IEC 60728-14:2014

IEC 60728-14 ®
Edition 1.0 2014-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Cable networks for television signals, sound signals and interactive services –
Part 14: Optical transmission systems using RFoG technology

Réseaux de distribution par câbles pour signaux de télévision, signaux de
radiodiffusion sonore et services interactifs –
Partie 14: Systèmes de transmission optique appliquant la technologie RFoG
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IEC 60728-14 ®
Edition 1.0 2014-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Cable networks for television signals, sound signals and interactive services –

Part 14: Optical transmission systems using RFoG technology

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

radiodiffusion sonore et services interactifs –

Partie 14: Systèmes de transmission optique appliquant la technologie RFoG

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX XA
ICS 33.060.40; 33.160; 33.180 ISBN 978-2-8322-1439-8

– 2 – IEC 60728-14:2014 © IEC 2014
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions, symbols and abbreviations . 10
3.1 Terms and definitions . 10
3.2 Symbols . 16
3.3 Abbreviations . 16
4 System reference model . 17
5 RFoG ONU reference architecture . 18
6 Method of measurements . 19
6.1 Optical power . 19
6.2 Centroidal wavelength and spectral width under modulation . 19
6.3 Optical wavelength . 20
6.4 Linewidth and chirping of transmitters with single mode lasers . 20
6.5 Optical modulation index . 20
6.6 Reference output level of an optical receiver. 20
6.7 Noise parameters of optical transmitters and optical receivers . 20
6.8 Relative intensity noise (RIN), optical modulation index and equivalent
input noise current (EINC) . 20
6.9 Carrier level and carrier-to-noise ratio . 20
6.10 Noise power ratio (NPR) . 20
6.11 Carrier-to-noise ratio defined by optical signal . 21
6.12 Carrier-to-crosstalk ratio (CCR) . 21
7 System performance requirements . 21
7.1 Digital data system . 21
7.1.1 ODN . 21
7.1.2 Performance allocation . 21
7.2 Forward path and return path frequency split . 22
8 RFoG equipment specifications . 22
8.1 General specifications . 22
8.1.1 Safety . 22
8.1.2 Electromagnetic compatibility (EMC) . 22
8.1.3 Environmental conditions . 22
8.1.4 Marking . 23
8.2 R-ONU . 23
8.2.1 Indicators . 23
8.2.2 R-ONU forward path receiver specifications . 23
8.2.3 Return path performance of R-ONU . 25
8.2.4 Remote control functions . 29
8.3 Headend specifications . 34
8.3.1 Headend forward path specifications . 34
8.3.2 Headend return path specifications: R-RRX . 34

Annex A (informative) Implementation notes . 36
Annex B (informative) System loss specification . 38
B.1 General . 38
B.2 Forward path considerations . 38
B.3 Return path considerations . 39
Annex C (informative) Optical beat interference . 42
C.1 General . 42
C.2 Operating conditions of ODN . 42
C.3 Operating conditions of optical receiver at the headend system. 42
C.4 Operating conditions of CMTS . 43
C.5 Environmental conditions. 43
C.6 Relation between optical transmission loss and OMI . 43
C.7 Design margin of ODN . 44
C.8 Example of system design . 45
C.9 Method of measurement of OBI . 46
C.9.1 Purpose . 46
C.9.2 Measurement setup . 46
C.9.3 Example of measurement conditions . 46
C.9.4 Procedure . 47
C.9.5 Presentation of results . 47
C.10 Method of measurement of OBI (measurement with CW signals) . 47
C.10.1 Purpose . 47
C.10.2 Measurement setup . 47
C.10.3 Procedure . 48
Annex D (normative) Optional remote control manager . 49
Annex E (informative) Outdoor housings for R-ONU protection . 50
Annex F (informative) Effect of off-state optical power on C/N ratio of transmission
signal. 51
Bibliography . 53

Figure 1 – Optical system reference model for RFoG . 18
Figure 2 – Principle schematics of R-ONU . 19
Figure 3 – Measurement of optical wavelength using WDM coupler . 20
Figure 4 – R-ONU turn-on and turn-off diagram . 29
Figure 5 – Example of the remote control system configuration . 30
Figure 6 – Data format . 31
Figure 7 – Structure of data packet . 31
Figure 8 – Control transfer process . 32
Figure 9 – Timing of data transmission . 32
Figure A.1 – Placement of attenuators when system loss is too low . 37
Figure B.1 – Performance allocation of the return path transmission system . 39
Figure B.2 – Section C/N specification for SDU and MDU in-house wiring. 41
Figure C.1 – Optical transmission loss and OMI . 44
Figure C.2 – ODN design margin . 44
Figure C.3 – Setup used for the measurement of OBI . 46

– 4 – IEC 60728-14:2014 © IEC 2014
Figure C.4 – Setup used for the measurement of OBI (CW method). 48

Table 1 – ODN Specifications . 21
Table 2 – RF frequencies . 22
Table 3 – Classification of R-ONU optical receivers . 24
Table 4 – Data publication requirements for R-ONU optical receivers. 24
Table 5 – Recommendations for R-ONU optical receivers . 24
Table 6 – Performance requirements for R-ONU optical receivers. 25
Table 7 – Classes of optical return path transmitters . 25
Table 8 – Data publication requirements for optical return path transmitters . 26
Table 9 – Performance requirements for optical parameters and interfaces. 26
Table 10 – Electrical properties requirements for R-ONU optical return path transmitters . 27
Table 11 – R-ONU turn-on and turn-off specifications . 27
Table 12 – Remote control items . 30
Table 13 – Fundamental specification of data communication . 31
Table 14 – Content of data packets . 31
Table 15 – R-ONU address . 32
Table 16 – Recommendation for timing of data transmission. 33
Table 17 – Remote control command codes . 33
Table 18 – Specification of modulation for the remote control signal . 34
Table 19 – Data publication requirements for return path optical receivers . 35
Table 20 – Performance requirements for optical return path receivers . 35
Table C.1 – Operating conditions related to ODN parameters . 42
Table C.2 – Operating conditions related to ODN parameters . 43
Table C.3 – Environmental conditions for system evaluation . 43
Table C.4 – Factors affecting the transmission loss of ODN . 45
Table C.5 – System design example 1 . 45
Table C.6 – System design example 2 . 45
Table C.7 – Example of list of measurement conditions . 46
Table C.8 – Presentation of OBI measurement results . 47
Table C.9 – Presentation of OBI measurement results . 48
Table D.1 – Performance requirements for the FSK transmitter . 49

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
CABLE NETWORKS FOR TELEVISION SIGNALS,
SOUND SIGNALS AND INTERACTIVE SERVICES –

Part 14: Optical transmission systems using RFoG technology

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 60728-14 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
100/2248/FDIS 100/2284/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.

– 6 – IEC 60728-14:2014 © IEC 2014
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The list of all the 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.
This standard follows closely (where applicable) the ANSI/SCTE 174 2010 standard “Radio
Frequency over Glass / Fiber-to-the-Home Specification”. In agreement with SCTE major
parts of ANSI/SCTE 174:2010 have been copied into this standard.
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.
___________
SCTE = Society of Cable Telecommunications Engineers

INTRODUCTION
Standards and other deliverables of the IEC 60728 series deal with cable networks including
equipment and associated methods of measurement for headend reception, processing and
distribution of television and sound signals and for processing, interfacing and transmitting all
kinds of data signals for interactive services using all applicable transmission media. These
signals are typically transmitted in networks by frequency-multiplexing techniques.
• regional and local broadband cable networks,
• extended satellite and terrestrial television distribution systems,
• individual satellite and terrestrial television receiving systems,
and all kinds of equipment, systems and installations used in such cable networks, distribution
and receiving systems.
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 of the customer
premises equipment.
The standardization work will consider coexistence with users of the RF spectrum in wired and
wireless transmission systems.
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.
The Annexes provide the following information.
Annex A describes implementation notes with design consideration based on this standard
Annex B describes the system loss specification
Annex C describes multiple CMTS operation
Annex D contains specifications for an optional remote control system
Annex E gives a design guideline of housings for R-ONU protection
Annex F contains information on the effect of off-state optical power on C/N ratio of
transmission signal
– 8 – IEC 60728-14:2014 © IEC 2014
CABLE NETWORKS FOR TELEVISION SIGNALS,
SOUND SIGNALS AND INTERACTIVE SERVICES –

Part 14: Optical transmission systems using RFoG technology

1 Scope
This part of IEC 60728 describes the system and equipment specification of FTTH/FTTB (fibre
to the home/fibre to the building) networks where information is transmitted in both, forward
and return path directions using RF subcarrier multiplexing technology, and where the return
path transmission uses additionally time division multiple access technique imposed by the
transmission of the return path signals using a TDMA (e.g. TDMA mode of DOCSIS) protocol.
Such systems are called RF over Glass (RFoG) and consist of an RFoG optical network unit
(R-ONU), an optical distribution network based on xPON structure, and an RFoG optical return
path receiver. This standard specifies the basic system parameters and methods of
measurement for RFoG systems in order to assess the system performance and its
performance limits.
The detailed description of physical layer is out of the scope of this standard and it does not
include IP transport technologies.
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 60068-1:1988, Environmental testing – Part 1: General and guidance
IEC 60068-2-1, Environmental testing – Part 2-1: Tests – Test A: Cold
IEC 60068-2-2, Environmental testing – Part 2-2: Tests – Test B: Dry heat
IEC 60068-2-6:2007, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-14, Environmental testing – Part 2-14: Tests – Test N: Change of temperature
IEC 60068-2-27, Environmental testing – Part 2-27: Tests – Test Ea and guidance: Shock
IEC 60068-2-30, Environmental testing – Part 2-30: Tests – Test Db: Damp heat, cyclic (12 h +
12 h cycle)
IEC 60068-2-31, Environmental testing – Part 2-31: Tests – Test Ec: Rough handling shocks,
primarily for equipment-type specimens
IEC 60068-2-40, Environmental testing – Part 2-40: Tests – Test Z/AM: Combined cold/low air
pressure tests
IEC 60529, Degrees of protection provided by enclosures (IP Code)

IEC 60728-1, Cable networks for television signals, sound signals and interactive services –
Part 1: System performance of forward paths
IEC 60728-2, Cable networks for television signals, sound signals and interactive services –
Part 2: Electromagnetic compatibility of equipment
IEC 60728-3, Cable networks for television signals, sound signals and interactive services –
Part 3: Active wideband equipment for cable networks
IEC 60728-6:2011, Cable networks for television signals, sound signals and interactive
services – Part 6: Optical equipment
IEC 60728-10:2014, Cable networks for television signals, sound signals and interactive
services – Part 10: System performance of return path
IEC 60728-11, Cable networks for television signals, sound signals and interactive services –
Part 11: Safety
IEC 60728-13:2010, Cable networks for television signals, sound signals and interactive
services – Part 13: Optical systems for broadcast signal transmissions
IEC 60728-13-1:2012, Cable networks for television signals, sound signals and interactive
services – Part 13-1: Bandwidth expansion for broadcast signal over FTTH system
IEC 60793-2-50:2012, Optical fibres – Part 2-50: Product specifications – Sectional
specification for class B single-mode fibres
IEC 60794-3-11:2010, Optical fibre cables – Part 3-11: Outdoor cables – Product specification
for duct, directly buried, and lashed aerial single-mode optical fibre telecommunication cables
IEC 60825-1, Safety of laser products – Part 1: Equipment classification and requirements
IEC 61169-2, Radio-frequency connectors – Part 2: Sectional specification – Radio frequency
coaxial connectors type 9,52
IEC 61169-24, Radio-frequency connectors – Part 24: Sectional specification – Radio-
frequency coaxial connectors with screw coupling, typically for use in 75 ohm cable distribution
systems (Type F)
IEC 61280-1-1, Fibre optic communication subsystem basic test procedures – Part 1-1:Test
procedures for general communication subsystems – Transmitter output optical power
measurement for single-mode optical fibre cable
IEC 61280-1-3, Fibre optic communication subsystem test procedures – Part 1-3: General
communication subsystems – Central wavelength and spectral width measurement
IEC 61754-4, Fibre optic interconnecting devices and passive components – Fibre optic
connector interfaces – Part 4: Type SC connector family
IEC/TR 61931:1998, Fibre optics – Terminology
IEEE Standard 802.3-2008, Carrier sense multiple access with Collision Detection (CSMA/CD)
Access Method and Physical Layer Specifications (Includes the EPON standard). See also
subsequent corrigenda
– 10 – IEC 60728-14:2014 © IEC 2014
IEEE Standard 802.3av-2009, IEEE Standard for Information Technology-Part 3: Amendment 1:
Physical Layer Specifications and Management Parameters for 10Gb/s Passive Optical
Networks, October 2009
3 Terms, definitions, symbols and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60728-1 and
IEC/TR 61931 as well as the following apply.
3.1.1
carrier-to-crosstalk ratio
CCR
level difference of desired signal carrier level and worst case of other services single frequency
crosstalk signal measured at RF output port of optical receiver
Note 1 to entry: CCR is defined by the following equation:

CCR = D −U
(1)
OtherService
where
D is the nominal level of the desired signal in dB(µV) at RF output port of optical receiver;
is the worst case level of another service’s single frequency crosstalk in dB(µV) at RF output port
U
OtherService
of the optical receiver.
Note 2 to entry: CCR is expressed in dB.
3.1.2
equivalent input noise current density
notional input noise current density which, when applied to the input of an ideal noiseless
device, produces an output noise current density equal in value to that observed at the output
of the actual device under consideration
Note 1 to entry: It can be calculated from the carrier-to-noise ratio C/N (see IEC 60728-6) of a device or system
using:
C
=
I
r
(2)
C/N
Z
where
C is the power of the carrier at the input of the device or system, in W/Hz;
Z is its input impedance, in Ω.
Note 2 to entry: The equivalent input noise current density is expressed in A/√Hz.
3.1.3
extended satellite television distribution network or system
distribution network or system designed to provide sound and television signals received by
satellite receiving antenna to households in one or more buildings
Note 1 to entry: This kind of network or system can be combined with terrestrial antennas for the additional
reception of TV and/or radio signals via terrestrial networks.
Note 2 to entry: This kind of network or system can also carry control signals for satellite switched systems or
other signals for special transmission systems (e.g. MoCA or WiFi) in the return path direction.

3.1.4
extended terrestrial television distribution network or system
distribution network or system designed to provide sound and television signals received by
terrestrial receiving antenna to households in one or more buildings
Note 1 to entry: This kind of network or system can be combined with a satellite antenna for the additional
reception of TV and/or radio signals via satellite networks.
Note 2 to entry: This kind of network or system can also carry other signals for special transmission systems (e.g.
MoCA or WiFi) in the return path direction.
3.1.5
fibre optic branching device
branching device
splitter
DEPRECATED: coupler
device, possessing three or more optical ports, which shares optical power among its ports in a
predetermined fashion, at the same wavelength or wavelengths, without wavelength conversion
Note 1 to entry: The ports may be connected to fibres, sources, detectors, etc.
[SOURCE: IEC/TR 61931:1998, definition 2.6.21]
3.1.6
flatness
difference between the maximum and the minimum RF gain or attenuation not taking into
account the slope within the specified modulation frequency range of a device or system
3.1.7
headend system
system comprising modulators, demodulators, CMTS, an optical transmitter with optional
optical amplifiers and a WDM for the transmission of analogue video as well as digitally
modulated signals located at the central office side of the optical network
Note 1 to entry: The headend system is equipped with an optical return path receiver receiving digitally modulated
signals of data in the return path direction to enable e.g. VoIP, VOD and internet services.
Note 2 to entry: V-OLT is a part of the headend system and deals with video transmission in the forward path only.
3.1.8
individual satellite television receiving system
system designed to provide sound and television signals received from satellite(s) to an
individual household
Note 1 to entry: This kind of system can also carry control signals for satellite switched systems or other signals
for special transmission systems (e.g. MoCA or WiFi) in the return path direction.
3.1.9
individual terrestrial television receiving system
system designed to provide sound and television signals received via terrestrial broadcast
networks to an individual household
Note 1 to entry: This kind of system can also carry other signals for special transmission systems (e.g. MoCA or
WiFi) in the return path direction.
3.1.10
local broadband cable network
network designed to provide sound and television signals as well as signals for interactive
services to a local area (e.g. one town or one village)

– 12 – IEC 60728-14:2014 © IEC 2014
3.1.11
multiplexing device
WDM device
wavelength selective branching device (used in WDM transmission systems) in which optical
signals can be transferred between two predetermined ports, depending on the wavelength of
the signal
[SOURCE: IEC/TR 61931:1998, definition 2.6.51]
3.1.12
noise power ratio
NPR
ratio of the signal power density to the power density of the combined noise and
intermodulation distortion
3.1.13
off-state optical power
residual optical output power emitted from the fibre of the R-ONU when the laser is switched to
off-state
Note 1 to entry: In a typical burst mode transmitter, for fast switching operation, the laser bias may be kept near
the threshold bias level to avoid turn-on and turn-off delays. The off-state optical power affects the system
performance when a large number of transmitters are connected to the same distribution network.
3.1.14
optical amplifier
OA
optical waveguide device containing a suitably pumped, active medium which is able to amplify
an optical signal
[SOURCE: IEC/TR 61931:1998, definition 2.7.75]
3.1.15
optical distribution network
ODN
passive optical network (PON) mainly consisting of optical fibres and splitters
3.1.16
optical receiving unit
optical receiver
Rx
receive fibre optic terminal device accepting at its input port a modulated optical carrier, and
providing at its output port the corresponding demodulated electrical signal (with the associated
clock, if digital)
[SOURCE: IEC/TR 61931:1998, definition 2.9.7]
Note 1 to entry: For the purposes of this standard, optical receivers may have more than one output port providing
electrical RF signals.
3.1.17
optical modulation index
index defined as
φ - φ
h l
m =
(3)
+
φ φ
h l
where φ is the highest and φ is the lowest instantaneous optical power of the intensity
h l
modulated optical signal
Note 1 to entry: This definition does not apply to systems where the input signals are converted and transported
as digital baseband signals. In this case, the terms modulation depth or extinction ratio defined in 2.6.79 and 2.7.46
of IEC/TR 61931:1998 are used. A test procedure for extinction ratio is described in IEC 61280-2-2.
[SOURCE: IEC 60728-6:2011, definition 3.1.10, modified – repetition of "optical modulation"
has been deleted.]
3.1.18
optical return loss
return loss
ORL
ratio of the total reflected power to the incident power from an optical fibre, optical device, or
optical system, and defined as:

P
r
−10lg
(4)
P
i
where
P is the reflected power;
r
P is the incident power
i
Note 1 to entry: When referring to a reflected power from an individual component, reflectance is the preferred
term.
[SOURCE: IEC/TR 61931:1998, definition 2.6.49]
Note 2 to entry: For the purposes of this standard, the term reflectance is used for optical amplifiers only. The
term optical return loss is used for ports of all other types of equipment.
Note 3 to entry: The term return loss is also used for electrical ports. The definition relates to electrical powers in
this case.
Note 4 to entry: The ratio is expressed in dB.
3.1.19
optical transmitting unit
optical transmitter
Tx
transmit fibre optic terminal device accepting at its input port an electrical signal and providing
at its output port an optical carrier modulated by that input signal
[SOURCE: IEC/TR 61931:1998, definition 2.9.6]
Note 1 to entry: For the purposes of this standard, optical transmitters may have more than one input port
accepting electrical RF signals.

– 14 – IEC 60728-14:2014 © IEC 2014
3.1.20
radio frequency over glass
RFoG
transmission technology on optical networks where information is transmitted in both, forward
and return path directions, using RF subcarrier multiplexing technology, and where the return
path transmission uses additionally time division multiple access technique imposed by the
transmission of the return path signals using a TDMA (e.g. TDMA mode of DOCSIS) protocol
3.1.21
reference output level of an optical receiver
offset x by which the electrical output level of an optical receiver can be calculated from the
optical input level at a modulation index of m = 0,05 using the following equation:

U = 2 P + x dB(µV) (5)
opt,RX
where
U is the electrical output level in dB(µV)
is the optical input level in dB(mW)
P
opt,RX
x is the reference output level in dB(µV)
3.1.22
responsivity
ratio of an optical detector’s electrical output to its optical input at a given wavelength
Note 1 to entry: The responsivity is expressed in ampere per watt (A/W) or volts per watt (V/W) of incident radiant
power.
Note 2 to entry: Sensitivity is sometimes used as an imprecise synonym for responsivity.
[SOURCE: IEC 60050-731:1991, 731-06-36, modified – "given wavelength" has been added
and Note 1 has been clarified.]
Note 3 to entry: The wavelength interval around the given wavelength may be specified.
[SOURCE: IEC/TR 61931:1998, definition 2.7.56]
3.1.23
relative intensity noise
RIN
ratio of the mean square of the intensity fluctuations in the optical power of a light source to the
square of the mean of the optical output power
−1
Note 1 to entry: The RIN is usually expressed in dB(Hz ) resulting in negative values.
Note 2 to entry: The value for the RIN can be calculated from the results of a carrier-to-noise measurement for the
system.
[SOURCE: IEC 60728-6:2011, 3.1.12]
3.1.24
RFoG optical network unit
R-ONU
fibre optic terminal comprising an optical receiver for reception of analogue signals and an
optical transmitter for the transmission of analogue signals originating from the customer side
of the optical network and a coaxial interface for the transmission of analogue signals to the
customer network and reception of analogue signals from the customer network generally
consisting of digital data using a TDMA (e.g. TDMA mode of DOCSIS) protocol

3.1.25
slope
gain or attenuation difference at two defined frequencies between two ports of a device or
system
Note 1 to entry: In this standard the term slope relates only to the electrical gain or attenuation of equipment.
Note 2 to entry: In equipment for cable networks a line of best fit of the amplitude frequency response is
considered at the band limits (see IEC 60728-6).
[SOURCE: IEC 60728-6:2011, 3.1.29]
3.1.26
Brillouin scattering
SBS
non-linear scattering of optical radiation characterized by a frequency shift as for the Raman
scattering, but accompanied by a lower frequency (acoustica
...