SIST EN 61603-1:1999

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

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NORME CEI
INTERNATIONALE
IEC
61603-1
INTERNATIONAL
Première édition
STANDARD
First edition
1997-01
Transmission de signaux audio et/ou vidéo
et de signaux similaires au moyen
du rayonnement infrarouge –
Partie 1:
Généralités
Transmission of audio and/or video and
related signals using infra-red radiation –
Part 1:
General
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T
PRICE CODE
International Electrotechnical Commission
Pour prix, voir catalogue en vigueur
For price, see current catalogue

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61603-1 © IEC:1997 – 3 –
CONTENTS
Page
FOREWORD . 7
INTRODUCTION. 9
SECTION 1: GENERAL
Clause
1.1 Scope. 11
1.2 Normative references. 11
1.3 Definitions. 13
1.4 Abbreviations. 13
SECTION 2: EXPLANATION OF TERMS AND GENERAL INFORMATION
2.1 General. 15
2.2 Operating environment. 15
2.3 IR source. 15
2.4 IR propagation medium and receiver. 17
2.5 Modulation. 19
2.6 IR interference. 23
2.7 Electromagnetic compatibility. 23
2.8 Safety aspects. 23
SECTION 3: GENERAL CONDITIONS FOR MEASUREMENTS
3.1 Operating environment and measurement conditions . 25
3.2 Pre-conditioning. 25
3.3 Interface (matching) values. 25
3.4 Presentation of results in specifications. 25
SECTION 4: CHARACTERISTICS TO BE SPECIFIED AND THEIR METHODS OF MEASUREMENT
4.1 Characteristics of IR sources . 25
4.2 Characteristics of the IR propagation medium and receiver . 29
4.3 Characteristics of modulation. 33
SECTION 5: PERFORMANCE REQUIREMENTS AND RECOMMENDATIONS
5.1 Maximum power density of the irradiation. 35
5.2 Spurious IR emission . 35
5.3 Polarity. 35
5.4 Electrical interfaces. 35
5.5 Spurious modulation signals . 35
5.6 IR emissions from other devices and equipment . 35

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61603-1 © IEC:1997 – 5 –
Page
SECTION 6: CLASSIFICATION OR SYSTEMS AND EQUIPMENT
Clause
6.1 General. 37
6.2 Classification criteria and coding. 37
SECTION 7: MARKING AND CONTENTS OF SPECIFICATIONS
7.1 Marking. 37
7.2 Contents of specifications . 37
Tables
1 Interference between IR sources and systems. 39
2 Channel allocation scheme. 41
3 Marking and contents of specifications . 45
Figures
1 Signal chain and related IEC standards. 37
2 Presentation of channel grids. 41
3 Preferred electrical spectrum allocation for IR modulation, and the relevant parts
of this standard. 43
Annex A – Details of the applications of parts 2 to 6 of IEC 1603. 47

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61603-1 © IEC:1997 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_________
TRANSMISSION OF AUDIO AND/OR VIDEO AND RELATED
SIGNALS USING INFRA-RED RADIATION –
Part 1: General
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 1603-1 has been prepared by subcommittee 100C: Equipment and
systems in the field of audio, video and audiovisual engineering, of IEC technical committee
100: Audio, video and multimedia systems and equipment.
This standard should be read in conjunction with IEC 1147 (technical report).
The text of this standard is based on the following documents:
FDIS Report on voting
100C/31/FDIS 100C/58/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.
Annex A is for information only.
This standard supersedes IEC 764 and consists of six parts:
Part 1: General
Part 2: Transmission systems for audio wideband and related signals
Part 3: Transmission systems for audio signals for conference and similar applications
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 audovisual signals of high quality
The contents of the corrigendum of May 1997 have been included in this copy.

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61603-1 © IEC:1997 – 9 –
INTRODUCTION
This part of IEC 1603 covers the transmission of audio, video, data and control signals which
use free radiation of infra-red (IR).
Transmission using infra-red radiation is in growing use for many different applications. This
standard gives guidance for the generic usage of infra-red. It provides information for
designers and users of infra-red systems which allow the evaluation of the operation of
different systems.
IEC 764 specifies requirements for audio transmission with high quality audio transfer via two
infra-red channels and for conference systems with up to nine audio channels and using
frequency modulation on subcarriers which amplitude modulate the IR intensity. However, this
number of channels sets limits on technical evolution. The growing use of IR transmission,
such as for remote control or data transmission, and the increasing number of cases, where
modulated IR is emitted as a side-effect, reveals the need for a more general concept.
Infra-red systems typically use radiation in the range of wavelengths from 830 nm to 950 nm.
To take into account possible future development, this standard covers wavelengths from
700 nm to 1600 nm. A direct modulation of the frequency of the infra-red radiation is possible,
but is not yet used for transmission through air. It should not be excluded in the long term.
The prevention of interference between different applications by the use of different
wavelengths is not yet economically feasible, but the situation may soon change; therefore this
possibility is allowed for in this standard.
Most of the applications in the complete standard (six parts) already exist as wired systems. In
extending to wireless links using infra-red, the aim is to retain the transmission properties of
the wired versions. This standard is therefore as consistent as possible with existing standards
for wired systems.
This standard gives guidance only on avoiding interference from light sources. For a fully
compatible system, it is necessary to set limits both for the emission from light sources and for
the immunity of the infra-red transmission systems.
For ease of reference, the applications covered in the different parts of this standard are
explained in more detail in annex A.

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61603-1 © IEC:1997 – 11 –
TRANSMISSION OF AUDIO AND/OR VIDEO AND RELATED
SIGNALS USING INFRA-RED RADIATION –
Part 1: General
1 Section 1: General
1.1 Scope
This part of IEC 1603 gives methods of measuring and specifying the common technical
features of the parts of systems which use diffusely radiated or wide beams of infra-red
radiation as carriers of information, mainly representing audio and/or video signals but also
control data related to audio and video apparatus.
This standard applies to signal transmission by use of freely radiated infra-red, normally used
indoors in rooms and for groups of varying sizes. It does not cover security systems or other
industrial applications, such as measurement and automation equipment. It also does not cover
traffic systems or systems for the help of handicapped people. Narrow-beam and cable-like
infra-red applications are excluded, although the former could interfere with the systems covered.
1.2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this part of IEC 1603. 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 1603 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.
International Electrotechnical Vocabulary – Lighting
IEC 50(845): 1987,
IEC 65: 1985, Safety requirements for mains operated electronic and related apparatus for
household and similar general use
IEC 68: Environmental testing
IEC 268-1: 1985, Sound system equipment – Part 1: General
IEC 268-15: 1996, Sound system equipment – Part 15: Preferred matching values for the
interconnection of sound system components
IEC 417: Graphical symbols for use on equipment
IEC 574-3: 1983, Audiovisual, video and television equipment and systems – Part 3:
Connectors for the interconnection of equipment in audiovisual systems
IEC 574-4: 1982, Audiovisual, video and television equipment and systems – Part 4: Preferred
matching values for the interconnection of equipment in a system
IEC 825-1: 1993, Safety of laser products – Part 1: Equipment classification, requirements and
user's guide
IEC 1147: 1993, Uses of infra-red transmission and the prevention or control of interference
between systems
ISO 7000: 1989, Graphical symbols for use on equipment – Index and synopsis

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61603-1 © IEC:1997 – 13 –
1.3 Definitions
For the purpose of this part of IEC 1603, the following definitions apply.
1.3.1 channel identification number: In a multichannel system, the number given to a
specific single channel for identification purposes.
1.3.2 detector; IR detector: Front end of an IR receiver, such as photodiode, phototransistor.
1.3.3 number of channels: The total number of information channels offered by a system, as
specified by the manufacturer.
1.3.4 power density
1) In general, the quotient of the IR power and a specified unit area.
2) For diffuse IR radiation in a room, the total installed IR power divided by the floor area of
the room.
NOTE – This special definition has proved to be helpful for planning purposes.
1.3.5 radiator; IR radiator: Device for converting the electrical input supplied by a separate
transmitter into IR.
1.3.6 receiver; IR receiver: Device with IR detector and signal processing which reconstructs
the original message or transcodes it for special use, such as remote control.
1.3.7 source; IR source: Any device supplying IR for transmitting signals.
1.3.8 transmitter; IR transmitter: Device containing an electronic circuitry which processes a
message into a signal suitable for the modulation of an IR source in the same or in a separate unit.
1.3.9 Ulbricht sphere: Device, in the shape of a sphere with its inner surface coated with
scattering material, for making source power measurements.
NOTE – The scattering material generates a uniform diffuse IR field inside the sphere.
1.4 Abbreviations
1.4.1 IR: Infra-red, infra-red radiation.
NOTE – The deprecated term 'infra-red light' is in use instead of the correct term 'infra-red radiation', in an
attempt to prevent any misleading association with ionizing radiation.
1.4.2 IRED: Infra-red emitting diode.

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61603-1 © IEC:1997 – 15 –
2 Section 2: Explanation of terms and general information
2.1 General
The equipment necessary for IR transmission can be divided into three elements (see figure 1):
an IR transmitter, an IR radiator and an IR receiver. In practice, their design depends on the
application and the transmitter and radiator may be combined in one unit, or alternatively, they
may be supplemented by extra units, such as separate distribution amplifiers.
combined applications, the signal character may be derived
When the IR carrier is used in
either from audio input or from data used for the control of devices or for information.
2.2 Operating environment
The equipment is mainly used indoors, although some applications may be outdoors, if the
disturbance by the infra-red portion of the sun's radiation is acceptable.
2.3 IR source
2.3.1 Choice of source
The source for the transmission of signals by infra-red radiation may be any device capable of
generating infra-red and of being modulated.
NOTE – To increase efficiency and reduce cost, sources which supply their energy mainly in the range which is
usable for the signal path are chosen. These are mostly semiconductor infra-red emitting diodes (IREDs).
2.3.2 IR wavelength
Every IR-emitting element shows a more or less wide spectrum of energy lines. At one extreme
are lasers which produce only a few lines in their spectrum; and at the other extreme are
incandescent lamps which produce a wideband continuous spectrum.
Available IREDs offer a wide variety of wavelength maxima, so it is possible for several
services using IR connections to operate in the same area without disturbing each other.
2.3.3 IR wavelength bandwidth
The usual sources of infra-red radiation for transmission are of limited IR bandwidth. Lasers
have the narrowest bandwidth of a few nanometres around the wavelength of maximum
emission. The spectra of the most commonly used IR emitting diodes have a width of about 50 nm.
2.3.4 Efficiency
All existing sources convert only a small part of the input power into infra-red radiation. The
efficiency depends on the technology used. Common IREDs convert about 10 % of the
electrical input energy into IR for this use. The rest is lost as heat.
2.3.5 Radiant intensity
The radiant intensity (IEV 845-01-30) of a source is the characteristic which determines the
irradiance at a given distance. It depends strongly on the directional characteristic of the
source. Most sources have specified directional properties determined by the manufacturing
process.

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61603-1 © IEC:1997 – 17 –
The use of standard sources in large arrays may lead to differences between the main direction
of the array and that of a single element. This phenomenon should be allowed for in measuring
the radiant intensity. In order to avoid the harmful effects of infra-red radiation on human
beings, limits are set for radiant intensity.
2.3.6 Intensity close to a radiator
Most of the IREDs available produce typically 15 mW continuous power, but in many systems
the beam is concentrated by optical means so that the intensity of the homogeneous radiation
is multiplied. The use of IRED arrays in radiators with higher power further increases this
value. Even though an irradiance of only a few milliwatts per square metre is needed for most
receiver systems, care is required to ensure that the intensity near the radiators is kept to a
safe level.
2.3.7 Directivity
Depending on the area illuminated by the infra-red signal, information may be required on the
variation of intensity with direction of radiation, usually expressed as the angle between the
specified direction and the normal to the surface of the IR source. Most sources have specified
directional properties which are determined by the design. An array of sources may be used to
create a specified directional response which differs from that of a single source.
2.3.8 Spurious IR emission
Spurious emission is the amount of IR power output of a source in spectral bands other than
the band intended for use in the system. This emission can be subdivided into an unmodulated
part (similar to white noise) and a modulated part (mostly discrete spectral lines).
2.4 IR propagation medium and receiver
2.4.1 General
The transmission performance depends on three major factors. In addition to restrictions in
source bandwidth, the influence of the transmission medium and the receiving equipment shall
be considered. It is useful to consider the medium and receiver together. The receiver
characteristics, however, dominate the overall performance; these include electrical and
mechanical characteristics, such as size and design. Depending on the application, receivers
may be pocket-sized stand-alone units or parts of combinations, such as for conference
systems including extra features. Receivers have a front end of one or more opto-detectors,
usually integrated in plastic optical units and combined with cut-off filters against daylight.
2.4.2 IR response
The IR response of the detector element itself can be influenced by optical elements such as
filters, lenses and mirrors. The overall response includes all these elements and is measured
via the electrical output of the receiver detector. The response can depend on the angle of
incidence, such as when using interference filters.
2.4.3 IR bandwidth
The transmitter and receiver may have different IR bandwidths, and the overall performance
may be influenced substantially if they do not match efficiently.

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61603-1 © IEC:1997 – 19 –
2.4.4 Sensitivity for random incidence
Most applications covered by this standard use no fixed local installation for source or receiver.
For these applications the sensitivity to diffuse IR is the characteristic of primary importance.
2.4.5 Maximum sensitivity
For certain applications, such as remote control, the source and receiver can be directed
towards each other. Most receivers have a non-uniform directional response, with an axis of
maximum sensitivity (the main receiving axis), so that correct reception can be achieved over
much longer distances than under diffuse radiation conditions.
2.4.6 Directivity
For comparison of the performance of different systems, it is important to know the directional
characteristic of the receiver units.
2.5 Modulation
2.5.1 General
Systems using infra-red radiation for information transfer encode the information by varying the
intensity of the radiation. This can be done either directly by the information signal or indirectly
by electrically modulating sinusoidal or other periodic subcarriers, such as pulse trains, which
themselves modulate the intensity of the source.
The use of baseband transmission without a subcarrier, such as by pulse code modulation
(PCM), results in a very high pulse rate, increasing with the number of signals to be
transmitted. An extremely high pulse rate can require the use of laser diodes.
An extension to higher frequencies of the bandwidth available for modulating signals can be
achieved by frequency or time multiplex procedures. Frequency multiplex is well known from
broadcasting technology and leads to economic use of the available bandwidth. Time multiplex
concepts with a larger number of channels and low duty-cycle, such as in pulse phase or
position modulation, lead to low average IR power. However, the necessary electrical
bandwidth is inversely proportional to the rise time or duration of the pulses used. This
bandwidth is expected to increase in the future, due to increasing requirements concerning
transmission quality, number of channels and the rapidly ongoing evolution of components.
In order to compare different modulation techniques, it is necessary to specify consistent
reference values. The reference modulation value depends on the technique used and is either
given in the relevant part of this standard or has to be stated by the manufacturer.
2.5.2 Baseband modulation
In systems using baseband modulation, the intensity of the infra-red varies directly with the
amplitude of the information signal, which may be either analogue or digital in nature.
2.5.3 Carrier-based modulation
2.5.3.1 Principle
In systems using carrier-based modulation, the intensity of the radiation is modulated by a
periodic subcarrier. This (usually sinusoidal) subcarrier signal is itself modulated with the
message, using, for example, frequency modulation (FM).

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61603-1 © IEC:1997 – 21 –
2.5.3.2 IR modulation index
The modulation index describes the ratio of the IR power carrying the information of one
transmission channel to the total emitted IR power in the reception band. For reasons of
linearity, this index is sometimes very low depending on the type of modulation.
NOTE – This use of the term modulation index is different from its use in purely electrical modulation, because
electrical RF carriers are bipolar and can be modulated symmetrically, whereas the IR radiation from a source is
a unipolar signal which can be modulated by the superimposed subcarrier only from maximum down to zero.
2.5.4 Signal bandwidth
The information rate and the modulation technique influence the electrical bandwidth of the
modulated signal. Only narrow bandwidths are necessary for a slow remote control signal
carrying only a few functions, whereas digitized music or video signals (without bit-rate
reduction) need very wide bandwidths. Multiple use of IR transmission systems at the same
location require economic use of the available bandwidth.
2.5.5 Channel allocation and channel width
2.5.5.1 General
The highest usable subcarrier frequency depends on the transmission medium, the
environment and the properties of the infra-red emitting and receiving devices used.
NOTE – With present techniques, frequencies up to several megahertz are used and an increase of this
frequency is likely. To take this development into account the channel allocation scheme specified in this
standard is not limited at the upper end.
The range of subcarrier frequencies is subdivided into grids A to G, with channel widths from
4 kHz upwards in a sequence 4, 10, 40, 100.kHz. If necessary, further grids can be added in
the same way. The subdivision scheme is shown in table 2 and figure 2.
For example, C1 is a channel of grid C, 40 kHz wide, covering the range 40 kHz to 80 kHz, and
it occupies the same frequency range as channels B4 to B7, each of which is 10 kHz wide.
2.5.5.2 Preferred electrical spectrum allocation
IREDs are available which offer a modulation bandwidth up to at least 30 MHz. The
recommended allocations of channel frequencies within the modulation bandwidth for different
applications are shown in figure 3.
NOTES
1 Lighting equipment may cause interference (see IEC 1147). In addition to interference in the 45 kHz to 250 kHz
range and its harmonics and subharmonics, newly developed induction gas discharge lamps generate
modulated IR signals mainly concentrated at the MHz range, for example ISM frequency. Other devices, such as
video screens and data monitors, can affect other frequency ranges.
2 Other existing or future applications working in the range shown in figure 3 are regarded as secondary, such
as digital wideband transmission for office and factory communication. These applications may interfere with the
recommended range for video transmission. Careful coordination is therefore necessary before different
systems using IR are installed in the same space (see 2.6.1).
3 Channel C11 is kept free for use as the intermediate frequency in AM broadcast radio and some IR
rec
...