IEC 60728-3-1:2012

Cable networks for television signals, sound signals and interactive services - Part 3-1: Active wideband equipment for cable networks - Methods of measurement of non-linearity for full digital channel load with DVB-C signals

IEC 60728-3-1:2012 is applicable to the methods of non-linearity measurement for cable networks which carry only digitally modulated television signals, sound signals and signals for interactive services. These methods take into account the specific signal form and behaviour of digitally modulated signals which differ from the analogue broadcast signals represented mainly by the existence of discrete carrier signals.

Réseaux de distribution par câbles pour signaux de télévision, signaux de radiodiffusion sonore et services interactifs - Partie 3-1: Matériel actif à large bande pour réseaux de distribution par câbles - Méthodes de mesure de la non-linéarité pour une charge tout numérique de signaux DVB-C

La CEI 60728-3-1:2012 s'applique aux méthodes de mesure de la non-linéarité pour des réseaux de distribution par câbles qui ne transportent que des signaux en modulation numérique, pour la télévision, la radiodiffusion sonore et les services interactifs. Ces méthodes prennent en compte la forme et le comportement particuliers des signaux en modulation numérique, différents des signaux de diffusion analogique, pour leur part essentiellement représentés par des porteuses discrètes non modulées.

General Information

• Status: Replaced
• Publication Date: 05-Jul-2012
• ICS: 33.060.40 - Cabled distribution systems
• ICS: 33.170 - Television and radio broadcasting
• Technical Committee: TC 100 - Audio, video and multimedia systems and equipment
• Current Stage: WPUB - Publication withdrawn
• Start Date: 10-May-2019
• Completion Date: 10-May-2019

Relations

• Replaced By: IEC 60728-3:2017 - Cable networks for television signals, sound signals and interactive services - Part 3: Active wideband equipment for cable networks
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60728-3-1


®


Edition 1.0 2012-07



INTERNATIONAL



STANDARD



NORME
INTERNATIONALE


Cable networks for television signals, sound signals and interactive services –
Part 3-1: Active wideband equipment for cable networks – Methods of
measurement of non-linearity for full digital channel load with DVB-C signals

Réseaux de distribution par câbles pour signaux de télévision, signaux de
radiodiffusion sonore et services interactifs –
Partie 3-1: Matériel actif à large bande pour réseaux de distribution par câbles –
Méthodes de mesure de la non-linéarité pour une charge tout numérique de
signaux DVB-C


IEC 60728-3-1:2012

---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60728-3-1



®



Edition 1.0 2012-07







INTERNATIONAL





STANDARD







NORME



INTERNATIONALE











Cable networks for television signals, sound signals and interactive services –

Part 3-1: Active wideband equipment for cable networks – Methods of

measurement of non-linearity for full digital channel load with DVB-C signals




Réseaux de distribution par câbles pour signaux de télévision, signaux de

radiodiffusion sonore et services interactifs –


Partie 3-1: Matériel actif à large bande pour réseaux de distribution par câbles –

Méthodes de mesure de la non-linéarité pour une charge tout numérique de

signaux DVB-C











INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE

PRICE CODE
INTERNATIONALE

CODE PRIX Q


ICS 33.060; 33.170 ISBN 978-2-83220-211-1



Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

---------------------- Page: 3 ----------------------
– 2 – 60728-3-1  IEC:2012



CONTENTS


FOREWORD . 3

INTRODUCTION . 5

1 Scope . 6

2 Normative references . 6

3 Terms, definitions, symbols and abbreviations . 6


3.1 Terms and definitions . 6

3.2 Symbols . 7
3.3 Abbreviations . 7
4 Methods of measurement of non-linearity for full digital channel load . 8
4.1 Maximum operating output level using the measurement of bit error ratio

(BER) . 8
4.1.1 General . 8
4.1.2 Equipment required . 8
4.1.3 Connection of equipment . 9
4.1.4 Measurement procedure . 9
4.1.5 Presentation of the results . 10
4.2 Measurement of the carrier-to-interference noise ratio CINR . 10
4.2.1 General . 10
4.2.2 Equipment required . 10
4.2.3 Connection of the equipment . 11
4.2.4 Measurement procedure . 11
4.2.5 Presentation of the results . 12
Equipment characteristics required to be published . 12
5
Annex A (informative) Examples of measurement channels . 13
Annex B (normative) Null packet and PRBS definitions . 14
Bibliography . 16

Figure 1 – BER measurement test configuration . 9
Figure 2 – CINR measurement test setup . 11
Figure 3 – Plot of CINR curve versus EUT channel output signal level in dB(µV) . 12


Table B.1 – Null transport stream packet definition . 15

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60728-3-1  IEC:2012 – 3 –


INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________



CABLE NETWORKS FOR TELEVISION SIGNALS,

SOUND SIGNALS AND INTERACTIVE SERVICES –



Part 3-1: Active wideband equipment for cable networks –

Methods of measurement of non-linearity for

full digital channel load with DVB-C signals




FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60728-3-1 has been prepared by technical area 5: Cable networks
for television signals, sound signals and interactive services, of IEC technical committee 100:
Audio, video and multimedia systems and equipment.
The text of this standard is based on the following documents:
FDIS Report on voting
100/1969/FDIS 100/2006/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.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

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– 4 – 60728-3-1  IEC:2012


The list of all parts of the IEC 60728 series, under the general title, Cable networks for

television signals, sound signals and interactive services, can be found on the IEC website.


The committee has decided that the contents of this publication will remain unchanged until

the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data

related to the specific publication. At this date, the publication will be


• reconfirmed,

• withdrawn,

• replaced by a revised edition, or

• amended.

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60728-3-1  IEC:2012 – 5 –


INTRODUCTION


Standards of the IEC 60728 series deal with cable networks including equipment and

associated methods of measurement for headend reception, processing and distribution of

television signals, sound signals and their associated data signals and for processing,

interfacing and transmitting all kinds of signals for interactive services using all applicable

transmission media.


This includes


1
• CATV -networks,

• MATV-networks and SMATV-networks,
• individual receiving networks,
and all kinds of equipment, systems and installations installed in such networks.
For active equipment with balanced RF signal ports this standard applies only to those ports
which carry RF broadband signals for services as described in the scope of this standard.
The extent of this standardization work is from the antennas and/or special signal source
inputs to the headend or other interface points to the network up to the terminal input.
The standardization of any user terminals (i.e., tuners, receivers, decoders, multimedia
terminals, etc.) as well as of any coaxial, balanced and optical cables and accessories thereof
is excluded.

___________
1
 This word encompasses the HFC networks used nowadays to provide telecommunications services, voice,
data, audio and video both broadcast and narrowcast.

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– 6 – 60728-3-1  IEC:2012


CABLE NETWORKS FOR TELEVISION SIGNALS,

SOUND SIGNALS AND INTERACTIVE SERVICES –



Part 3-1: Active wideband equipment for cable networks –

Methods of measurement of non-linearity for

full digital channel load with DVB-C signals








1 Scope
This part of IEC 60728 is applicable to the methods of non-linearity measurement for cable
networks which carry only digitally modulated television signals, sound signals and signals for
interactive services. These methods take into account the specific signal form and behaviour
of digitally modulated signals which differ from the analogue broadcast signals represented
mainly by the existence of discrete carrier signals.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60728-3, Cable networks for television signals, sound signals and interactive services –
Part 3: Active wideband equipment for cable networks
ISO/IEC 13818-1:2007, Information technology – Generic coding of moving pictures and
associated audio information: Systems
3 Terms, definitions, symbols and abbreviations
For the purposes of this document, the following terms, definitions, symbols and abbreviations
apply.
3.1 Terms and definitions
Subclause 3.1 of IEC 60728-3 is applicable except as follows.

Addition:
3.1.25
maximum operating output level
average channel power level of a digitally modulated signal in the 256 QAM format with a
symbol rate of 6,9 MSymb/s with 15 % cosine roll-off, measured with full digital channel load
Note 1 to entry: This maximum operating output level has no direct correlation to that derived from CTB/CSO
measurements of analogue or mixed analogue-digital channel loads.

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60728-3-1  IEC:2012 – 7 –


3.2 Symbols


The following graphical symbols are used in the figures of this standard. These symbols are

either listed in IEC 60617 or based on symbols defined in IEC 60617.


Symbols Terms Symbols Terms

Equipment Under



Test  Band-pass filter
EUT



based on [IEC 60617-S01249

[IEC 60617-S00059 (2001-07)]

(2001-07)]

Spectrum analyzer



Variable attenuator (electrical)

P(f)
A
[IEC 60617-S01245 based on
(2001-07)] [IEC 60617-S00910
(2001-07)]
Combiner

Amplifier

based on
Σ

[IEC 60617-S01239
[IEC 60617-S00059
(2001-07]
(2001-07)]

Modulator Demodulator

based on based on

[IEC 60617-S01278 [IEC 60617-S01278
(2001-07)] (2001-07]

3.3 Abbreviations
BER bit error ratio
CATV community antenna television (system)
CINR carrier to intermodulation noise ratio
CSO composite second order
CTB composite triple beat
DVB digital video broadcasting
EUT equipment under test
HFC hybrid fibre coax
MATV master antenna television (system)

MEAS measured
PRBS pseudo-random bit sequence
QAM quadrature amplitude modulation
RF radio frequency
SMATV satellite master antenna television (system)
SYS system
UHF ultra-high frequency
VHF very-high frequency
U maximum operating output level with channel load of 112 carriers in
max (N)
the 256 QAM format

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– 8 – 60728-3-1  IEC:2012


4 Methods of measurement of non-linearity for full digital channel load


4.1 Maximum operating output level using the measurement of bit error ratio (BER)


4.1.1 General


The method of measurement describes the measurement of the bit error ratio (BER) (before

Reed Solomon decoder of the measurement receiver) of the output signal of the equipment
under test (EUT) (e.g. an amplifier) when handling a full load of digitally modulated TV
signals.


This test is able to define the performance (maximum output level) of the EUT when loaded
with a number (N = 112) of digitally modulated signals in the 256 QAM format covering a
frequency range from 110 MHz to 1 006 MHz with a raster of 8 MHz.
NOTE 1 Due to different channel spacing plans in use, the lower frequency limit may not be exactly 110 MHz, but
may differ by some megahertz, e.g. 109 MHz. In the same way, the upper frequency limit may not be exactly
1 006 MHz, but may differ by some megahertz. The notation 110 MHz to 1 006 MHz in this standard is intended to
include such small deviations.
The number N can be reduced according to the used frequency range of the EUT, e.g. to
N = 94 for 862 MHz upper frequency limit. In all cases the EUT shall be fully loaded.
The measurement shall be performed for the following three channels:
a) the lowest RF channel according to the specified operating frequency range of the EUT;
b) the highest RF channel according to the specified operating frequency range of the EUT;
c) an RF channel at the arithmetic mean between the lowest and the highest RF channels
according to a) and b).
NOTE 2 Examples of these measurement channels are given in informative Annex B.
The worst case value of U of the EUT out of the three measured values according to a)
max (N)
to c) shall be presented together with the worst case channel.
4.1.2 Equipment required
The equipment required is the following:
a) a number N of 256 QAM modulators (with channel coders) having a suitable linearity (BER
–10
better than 1 × 10 ) and an occupied bandwidth of 8 MHz. The channels generated by
the modulators shall be placed in the frequency range from 110 MHz to 1 006 MHz or in a
subset of this frequency range with a raster of 8 MHz;

b) a number N of null packet or of pseudo-random bit sequence (PRBS) generators (see
Annex B);
c) a combiner for the output signals of the 256 QAM modulators with negligible distortion;
d) a wide band amplifier with suitable linearity and gain over the full bandwidth of the EUT;
e) precision attenuators (1 dB steps) to be placed before and after EUT;
f) a test receiver able to measure the BER of the received 256 QAM signals; its distortion
–10
should be sufficiently lower than that to be measured (e.g. a BER better than 1 × 10 ).
All applied QAM channels (channel load and measurement channels) shall have the same
output level within a deviation of maximum ±0,5 dB.
–10
The total BER introduced by source and measurement equipment shall not exceed 1 × 10 .

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60728-3-1  IEC:2012 – 9 –


4.1.3 Connection of equipment


Connect the measuring equipment as indicated in Figure 1. The input signal is applied to the

equipment under test (EUT) input and its output signal level is measured by means of a

suitable measuring receiver, connected to a BER measuring set if not included in the

measuring receiver.


G Channel
coder



G
Channel
coder
BER
measuring
EUT A
A
Σ
set
Variable
Variable Measuring
attenuator B
attenuator A receiver with
RF demodulator
G
Channel
coder
Null packet
IEC  1278/12
or PRBS RF-modulator
generator

Figure 1 – BER measurement test configuration
4.1.4 Measurement procedure
The measurement shall be performed according to the steps described hereafter.
a) Tune the measuring receiver to an operating channel.
b) Measure the performance of the test configuration by connecting directly the output of the
variable attenuator A to the input of the variable attenuator B, reducing the attenuation of
the variable attenuator A to 0 dB and setting the variable attenuator B to a value that
–10
allows the best performance of the measuring receiver in terms of BER (<1 × 10
measured over an observation time >10 min). Note the level of the signal applied to the
measuring receiver and the BER value obtained.
c) Connect the EUT between the variable attenuator A and the variable attenuator B.
d) The equipment under test shall be operated at nominal gain and with nominal slope.
e) Using the variable attenuator A, set the channel output signal level of the EUT to a value

at least 10 dB lower than the maximum value (according to the methods of measurement
described in IEC 60728-3, using the CENELEC 42 channel test frequency plan); set the
variable attenuator B so as to obtain the previously determined optimum signal level at the
input of the measuring receiver.
–9
f) Read the BER on the measuring set which shall be <1 × 10 (measured over an
observation time >60 s).
g) Using the attenuator A, increase the output level of all applied channels by 1 dB and set
the variable attenuator B so as to obtain the previously determined optimum signal level at
the input of the measuring receiver.
–9
h) Repeat procedure g) until the BER measuring set shows a value >1 × 10 .
i) Then reduce the output level of all applied channels by 1 dB and set the variable
attenuator B so as to obtain the previously determined optimum signal level at the input of
the measuring receiver.
–9
j) Read the BER on the measuring set which once more shall be <1 × 10 (measured over
an observation time of >60 s). If not, repeat step i).

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– 10 – 60728-3-1  IEC:2012


k) Note the output level of the EUT which represents the maximum operating output level of

the EUT.


This procedure shall be repeated for each channel as defined in 4.1.1 and the worst case

(lowest value of the maximum operating output level) shall be determined.


4.1.5 Presentation of the results

The worst case value of the maximum operating output level U of the EUT, with N

max (N)
channels applied and expressed in dB(µV), as defined in 4.1.1, shall be published. The worst-

case-channel condition shall be determined.


If the three test channels are applied to an amplifier with frequency slope, the same method of
measurement shall be applied as for amplifiers without frequency slope. But in this case the
maximum operating output level of the EUT shall always be stated for the highest
measurement channel, taking into account the relative slope value (slope value difference)
between the worst case channel and the highest measurement channel.
The frequency response (slope) of the EUT used for the measurements shall be published.
4.2 Measurement of the carrier-to-interference noise ratio CINR
4.2.1 General
In addition to the measurement of the maximum operating output level U of broadband
max (N)
–9
equipment at the borderline of the bit error ratio (1 × 10 ) according to 4.1 the carrier-to-
interference noise ratio shall be determined.
4.2.2 Equipment required
Figure 2 shows the measurement test setup.
The equipment required is the following:
a) a number N of 256 QAM modulators (with channel coders) having a suitable linearity
(shoulder attenuation) and an occupied bandwidth of 8 MHz; the channels generated by
the modulators shall be placed in the frequency range from 110 MHz to 1 006 MHz or in a
subset of this frequency range with a raster of 8 MHz;
b) a number N of null packet or of pseudo-random bit sequence (PRBS) generators (see
Annex B);
c) a combiner for the output signals of the 256 QAM modulators with negligible distortion;
d) a wide band amplifier with suitable linearity and gain over the full bandwidth of the EUT;

e) precision attenuators (1 dB steps) with sufficient attenuation range to be placed before
and after EUT;
f) a spectrum analyzer able to measure the CINR in a non-occupied measurement channel.
All applied QAM channels (channel load and measurement channels) shall have the same
output level within a deviation of maximum ±0,5 dB.
The complete measurement setup as described above should have a CINR >60 dB.
If the shoulder attenuation of the modulators is not sufficient or in the case of residual general
spurious signals transmitted by the modulators a notch filter (dashed box in Figure 2) should
be inserted in front of the EUT to achieve for the test equipment the required CINR value
>60 dB.

---------------------- Page: 12 ----------------------
60728-3-1  IEC:2012 – 11 –


Furthermore, the CINR value of the test equipment may be improved by inserting a bandpass

filter at the input of the spectrum analyzer (dashed box in Figure 2). In this case, the minimum

attenuation of the variable attenuator B shall not go below a limit of 5 dB to assure sufficient

broadband impedance matching and appropriate return loss for correct measurement results.


G
Channel
coder



G
Channel

coder

P(f)
EUT A
A
Σ
Variable Notch Variable
attenuator A filter attenuator B
G
Channel
coder
IEC  1279/12

Figure 2 – CINR measurement test setup
4.2.3 Connection of the equipment
Connect the measuring equipment as indicated in Figure 2. The input signal is applied to the
equipment under test (EUT) input and its output signal level is measured by means of a
suitable spectrum analyzer. See also the remarks in 4.2.2 concerning additional means for
CINR value improvement of the test equipment.
4.2.4 Measurement procedure
The measurement shall be performed according to the steps described hereafter.
a) Tune the spectrum analyser to the channel to be measured in the used frequency band
and measure the system level as reference. The system level is defined as the level of
one of the occupied QAM channels. Switch the channel modulator temporarily off for the
CINR-measurement.
b) Measure the performance of the test setup connecting directly the output of the variable
attenuator
...