SIST EN 61603-3:1999

SLOVENSKI STANDARD
SIST EN 61603-3:1999
01-april-1999
1DGRPHãþD
SIST HD 455 S1:1999
Transmission of audio and/or video and related signals using infra-red radiation --
Part 3: Transmission systems for audio signals for conference and similar
systems (IEC 61603-3:1997)
Transmission of audio and/or video and related signals using infra-red radiation -- Part 3:
Transmission systems for audio signals for conference and similar systems
Übertragung von Ton- und/oder Bildsignalen und verwandten Signalen mit Infrarot-
Strahlung -- Teil 3: Übertragungssysteme für Audiosignale für Konferenzsysteme und
ähnliches
Transmission de signaux audio et/ou vidéo et de signaux similaires au moyen du
rayonnement infrarouge -- Partie 3: Transmission audio pour systèmes de conférence et
systèmes similaires
Ta slovenski standard je istoveten z: EN 61603-3:1998
ICS:
33.160.99 Druga avdio, video in Other audio, video and
avdiovizuelna oprema audiovisual equipment
SIST EN 61603-3:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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NORME
CEI
INTERNATIONALE
IEC
61603-3
INTERNATIONAL
Première édition
STANDARD
First edition
1997-10
Transmission de signaux audio et/ou vidéo
et de signaux similaires au moyen
du rayonnement infrarouge –
Partie 3:
Transmission audio pour systèmes
de conférence et systèmes similaires
Transmission of audio and/or video and
related signals using infra-red radiation –
Part 3:
Transmission systems for audio signals
for conference and similar systems
 IEC 1997 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun any form or by any means, electronic or mechanical,
procédé, électronique ou mécanique, y compris la photo- including photocopying and microfilm, without permission in
copie et les microfilms, sans l'accord écrit de l'éditeur. writing from the publisher.
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Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http: //www.iec.ch
CODE PRIX
Commission Electrotechnique Internationale
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PRICE CODE
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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61603-3 © IEC:1997 –
3 –
CONTENTS
Page
FOREWORD . 5
Clause
1 General. 7
1.1 Scope. 7
1.2 Normative references. 7
1.3 Definitions. 9
2 Explanation of terms and general information . 9
3 System considerations. 13
3.1 Application area. 13
3.2 Environment. 13
3.3 System planning and installation . 13
3.4 Partition of functions between elements of the system . 13
4 General conditions for measurements . 13
5 Characteristics to be specified and their methods of measurement . 13
5.1 Characteristics of the IR source . 13
5.2 Characteristics of the receiver. 15
6 Interface (matching) values, performance requirements and recommendations. 15
6.1 Interface values for transmitter output signals . 15
6.2 Interface values for radiator input signals . 17
6.3 Polarity. 19
6.4 Spurious emissions and signals . 19
6.5 Sensitivity to random incidence . 19
6.6 Rated signal-to-noise ratio . 19
6.7 Channel allocation and modulation characteristics. 21
6.8 Interface values for audio signals . 21
6.9 Overall audio frequency performance requirements . 23
7 Marking and contents of specifications . 23
7.1 Marking . 23
7.2 Contents of specifications . 23
Tables
1 Channel code, identification number and subcarrier frequency. 21
2 Marking and contents of specifications . 23
Figures
1 Schematic representation of a conference sound system . 25
2 Signal chain and related IEC standards . 25
3 Allocation of channels and recommended carriers L . 27

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61603-3 © IEC:1997 –
5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
TRANSMISSION OF AUDIO AND/OR VIDEO AND
RELATED SIGNALS USING INFRA-RED RADIATION –
Part 3: Transmission systems for audio signals for
conference and similar systems
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61603-3 has been prepared by subcommittee 100C: Audio, video
and multimedia subsystems and equipment, of IEC technical committee 100: Audio, video and
multimedia systems and equipment.
This standard should be read in conjunction with IEC 61147 (technical report).
The text of this standard is based on the following documents:
FDIS Report on voting
100C/129/FDIS 100C/181/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The series of publications IEC 61603 supersedes IEC 60764 and consists of the following
six parts:
Part 1: General (1997)
Part 2: Transmission systems for audio wide band and related signals (1997)
Part 3: Transmission systems for audio signals for conference and similar systems
Part 4: Transmission systems for low speed remote control
Part 5: Transmission systems for high speed data and remote control
Part 6: Transmission systems for video and audiovisual signals of high quality

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61603-3 © IEC:1997 –
7 –
TRANSMISSION OF AUDIO AND/OR VIDEO AND
RELATED SIGNALS USING INFRA-RED RADIATION –
Part 3: Transmission systems for audio signals for
conference and similar systems
1 General
1.1 Scope
This part of IEC 61603 gives methods for measuring and specifying those characteristics of
audio infra-red (IR) transmission systems for conference and similar systems which are not
covered by part 1 (see also 3.1). It allows systems which make different economic use of the
available bandwidth to be described in order that conclusions regarding interference and
compatibility can be drawn. Interface (matching) values and other system characteristics are
also covered. The standard replaces chapter 2 of IEC 60764.
1.2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 61603. At the time of publication, the editions indicated
were valid. All normative documents are subject to revision, and parties to agreements based
on this part of IEC 61603 are encouraged to investigate the possibility of applying the most
recent editions of the normative documents indicated below. Members of IEC and ISO maintain
registers of currently valid International Standards.
IEC 60068: Environmental testing
IEC 60268-15: 1996, Sound system equipment – Part 15: Preferred matching values for the
interconnection of sound system components
IEC 60315-4: 1982, Methods of measurement on radio receivers for various classes of
emission – Part 4: Radio-frequency measurements on receivers for frequency modulated
sound-broadcasting emissions
IEC 60417: 1973, Graphical symbols for use on equipment – Index, survey and compilation of
the single sheets
IEC 60764: 1983, Sound transmission using infra-red radiation
IEC 60914: 1988, Conference systems – Electrical and audio requirements
IEC 61147: 1993, Uses of infra-red transmission and the prevention or control of interference
between systems
IEC 61603-1: 1997, Transmission of audio and/or video and related signals using infra-red
radiation – Part 1: General
IEC 61938: 1996, Audio, video and audiovisual systems – Interconnections and matching
values – Preferred matching values of analogue signals
ISO 7000: 1989, Graphical symbols for use on equipment – Index and synopsis
ITU-R 412-6: 1995, Planning standards for FM sound broadcasting at VHF
ITU-R 641: 1990, Determination of radio-frequency protection ratios for frequency-modulated
sound broadcasting
ITU-R 704: 1990, Characteristics of FM sound broadcasting reference receivers for planning
purposes

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61603-3 © IEC:1997 –
9 –
1.3 Definitions
For the purpose of this part of IEC 61603, the definitions given in part 1 apply.
2 Explanation of terms and general information
2.1 Transmitter
A transmitter (link A-B in figure 2) has an audio signal input (analogue or digital), and a special
form of electrical output to feed a radiator.
2.2 Combined transmitter and radiator
A combined transmitter and radiator (link A-C in figure 2) does not have an electrical output,
and interface values therefore apply only at the input.
2.3 Radiator
A radiator (link B-C in figure 2) has a special form of electrical input, to be fed by a transmitter.
A radiator may be combined with other functions, such as a transmitter. At present, radiators
normally consist of a number (from ten and more) of infra-red emitting diodes (IREDs)
employing different technologies. These devices have peak emissions in the wavelength
range 830 nm to 950 nm, and an IR bandwidth of about 100 nm.
2.4 Receiver
Besides the general characteristics given in part 1 and shown as link C-D in figure 2, others
may need to be specified if a receiver is combined with other units to serve, for example, as a
transmitter for up-stream signals in a duplex system.
To eliminate interference from other modulated IR sources, the receiver shall provide enough
selectivity with regard to the modulated subcarrier in addition to selectivity in the IR band.
Normally, this selectivity shall correspond to the spectral bandwidth of the modulated
subcarrier signal, with some margin for instabilities and possible extra features.
Definitions and methods of measurement for selectivity in relation to analogue FM signals
are given in the standards dealing with FM broadcast systems, such as IEC 60315-4 and
ITU-R 412, 641 and 704.
NOTE – For digital audio transmission, the subject of receiver selectivity is under consideration.
2.5 Ancillary equipment
Ancillary equipment, such as power supplies or battery chargers, may be required for the
operation of the system. The manufacturer should specify all the data necessary for correct
operation and maintenance.

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61603-3 © IEC:1997 –
11 –
2.6 Transmission of audio signals
2.6.1 Analogue audio signals
Due to its technical performance and bandwidth economy, frequency modulation multiplex is
mainly used for multichannel operation and is, at present, the only technique for which
compatible equipment is available from different manufacturers.
With this modulation technique, the transmitter output signal consists of a group of modulated
subcarriers; this frequency-division multiplex makes economic use of the
...