Hfc a catv-101

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Broadband System Broadband System -- AA

CATV CATV -- 101.101.

Satellites are spaced every2nd degrees above earth

TVTRANSMITTER

Cable area

"C" BandToward satellite 6.0 GHzToward earth 4.0 GHz

"L" BandToward satellite 14.0 GHzToward earth 12.0 GHz

Headend

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To give you plenty of time to read the details of each presentatTo give you plenty of time to read the details of each presentation, ion,

you’ll need to press the RIGHT ARROW KEY on your PC, so you you’ll need to press the RIGHT ARROW KEY on your PC, so you

have access to the next slide on this and in all future have access to the next slide on this and in all future

presentations.presentations.

3

Before we start the Seminar on Broadband system, let have a lookBefore we start the Seminar on Broadband system, let have a look

at the beginning of the CATV industry.at the beginning of the CATV industry.

This will help This will help youyou better understand what are the requirements for better understand what are the requirements for

toto--day’s Broadband System.day’s Broadband System.

This presentation is only a general idea and every subject This presentation is only a general idea and every subject

demonstrated in this presentation will be explained in more detademonstrated in this presentation will be explained in more details ils

in future presentations.in future presentations.


..

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CATVCATV : : CCommunity ommunity AAntenna ntenna TTelevisionelevision

CATV systems started in around 1952 and were a one way CATV systems started in around 1952 and were a one way

communication system, using coaxial cable and RF amplifiers. communication system, using coaxial cable and RF amplifiers.

These CATV system distributed television signals, from a These CATV system distributed television signals, from a

distribution center distribution center (Headend(Headend) to all the homes in a the cabled ) to all the homes in a the cabled

area. area.

Then, these systems were capable of distributing between 2 to Then, these systems were capable of distributing between 2 to

4 TV channels. From been able to distribute 2 to 4 TV channel at4 TV channels. From been able to distribute 2 to 4 TV channel at

their start, some of the systems finally carried as much as 12 their start, some of the systems finally carried as much as 12

television channels and some FM music.television channels and some FM music.

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In both country, Canada and the USA, you required a license to oIn both country, Canada and the USA, you required a license to operate a CATV perate a CATV

system. system.

In the United States, the cities give the permit to operate a CAIn the United States, the cities give the permit to operate a CATV system and TV system and

the the FCCFCC controls the technical data.controls the technical data.

FFederalederal

CCommunications ommunications

CCommissionommission

In Canada, the license is warded by theIn Canada, the license is warded by the CRTC CRTC

••CCanadiananadian

••RRadioadio

••TTelecommunicationselecommunications

••CCommissionommission

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•• TV Stations, VHF or UHF.TV Stations, VHF or UHF.

•• FM Stations.FM Stations.

•• Satellites, 4 and 12 GHz (around 1975).Satellites, 4 and 12 GHz (around 1975).

•• AML (microwave system).AML (microwave system).

•• TV Program from local studio.TV Program from local studio.

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4.5 MHz

3.59 MHz

6.0 MHz 0

-10

-20

-30

-40

-50

-60

-70

dBVideo sectionVideo section

4.2 MHz4.2 MHz

AnalogAnalog

technologytechnology

Audio sectionAudio section

0.9 MHz0.9 MHz

FM technologyFM technology

Color sectionColor section

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CHCH--2 : 55.25 MHz2 : 55.25 MHz CHCH--7 : 175.25 MHz7 : 175.25 MHz

CHCH--3 : 61.25 MHz3 : 61.25 MHz CHCH--8 : 181.25 MHz 8 : 181.25 MHz

CHCH--4 : 67.25 MHz4 : 67.25 MHz CH:CH:--9 : 187.25 MHz9 : 187.25 MHz

* 73.5 MHz Int. disaster freq.* 73.5 MHz Int. disaster freq. CHCH--10 : 193.25 MHz10 : 193.25 MHz

CHCH--5 : 77.25 MHz5 : 77.25 MHz CHCH--11 : 199.25 MHz 11 : 199.25 MHz

CHCH--6 : 83.25 MHz6 : 83.25 MHz CHCH--12 : 205.25 MHz12 : 205.25 MHz

FM : 88 to 108 MHzFM : 88 to 108 MHz CHCH--13: 211.25 MHz13: 211.25 MHz

* Notice, the difference in frequency, between CH* Notice, the difference in frequency, between CH--4 and CH4 and CH--5, which is 5, which is

not a multiple of 6 MHz. The reason being, thatnot a multiple of 6 MHz. The reason being, that 73.5 MHz73.5 MHz is allocated as is allocated as

an international disaster frequency, that is used by the Red Croan international disaster frequency, that is used by the Red Cross and ss and

some other international organization. some other international organization.

VHF TelevisionVHF Television Signal.Signal.

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UHF Television signal.UHF Television signal.

CHCH--14 : 471.25 MHz to CH14 : 471.25 MHz to CH--69 : 805.25 MHz69 : 805.25 MHz

All All UHFUHF signals, like the signals, like the VHFVHF signals, are located in a 6.00 signals, are located in a 6.00

MHz spacing, the UHF stations are located between MHz spacing, the UHF stations are located between 471 471 to to

810 MHz810 MHz. .

UHF channel, UHF channel, CHCH--3737, , 609.25 MHz609.25 MHz, in generally not used as it , in generally not used as it

is employed for Radio Astronomy.is employed for Radio Astronomy.

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Each television channel leaving the headend are controlled by;Each television channel leaving the headend are controlled by;

••Channel processor, ( RF in, RF out)Channel processor, ( RF in, RF out)

••Modulator, ( Baseband in, RF out)Modulator, ( Baseband in, RF out)

••Satellite Receiver, (4 or 12 GHz in, RF out) Satellite Receiver, (4 or 12 GHz in, RF out)

All the television channels are combined together with a channelAll the television channels are combined together with a channel

combiner before they are sent on to the coaxial system. combiner before they are sent on to the coaxial system.

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Combining Signal at a CATV HeadendCombining Signal at a CATV Headend

Processor

Modulator

Satellite

Receiver

Microwave

Receiver

RF Combiner

First Amplifierof the CATV system

Inputch.

IFfreq.

Outputch.

Outputch.

IFfreq.

Basebandsignal

ModulatorOutput

ch.IF

freq.Baseband

signal

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FM stationsFM stations22 66 77 1313

12 channel plan12 channel plan

This number television channels (12) was the maximum This number television channels (12) was the maximum

possible before the coming out of Push Pull amplifier. possible before the coming out of Push Pull amplifier.

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FM stationsFM stations2 6 7 131414 2222

21 channel plan21 channel plan

With Push Pull amplifier, it became possible to carry Mid Band With Push Pull amplifier, it became possible to carry Mid Band

channels (9) between 121 to 170 MHz, for a total of 21 channels channels (9) between 121 to 170 MHz, for a total of 21 channels

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FM

transmitter

TV

transmitter

Headend

CATVsystem

Satellitereception

TVtransmitter

FMtransmitter

4GHz

12GHz

MicrowaveSystem

SatellitesSatellites

Up LinkUp Link

TransmissionTransmission

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Coaxial cable consist ofCoaxial cable consist of ::

••75 ohms cable.75 ohms cable.

••Center conductor.Center conductor.

••Foam Foam (hold the center conductor in place)(hold the center conductor in place)

••Aluminum tube.Aluminum tube.

••Sometimes covert with PVC jacket.Sometimes covert with PVC jacket.

Coaxial cable are the most common way to distribute television cCoaxial cable are the most common way to distribute television channel.hannel.

••It frequency range is from 5 to 1000 MHzIt frequency range is from 5 to 1000 MHz

••It is also capable of handling It is also capable of handling 90 Volts AC90 Volts AC requires to operate RF amplifiers.requires to operate RF amplifiers.

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TYPETYPE 55 5050 300300 550550 865865 1,0001,000 MHzMHz

Main coaxial cable:Main coaxial cable: LossLoss

PP--IIIIII--500500 0.160.16 0.520.52 1.311.31 1.821.82 2.33 2.33 2.522.52 dB/100’dB/100’

PP--IIIIII--625625 0.130.13 0.420.42 1.081.08 1.511.51 1.941.94 2.072.07 “ ““ “

PP--IIIIII--750750 0.110.11 0.300.30 0.780.78 1.251.25 1.601.60 1.741.74 “ ““ “

Main drop installation cable:Main drop installation cable:

RGRG--5959 0.860.86 1.951.95 4.454.45 5.955.95 7.527.52 8.128.12 “ ““ “

RGRG--66 0.580.58 1.531.53 3.553.55 4.904.90 6.106.10 6.556.55 “ ““ “

Above loss are giving @ 68 degrees F. or 20 degrees C.Above loss are giving @ 68 degrees F. or 20 degrees C.

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50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 80031

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30

850

50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850

Input next amplifier after 30 dB spacing at 860 MHz

60 o

-40 o

140 o

499.25

Signal after cable equalizer

Signal after cable equa

lizer

Signal after cable equalizer

50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850

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Output previous amplifier

Behaviour of the coaxial cable response versus temperature change

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RF amplifier amplifies the signal when it becomes weakRF amplifier amplifies the signal when it becomes weak

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Connectors are required to make a connection between the Connectors are required to make a connection between the

amplifiers and the passives equipments on the coaxial cable.amplifiers and the passives equipments on the coaxial cable.

Ingress SleeveIngress Sleeve

Connection toConnection to

Outside tubeOutside tube

Connection toConnection to

central conductorcentral conductor

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RF splitter and coupler give the possibly to send coaxial RF splitter and coupler give the possibly to send coaxial

cable into two or more directions. cable into two or more directions.

Inputcable

Outcable

Outcable

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Standby powerStandby power

supply are workingsupply are working

on 110 volts ACon 110 volts AC

oror

36/48 Volts DC36/48 Volts DC

Power supply delivers 60 or 90 volts AC thru the Power supply delivers 60 or 90 volts AC thru the

coaxial cable, to permit RF amplifiers to work.coaxial cable, to permit RF amplifiers to work.

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RGRG--59 or RG59 or RG--66

Multitap make the connection between the CATVMultitap make the connection between the CATV

system and the customer.system and the customer.

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BTD BLE

Power

Passing

Tap

50-750 MHz5-40 MHz

From HeadendFrom Headend

RGRG--59 or RG59 or RG--66

A CATV systemA CATV system

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RF amplifier Coaxial cable Power Supply

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Broadband CATV systems are now a very complex, BiBroadband CATV systems are now a very complex, Bi--directional directional communications network, called; communications network, called; HFCHFC ((HHybrid ybrid FFiber iber CCoaxial) using oaxial) using Fiber Optic and Coaxial Cable technologies. Fiber Optic and Coaxial Cable technologies.

These systems are now delivering the following;These systems are now delivering the following;

••Analog Television programs.Analog Television programs.

••Television on demand or pay per view television.Television on demand or pay per view television.

•• Digital Television.Digital Television.

••HDTV (High Definition Television).HDTV (High Definition Television).

••High speed Internet service, by CablemodemHigh speed Internet service, by Cablemodem..

••Security systemSecurity system..

••IP telephony (VoIP).IP telephony (VoIP).

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HFC Broadband systems are using fiber optic technology to HFC Broadband systems are using fiber optic technology to transport the signals for the longest distance, between the headtransport the signals for the longest distance, between the headend end to a NODE (optical receiver). The node transfers the light signato a NODE (optical receiver). The node transfers the light signal to RF l to RF signal. The signals then continue thru the coaxial system to feesignal. The signals then continue thru the coaxial system to feed all d all the customers. The coaxial system permits to deliver the signalsthe customers. The coaxial system permits to deliver the signals at at less cost. Fiber optic delivers a better quality signal than coaless cost. Fiber optic delivers a better quality signal than coaxial xial cable, this is why fiber optic is used to transport the signal fcable, this is why fiber optic is used to transport the signal for the or the long distance. long distance.

A HFC system is a biA HFC system is a bi--directional system, and the working bandwidth directional system, and the working bandwidth from the headend to the customer is: from the headend to the customer is: 50 to 87050 to 870--1,000 MHz1,000 MHz, and from , and from customer to the headend is: customer to the headend is: 5 to 40 or 42 MHz5 to 40 or 42 MHz. .

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23 40 43 50

51 77

50

MHz

225

MHz

225

MHz

380

MHz

380

MHz

550

MHz

F M s t a t io n sF M s t a t io n s 1 4 2 2

In a modern Broadband system, the frequencies In a modern Broadband system, the frequencies below below 550 MHz are generally 550 MHz are generally

used for the transport used for the transport analogical channels (NTSC).analogical channels (NTSC).

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DD = Digital, Data, IP Telephony, Video On Demand= Digital, Data, IP Telephony, Video On Demand

78 103

DD DD DD DD DD D DD

550

MHz

870

MHz

Standard Television channels can be replaced by digital televisiStandard Television channels can be replaced by digital television on

or other digital services (or other digital services (Data, Cablemodem, Security system, IP Data, Cablemodem, Security system, IP

Telephony system, etcTelephony system, etc.) on a modern HFC system..) on a modern HFC system.

In a modern Broadband system, the frequencies above 550 MHz are In a modern Broadband system, the frequencies above 550 MHz are generally generally

used for the transport of the digital portion of the HFC system.used for the transport of the digital portion of the HFC system. QAM digital QAM digital

channels and a standard television channels can well exits side channels and a standard television channels can well exits side by side.by side.

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Response of a 870 MHz HFC systemResponse of a 870 MHz HFC system

15 to 20dBmV

300MHz

450MHz

225MHz

121.25MHz

108MHz

50MHz

550MHz

750MHz

870MHz

80 NTSC, Analog channels.80 NTSC, Analog channels. 220 MHz of 64 or 256 QAM signals.220 MHz of 64 or 256 QAM signals.

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core

cladding

coating

9 mc

The transmitted light is guided down the fiber by reflecting offThe transmitted light is guided down the fiber by reflecting off the outside of the the outside of the

core. The core's index of refraction is slightly higher than thacore. The core's index of refraction is slightly higher than that of the surrounding t of the surrounding

cladding to insure internal refraction. The core is surrounded bcladding to insure internal refraction. The core is surrounded by optical material y optical material

called the cladding. The cladding causes the light to remain inscalled the cladding. The cladding causes the light to remain inside the core. The ide the core. The

core and the cladding are usually made of ultracore and the cladding are usually made of ultra--pure glass called silica. The pure glass called silica. The

materials need to be ultramaterials need to be ultra--pure because impurities in the material can lead to a pure because impurities in the material can lead to a

reduction of power output. Impurities can add to absorption and reduction of power output. Impurities can add to absorption and scattering, scattering,

which would reduce the effectiveness of the fiber. The buffer cowhich would reduce the effectiveness of the fiber. The buffer coating covers the ating covers the

core and the cladding. The buffer coating is generally made of pcore and the cladding. The buffer coating is generally made of plastic, which lastic, which

protects the fiber from moisture and other damages.protects the fiber from moisture and other damages.

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T k’T

MonoMono--mode fiber optic operating frequencies in a HFC system mode fiber optic operating frequencies in a HFC system

areare 11310310 or or 15501550 nanometers.nanometers.

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Performance Characteristics of single mode fiber optic.Performance Characteristics of single mode fiber optic.

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0800 1000 1200 1400 1600

nm

a

b c d e

Spectral Attenuation ( typical fiber ):

SINGLE-MODE STANDARD FIBER OPTIC

dB

ALLWAVE SINGLE-MODE FIBER OPTIC

Spectral Attenuation ( All Wave fiber ):

dB

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0800 1000 1200 1400 1600

nm

Loss at :850 nm = 1.31 dB/km

1310 nm = 0.33 dB/km

1550 nm= 0.19 dB/km

Loss at :850 nm = 1.31 dB/km

1310 nm = 0.33 dB/km

1550 nm= 0.19 dB/km

The standard fiber optic is mostly used for every day signal traThe standard fiber optic is mostly used for every day signal transport.nsport.

The new AllWave fiber is used for the DWDM and long distance traThe new AllWave fiber is used for the DWDM and long distance transport.nsport.

Notice that the humidity peak at 1400 nm, have been removed on ANotice that the humidity peak at 1400 nm, have been removed on AllWave fiberllWave fiber

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Dual armored fiber optic cable.Dual armored fiber optic cable.

NonNon--metallic covert fiber optic cable.metallic covert fiber optic cable.

FigFig--8 Self supporting fiber optic cable.8 Self supporting fiber optic cable.

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Optical TransmitterOptical Transmitter

andand

Return Optical ReceiverReturn Optical ReceiverOptical NodeOptical Node

5050--870 MHz870 MHz

55--40 MHz40 MHz

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RF Amp. RF Amp. RF Amp. RF Amp. RF Amp. RF Amp.RF Amp. RF Amp. RF Amp. RF Amp. RF Amp. RF Amp. RF Amp. RF Amp.RF Amp.

30 kilometersof P-III-625 coaxial cable

This coaxial length spaced at:

22 dB spacing at 450 MHz,able to carry 60 NTSC TV signal,will requires 80 RF Amplifiers.

C/N here will be:40.97 dB for 4.2 MHz spacing.

30 kilometres of fiber optic, operating at 1310 nmwill means a 9.9 dB loss

C/N here will be:53.00 dB for 4.2 MHz spacing.

Above, shows advantage of fiber optic, over coaxial cable, whichAbove, shows advantage of fiber optic, over coaxial cable, which are:are:

••Better Carrier to NoiseBetter Carrier to Noise, CTB, CSO, CTB, CSO specificationspecificationss at the end of the system.at the end of the system.

••The 30 km fibre link will give more stable signal The 30 km fibre link will give more stable signal even witheven with temperature change.temperature change.

••The fibre optic link will require less actives equipments than tThe fibre optic link will require less actives equipments than the he coaxialcoaxial link.link.

••AA 30 30 kkm coaxial section will require 80 amplifiers.m coaxial section will require 80 amplifiers.

••AA 30 km fiber optic link will require 30 km fiber optic link will require aa 1122 dBmdBm optical transmitter and one optical receiver.optical transmitter and one optical receiver.

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An OTDR uses microwave technology to verify the quality and the An OTDR uses microwave technology to verify the quality and the length of fiber optic.length of fiber optic.

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Headend EquipmentCablemodem

IP-Telephone

RSVP

Monitoring System

NODE

Fiber optic Return 5 / 40 MHz

Fiber Optic Forward 50 / 870 MHz

Coaxial SectionCoaxial Section

Optical EquipmentOptical Equipment

Optical InterconnectionOptical Interconnection

RF InterconnectionRF Interconnection5 to 42 MHz5 to 42 MHz

RF Sweep

Coaxial Return 5 / 40 MHz

Coaxial Forward 50 / 870 MHz

50 to 52 or 73.5 MHz

Return Alignment andReturn Alignment and

Ingress Control SystemIngress Control System

RF InterconnectionRF Interconnection50 to 870 MHz50 to 870 MHz

T1 / OC 192to Tel Co

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300MHz

450MHz

225MHz

121.25MHz

108MHz

50MHz

550MHz

750MHz

870MHz

47.0 dBmV

37.0 dBmV

4 dB6 dB

10 dB 11.5 dB

48.5 dBmV

Response of a Optical Receiver or a RF amplifierResponse of a Optical Receiver or a RF amplifier

for a 870 MHz HFC system.for a 870 MHz HFC system.

80 NTSC, Analog channels.80 NTSC, Analog channels. 220 MHz of 64 or 256 QAM signals.220 MHz of 64 or 256 QAM signals.

44Optical receiver Coaxial cable Fiber optic cable Bi-directional RF amplifier

Each pocket (Each pocket (sectionsection) of a HFC system can have 50 to 1,500 subs.) of a HFC system can have 50 to 1,500 subs.

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••Headend of a HFC system.Headend of a HFC system.

••DescriptionDescription of a HFC Headend.of a HFC Headend.

••Coaxial cable Coaxial cable -- Fiber optic.Fiber optic.

••Passive equipments for a HFC system.Passive equipments for a HFC system.

••Description of the Description of the outside plan.outside plan.

••RF AmplifierRF Amplifierss..

••Fiber optic.Fiber optic.

••Fiber optic management.Fiber optic management.

••System distortion calculation.System distortion calculation.

••Understanding biUnderstanding bi--directionality.directionality.

••Adjusting a HFC system.Adjusting a HFC system.

••Home installation.Home installation.

••Test equipmentTest equipmentss required for a HFC system.required for a HFC system.

••CLI.CLI. (Ingress & Egress)(Ingress & Egress)

••CMTS, DOCSIS, QAM signal. Cablemodem.CMTS, DOCSIS, QAM signal. Cablemodem.

Hfc a catv-101

Technology

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