Hfc a Catv 101 Voice

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Broadband System - ABroadband System - A

CATV - 101.CATV - 101.

Satellites are spaced every

2nd degrees above earth

TV

TRANSMITTER

Cable area

"C" Band

Toward satellite 6.0 GHzToward earth 4.0 GHz

"L" BandToward satellite 14.0 GHz

Toward earth 12.0 GHz

Headend



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To give you plenty of time to read the details of each presentation,To give you plenty of time to read the details of each presentation,you’ll need to press the RIGHT ARROW KEY on your PC, so youyou’ll need to press the RIGHT ARROW KEY on your PC, so you

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

presentations.presentations.



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Before we start the Seminar on Broadband system, let have a lookBefore we start the Seminar on Broadband system, let have a lookat the beginning of the CATV industry.at the beginning of the CATV industry.

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

to-day’s Broadband System.to-day’s Broadband System.

This presentation is only a general idea and every subjectThis presentation is only a general idea and every subjectdemonstrated in this presentation will be explained in more detailsdemonstrated in this presentation will be explained in more details

in future presentations.in future presentations.


..



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CATVCATV :: CCommunityommunity AAntennantenna TTelevisionelevision

CATV systems started in around 1952 and were a one wayCATV 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 aThese 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 cabledarea.area.

Then, these systems were capable of distributing between 2 toThen, 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 12their 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 operate a CATVIn both country, Canada and the USA, you required a license to operate a CATV

system.system.

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

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

FFederalederal

CCommunicationsommunications

CCommissionommission

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

•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 MHz0

-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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CH-2 : 55.25 MHzCH-2 : 55.25 MHz CH-7 : 175.25 MHzCH-7 : 175.25 MHz


CH-4 : 67.25 MHzCH-4 : 67.25 MHz CH:-9 : 187.25 MHzCH:-9 : 187.25 MHz

* 73.5 MHz Int. disaster freq.* 73.5 MHz Int. disaster freq. CH-10 : 193.25 MHzCH-10 : 193.25 MHz



FM : 88 to 108 MHzFM : 88 to 108 MHz CH-13: 211.25 MHzCH-13: 211.25 MHz

* Notice, the difference in frequency, between CH-4 and CH-5, which is* Notice, the difference in frequency, between CH-4 and CH-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 asis allocated as

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

some other international organization.some other international organization.

VHF TelevisionVHF Television Signal.Signal.



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UHF Television signal.UHF Television signal.

CH-14 : 471.25 MHz to CH-69 : 805.25 MHz CH-14 : 471.25 MHz to CH-69 : 805.25 MHz

AllAll UHFUHF signals, like thesignals, like the VHFVHF signals, are located in a 6.00signals, are located in a 6.00

MHz spacing, the UHF stations are located betweenMHz spacing, the UHF stations are located between 471471 toto

810 MHz810 MHz..

UHF channel,UHF channel, CH-37CH-37,, 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 pr ocessor, ( 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 aAll the television channels are combined together with a

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





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FM stationsFM stations22 66 77 1313

12 channel plan12 channel plan

This number television channels (12) was the maximumThis 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 BandWith Push Pull amplifier, it became possible to carry Mid Band

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



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FM

transmitter

TV

transmitter

Headend

CATV

system

Satellite

reception

TV

transmitter

FM

transmitter

4

GHz

12

GHz

Microwave

System

SatellitesSatellites

Up LinkUp Link

TransmissionTransmission



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Coaxial cable consist of Coaxial cable consist of ::

•75 ohms cable.75 ohms cable.•Center conductor.Center conductor.•FoamFoam (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 channel.Coaxial cable are the most common way to distribute television channel.

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

•It is also capable of handlingIt 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

P-III-500P-III-500 0.160.16 0.520.52 1.311.31 1.821.82 2.332.33 2.522.52 dB/100’dB/100’

P-III-625P-III-625 0.130.13 0.420.42 1.081.08 1.511.51 1.941.94 2.072.07 “ ““ “

P-III-750P-III-750 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:

RG-59RG-59 0.860.86 1.951.95 4.454.45 5.955.95 7.527.52 8.128.12 “ ““ “

RG-6RG-6 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 a f ter cable equali

zer

Signal af t er cable equalizer

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

47

36

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47

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48

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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 theConnectors 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 conductor central conductor



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

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

Input

cable

Out

cable

Out

cable



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Standby power Standby power

supply are workingsupply are working

on 110 volts ACon 110 volts AC

or or

36/48 Volts DC36/48 Volts DC

Power supply delivers 60 or 90 volts AC thru thePower 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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RG-59 or RG-6RG-59 or RG-6

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

PowerPassing

Tap

50-750MHz5-40 MHz

From HeadendFrom Headend

RG-59 or RG-6RG-59 or RG-6

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, Bi-directionalBroadband CATV systems are now a very complex, Bi-directional

communications network, called;communications network, called; HFCHFC ((HHybridybrid FFiber iber CCoaxial) usingoaxial) usingFiber 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 toHFC Broadband systems are using fiber optic technology totransport the signals for the longest distance, between the headendtransport the signals for the longest distance, between the headendto a NODE (optical receiver). The node transfers the light signal to RFto a NODE (optical receiver). The node transfers the light signal to RFsignal. The signals then continue thru the coaxial system to feed allsignal. The signals then continue thru the coaxial system to feed allthe customers. The coaxial system permits to deliver the signals atthe customers. The coaxial system permits to deliver the signals at

less cost. Fiber optic delivers a better quality signal than coaxialless cost. Fiber optic delivers a better quality signal than coaxialcable, this is why fiber optic is used to transport the signal for thecable, this is why fiber optic is used to transport the signal for thelong distance.long distance.

A HFC system is a bi-directional system, and the working bandwidthA HFC system is a bi-directional system, and the working bandwidthfrom the headend to the customer is:from the headend to the customer is: 50 to 870-1,000 MHz50 to 870-1,000 MHz, and from, and fromcustomer 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 ta t io n sF M s ta t io n s 14 22

In a modern Broadband system, the frequenciesIn a modern Broadband system, the frequencies belowbelow 550 MHz are generally550 MHz are generally

used for the transportused 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

550MHz

870MHz

Standard Television channels can be replaced by digital television or Standard Television channels can be replaced by digital television or

other digital services (other digital services (Data, Cablemodem, Security system, IPData, 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 generallyIn a modern Broadband system, the frequencies above 550 MHz are generally

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

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



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

15 to 20

dBmV

300

MHz

450

MHz225

MHz

121.25

MHz

108

MHz

50

MHz

550

MHz750

MHz

870

MHz

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

core. The core's index of refraction is slightly higher than that of the surroundingcore. The core's index of refraction is slightly higher than that of the surrounding

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

called the cladding. The cladding causes the light to remain inside the core. Thecalled the cladding. The cladding causes the light to remain inside the core. The

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

materials need to be ultra-pure because impurities in the material can lead to amaterials need to be ultra-pure because impurities in the material can lead to areduction of power output. Impurities can add to absorption and scattering, whichreduction of power output. Impurities can add to absorption and scattering, which

would reduce the effectiveness of the fiber. The buffer coating covers the corewould reduce the effectiveness of the fiber. The buffer coating covers the core

and the cladding. The buffer coating is generally made of plastic, which protectsand the cladding. The buffer coating is generally made of plastic, which protects

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



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T k’T

Mono-mode fiber optic operating frequencies in a HFC systemMono-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

3.02.5

2.0

1.5

1.0

0.5

0.0800 1000 1200 1400 1600nm

a

b c d e

Spectral Attenuation ( typical fiber ):

SINGLE-MODE STANDARD FIBER OPTIC

d B

ALLWAVE SINGLE-MODE FIBER OPTIC

Spectral Attenuation ( All Wave fiber ):

d B

4.0

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0.0

800 1000 1200 1400 1600nm

Loss at :

850 nm = 1.31 dB/km1310 nm = 0.33 dB/km

1550 nm= 0.19 dB/km

Loss at :

850 nm = 1.31 dB/km1310 nm = 0.33 dB/km

1550 nm= 0.19 dB/km

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

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

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



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

Non-metallic covert fiber optic cable.Non-metallic covert fiber optic cable.

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



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Optical Transmitter Optical Transmitter

andand

Return Optical Receiver Return Optical Receiver Optical NodeOptical Node



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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, which are:Above, shows advantage of fiber optic, over coaxial cable, which 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 signalThe 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 theThe fibre optic link will require less actives equipments than the coaxialcoaxial link.link.

•AA 3030 kkm coaxial section will require 80 amplifiers.m coaxial section will require 80 amplifiers.

•AA 30 km fiber optic link will require30 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 length of fiber optic.An OTDR uses microwave technology to verify the quality and the length of fiber optic.



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Headend EquipmentCablemodemIP-Telephone

RSVP

Monitoring System

NODE

Fiber optic Return 5 / 40 MHzFiber 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 MHzCoaxial 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 dBmV4 dB

6 dB10 dB

11.5 dB

48.5 dBmV

Response of a Optical Receiver or a RF amplifier Response 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.





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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 - Fiber optic.Coaxial cable - Fiber optic.

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

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

•RF Amplifier RF Amplifier ss..

•Fiber optic.Fiber optic.

•Fiber optic management.Fiber optic management.

•System distortion calculation.System distortion calculation.

•Understanding bi-directionality.Understanding bi-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.



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Hfc a Catv 101 Voice