interface
O
O
O
O If data interface fitted, options for interface given in Section 15.0
Interfaces and Connectors
E
E
E
E Australian PG tables as defined
12.0 Parental Guidance
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ETR 162
ETR-154(Aus)
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ITEM
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
ETR 289; DVB
A011
13.0 Conditional Access15
13.1
Common Interface Connector
R
E
R
E Software implementation of CA is recommended with at least one
smartcard.
13.2
Additional socket
O
R
O
R
Activated by copyright bit descriptor
14.0 Copyright Protection on
Outputs16
14.1
Activation
E
E
E
E Activated by copyright bit descriptor
14.2
Digital outputs
?
?
?
?
14.3
High definition Analogue outputs
?
?
?
?
14.4
Standard definition analogue outputs
?
?
?
?
15.11 RF input
E
E
E
E IEC169-2 female, 75 ohm.
15.12 RF modulated PAL composite output
O
O
IEEE 1394 under international discussion
15.0 Interfaces and Connectors
15.1
15
16
RF Input / Output
NA NA If fitted, complies with AS-
Refer footnote 9
Use and type of Copyright Protection system(s) subject to Broadcaster and Industry discussions.
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ITEM
15.2
Base-band analogue video
Connectors
15.21 High Definition R, G and B or Y,Pr
and Pb
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
E
E
O
O Where fitted, option are:
O
R
O
O Consumer Television Interfaces, Part 2 Analogue Interfaces
SA XXXX Part2
15.22 PAL composite
O
O
O
O Consumer Television Interfaces, Part 2 Analogue Interfaces
IEC48B Sec.316 ( aka RCA or Cinch)
SA XXXX Part2
15.23 S-Video Component in / out
O
O
O
O Consumer Television Interfaces, Part 2 Analogue Interfaces
SA XXXX Part2
15.24 SCART Component or RGB in / out
O
O
O
O (aka Petritelevision or Euroconnector) Consumer Television
Interfaces- Part 2 Analogue Interfaces
SA XXXX Part2
15.3
Base band Audio output connectors
E
E
O
O Where fitted, option are:
15.3
Separate audio
O
O
O
O One (mono) to six connectors as required; IEC48B Sec.316
aka RCA phono (Cinch) or Scart for Mono Stereo
SA XXXX Part2
15.4
Audio AC3 bit stream output
O
O
O
O To feed separate external Dolby Digital AC3 5.1 channel decoder
Refer Dolby
15.5
Digital Program Stream
O
R
O
R Transport or Program stream
IEEE-1394A or 1394B
15.6
Data connectors
SA XXXX Part 3
Where fitted, options are:
SA XXXX Part 3 ;
IEC-61883-1; IEC61883-4 1998-02
15.63 IEEE-1394A or 1394B
O
R
O
R Could be two-way transport stream, program stream or data. In the
case of transport stream or program stream, the requirements of
copyright protection must be applied. (aka “FireWire”, “I-Link”)
15.61 Serial port
O
O
O
O 9 pin D male,(EIA-RS-232C) Capable of connection to an external modem SA XXXX Part 3
or a PC.
15.64 USB
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O
O
O
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O
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ITEM
LC- FF- LC- FF- Remarks
STB STB Rx Rx
Reference
Standards
15.62 Parallel data port
O
O
O
O 25-pin D female IEEE 1284
16.0 Back Channel Return Path
R
E
R
E For interactive applications option are:
16.1
Modem Capability
O
R
O
R Software and Hardware capability either by internal or external
modem.
16.2
Type of Operation –
Internal or External
O
O
O
O Connection via Telephony PSN, GSM or other.
16.3
Internal Modem
O
O
O
O
16.4
Internal Modem Port Connector
O
O
O
O RJ11
Ability to upgrade
R
R
R
R
17.1
Via DTTB transmission
?
?
?
?
17.2
Other Methods
Via RS-232C Serial port
?
?
?
?
17.3
Via Parallel data port
?
?
?
?
17.4
Via Modem Port
?
?
?
?
17.5
Via IEEE1394 port
?
?
?
?
18
Memory Expansion
R
R
R
R Future applications
17.0 System Software Upgrade
Ability to expand
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If this option is enabled, then the broadcaster would require that the
download would not interfere with any other receivers and be in a
“background” mode to the affected units.
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SA XXXX Part 3
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ANNEX A: Notional DTTB Receiver Specification - Summary
Digital Terrestrial TV
Note: Notional Receiver specifications are used for emission planning purposes.
1.
2.
Receiver Noise Figure (Measured at receiver RF 75 ohm input socket)
VHF Band III
6dB max
UHF Band IV
7dB max
UHF Band V
8dB max
Tuner Selectivity
7MHz Channel
sufficient to reject Analogue or Digital services on the
lower and upper adjacent channels which are 40 dB
higher than wanted digital service being received
3.
AFC Range
stability
4.
Minimum Decodable Carrier to Noise
dependent)
19 dB (for 64QAM @ 2/3 FEC) (Modulation
5.
Maximum Decodable Carrier to Noise
32 dB
6.
Signal level range (Receiver input 75ohm)
7.
sufficient to accept incoming signal with +/- 1 KHz
VHF Band III
100dBuV max
UHF Band IV
100dBuV max
UHF Band V
100dBuV max
Receiver RF Input Return Loss
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ANNEX-B References:
Document
Edition-
Title
Cross
Reference
Version
(date)
ISO/IEC 11172-x
ISO/IEC standards 11172-1 (Systems), 11172-2 (Video),
11172-3 (Audio), 11172-4 (Compliance Testing), and 11172-5
(Technical Report).
ISO/IEC 13818-1
1996
Generic Coding of Moving Pictures and Associated Audio
Information –Recommendation H.222.0
Part 1 – Systems
ISO/IEC 13818-2
1996
Generic Coding of Moving Pictures and Associated Audio
Information –Recommendation H.222.0
Part 2 – Video
Generic Coding of Moving Pictures and Associated Audio
Information –Recommendation H.222.0
Part 3 – Audio
ISO/IEC 13818-3
ETSI
EN 300 468
1.3.1
(02/98)
Specification for Service Information (SI) in DVB systems
DVB Blue
Book A038
ETSI
ETR 211
2 (08/97)
Guidelines on implementation and usage of Service
Information (SI)
DVB Blue
Book A005
Rev2
ETSI
ETR 162
Latest
available
from www
Allocation of Service Information (SI) codes for DVB
systems
ETSI
EN 300 472
1.2.1
(08/97)
Specification for conveying ITU-R System B Teletext in
DVB bitstreams
ETSI
ETS 300 743
1 (09/97)
Subtitling systems
DVB Blue
Book A009
ETSI
ETR 154
3 (10/97)
Implementation guidelines for the use of MPEG-2
Systems, Video and Audio in satellite, cable and
terrestrial broadcasting applications
DVB Blue
Book
A001R4
ITU-R BS. 1196
1995
Audio Coding for Digital Terrestrial Television
Broadcasting
Standards
Australia
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ANNEX-C
Abbreviations & Glossary
5.1 Channel Sound
A Five point one channel sound system is actually 6 channels of stereo surround
sound. The first 5 channels are centre speaker then left, right, rear left and rear
right. The extra point one refers to the reduced bandwidth “sub-woofer” or very low
frequency channel which does not have to be directionalized because the human ear
has no direction capability below about 100 Hertz.
Advanced home 5.1 channel “surround sound” systems can source the six channels
either from information derived from incoming stereo (two channel) using systems
such as Dolby ProLogic™ or, for best performance, from separate 5.1 channel
information carried in advanced digital audio systems such as Dolby AC3 (5.1
version) or MPEG-2 (5.1 / 7.1 channel version). These are available from Laser
disc, DVD and from digital broadcasts signals. Other systems in use for home
theatre applications include Lucas Film THX, Digital Theatre Sound (DTS) and
Advanced Audio Coding (AAC).
AC3
A proprietary digital sound system developed (and patented) by Dolby. It can carry
multiple channels, stereo with ProLogic and 5.1 discrete channel. Also known as
Dolby Digital, variants of the system are used in movie theatres, domestic laserdisk
and DVD and in the US ATSC and Australian DVB-T digital broadcast systems.
Decode systems can include a second decoder for special requirements.
Advanced Television Systems
Committee (ATSC)
The ATSC is a private sector organization formed in 1983 and with headquarters in
Washington D.C., USA. Its purpose is the development of voluntary standards for
the entire spectrum of advanced television systems. The ATSC is composed of over
fifty member corporations, associations and educational institutions. It has
developed a variety of technical standards including the ATSC Digital Television
Standard which grew out of a combination of parts of various systems put forward
by a consortium of various manufacturers and other interests known as the “Grand
Alliance”. Its basis is a system using 8-VSB modulation to transmit MPEG-2 video
and AC3 audio approved by the FCC for US broadcasters in December 1996. The
MPEG-2 video can include 18 different formats including several HDTV formats.
In addition to the development of standards, the ATSC is also developing
implementation strategies for advanced television and data broadcasting.
American National Standards
Institute (ANSI)
A US standards body.
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CA
Conditional Access. Refers to methods which scramble or encrypt the program or
private data so that it can be received only by “authorised” receivers. While a
number of different “private” schemes using “smartcards” have been used by PayTV operators working primarily via satellite, the arrangements for terrestrial
services are different because free-to-air services should be receivable without CA
authorisation. CA systems are currently (Jan’99) under consideration for the ATSC
standard.
In Europe, a Common Scrambling Algorithm was designed to minimise the
likelihood of piracy attack over a long period of time. By using the Common
Scrambling Algorithm system in conjunction with the standard MPEG data
transport and selection mechanisms it is possible to incorporate in a DVB
transmission the means to carry multiple messages which all enable control of the
same scrambled broadcast but are generated by a number of different CA systems.
This 'Simulcrypt' technique allows both the delivery of one Programme to a number
of different decoder populations that contain different CA systems, and also for the
transition between different CA systems in any decoder population, for example to
recover from piracy.
The 'Multicrypt' option is also available, facilitated by the Common Interface (DVBCI) specification proposed for standardisation by CENELEC (European Committee
for Electrotechnical Standardisation). The CA Module may operate in conjunction
with a smartcard or with a PCMCIA card as popularly used with lap-top PCs.
Carrier-to-Noise Ratio (C/N or
CNR)
A measurement of the received carrier power relative to the power of background
noise at the receiver input.
CENELEC
European Committee for Electrotechnical Standardisation.
Colour Look-Up Table (CLUT)
For DTV On-Screen-Displays, the CLUT is a look-up table of colour values for
translating an object’s pseudo-colours into screen display colours. It is a way of
simplifying the amount of data required to display an object but has the limitation
that only 4, 16 or 256 colour values are allowed somewhat like early PC EGA
graphics systems. Not all decoders may support a CLUT with 256 entries. A palette
of four colours would be enough for graphics that are basically monochrome, , like
subtitles, while a palette of sixteen colours allows for cartoon-like coloured objects.
COFDM
A method of Coded OFDM used by DVB for digital terrestrial television
broadcasting.
DVB (Digital Video Broadcast)
The Digital Video Broadcast is a consortium of over 200 manufacturers, research
institutes, and broadcast organisations principally located in Europe but spread
throughout the world. The Project has produced a series of interlinked broadcasting
standards for satellite, cable and terrestrial. Through other European groups such
as “ACTS” the work is now going on to interlink computer networking and
multimedia.
DVB-T
The DTB-T terrestrial digital television broadcasting specification is based on a
transmission system of COFDM carrying program and data as MPEG packets. It
was approved by the Steering Board, in December 1995 and subsequently accepted
by ETSI as a European standard. The work was based on a set of user requirements
produced by the Terrestrial Commercial Module of the DVB Project. DVB
members contributed to the technical development of DVB-T through the DTTVSA (Digital Terrestrial Television - Systems Aspects) of the Technical Module. The
European Projects SPECTRE, STERNE, HD-DIVINE, HDTVT, dTTb, and several
other organisations, developed system hardware and produced results which were
fed back to DTTV-SA.
Dolby
A US based company specializing in proprietary compression and noise reduction
techniques for audio transmission and recording.
Dolby Pro-logic™©
A method of encoding rear “surround” sound information in a 2 channel stereo
audio signal
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Dynamic Range
The ratio between the greatest signal power that can be transmitted over a
multichannel analog transmission system without exceeding distortion or other
performance limits, and the least signal power that can be utilized without
exceeding noise, error rate or other performance limits.
EDTV
Extended Definition TV. Refers to mainly wide screen formats using the current
scanning rates but not limited by bandwidth restrictions or artifacts of modulated
PAL or NTSC; - usually by full digital connection from camera to baseband input
on the home receiver (component Scart/Peritel or S-Video connection).
Electronic Industries Association
(EIA)
A US voluntary body of manufacturers which, among other activities, prepares and
publishes standards.
EPG
Electronic Program Guide
European Telecommunication
Standards Institute (ETSI)
The major European standards publishing body.
Forward Error Correction (FEC)
Methods of improving the ability to recover error-free data from a transmission or
storage system usually by adding extra data (about the payload data) before
transmission. For example in the DVB system a 188Byte MPEG-2 transport stream
packet may have added a further 16 bytes for error correction making a new packet
size of 204bytes.
Header
In data transmission, the header is protocol control information located at the
beginning of a protocol data unit.
Hierarchical Modulation
A method of transmission and reception of a radio-frequency carrier where part of
the information carried is capable of being more reliably received than the main
body under difficult reception conditions. In the case of DVB-COFDM
transmissions, two data streams can be modulated onto a 16 or 64 QAM signal and
the high priority stream protected by stronger FEC and/or a shift of the modulation
pattern (alpha factor).Refer to ETSI EN 300 744
Hierarchical Coding
Refers to a possible feature of MPEG-2 where the video and/or audio information
can be coded and scaled spatially or temporally. That is where a base or course
layer and a fine detail layer can be sent separately. For example, the Simple, Main,
SNR Scalable, Spatially Scalable and High profiles have a hierarchical relationship.
Therefore the syntax supported by a ‘higher’ profile includes all the syntactic
elements of ‘lower’ profiles (e.g., for a given level, a Main profile decoder shall be
able to decode a bitstream conforming to Simple profile restrictions). Refer
ISO/IEC 13818 –1,2,3.
High Definition Television
(HDTV)
High definition television has a resolution of approximately twice that of standard
television in both the horizontal (H) and vertical (V) dimensions and a wide screen
picture aspect ratio (H : V) of 16:9. ITU-R Recommendation 1125 further defines
“HDTV quality” as the delivery of a television picture which is subjectively
identical with the interlaced HDTV studio standard.
Hybrid Fiber/Coax (HFC)
System
A broadband bidirectional shared-media transmission system using fiber trunks
between the headend and the fiber nodes, and coaxial distribution from the fiber
nodes to the customer locations.
Hyper-Text-Transfer Protocol
(http)
An Internet protocol for transferring text files with layout information.
IEEE
See Institute of Electrical and Electronic Engineers.
IETF
See Internet Engineering Task Force.
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Institute of Electrical and
Electronic Engineers (IEEE)
An international voluntary organization based in the US which, among other things,
sponsors standards committees and is accredited by the American National
Standards Institute.
Various standards such as IEEE 1394 (a.k.a. Firewire) have recently been
developed for domestic high-speed digital interlinking of TV cameras, recorders
and computer equipment.
International Electrotechnical
Commission (IEC)
An international standards body based in Europe.
International Organization for
Standardization (ISO)
An international standards body, commonly known as the International Standards
Organization.
International Telecommunication
Union - Radiocommunication
(ITU-R)
An international standards body and a part of the ITU, based in Geneva which is the
recognised standards publisher for broadcast radio and television transmission
standards and standards on program interchange.
Internet Engineering Task Force
(IETF)
A body, based in Europe, responsible, among other things, for developing
standards used in the Internet.
Local Area Network (LAN)
A non-public data network in which serial transmission is used for direct data
communication among data stations located on the user's premises.
Master Headend
A headend which collects television program material from various sources by
satellite, microwave, fiber and other means, and distributes this material to
Distribution Hubs in the same metropolitan or regional area. A Master Headend
may also perform the functions of a Distribution Hub for customers in its own
immediate area.
MHEG
Multimedia and Hypermedia information coding Expert Group. A standards
working group of the ISO/IEC Joint Technical Committee 1- Sub Committee 29/
Working Group 12 who are developing coding of multimedia and hypermedia for
information technology applications including digital TV. This relates to on-screen
text and picture displays for menus, interactive TV etc.
Moving Picture Experts Group
(MPEG)
A voluntary body ISO/IEC Joint Technical Committee 1- Sub Committee 29 /
Working Group 11 which has and continues to develop standards for digital
compressed moving pictures and associated audio. Their standards are published in
the ISO/IEC 11172 and ISO/IEC 13818 series of documents.
MPEG-1 and MPEG-2
These are the most common video and audio compression schemes now in use.
MPEG-1 was used for lower data rate video on early CDi and VideoCDs. MPEG-2
provides for better quality (at higher data rates) and is used in a variety of
professional and consumer applications from SDTV to HDTV on terrestrial,
satellite and cable broadcast and Digital Video (Versatile) Disks. MPEG-4 and
MPEG-7 are further schemes for compression under development
MPEG packets
A way of breaking up the continuous stream of MPEG compressed video, audio and
other data for ease of passing through various transmission systems such as
broadcast. The raw transport packet is 188-bytes including a 4 byte header which
contains a “PID” for identification. The 184byte payload may include information
on the format of the contents (PSI).
National Television Systems
Committee (NTSC)
A US Committee formed in the late 1940s and ‘50s which defined the analog color
television broadcast standard used today in North America.
OSD
On Screen Display of menu for user’s setup of receiver’s operating parameters.
Also refers to display of choices and interaction with receiver and/ or program
Orthogonal Frequency Division
Multiplexing) (OFDM)
A modulation system which uses a very large number of separate radio frequency
carriers each of which carry a small proportion of the total information content to be
sent. Also used in DAB (Digital Audio Broadcasting), OFDM has good
performance in a very strong multipath (ghosting) environment. DVB based digital
television broadcasts use Coded OFDM.
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Packet Identifier (PID)
A unique integer value used to identify elementary streams of a program in a singleor multi-program MPEG-2 stream. Carried in each packet header (13 bits)
PAL
Phase Alternate Line. An analog encoding system for color television. Compatible
with analog monochrome systems of the same scanning rates, it has a high
frequency subcarrier to carry two color component signals, similar to the principles
used in NTSC but alternates the phase of one of the color signals so that the
receiver may correct color errors with a delay line. It was developed by AEG
Telfunken Laboratories in Hanover, Germany.
Program-Specific Information
(PSI)
In MPEG-2, normative data necessary for the demultiplexing of Transport Streams
and the successful regeneration of programs.
Program Stream
In MPEG-2, a multiplex of variable-length digital video and audio packets from one
or more program sources having a common time-base.
Protocol
A set of rules and formats that determines the communication behavior of layer
entities in the performance of the layer functions.
QAM
See Quadrature Amplitude Modulation.
QPSK
See Quadrature Phase-Shift Keying.
Quadrature Amplitude
Modulation (QAM)
A method of modulating digital signals onto a radio-frequency carrier signal
involving both amplitude and phase coding.
Quadrature Phase-Shift Keying
(QPSK)
A method of modulating digital signals onto a radio-frequency carrier signal using
four phase states to code two digital bits.
Radio Frequency (RF)
In broadcast and cable television systems, this refers to electromagnetic signals in
the range 5 to 1000 MHz.
Reverse Channel
A path for return information from the end-user. Necessary for full interactivity. In
Cable systems, the signal flows towards the headend, away from the subscriber;
equivalent to Upstream.
SCART plug
Large flat multipin plug - socket usually on larger domestic TVs and European
VCRs. Used for analogue audio and video baseband interconnect and for “SVideo” or component video connections which bypass the resolution loss and
artifacts caused by disassembling the component colour signals from composite
PAL or NTSC. (Also known as Peritel peripheral television interconnect or
Euroconnector).
Service multiplex and transport
In an MPEG system, “service multiplex and transport” refers to the division of the
digital data stream into "packets" of information and the means of uniquely
identifying each packet or packet type. Also the appropriate methods of
multiplexing these video data stream packets with audio data stream packets and
ancillary data stream packets into a single data stream consisting of a sequence of
188-byte transport packets.
Set-Top-Box (STB)
A modular unit for decoding video, audio, and data services physically separated
from a display device. Also known as an IRD (Integrated Receiver Decoder)
Standard Definition Television
(SDTV)
This term is used to signify a digital television system in which the quality is
approximately equivalent to that of broadcast or cable NTSC and PAL as seen in
the customer’s TV receiver.
Note: the term Conventional Definition Television (CDTV) has been used to signify
the analog PAL or NTSC television system as defined in ITU-R Recommendation
470.
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Surround Sound
Refers to listening environments where loudspeakers are positioned around the
listener(s). Besides the front loudspeakers, other loudspeaker(s) are positioned to
the rear and sometimes to the sides. The intention is to recreate the ambience and
directionality of the original scene being reproduced. Sound systems employing
surround sound can recreate such effects by processing the program stereo channels;
or better stereo with phase encoded material such as Dolby ProLogic™; or best,
from a discrete multichannel system of at least 6 channels including a low
frequency sub-woofer channel.
Service Information (SI)
In an MPEG data stream, Service Information (SI) is included within an MPEG-2
Transport Stream to assist the user in selection of services and/or events within the
digital multiplex, and so that the receiver can automatically configure itself for the
selected service. Information carried within SI allows for identification of services
or events for the user and can also provide information on services carried by
different multiplexes and even other networks. SI data complements the PSI tables
by providing other data to aid automatic tuning of decoders, and information
intended for display to the user. In general, SI augments and extends the relevant
Program Specific Information (PSI) specified in ISO/IEC 13818-1 (MPEG-2
Systems), the Program Association Table (PAT) and Program Map Table (PMT).
S-Video plug
A domestic analogue baseband video inter connection on a small plug where the
video is in a separated form so as to avoid the resolution loss and artefacts caused
by PAL or NTSC. (Also known as S-VHS)
Transmission Link
The transmission connection between interconnected points.
Transmission Medium
The medium on which information signals may be carried; e.g.,radio waves, optical
fiber, coaxial cable or twisted-wire pairs
Transport Stream
In MPEG-2, a packet-based method of multiplexing one or more digital video and
audio streams having one or more independent time bases into a single stream.
Upstream
The direction from the subscriber location toward the headend.
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ANNEX-E
Typical Receiver Block Diagram
To be added
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ANNEX-F - Informative
Reception Quality OSD Meter
Satisfactory reception of digital terrestrial television is dependent upon total signal quality.
Satisfactory reception cannot be guaranteed on signal strength alone. A tuning meter should not
be activated by signal strength or AGC level alone as there are other effects such as multipath
(ghosting) which even with a strong signal strength may result in error levels that renders the
signal undecodable.
Shown below is a suggested display of decoding margin for use on DTTB receivers and
decoding equipment to be used by either a Technician or Viewer.
Numerical Scale:
0
1
Insufficient
C/N
for decoding
2
3
4
5
Insufficient
Margin for
reliable reception
6
7
8
9
Adequate
Margin for
reliable reception
Level too
high
Note : The display must be the result of both the receiver level, C/N and decoded bit error rate,
for the display to be meaningful in the DVB-T COFDM environment. A numerical scale is
considered essential to quantify the reception quality for reference back to the manufacturer in
cases of user enquiry.
This type of indicator will allow :
•
Proper installation of fixed antennas;
•
Alignment of portable or “rabbit ears” antenna;
•
Correct distribution system outlet levels.
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