CLC/TR 50083-10-1:2009

Cable networks for television signals, sound signals and interactive services - Part 10-1: Guidelines for the implementation of return paths in cable networks

1.1 General Standards of the EN 50083 and EN 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 • CATV )-networks; • MATV-networks and SMATV-networks; • individual receiving networks; and all kinds of equipment, systems and installations installed in such networks. 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. 1.2 Specific scope of this Technical Report This document is intended to provide guidance to network designers on the issues which should be addressed, when considering the design of a CATV (HFC) return path. Items such as return path architecture & design, channel performance, channel planning & sources of interference, measurements, segmentation & re-segmentation, in home networks, distortion and commissioning are included. This document is not intended as a design reference but provides details which need to be addressed on individual issues relating to the design of the CATV/HFC return path.

Kabelnetze für Fernsehsignale, Tonsignale und interaktive Dienste - Teil 10-1: Leitfaden für die Einrichtung von Rückkanälen in Kabelnetzen

Réseaux de distribution par câbles pour signaux de télévision, signaux de radiodiffusion sonore et services interactifs - Partie 10-1: Lignes directrices relatives à la mise en oeuvre de la voie de retour dans les réseaux câblés

Kabelska omrežja za televizijske in zvokovne signale ter interaktivne elemente - 10-1. del: Smernice za uporabo povratnih poti v kabelskih omrežjih

General Information

• Status: Withdrawn
• Publication Date: 12-Feb-2009
• ICS: 33.060.40 - Cabled distribution systems
• Technical Committee: CLC/TC 209 - Cable networks for television signals, sound signals and interactive services
• Parallel Committee: IEC/TC 100 - IEC_TC_100
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 06-Jun-2014
• Completion Date: 06-Jun-2014
• Ref Project: SIST-TP CLC/TR 50083-10-1:2009 - Cable networks for television signals, sound signals and interactive services - Part 10-1: Guidelines for the implementation of return paths in cable networks

Relations

• Replaced By: CLC/TR 50083-10-1:2014 - Cable networks for television signals, sound signals and interactive services - Part 10-1: Guidelines for the implementation of return paths in cable networks
• Effective Date: 29-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2009
Kabelska omrežja za televizijske in zvokovne signale ter interaktivne elemente - 10
-1. del: Smernice za uporabo povratnih poti v kabelskih omrežjih
Cable networks for television signals, sound signals and interactive services - Part 10-1:
Guidelines for the implementation of return paths in cable networks
Kabelnetze für Fernsehsignale, Tonsignale und interaktive Dienste - Teil 10-1: Leitfaden
für die Einrichtung von Rückkanälen in Kabelnetzen
Réseaux de distribution par câbles pour signaux de télévision, signaux de radiodiffusion
sonore et services interactifs - Partie 10-1: Lignes directrices relatives à la mise en
oeuvre de la voie de retour dans les réseaux câblés
Ta slovenski standard je istoveten z: CLC/TR 50083-10-1:2009
ICS:
33.060.40 Kabelski razdelilni sistemi Cabled distribution systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CLC/TR 50083-10-1
RAPPORT TECHNIQUE
February 2009
TECHNISCHER BERICHT
ICS 33.060.40
English version
Cable networks for television signals,
sound signals and interactive services -
Part 10-1: Guidelines for the implementation of return paths
in cable networks
Réseaux de distribution par câbles Kabelnetze für Fernsehsignale,
pour signaux de télévision, Tonsignale und interaktive Dienste -
signaux de radiodiffusion sonore Teil 10-1: Leitfaden für die Einrichtung
et services interactifs - von Rückkanälen in Kabelnetzen
Partie 10-1: Lignes directrices relatives
à la mise en oeuvre de la voie de retour
dans les réseaux câblés
This Technical Report was approved by CENELEC on 2008-12-05.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: avenue Marnix 17, B - 1000 Brussels

© 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. CLC/TR 50083-10-1:2009 E

Foreword
This Technical Report was prepared by the Technical Committee CENELEC TC 209, Cable networks for
television signals, sound signals and interactive services.
The text of the draft was submitted to the vote in accordance with the Internal Regulations, Part 2,
Subclause 11.4.3.3 (simple majority) and was approved by CENELEC as CLC/TR 50083-10-1 on
2008-12-05.
__________
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Contents
1 Scope . 7
1.1 General. 7
1.2 Specific scope of this Technical Report . 7
2 Normative references . 7
3 Terms, definitions, symbols and abbreviations . 8
3.1 Terms and definitions . 9
3.2 Symbols .11
3.3 Abbreviations .12
4 Network architecture .14
4.1 HFC architecture .14
4.2 Upgrade alternatives .16
4.3 Active or passive return path .26
4.4 In building network .26
4.5 In home network .27
5 Network design .28
5.1 Considerations .28
5.2 Return path loss, path loss difference and return path slope .28
5.3 Noise and nonlinearity, optimising signal levels .32
5.4 Isolation between outlets.35
5.5 Equalisation and filtering in return paths .35
6 Channel planning .38
6.1 Purpose of this section .38
6.2 Introduction .38
6.3 Summary .38
6.4 Considerations for channel planning .39
6.5 Common path distortion products .44
6.6 European upstream bandwidths .44
6.7 Channel width .44
6.8 QPSK/16QAM operation and channel widths .44
6.9 Available return path spectrum (Table 8) .45
6.10 Channel plans .46
6.11 Network radiation .48
7 Equipment for return path implementation .48
7.1 General.48
7.2 Return path amplifiers .48
7.3 Equipment for fibre optic return links .51
8 Installation and maintenance .51
8.1 Signal level adjustment .51
8.2 Monitoring and measurements .56

Annex A (informative) Interference on return path .59
A.1 Multiple interference .59
A.2 Impulse interference .69
A.3 Interference from home terminals .71
A.4 Hum modulation .71
A.5 Common path distortion (CPD) .72
Annex B (informative) Methods of measurement .82
B.1 Noise power ratio (NPR) measurement on return path .82
B.2 10-Tone measurement .88
B.3 Modulation error ratio (MER) measurement on return path .91
B.4 Null packet and PRBS definitions .93
Annex C (informative) ITU DWDM grid .95
Bibliography .97
Figures
Figure 1 – Typical HFC topology . 14
Figure 2 – Regional network . 15
Figure 3 – Trunk-and-distribution architecture using only coaxial equipment . 16
Figure 4 – HFC system . 17
Figure 5 – Generic diagram showing the mapping of nodes and CMTS(s) to segments . 18
Figure 6 – Segment comprising a single CMTS to six optical nodes . 18
Figure 7 – Spectrum allocation bandwidth . 19
Figure 8 – Basic node architecture . 20
Figure 9 – Re-arranged feeds (two CMTS serving four nodes) . 21
Figure 10 – Optical node with frequency stacking . 22
Figure 11 – Divided node . 22
Figure 12 – Return path segmentation . 23
Figure 13 – Division of the node areas using additional fibres. . 23
Figure 14 – DWDM (CWDM) return path transmission . 24
Figure 15 – Digital return technology basic concept . 25
Figure 16 – Two return paths multiplexed to the transmission stream . 25
Figure 17 – Optical node segmentation . 26
Figure 18 – In house structures for transparent return path transmission . 27
Figure 19 – Example of forward and return path network with operating levels for the drop and
in home parts of the network . 29
Figure 20 – Example of a block diagram of return path amplifier. 49
Figure 21 – Commissioning of the forward path. 52
Figure 22 – Commissioning of the return path amplifiers using the same method as on the
forward path . 52
Figure 23 – Problem when commissioning return path amplifiers following the method used for
downstream amplifiers (standard output levels) . 53
Figure 24 – Unity gain method . 54
Figure 25 – Optical reverse path . 54

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Figure 26 – Optical node with reverse transmitter . 55
Figures in annexes
Figure A.1 – Typical spectrum of a return path . 59
Figure A.2 – Noise funnelling . 60
Figure A.3 – Average noise level vs. the number of subscribers and the return path frequency [6] . 61
Figure A.4 – Simplified equivalent circuit of a drop cable .
...