[202302103] [Moayad] [AlZoghiby] [ICT]

FTTx Architecture

Technical Trainer College

ICT Department

Bachelor Thesis: FTTx Architecture

First Supervisor: Dr. Wolfgang Frohberg.

Second Supervisor: Dr. Salem Lepaja.

ID.NO. 202302103 - Moayad AlZoghiby

Submission Date: 28.4.2012


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Abstract

The growing of telecom companies and the popularity of the Internet service is the

key beyond the development of new access methods, which enables a customer

to use high speed Internet connection. Fiber optic technology is the technology of

the modern era by offering an ultimate solution to the customer premises. There

are several reasons to motivate telecom business use the fiber cables rather than

the copper cables. The inexpensive material used to make optical fiber cables

where the high bandwidth that fibers can offer over long distance. Also, fiber is not

attracted to interference, because the optical source is laser. The different

technical aspects of fiber optics have been presented on this thesis to describe

how the rollout of the Fiber To The x (FTTx) is applied including its equipment.

In this paper we present a brief overview of optical fiber cable including the

concept, types, operating wavelengths, advantages and disadvantages, the signal

transmission mechanism, transmission characteristics and the different optical

architectures passive/active networks which are related to the general architecture

FTTx. In our analysis the comparison of the different architecture methods is

presented of all FTTx types. The applications of each system are looked at

different viewpoints from their advantages and disadvantages are mentioned.

However, there is series factor should be taken on consideration as telecom

providers of deploying these kind of architectures. By deciding which method is

appropriate to deliver services to subscribers and the best budget to maintain it.

Also, which best for them is by deploying AON network that is point-to-point, or

passive network point-to-multipoint?


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1 FTTx Abstract

2 Introduction ................................................................................................................... 5

3 Fiber Optic Overview ................................................................................................ 7

3.1 Definition ............................................................................................................................. 7 3.2 Fiber Structure .................................................................................................................. 7 3.3 Decibel Unit ........................................................................................................................ 8 3.4 Electromagnetic Spectrum .......................................................................................... 9 3.5 Optical communication bands ................................................................................. 11 3.6 Operating Wavelength Windows ............................................................................ 12 3.7 Basic Concept of Fiber Optic Communication System ................................ 12 3.8 Advantages of Communication systems ............................................................ 14

4 Fiber Optic Cable Types ....................................................................................... 15

4.1 Based on refractive index profile ........................................................................... 15 4.2 Based on Fiber Modes ................................................................................................. 17 4.3 Mode Field diameter ..................................................................................................... 19 4.4 Based on the material used ...................................................................................... 20 4.5 Signal Transmission Mechanism ........................................................................... 20 4.6 Snell’s Law ....................................................................................................................... 20 4.7 Critical Angle (Øc) ......................................................................................................... 21 4.8 Total Internal reflection ............................................................................................... 21 4.9 Acceptance Angle ......................................................................................................... 22

5 Transmission Characteristics FO ..................................................................... 23

5.1 Attenuation ....................................................................................................................... 23 5.2 Fiber Dispersion ............................................................................................................. 26 5.3 Signal Multiplexing ....................................................................................................... 28 5.4 PON-WDM Components ............................................................................................. 29

6 Access technologies .............................................................................................. 30

6.1 Network Architecture Concept ................................................................................ 30 6.2 Types of Network ........................................................................................................... 31 6.3 Network Terminology................................................................................................... 31 6.4 Premises Terminology ................................................................................................ 32

7 FTTx overview ........................................................................................................... 33

7.1 FTTx Concept .................................................................................................................. 33 7.2 Why FTTx? ........................................................................................................................ 33 7.3 Features and benefits .................................................................................................. 34 7.4 FTTx scenarios ............................................................................................................... 34 7.5 FITL ...................................................................................................................................... 36

8 Optical Part ............................................................................................................... 37

8.1 Direct Fiber ......................................................................................................... 37

8.2 Shared Fiber ....................................................................................................... 38

8.2.1 Active Optical Network (AON) ............................................................. 39

8.2.2 Advantages and disadvantages of AON ......................................... 40


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8.2.3 Passive Optical Network (PON) .......................................................... 40

8.2.4 Types of PONs ........................................................................................... 42

8.2.5 Advantages and disadvantages of PONs ................................................ 43 8.3 Comparison AON Vs. PON ........................................................................................ 44

9 FTTx Architecture .................................................................................................... 45

9.1 FTTH Architecture ......................................................................................................... 45 9.2 FTTC Architecture ......................................................................................................... 47 9.3 FTTB Architecture. ........................................................................................................ 48 9.4 FTTP Architecture ......................................................................................................... 49 9.5 Advantages and Disadvantages of all FTTx ...................................................... 52

10 FTTx issues ................................................................................................................ 53

10.1 FTTx design issues .................................................................................................... 53 10.2 FTTx Installation Issues ........................................................................................... 54 10.3 FTTx Testing Issues ................................................................................................... 54 10.4 FTTx Safety issues ..................................................................................................... 55

11 Conclusion ................................................................................................................. 56

12 Vocational Pedagogy part: (FTTx Concept 50min) ................................... 58

12.1 Curriculum analysis. .................................................................................................. 58 12.2 Content analysis .......................................................................................................... 60 12.3 Didactic analysis ......................................................................................................... 61 12.4 Learning objectives .................................................................................................... 63 12.5 Process Overview of a lesson plan ..................................................................... 63

13 Bibliography .............................................................................................................. 66

14 Annex ............................................................................................................................ 68

15 Statutory declaration ............................................................................................. 70


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2 Introduction

Using light to transmit information is not exactly new; in1870 AD Tyndall was the

first scientist who introduced the principle of optical transmission in light of internal

reflection to follow desired path or specific path that is called as “Tyndall

Hypothesis”. The first person that used an optical medium to send an AM audio

link was Alexander Graham Bell in 1880 AD and the modulation of sunlight to send

that message over 200km. However, The development of optical fiber started in

1960s by the invention of Laser, and the real use of optical fiber began in 1980s by

transmitting video message at Lake Placid.

In this thesis on chapter three; presents the fundamental understanding of optical

fiber cables by defining the fiber structure, the unit used to measure fiber power.

Also, the basic concept of fiber optic system is explained with their equivalent

equipment. Operating wavelengths and its spectral bands were touched and finally

the advantages of using fiber as a modern communication system. On chapter

four; the types of optical fiber based on their materials, modes, and the refractive

index were thoroughly mentioned. Also, the technique used in fiber that shows

how does the light rays propagated through fiber?

The last chapter of optical fiber fundamental the fifth; concerns about the fiber

characteristics, which rather dealing with defects of fiber whether caused by long

distance transmission or by manufacturers.

The type of network is important to design the FTTx, In FTTx we on MAN network

and the geographical area is about 20km long. Each of the premises has the own

name, which is to identify the needs of the data rate.

FITL fiber in the loop is the old name of FTTx it was used in the past, its carry the

POTS telephone line from the central offices to the premises. FITL today is much

more components between the CO to the premises it contains of OLT, ONT, ONU

and Box splicing and PON or AON network technology, each of these elements

has the own functions and its will coming in chapter seven.


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Since that year, the development of fiber grows continuously until the

telecommunication network based on fiber optic technology dominating the

transmission communication systems.

Optical fiber plays a vital role of the infrastructure of communication system due to

the high capacity, the security, and the long life span that fiber cables can offer

compared to any other communication link. In modern communication network

there are several architectures has been introduced, in order to provide services to

customers. These communication networks are depending on the terminology, as

the following:

1. FTTP, which refers to all type of premises.

2. FTTH, which refers to homes and small business.

3. FTTC, which refers to the nearest curb of premise (from the curb to premises

using the copper cable).

4. FTTB, which similar to FTTC but copper cable is located at the entrance of

building without using curb. Types of FTTx architecture will introduce in

chapter nine.

At the end of the thesis the explaining of which steps are taken to build the full

type of FTTx network and the requirement for that starting from Designing the

network (in which network topology is?), Installing the whole FTTx equipment in

FITL and the Testing after implemented the FTTx network and finally the Safety

part. All that will be in chapter ten.


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3 Fiber Optic Overview

3.1 Definition

Optical fiber is a type of medium that carries information from one point to another

in form of light pulses. Optical fiber cable uses smooth, thin hair strands that made

of glass or plastic to transmit data as a pulse of light, and the cable’s diameter

around the human hair in size. Optical fiber communication technology uses light

as a signal carrier, which is an electromagnetic radiation. The light is transmitted

using laser, or LED as a transmitter that encodes frequency signals into light

pulses (ones and zeros) along the fiber. The receiving end has a detector, which

converts the light pulses back into data through fiber optic. Optic fiber cable

consists of three main components, which play a role of transmitting the signal see

the following figure.

3.2 Fiber Structure

Fiber optic cable mainly consists of core and cladding, which are made up of fused

silica. Germanium dopant is added to the core to raise the refraction index. Figure

3.1: FO structure.

Core

The central part of the fiber cable where the light is transmitted, and is made of

silica glass. The core diameter is 8 µm for single mode fiber, and 50 µm or 62.5

µm for multi mode fiber.

Cladding

The second layer of the fiber cable that surrounds the core where the light is

trapped in the core and guides it along the fiber. The typical cladding diameter is

125 µm.

Figure3.1: Construction of optical fiber.


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Primary Coating

Primary coating or buffer coating is a plastic coating that provides protection to the

glass from physical damages of both core and cladding.

Strength Members (Kevlar)

The benefit of Kevlar is to pull out the fiberglass during installation, also to protect

the fiberglass from damages.

3.3 Decibel Unit

In communication systems decibel is often used to measure the power, which

gives the ratio of the input power (Pin) to the output power (Pout). The ratio is

expressed in a logarithmic unit (based on power 10). For power measurement, dB

is defined as: dB = 10 x log (output power/input power). For example, the signal

strength in fiber results from loss mechanism (attenuation) in a transmission where

the output power level becomes (50%) of its input, therefore the loss of the cable

is expressed by this formula 10 x log (0.5) = -0.3 dB. (Which is the reduction of the

signal).

Decibel unit is used in two cases:

To express fiber and component loss.

To express power quantities in various points of optical cable that are called

`(power level).

The benefit of using decibel unit is to convert high values to small ones, which

converts multiplications to addition and division to subtraction.

Metric Prefixes

The metric prefixes define units, terms and the real size of units with their

corresponding symbols, which are used in optical fiber communications. These

prefixes show the measurements of data of very big and very small values. In the

metric prefixes table below, prefixes are defined to the power of ten factor; where

the positive units represent the number of zeros after figure it out, whereas the

negative units represent the number of decimal places after the decimal point. For

instance one Kilowatt = 10x10x10 = 103 (10 to the power of three is ten multiplied

by itself three times), one mill watt is 1 x 10-3 = 0.001W).


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3.4 Electromagnetic Spectrum

Telecommunication systems transmit signals in the form of electromagnetic

energy, which contains radio waves, microwaves, infrared light, and ultra light, x-

rays, Gama rays, and visible light portions of spectrum can all be used for

transmitting information by modulating various measurements that related to

electromagnetic waves.

Waves in electromagnetic spectrum are varying in size from very long radio waves

to very short radio waves. The electromagnetic spectrum is a sequence of

electromagnetic waves (electrical and magnetic fields) both fields have direction

and amplitude (strength). The electromagnetic spectrum from very low frequency

to optical frequencies is shown in figure 3.2.

Figure3.2: Spectrum of electromagnetic waves.


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Light has a wave nature, which propagates

through the space as much same as radio

waves. Light in fiber has different colors, and

each color has a specific wavelength in the

electromagnetic spectrum. The following

figure 3.3 shows the Different wavelengths

represent colors represents specific colors.

All electromagnetic waves shown above are travel at the speed of light, which is

around (3x108 m/s) or (1.8x105 miles/second) in a vacuum. The speed of light in a

material is less than the speed of light in a vacuum. The physical property of the

waves can be measured in different ways, by measuring the oscillating frequency

of the waves. Whereas electrical signal transmission tends to use frequency to

designates the signal operating bands. Optical communication uses wavelength to

designate the spectral operating region and photon energy waves (optical power).

So, there are three ways to measure various regions in the electromagnetic

spectrum. First the frequency (f) is equal to the speed of light (C) divided by the

wavelength (λ).

f = c / λ

Another way of measuring the propagated waves by using “Quantum Theory” that

light wave consists of many tiny particles. Each one of these particles represents

discrete quanta (packet of energy), or photons. The photons are uncharged

particles within a light and their energy content is determined by the frequency, or

the wavelength. This equation is known as Planck’s law.

E = h x f

Where the parameters, E = energy, and h = 6.63x10-34 J.s = 4.14 eV.s, which is

called Plank’s constant. J refers to the unit Joules, and eV refers to the electron

volts that is given by:

E (eV) =

Figure3.3: the visible lights in a rainbow


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3.5 Optical communication bands

Optical spectrum ranges from (5nm) ultraviolet to (1mm) infrared, and the visible

region begins from 400nm to 700nm bands. Optical fiber uses the spectral band

from 800nm to 1675nm. International Telecommunications Union (ITU) has

designated six spectral bands, which are used for intermediate range and long

distance range dedicated for optical fiber communications. These wavelength

ranges begin from 1260nm to 1675nm regions. These bands designations are

matching the physical characteristics of the optical fiber cable and the

performance of the optical amplifiers. These regions are known by (O, E, S, C, L

and U) letters, which are defined in the figure 3.4:

Each letter represents specific bands range, which defines the operation of its

wavelengths, as the follows of Table 3.2:


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3.6 Operating Wavelength Windows

Optical fiber transmission uses wavelengths, which are near located to the infrared

portion of the electromagnetic spectrums, and above the visible light. Hence, the

human eyes cannot see it. The typical optical transmission wavelength windows

are shown as the following:

o First Window

o Second Window

o Third Window

o For Plastic Fiber

Both lasers and Light Emitting Diodes (LEDs) are used to transmit optical light. In

practical lasers usually used for 1310nm and 1550nm in single mode applications,

and LEDs usually used for 850nm and 1310nm in multimode applications. But in

advanced communication systems operate at , because it has a

minimum attenuation at this wavelength. While Different wavelengths windows are

operating at different types of fibers, as the follows table 3.3.

3.7 Basic Concept of Fiber Optic Communication System

The following figure 3.5 shows a block diagram of a typical communication system

to transfer messages from the transmitter to the receiver.


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Optical communication system is different of any other communication system in

principle of carrying information signals, where the medium is completely digital;

therefore analog signals need to be converted into digital signal. The typical optical

carrier frequency is very large around 100 THz, which is exceeding other

communication systems. The following diagram shows the optical communication

system block diagram.

Transmitter Section: Transmitting information e.g. voice, video, or computer in

form light signal. As it shown above the circuit it’s an A/D (Analog to Digital

converter) by coder (converter) circuit. If the input signal is digital it’s directly

connected to the light source circuit, if the input signal is analog it’s first converted

into digital signal and passed the light source circuit.

The light source block either a Light Emitting Diode (LED) or a laser beam source,

or in some cases infrared beam is also used. The rate o light source at turns to

ON/OFF depends on the frequency of digital pulses. Once the signal is converted

into equivalent light pulses and focused at the fiber optic cable. Then it is received

at the other end of the fiber optic cable.

Fiber Optic Cable: When light pulses are fed into one end of the fiber optic cable

they passed onto the other end (at the receiver).

Passive Devices: Optical components are passive devices that do not require

electronic controlling of their operations. Optical connectors are used to connect

cables to the indoor/outdoor devices optical splices to join two optical cables

together. Also, optical isolators are used to prevent unwanted light to go in a back

Figure 3.6: Block diagram of typical optical system


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direction, and optical filters, which selects narrow band to pass through the fiber

cable these are work as passive devices.

Optical Amplifiers: When the signal becomes weakened (power loss) after the

signal has travelled along the fiber. At that point the light signal needs to be

regenerated or boost up. In fact, the signal is converted to electrical signal to be

amplified (regenerated), and then converted back into light optical signal.

Receiver Section: at the receiving end, the light detector, or a photodiode is used

to detect the light pulse, which called a (transducer). To convert light signals into

electrical signals, then gets amplified and reshaped into original digital pulses.

These units are used in optical communication system, however if the distance

between the transmitter and the receiver is very large, then Repeater units are

used. Once the repeaters are used the attenuation is recovered, thus light signals

at the far end are converted into electrical signals, amplified, and then

retransmitted.

3.8 Advantages of Communication systems

1. Large Transmission Capacity.

The carrier (optical frequency) is very high in the range of 1014 HZ, which is a high

bandwidth rate; hence the system transmission capacity is increased.

2. Immunity to Interference and Crosstalk.

Optical fibers are fabricated from dielectric materials; therefore, they are

completely immune to electrostatic and electromagnetic interference. They are

made from either glass or plastic, which are electrically isolated. This property

makes the optical fiber transmission ideal solution in electrical hazardous

environment.

3. Low Loss.

The development of optical fiber over the last ten years has come up to the

production of optical fiber with very low transmission loss (Attenuation) compared

to other types of transmission lines. Optical fibers have been fabricated with loss

around ≈ 0.2dB/km, which means greater distance between repeaters and

becomes the best transmission line for very long distance.


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4. Long Life span.

Optical fibers have longer life span between 20 to 30 years compared to the

conventional copper wires. The reason is that the core of optical fiber is made from

silica, therefore does not corrode as metal.

5. Optical transmission system is capable to be expanding.

Fiber optic systems can be upgraded to expand the system capability by replacing

the transmitter laser, LED, or using the Wavelength Division Multiplexing (WDM).

6. Wide temperature Range.

Optical fibers are manufactured to operate at low temperature degree around -40˚

to +85˚.

7. Large Bandwidth with small diameter and lightweight.

The amount of information that carried out in the fiber is very large compared to

the copper line. Optical fiber has very small diameter in the range of micrometers

[µm]. The demand of bandwidth is increased rapidly with advanced technology,

which makes the fiber paly a vital role for long distance and short distance with

high-speed interconnection applications. Therefore, this size is smaller and much

lighter than copper cables, and they can be used effectively in aircrafts, ships,

trains, and satellite. Also, they provide high quality transmission, thus will increase

the amount of bandwidth with high bit error rate (BER) ≈ 10-9.

4 Fiber Optic Cable Types

Optical fiber can be classified into three categories depending on; refractive index

profile, number of modes, and the materials used.

4.1 Based on refractive index profile

The different of them is the way of the light is travelling through the fiber. The

different main parts of the fiber are dedicated as the core and the cladding where

the cladding is surround the core. But in advance the cladding has a different

refractive index than in the core. Optical fibers can be divided into two major types

step-index fibers and graded-index fibers.


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Step-Index Fiber.

The fiber has a refractive index that steps from low to high and so on, which

bounces between the core and the cladding and the refractive index in the core

has a constant value slightly greater than the value for cladding and change at the

core-cladding interface. The physical parameters such as the refractive index,

differences at fiber index, core radius that determines the maximum number of

guided modes in both multimode and single mode fibers. In a multimode step

index fiber the core diameter is around 50µm, with multi propagation modes of

light waves are shown on figure 4.1.

Single mode fiber has a core diameter of the order of 2 to 10µm, and the relative

refractive index (∆) is about 0.001 with single propagation mode of light wave.

.

The parameters (n) refer to the core radius [µm], and the cladding radius referred

as (d) in [µm]. In multimode step-index fibers the number of propagating modes

(Ms) that is used to determine the propagated signal inside the fiber by using the

following formula:

Ms = v2/2

When the refractive index of the core is constant, and the velocity of all

propagated modes is constant and determine the rays inside by the following

equation:

V =

Here V is known as cut-off frequency, which is referred as V-number, but it is

related to the fiber size, or the refractive index.


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The distinct disadvantage of multimode step-index fiber is the rays that have

different paths due to the constant velocity. The rays will reach the fiber end at

different times, which leads to a time delay between the propagating modes

through the fiber. These modes are known as an intermodal dispersion that limits

the transmission bit rate and therefore the fiber transmission distance.

Graded-Index Fibers

Graded-index fibers decreasing the core index n(r) with a radial distance from the

maximum value of n1 at the axis of n2 beyond the core radius (a) in the cladding.

On this fiber the light is transmitted through the fiber either at the wavelength

1300nm, or at 850nm bands. The best design of optical propagation is for

multimode graded-index fiber near to the parabolic refractive index with

. The number of propagating modes Mg is supported by the graded index

Where is the parameter profile that gives the characteristics of refractive index

profile of the fiber core. When the fiber has the following profile values they

indicated to specific core shape:

o

o

o

The shape of refractive index profile is illustrated in Figure 4.2:

4.2 Based on Fiber Modes

Light inside the optical fiber propagates as different rays with specific propagating

angles. The different rays are called (Modes), and each mode propagates at

specific order such as smaller mode in propagation angle indicated to lower in

order of modes. Thus, the propagating modes in fiber in central axis is called

(zero-order mode), or the fundamental mode. However, when the propagation


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mode is transmitted at critical angle is indicating to the highest order mode for the

fiber. There are four different types of propagation modes:

1. Transverse electric (TE) modes.

2. Transverse magnetic (TM) modes.

3. HE modes.

4. EH modes.

Where, (E) indicated to denotes electric field, and (H) denotes magnetic field. The

propagating mode numbers are determined by the normalized frequency

parameter, which is called (V-number). However, there are two major types of

fiber optic cable, single-mode and multi-mode. See figure 4.3

Single-Mode - The core diameter of a single-mode is about 8-10 micron. The

small core size allows only one light mode to travel within the core. The higher the

bandwidth, the more information carrying, thus more capacity the cable has. This

type of cable is preferred used for long distance, and the telephone companies

use it for long haul transmissions. Single mode has a lower attenuation compared

to the multimode (about the half). The main advantage of single mode in optical

fiber is that intermodal dispersion might be avoided, because there is only one

propagated mode, therefore no time delay.

Multi-Mode - The core diameter of a multimode is about 50-100 micron. The large

core allows many light modes to travel through the core simultaneously. Mode

overlap can occur over longer distances and may cause bit errors. Multimode is

often used for short distance transmission. Multimode fiber provides high

bandwidth at high speeds (10 to 100 Mbps - Gigabits to 275m to 2km) over


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medium distances. For long distance fiber link can carry light signal (up to 2 km),

with multi-paths of signal can cause signal distortion at the receiving end.

Which type of fiber is in use for FTTx?

Well, both of them are used for FTTx and the decision depends on the distance

and the bandwidth used. However, the most common type used in Saudi Arabia is

single-mode fiber due to the high bandwidth that can carry over long distance.

4.3 Mode Field diameter

Is a parameter for classifying single mode fiber properties that takes into the partial

field penetration into the fiber cladding. It is a rather a measurement for the fiber

core. It can be regarded as the single analog mode of the fiber core diameter in

multimode fibers and is a little bit larger than single mode fiber in the core diameter.

Gaussian Function expresses the distribution filed

through single mode optical fiber, also called (bell

shapes, or bell curve). Gaussian function

approximates the shapes of the output light signal

of the normalized frequency. See figure 4.4.

Where w is the mode field radius or the stop size by

the following formula:

MFD = 2wc

Figure4.4: Gaussian distribution of single mode fiber.


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4.4 Based on the material used

Fiber cables are manufactured by either plastic, or glass. See operating

wavelength. Where the wavelength of plastic fiber is only used at 650nm, whereas

glass fiber uses three different wavelengths that are 850nm, 1300nm and 1550nm.

4.5 Signal Transmission Mechanism

The light propagation and the transmission of light along the fiber is described

by two theories:

1. The light rays propagated at different refractive index (n) and different

velocities and this is called (Ray Theory). Also, describes the two types of rays

can be propagated through the fiber.

Meridional rays: Defines the passing rays through the axis of the fiber. It is

used to show how the light in optical fiber is transmitted.

Skew rays: Defines the transmitted rays along the fiber by bouncing through

the line, instead of passing its axis.

While Ray theory is used to gives the approximate amount of acceptance light

and the guide of light in optical light and can be defined as:

n =

Where, c is the light velocity in the medium, and co is the speed of light in free

space. If n = 1 is indicated to the air, n = 1.33 is indicated to the water, and n =

1.5 is indicated to glass.

2. The light is described as an electromagnetic wave, which is called (Mode

theory). It describes the light wave modes of optical fiber by giving the

characteristics of optical fiber transmission of absorption, attenuation, and

dispersion. The propagated light rays through the fiber are based on three

parameters, total reflection, Acceptance angle, and numerical aperture.

4.6 Snell’s Law

Snell’s law defines the link between the incident and refracted rays and their

angles; the following figure 4.5 shows the Snell’s law.


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The Snell’s law applied in fiber optic as follows:

n1 sin Ø 1 = n2 sin Ø 2 or

=

Where:

n1 and n2: are the refractive index of first and second media.

Ø1: is the incident angle.

Ø2: is the refraction angle.

Ø3: is the reflection angle.

And n1 > n2, therefore Ø2 > Ø1

4.7 Critical Angle (Øc)

If the incident angle of Ø1 is increased where the

light rays in air are vertical to the glass surface

this is known as “Critical angle”. When the

incidence angle is high where the refraction angle

is (90˚) then it is called critical angle. If the light

ray of incident angle is greater than the critical

angle the light rays are completely reflected back

into the glass and that is called “total internal

reflection”. Figure 4.6: shows Critical Angle.

4.8 Total Internal reflection

The light rays propagate between two different media at different refractive index

n1 and n2. When Ø1 > Øc the light is totally reflected, and the total internal

Figure 4.6: Critical case if incidence angle.


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reflection is obtained when the incident light on the dielectric is at lower refractive

index (n2), and from dielectric to higher refractive index (n1). The transmission of

light along the fiber is based on the total internal reflection. Total internal reflection

occurs when n1 > n2 and the incident ray of light is makes an angle Øc, when this

occurs it doesn’t enter the medium it is rather transmit along the interface and this

is called “Critical angle” as it shown on figure4.7.

4.9 Acceptance Angle

Acceptance angle is the maximum angle where the light is enter the fiber axis to

be propagated and is expressed as “Øa”. Where the light can enter the fiber within

a certain range of angle. There is a relation between the acceptance angle and the

refractive indices including; core, cladding and the surrounding medium. The

relation is between the acceptance angle and the refractive indices angle is that

the refractive index of the fiber core is n1. And refractive index of the fiber cladding

is n2, and the refractive index of the surrounding medium is n0. Figure 4.8: shown

the light goes from the Emitter to the fiber core.

Figure 4.8: Acceptance angle to the fiber core


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5 Transmission Characteristics FO

5.1 Attenuation

Optical fiber communication system has two critical transmission characteristics

Attenuation and Dispersion, which play a major role of determining the

maximum distance that optical fiber cable can reach, or in other word can

determine the performance optical communication system. Fiber loss falls into two

categories Attenuation and Bandwidth (dispersion). Material absorption,

scattering, and bending loss are caused by attenuation; whereas bandwidth is the

amount of bits that can be transmitted that causes signal dispersion.

Attenuation is the loss of optical power due to the distance of travelling along the

fiber. Where the signal attenuation is defined as the ratio of input (Pin) power to

the output power (Pout). The general formula to measure the attenuation:

Attenuation (dB) = 10 / L * Log (Pin / Pout)

Attenuation values are vary depending on the fiber type and the wavelength,

where the higher the wavelengths the lower the attenuation as it shown on figure

5.1:

“Water peak” fiber refers to the manufacturing of single-mode fiber by reducing the

water mixed in fiber (H2O- ions) that causes higher spectral attenuation at

wavelengths 1244nm and 1383nm. At the water peaks the attenuation is around 2

dB/km while low water peak attenuation is around 0.4 dB/km. However,

attenuation is a wavelength dependent and is determined in decibel per kilometer

(dB/km) by the following formula:

Figure5.1: Attenuation Spectrum of optical fiber.


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Loss in decibel (dB) = 10 log₁ ₀ (

)

Where, Pin is the input power, and Pout is the output power. There are three

factors in fiber that can cause attenuation, as follows:

1. Material Absorption.

2. Scattering.

3. Bending Loss.

1. Material Absorption: This type of attenuation causes an absorption of light

signal, which occurs when both molecular and electronic excitation of

impurities in the fiber core i.e. metal particles and moisture. Metal particle is no

longer available due to the good manufacturing of very pure glass. However,

attenuation due to moisture is very common in fiber and it is called “Water

Peak”, which is located at the wavelength 1990nm. This wavelength region of

optical fiber is not used, but manufacturer struggling to reach the “Zero water

peak” region where the optical fiber eliminates the moisture absorption. Single

mode works in most of wavelength spectrum providing large bandwidth by

using coarse wavelength division multiplexing (CWDM) to avoid such an

attenuation that caused by moisture. Absorption is based on the manufacture

of optical fiber and controlling the amount of impurities during the manufacture

process can easily solve this issue.

Absorption losses can be classified into two main categories:

1.1. Intrinsic Attenuation occurs inside the fiber, which is caused by the

impurity in the glass while the manufacture.

1.2. Extrinsic Attenuation occurs due to both micro bending and macro

bending and is called “Bending loss”, which cause reduction in optical

power.

2. Scattering losses are caused by the interaction of light with density

fluctuations (interactions) within a fiber. It is divided into two categories, which

are Mie scattering and Rayleigh scattering.

2.1. Mie Scattering: occurs when the imperfection of manufacturing the

core, or the cladding diameter of when the light signal is propagating in

optical fiber.


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2.2. Rayleigh Scattering: Rayleigh scattering occurs when the light is

interacted with the atoms in the glass, therefore the light is scatter. Also,

when the size of the density fluctuation (fiber defect) of the core is less than

(λ/10). Loss caused by Rayleigh scattering is proportional to the fourth

power of the wavelength (λ/4). If the size of the defect is greater than

(λ/10), scattering is called Mie scattering (Insignificant).

Rayleigh scattering is the most common type of attenuation of optical fiber

and is counted as 96% of all types of attenuation. Some lights inside the

core are reflected back to the fiber input, and the electronic device used is

Optical Time Domain Reflectometer (OTDR) to test the fiber.

3. Bending Loss: Bending loss is classified according to the bend radius of

the curvature of fiber where the light signal is propagated at the bend and

gets lost. There are two main types of bending losses; Micro bending and

Macro bending.

3.1. Micro-bending loss: occurs when the light gets distorted along the

fiber that indicated by pressure on the fiber. Micro bending is very

localized and a small-scale bend and sometimes it cannot be seen, thus

special equipment is needed to test the power. Micro bending is a

wavelength dependent, hence in single mode fiber micro bend

sensitivity increases when the wavelength at 1550nm and higher. While

in multimode fiber the micro bend sensitivity is constant according the

wavelength such as in 50 µm core diameter the micro bend sensitivity is

more than 62 µm.

3.2. Macro-bending loss:

occurs when the fiber has a

large radius of curvature,

which is relative to the fiber

diameter. When the light is

exceeds the core and run

along the cladding and that

causes a “Critical angle”.

The bending radius affects the refractive index on the bending region

and reflects the light signal back to the core and then causes


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attenuation. The optical power will be increased when the radius of the

curvature is decreased less than 1dB, as it shown on figure 5.2.

Macro bending is a large-scale bending where the bending can be seen.

Optical fiber with minimum radius specification, and large numerical

aperture with low core and cladding has a less sensitivity to the macro

bending. See figure 5.3.

5.2 Fiber Dispersion

Fiber dispersion is the spreading out (broadening) of the light pulses as they

propagated through the fiber. Dispersion occurs when some components of input

signal i.e. numerical aperture, refractive index profile, core diameter, laser or LED

line width and wavelength are causes the pulse broadening. In attenuation the

power becomes weaker with distance that reduces the amplitude of the output

waveform, and it does not alter the shape of the output signal as on the following

figure 5.4:


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Dispersion on fiber has three types:

A. Chromatic dispersion (Material dispersion).

B. Modal dispersion.

C. Intermodal dispersion.

1. Chromatic Dispersion (Material Dispersion): Refractive index (n) of

Silica is a function of wavelength, exists in all fibers, function of the source

line width. Occurs as a product of the spectral width of the source (Laser or

LED), which consist different range of wavelengths that has different

velocities. In laser the spectral width is very small and carries few numbers

of wavelengths, because shorter wavelengths transmitted slower than

longer wavelengths (short frequency). Different light modes travel at

different velocities with different time, exist only in multimode fiber as it

shown on the following figure 5.5:

2. Modal Dispersion: The spread effect caused by using multimode fiber

where the time delay occurs and the fiber has different modes (Lower order

and higher order) and the light signals are propagated at different velocities.

Some of these light rays are transmitted through out the core (lower order

of modes) and higher order modes (those rays are bouncing between

cladding and core). See Figure 5.6:

Figure 5.6: Model Dispersion Propagation

Figure 5.5: Chromatic dispersion.


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3. Waveguide Dispersion: Signal in the cladding travel with a different

velocity than the signal in the core, significant in single mode conditions. It

caused by power distribution. This type of dispersion caused by the effect of

the shape of core index, where the light in core propagates faster than in

the cladding. The light is propagated through out the fiber in an area that

exceeds the diameter of the core, which called “Mode field diameter”. It is a

function of the wavelength where longer wavelengths propagate in larger

mode field, as it shown on the following 5.7:

5.3 Signal Multiplexing

Multiplexing is an essential part of any communication systems where multiple

users are sharing the same medium, which is in our case is optical fiber link.

Multiplexing is used to increase the capability of the system to transmit more

signals, and decrease the system costs. There are two main types of multiplexing

techniques for optical fiber communication systems; Time Division Multiplexing

(TDM), and Wavelength Division Multiplexing (WDM). Where TDM is performed in

the electrical domain where the multiple input signals are transmitted through the

optical fiber in the same time. And WDM is the process of combining multiple input

signals are transmitted through the optical fiber at different wavelengths, and the

popular operating wavelengths are 1310nm and 1550nm.

However, the most common type of Wavelength Division Multiplexing is called

“Coarse Wavelength Division Multiplexing”. CWDM operates up to 18 wavelengths

in a metropolitan network between 1310nm and 1550nm, which applies greater

spacing at 20nm. In single-mode fiber CWDM operating wavelengths are 1270nm

to 1610nm, whereas multimode fiber CWDM operating wavelengths are 778nm,

800nm, 825nm, and 850nm. The devices use this type of multiplexing have large


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frequencies greater than 100GHz with different spectral bands. The following

figure 5.6 shows the spectrum bands of CWDM.

5.4 PON-WDM Components

First thing before explaining the components of WDM technology, there is some

equipment of WDM, which are electrical devices that play major role in

communication systems.

1. Two fibers are required and another two for backup, because the fiber ring is

two directional of data flow.

2. In AON technology, generators are important (so the data is not going out).

The functions of regenerators are to reshape and amplify the signal. These are

required from the electrical circuits to do first two makes conversion from the

electrical single into optical, then regenerate and amplification and back to

conversion from optical signal to electrical.

3. ADM (Add-Drop Multiplexer), does three things in on time which they are:

Passing the data along of fiber line equally.

In the receiver fiber, take the optical signal from the coming fiber and

converted into electrical signal, then De-Multiplexing (Downlink) the out

come signal to take out the portion and then transmitting the signal portion

to the premises.

In Sender fiber, take the electrical signal that was be converted from the

premise, then multiplexing (uplink) the signal with other premises single

around the network ring, and finally converting the electrical signal to the

optical light signal, so to e transmitted to the network ring.

Some times, In PON technology each of premises has to have the Ethernet

switching, because each of customers has the own fiber cable.


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6 Access technologies

6.1 Network Architecture Concept

The concept of network architectures is commonly use when the discussion for

design and implementation of telecommunication network. The Architectures of

Network are sets the rules and for sure they conventions. Here, the Architectures

of Network in telecommunication system describes the physical arrangement and

operational of two equipment together which we need a protocols. Architectures

make the rules, which the name it is “protocols” and protocols commonly use to

make the rules of each of controlling, formatting, exchanging and interpretations of

data that send from point to other point. For that international organization for

standardization creating an OSI (Open System Layers interconnect) model.

OSI model has the seven layers and it’s a main protocol of whose build the

network, OSI guiding the telecoms companies for what steps they should start and

end. OSI model starts from bottom to the top (as shown at the Figure 6.1), which

the layers are physical, data link, network, Transport, session, presentation and

finally the application.

Each of OSI layers has the own functionality such

like layer No.1 Physical layer: is for the transmitting

data into transmission medium (which the FTTx

network are). For layer No.2 Data link layer: is to

exchanging the data between two points. And layer

No.3 a Network is about the routing and switching

the information. For layer No.4 a Transport is to

providing end-to-end transmission of data. And

layer No.5 Session layer is for maintains dialog

between two devices. For layer No.6 Presentation

layer is for formation the data like (encrypt, and

encoding the data). And finally the layer No.7 is

Application layer it’s for users accessory and file transferring. Layers No.1, 2 and 3

is responsibility of network and Layers No, 4, 5, 6 and 7 it’s for host system or

provider.

Figure 6.1: OSI layers


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6.2 Types of Network

There are many types of network, and the most important for this project are :

WAN (Wide area network): is the largest area its common between two

cities or facilities.

MAN (Metropolitan area network): are covers most area of one city it’s

become between neighborhoods and three or five blocks, which the FTTx

Network are.

LAN (local area network): its localized area network for homes, building

and rooms.

6.3 Network Terminology

To understanding FTTx network we must define some terms of network

terminology, and the function of each elements before the fiber cable goes to the

customer. (Look at the Figure 6.2) the network terminologies are:

Central office (CO): Generally, Central office is a building of switching for the

telephones line in one facility and three or more neighborhoods in public

network they called it Co (central office) or other called it a point of presence

(POP) and the old name for CO is EXCH (Exchange) which that’s mean to

exchange the telephone between two subscriber line. The main function of

Central office is to carry out the all telephone subscriber line (with MDF

Switches), which should be a thousand of subscribers and it has another

function todays is used to connect with the main mobile stations. CO can be

cover of two or three area and neighborhood. Central office most connects

with other central offices by techniques of trunk which theses day connecting

with single mode fiber optic.

Figure 6.2: Different term of public network


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Long-haul network: The function of long haul network is to take the

information from the central offices in one city and interconnecting to the other

long-haul city (transmission links between cities), this procedure required a

long cable of single mode fiber (could be a thousand of miles), with using of

Dense Wave Division Multiplexing (DWDM) and many repeater between two

long-hauls.

Backbone network: A high capacity network which connecting different types

of network segment to each other like WAN, MAN and LAN. Backbone

responsible to interconnecting the traffic, traffics move from one segment to

other segment.

Metro interoffice network: The function of metropolitan or Metro is to connect

all central offices together in one city. The distance between two central offices

could be a ten of miles. And it’s connecting with each other by a single mode

fiber cable.

6.4 Premises Terminology

At the end of users for each customer,

the last mile network or FITL

(12miles/20Km long) can be

transferring and delivered the

information for different group of

customer like family houses, institute,

apartment and business work. And

each of these premises has a limited

of bandwidth demand and the services

order it from them (Figure6.3 showing the different term of end users), each of

these types has acronyms and function as the following:

SDU: A single dwelling unit, to serve a singles of houses.

MDU: A multiple dwelling unit, to serve full of building and apartment complex.

MHU: A multiple hospitality unit, to serve hospitals, hotels or airports.

MTU: A multiple tenant unit, to serve institutions universities and colleges.

MTU is the largest premises terminology.

Figure 6.3 the different term of end users


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SFU: A single-family unit, its alternative of SDU.

SOHO: small office/home office, to serve a small office and its look like SDU.

Each of premises terminologies require a limited bandwidth and data rate by

consideration with how its will be customized.

To distinguish between fiber flow, the term of upstream refers transmission from

end users to the central office and the term of downstream is refer to transmission

from central offices to the end-users. Access network is the best topic of

interesting a passive optical network (PON).

7 FTTx overview

7.1 FTTx Concept

Fiber to the x (FTTx) is techniques or methods of fiber installation between central

offices (CO) to the customer. FTTx “last mile” is a generic term of network

topology that’s to replace the copper cable into fiber optic. Structures of FTTx start

from central office CO to the end users, which is the customer. Most of FTTx

scenarios are PON (passive optical network) network and the main reason why

the need of this technology is to provide a large broadband access network data to

the end users.

Fiber Optic is already exists for a long distance specially between two cities and

two Exchange’s, but traditionally copper cable is exists between the central offices

and customer for that the needs to replace the copper cable to Fiber optic is

require. The main reason that we need a fiber optic between two points are to

cover the evolution of the technology and the needed of broadband capacity.

7.2 Why FTTx?

With the evolution of communication around the world, Telecom companies now

are suffering from copper cables specially in Saudi Arabia, companies which use

copper cable providing the internet and video communication they lose broadband

customers, today customers want a high speed of data, dependable voice service

and high quietly video. For that customers replace the copper cable to satellite

communications few years ago.


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Today we face a problem with copper cable and the last statistics around the

world is said the cable telephone bulk is 10% for long distance (fiber optic cable)

and 10% for a local loop(fiber optic cable) and 80% Subscriber loop(copper cable)

for that the companies is suffering. Telecoms now are losing a CATV broadband

customers, telephone provider and VOIP. Shortly the reasons why we need FTTx

network are: -

• Fiber optic will be the main transmission medium to provide a high capacity

of bandwidth for homes broadband network.

• Fiber optic is the best choose to carry a high data and to upgrading

unlimited data.

• The costs of Fiber optic and copper cable are almost the same, but with

more capability with the fiber.

• Fiber optic is much lower for maintenance and for operational costs.

• New technologies of passive optical network (PON) with cheaper

components, which makes FTTx technology much cheaper.

7.3 Features and benefits

There are many Features and benefits to use FTTx technologies like:

Quick to install and easy to maintenance.

Best performance comparison with twisted pair or coaxial cable.

Flexible design and consistently high performance levels.

Easy to absorb from a new users and technologies.

Matching with a selection of mini-cables

Tubes are available as single tube or multiple tubes, for maximum flexibility.

Lower costs for building the FTTX network.

7.4 FTTx scenarios

In General FTTx fiber to the x and x is the term of what the end is terminated, Here

X is indicating letter to how is fiber endpoint close to the end users. (Figure 7.1

shows scenarios of FTTx).


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The four main scenarios, in order of an increasingly longer fiber loop are:

1. FTTH: Fiber to the Home, using fiber optic between central office and customer

to delivered high downstream data rates and

unlimited bandwidth.

2. FTTB: Fiber to the building or business, Its

used a fiber between central office CO to the

entrance of building after that is usually copper

cable. It’s used for a high data upstream for

business work.

3. FTTC: Fiber to Curb or cabinet, fiber optic

between the central offices (CO) to the cabinet,

which is not more than 300m far from the

customer. From the cabinet to the customer is

copper cable. Used for high capacity trunks.

(E.g. for DSL). And other transmission medium is used the curbside to connect

the equipment the customer in the building.

4. FTTP: Fiber to the Premises, Generic terms that include both FTTH and FTTB.

#FTTN: Fiber to the Node or neighborhood, it’s like FTTC but the different is how

far the cabinet from the user end. Which is could be a few miles FTTN refers to a

PON (Passive Optical network). Most of telecom companies now are using FTTN

scenario.

The differences between FTTH and FTTB are FTTB is demand large data rate for

business work not like FTTH one or 4 users for one Fiber optic cable. The most

commonly used are FTTH (fiber to the home), FTTP (fiber to the premises) and

FTTC (fiber to the curb).

Today, FTTx is oreder from:

Homeowners: want FTTH for high speed internet and video downloads.

Buildiers: want FTTB to make pravet and add the value to they apartments.

Hardware Provider: want the FTTx to summetry with they hardware sales.

Whose provideing the IPTV, HDTV and video demand(e.g. viewcast).

Any institue that using a high data rate.


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7.5 FITL

The old definition of FITL is to implement and upgrading the POTS (plain old

telephone service) of telephone line in the local loop to the customer premises by

using a components of FITL with a fiber optic technology.

Particularly the telephone carriers coming from central office and its remote to the

SAI (serving area interface) or the cabinet in the neighborhood to the ONU (optical

network unit), which is located at the customer premises. In FITL the fiber is the

base from central office to the ONT or depending on the type of FTTx (See figure

7.2).

The voice, Video and data it’s coming from central office in the neighborhood to

the customer premises, with the fiber Optic cable. Optical Line termination (OLT)

is placed in central office and the function of OLT to split the cables around the

network area that served, so its must be send in higher power because its send

the optical signal out, which is divide in several stream and the main function of

OLT is to take the incoming singles like voice, video or data from the MAN network

into the PON transport. After that its goes to the Optical Network Unit (ONU),

which is located at the nearest cabinet to the customer premises.

The function of Optical Network termination (OLT) is to divided the cables into the

customer premises, OLT and ONU is the same device but the OLT is located at

the customer premises and the ONU is located at the door of houses its usually

look like a small boxes, the function of these terms is to make an interfaces

between the customer premises and the PON network, then its goes directly to the

Figure 7.2: FITL NETWORK


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OLT in CO. ONT and ONU are receiving the light signal and converting into the

electrical signal to use at the premises ends. ONU is used when the fibers are

terminated out side of houses and ONT are used the fibers spreads to the

customer premises.

The function of PON splitters (usually, placed in outdoor of cabinet or at the end of

subscriber) are to split the single to the customer, 32 subscriber can be served in

two way of ATM, this way are not important to include an ATM (add-drop

multiplexer) or installing the OSP (Out side plant). The PON splitter can be in

many topologies of network like star, tree and or ring that’s help to increasing the

reliability. Fiber to the loop is the same techniques of FTTx but with different name,

it can use all the scenario of FTTx like FTTC, FTTN and FTTP.

8 Optical Part

In fiber optic technology there are many ways to distribute the fiber cable into

network area, for that why we use the technologies of each FTTx or FITL to tell

what method can we deployed the fiber to the premises. There is two ways to

deliver the cables to the customers by direct way or shared way and for

economical reason the telecoms companies preferred a shared way and for sure

each of these ways has a techniques to delivered the voice, video and data from

the CO (central office) to the customers.

Optical portion has two techniques to delivered the fiber cable to the customer,

which they are:

1. Direct Fiber.

2. Shared Fiber.

8.1 Direct Fiber

Generally, in direct fiber each of fiber cable coming up from central office and

goes directly to the premises, dedicated fiber (e.g. point to point links,

Ethernets link). Commonly a wavelength of downstream (coming from central

office to the premises) is 1550nm combined with voice, video and data service

in one glass fiber optic cable, and for upstream wavelength is 1330nm which is

back again to the central office with the same cable. This connection can be


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operating with 10Gbps for long up to 50 Kilometer distance. In this method it’s

required a large number of fiber optic cables, with each of one cable has own

transfer for one premises.

One of advantages in this method that is each of customers has own cable

that’s make greater bandwidth and larger data rate for last technologies of the

telecoms and information for next generation.

In unfortunately, to delivered one direct fiber to the customer a Provider ask at

least 1Gbps to operate this technology to the customer and its cost a lot of

money because each of customers has own fiber cable and that required the

companies to makes a hole along distance from the central office to the

premises, and for sure this method required own components like Ethernets

switch which is located in customer and transfer in customer all components

that needed.

The application of this technology is to deliver to the all kind of end users. A

Best example of direct fiber is FTTH technology, especially whose requesting

for high bandwidth and the largest data rate.

8.2 Shared Fiber

In this part, the fiber cables is going from the central office (CO) to the

customer in sharing way, the meaning of share is the customer can share with

other customer by using one cables or by using a splitter at the place of OSP

(out-side plant) to splitter the signal in sharing way the premises. An AON and

PON technologies are the best example of Shared fiber.

There are a lot of scenarios that can be help to deliver the single into the

customer premises. The type of FTTx that using the share fiber is FTTC and

FTTN. The cost of shared fiber is much lower than direct fiber. But it takes a

while to identify the problem and solve it. And for a bandwidth and data rate is

not greater like direct because the principle of this technique is a share network.

They are two main methods or techniques to distribute the fiber optic to the

network premises, which they are:

1. Active Optical Network (AON).

2. Passive Optical Network (PON).


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8.2.1 Active Optical Network (AON)

As I mentioned before, Active optical network

is could be a shared fiber, which that’s mean

point-to-point link, from central office CO to

the subscriber each of premises has own fiber

optic cable, which that’s terminated on an

optical concentrator (Access Node (AN)).

(Look at figure 8.1: Active optical network).

Here the Type of Access node (AN) can be

design in different way depending on

specification, Commonly its can be an IP-Edge, Multiple service access network

(MSAN) or Ethernet switching. In this case we refers to use an Ethernet switching.

Fiber optics can be terminated on optical network termination (ONT) but, its can be

also any of IP-route or Ethernet switches with an interface of uplink.

The biggest problem to makes a greater bandwidth in fiber optical, is the

conversion from electrical single to the optical and for receiver from optical to the

electrical by using an optical source and Photodetectors. For that reasons the

telecoms companies are building a huge Synchronous Optical Networking

(SONET), which is contains with long haul rings. These rings are same like a

freeways road, the problem is that the same as traffic of cars, Rings need to enter

and exit in ramps of data. But instead of that, a complex device is called ADM

(add-drop multiplexer).

Also need a repeater because a losses of fibers a long to the premises. And if

using a copper cable links a first mile to the premises, Digital subscriber line

Access network (DSLAM) or other MSAN are used. When MSANs are used, both

of optical lines and copper cables can be used for the first mile at the same access

node. The main problem with AON technology is that must to convert the signal

from electrical to optical (e.g. O-E-O conversion), which the equipment of this is

too highly expensive.

Figure.8.1: Active Optical Network


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8.2.2 Advantages and disadvantages of AON

Table 8.1: AON TECHNOLOGY: -

Advantages Disadvantages

1. Simple to install and Maintenance.

2. The highest bandwidth.

3. High Quality of service.

4. Much secure, because each of

subscriber has own fiber cables.

5. No port is shared any way.

6. Higher data rate and its can upgraded

easily.

7. Cost of equipment in subscriber

terminology.

8. Reliable for transmission.

9. No problem with the transmission,

because the signal is travel in optical.

1. An Expensive service.

2. Cost of network

components (e.g. O-E-

O conversion).

3. Needs to amplifying the

signal power at splitter

place.

8.2.3 Passive Optical Network (PON)

The concept of PON network is an attractive option

it’s reduce the operational cost and traffic signals.

The structure of PON network is from point to

multipoint point (PMP). (Figuer8.2: shows the

general structure of passive technology).

Only passive optical components are placed in the

transmission network, that’s to guide the single path

with specific wavelength to the customer premises

and back again to the central office. Because replacing the AON devices to the

passive components that’s help to save the money for telecoms companies. Since

there are no O-E-O conversion components or signal processing requirements,

that’s good for lower the cost of Maintenance especially for telecoms companies

that’s why more than 90% of network around the world are using PON network.

Generally, the function of splitter is to divide the light signal that’s coming from

Figure.8.2: Passive Optical Network


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OLT (Optical line terminology) in central office and communing them with the

signal coming from ONT (optical network terminology) in the nearest cabinet in

premises.

Here the signal is coming from CO, one signal fiber optic cable to run the passive

optical power to the nearest block of the premises in this point the function of

splitter is to spilt and divide the signal into separated path to the premises by

dividing the number of signals/power to be come for premises evenly, which that’s

mean in downlink is just to splits the power of optical signal to many fibers and for

uplink is doing TDM (time division multiplexing) or WDM (wavelength division

multiplexing, much advance) to protect intervals between time slots.

A PON is used for the first mile only, which the components of the first mile PON

are OLT, Fibers, splitter and ONT. In PON technique is similar to the switched, but

here is not required OSP (Out-side plant, in cabinet) because in PON technique is

replace the OSP with Optical splitter.

PON system has long way to delivered the signal from CO to the customer

premises, which a PON system consist of:

1. Optical terminal, which is located at the customer, premises it for

delivered the voice and data.

2. Switch at CO to send the PON protocols to the premises.

3. Splitter and passive couplers, which are located at the fiber, loop.

4. NMA: management of all PON system, located at OLT.

The distance between OLT to ONT is must be maximum 20km for 1:32 subscriber.

PON technology can have a multiple splitter for serve many types of terminologies

of premises, for example its can have a three splitter respectively. And for the

topologies of network the main three types of network topologies are ring, tree

(using one splitter) and bus. And the most advanced topology is tree-PON network.

Generally, the limit of subscribers are delivered to the central office is from 1:4, 1:8,

1:16 and 1:32 per fiber with 4, 8, 16 and 32 port splitter to serve multiple

customers. Here in PON, there are no active components between the central

office and the premises. Broadband PON (BPON), Ethernet PON (EPON), Gigabit

PON (GPON) and ATM PON (APON, subset of BPON) are the types of PON


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networks. Devices in PON loop is not much cost, but the problem with cost each of

SONET, ADM and power transmitter and because of splitter and PON couplers

are passive that’s mean is not required any power. PON technology doesn't have

much problem to maintain.

The most common applications in PON network are CATV (cable television) and

wireless provider. A PON network is grate solution for broadband access

technology x-DSL.

8.2.4 Types of PONs

1. Broadband-Passive Optical Network (BPON), ITU G.983.3:

BPON serve at maximum of 1:32 or 2:32 fiber to 32 subscriber, the

wavelength of fiber cable is 1550nm or 1490 for downstream and for

upstream is 1310nm, here the bandwidth is shared using an ATM protocol

and the type of multiplexing is WMD which is located at CO. 20Km is

maximum length between CO and the customer premises. The data rate

here are 622Mb/s for downstream and 155MB/s for the upstream. The

mains application services of this type are voice, data and IP video and its

possible to add CATV analog and digital channels.

2. Ethernet-Passive Optical Network (EPON), IEEE 802.3ah

EPON served maximum 1:32 and typically 1:16, 1 fiber to 16 or 32

subscriber, the wavelength of fiber cable is 1550nm or 1490 for

downstream and for upstream is 1310nm, here the bandwidth is shared

using an Ethernet protocols and the type of multiplexing is WMD which is

located at CO. 20Km is maximum length between CO and the customer

premises. The data rate here are 1Gb/s for downstream and 1GB/s for the

upstream. The mains application services of this type are voice, data and IP

video and its possible to add CATV analog and digital channels.

3. Gigabit-Passive Optical Network (GPON): ITU G.984.2

GPON served maximum 1:64 or 2:64 and typically 1:32 or 2:36, 1 fiber to

32 or 64 subscriber, the wavelength of fiber cable is 1550nm or 1490 for

downstream and for upstream is 1310nm, here the bandwidth is shared

using an ATM or Ethernet protocols and the type of multiplexing is WMD


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which is located at CO. 20Km is maximum length between CO and the

customer premises and it’s could serve at 60Km without analog video. The

data rate here are 1.2Gb/s or 2.4Gb/s for downstream and 155MB/s or

2.4Gb/s for the upstream. The mains application services of this type are

voice, data and IP video and its possible to add CATV analog and digital

channels. GPON is the best PONs system.

8.2.5 Advantages and disadvantages of PONs

Table 8.2: PON TECHNOLOGY: -


1. Quality of service for GPON.

2. Cost to get this service.

3. Range.

4. Cost of network components (e.g.

because no O-E-O conversion).

5. No need to amplifying the signal

power at splitter place.

6. Good for ISDN and high speed

Internet and CATV.

7. Prioritisting service.

1. Hard to install and

Maintenance.

2. Bandwidth is shared.

3. Cost of subscriber equipment.

4. Cannot upgrade the service

easily.


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8.3 Comparison AON Vs. PON

Table 8.3 AON Vs. PON

Bandwidth

High Bandwidth,

because each of

subscriber has own fiber

cable.

Average bandwidth, but its

could be high with GPON

technology.

Data rate

High data rate. And the

speed can upgrade

easily.

Average data rate, but with

GPON technology is good. For

Speed most of PONs is hard to

hard to upgrade.

Fiber consumption

Each subscriber has the

own fibers.

The signal fiber to the passive

splitter, after that is could be

shared or directly from the

splitter.

Testing

Testing is simple.

Testing is difficult. For example

testing each of connectors,

which located from CO to the

customers.

Trouble shooting

Very simple to identify

the problem and maintain

it.

Hard to identify the problem,

because the process between

the CO and the subscriber.

Cost

Very high price for

subscriber to have such

like this system. And the

components of network

are high.

Average price for the

subscriber. And for the

components much bitter

because of passive splitter.


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Geographical

Coverage

For small area.

It’s covered a large area of

network by using a multiple

splitter. And its use for long

distance. Mostly using a MAN

network.

Quality & Security High quality and much

secure. Because each

subscriber has own fiber.

Average quality and secure

depends on the types of PON.

The quality is good for GPON.

Energy

consumption

High energy, because

the number of laser

interface.

Low energy, because of

passive splitter doesn’t have a

amplifier or repeater.

Ranges

Good, Can be

transmitted for long of

70km without any

repeater.

Low, Because it’s dependable

of passive splitter. 20km as

Maximum.

9 FTTx Architecture

9.1 FTTH Architecture

Fiber To The Home FTTH, from the name of this type tells the fiber cable is used

from the central office to the customer, here there are a three methods to deliver a

fiber optic cable to the premises which they’re: Point to point (active fiber network),

Switched (Active Ethernet switched) and PONs. With FTTH technology can

service a long of independent fiber to the subscriber at least 450 subscriber.

In FTTH architectures all three methods that’s delivered the fiber are required a

aggregation devices in OLT (located at central office) and required an optical to

electrical device which is located in the ONT or the boxes in outdoor of houses its

depend on how far the OLT from customers and how many customers are served.

The most common about the FTTH fiber cables are the one cable allowed to be

bidirectional transceivers (BIDI), so one signal mode fiber can serve for upstream

and downstream, which usually the wavelength of downstream is 1550nm and for

upstream is 1310nm, the good about these wavelengths are to protect from


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attenuation and dispersion (the higher or longer the wavelength, the lower the

attenuation).

The main benefits of using BIDI are to reduce the quantity of fiber cables and

specially reducing the splicing labor. But that makes the cost of optical

transmission mush higher.

Point-to-Point (P2P or Active fiber)

architecture, one fiber cable from the

CO to the subscriber, P2P links is the

simplest architecture of FTTH and the

highest bandwidth and data rate, the

main advantages of P2P can operate,

upgrade, identify or maintain the

problem easily and specially is doesn’t

have any port in OLT to share (one

port for one subscriber). Here the

problem just with the quantities of fibers cables. From 32 to 64 subscribers the

distance is long 70Km without any repeaters. P2P is an expensive service to get.

(Figure.9.1 shows the Point-to-Point links).

Active Ethernet architecture,

Its same to the P2P link but the main

different is that from CO to the

customers there is an OSP cabinet, An

OSPs help to serve in big area or large

customer, the single fiber coming from

the CO to the OSP and divide the

cables to the customers with

bidirectional fibers. One fiber from OLT to

the OSP cabinet to serve 64subscribers.

Figure.9.1: Point to Point links

Figure.9.2: Active Ethernet Network


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PON Architecture:

This architecture is to serve a high

data rate with a large number of

premises, here From OLT to the

customer there are WDM multiplexer

and Passive splitter, the maximum

length from OLT to the premise is

20Km. In FTTH, here we use a GPON

system. Here the number o subscriber and the length depend on the type of PONs

system. (Figure 9.3: shows the general PON network).

As in chapter five, the different between AON (with didactic fiber cable to many

customers) and PON with many advantages in AON compared with PON

technologies. With no splitter in AON, along of distance to the customer premises

its good be a sustainable and for the base for of customers requirements for the

future. For that AON technology is the best service for each of subscriber or

network provider. With the high quality and bandwidth of FTTH, FTTH can be

serving to any services that have today. And to met the revolution of future

technologies.

9.2 FTTC Architecture

Fiber to the curb is based on fiber optic cable to the curb, from the CO to the

nearest cainet of premises. And each of these caninet to the customers is used for

transmession a coaxiel cable or twisted pair. The idea of fiber to the curb FTTC

architecture is to solve the problem with bandwidth and speed of broadband

Internet access network with a copper cable network.

FTTC helps to solve the broadband internet problem by building a full a single

mode fiber optic (two directional) from CO to the distribution hub and the function

of distribution hub is to distribute the fiber cable to the nearest ONU which the

called it “electronic cabinet”, and from FTTC electronic cabinet the cables goes

direct or share to the premise with copper cable. (Figure 9.4: shows the network of

FTTC).

Figure.9.3: General PON Network


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This methods help the telecoms companies to provide high broadband Internet to

the customer, but the distance from the electronic cabinet to the customers its

should be 300m. The big different of FTTC from the other types of FTTx like FTTN

or FTTP is the FTTC placed in the nearest cabinet of the customers, which FTTN

placed far a from the customers and FTTP is placed at the serving location. From

the using of copper cable in the last mile FTTC costs less to deploy but with the

lower bandwidth. The bandwidth and the speed of data rate in FTTC depend on

how far the cabinet from the customers.

FTTC can deliver a broadband service xDSL and CATV. FTTC is a good method

to serve small business and houses, especially for whose require a not more than

40Mbps speed.

9.3 FTTB Architecture.

Fiber to the building or business, here the fiber it’s goes directly or in share way to

the customer building, Fiber cable goes from CO to the entrance of building

premises and after that its goes directly with copper cable to the premises. The

main reason why we need FTTB is the most of Internal connections of building is

in copper cable and its cost very much to replace the copper cables into the fibers

cables that are the main reason why we need an FTTB.

The idea of FTTB is to cover the demand of high bandwidth; the solution is to have

a fiber optic cable connected from the CO to the building or business, and its

usually goes to the customer in copper cable for that reason of not loss the

bandwidth we used a DSLAM from the entrance to the subscriber by copper cable.

Figure.9.4: FTTC network


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Each of subscribers can get not less than 100Mbps in short distance of copper

cable by using a VDSL2 transmission. So the telecoms companies can provide the

subscribers many services such as VOIP, ISDN telephone, IPTV, CATV and high

access of broadband Internet with minimal costs of other services without losing

the bandwidth or the access speed.

Mile gates is a compact DSLAM, It’s connecting the subscribers in multiple

apartment or small business to the FTTB. Mile gates offer 8 VDSL-2 with

maximum bandwidth over distance of up 100m. Mile gates give the optional to

converting each of analogue and digital CATV signals. The mile gates is the

solution to have a large bandwidth with high data rate for a large building to serve

man customers without losing of the signal because of Copper cable problem and

losing broad band services.

9.4 FTTP Architecture

Fiber to the premises is a generic term of FTTH and FTTB. The idea of this

scenario is to cover a large MAN area with high quality and bandwidth of services

to the premises. FTTP can use two or more distribution hub (MAN splitter) and

other splitters to serve the premises at one area, the number of splitter depending

on the number of subscribers at each area.

FTTP can deliver to multiple premises terminologies such like MDU, MHU, MTU

and SDU all that are for serve to the business, building and houses. The

differences between FTTP and other FTTx scenarios, Is FTTP is multiple that can

serve to many premises terminologies and its can delivered a high bandwidth such

like FTTH and high quality of services and much secure. (Figure 9.5 shows the

FTTP network).


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FTTP includes the uses of ONTs at the FTTH and FTTB implementation and the

uses of ONU for FTTC and FTTN applications. The processes of FTTP from CO to

the customers are:

1. Distribution cable (distribution hubs): from CO to the optical splitter with

fiber cables, the distance from the CO to the optical splitter its usually 10km.

here the optical splitter can splits 1:2 or 1:4 or 1:8 1:32 one feeder cable

from CO to 2, 4, 8 or 32 splitter to serve a 32, 64, or 128 subscriber in one

area (the number of subscribers depends on the methodologies (E.g.

BPON, APON and GPON). From the optical splitter to the premises its can

connects directly to the customer or run a local splice box, which is located

at the nearest cabinet to the premises.

2. Local splice box: from splice box to the premises its connected with fiber

cable, and for cooper cable its just use to the business or building such as

FTTB. The distance between splice box to the premises normally its should

be 1-km long. The maximum distance from CO to the Premises 20km.

For the designing of FTTP network, must consider on two important thing, which

they are:

a. Type of optical splitter: the type of splitter it’s depend on how splitter can

split the fiber (how much?) and how many subscriber can serve in one big

area.

Figure.9.5: FTTP network.


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b. Location of optical power splitter: the location is important when the

demand of the bandwidth and the data rate of each customer, for example

the premises of building or business requires high bandwidth to serve them,

here the locate of optical power splitter should be nearest to whose

requesting the largest bandwidth.

FTTP includes all kind of methodologies to deliver the voice; video and data to the

premises and the popular methodology are BPON, EPON or GPON from PONs

system and includes WDM-PON system or WDM multiplexing and active optical

network (AON) or active Ethernet. With WDM-PON, which installed at the feeders

distribution hubs with other possible splitter at the cabinet, here each of customer

has specified a wavelength. And for active Ethernet the OSP located at the

distribution hubs. And finally with AON only one-fiber cables goes from CO directly

to the premises. The Conclusion of FTTP methodologies, each of one

methodology can serve depending on the bandwidth and the speed of data rate

requesting from the type of premises terminologies.

FTTP is the most expansive scenarios of FTTx, because its serve for big area and

can work with multiple methodologies which each of that required the own

components and elements. FTTP is the most popular scenarios at these days and

its can provide the same application services for all kind of FTTx. FTTP is the

solution of everything.


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9.5 Advantages and Disadvantages of all FTTx

Table

9.1


FTTH

1. Today, the cost is low.

2. The highest Bandwidth of all FTTx.

And its can upgrade easily.

3. Highest quality of all FTTx.

4. Greater reliability of all FTTx, and

no interference at all.

5. The best of data speed, for both

upstream and downstream.

6. No active components between the

CO to the customers.

7. The only technology that keep pace

with developments in

communications evolution.

8. Serve a lot of subscriber, over 450

subscribers (just for P2P).

9. Easy to maintain.

10. The FTTH network is a future of

FTTx architectures.

1. Required a lot of fiber

cables.

2. Cost of cables, e.g.

P2P.

3. If the cable is cut for

P2P. take a lot of work

to solve it.

FTTP

1. Generic terms can use all

methodologies to provide the

signals. E.g. AON and PON.

2. High Bandwidth.

3. Reliable for transmission.

4. Can serve a lot of subscribers.

5. The best of data speed, for both

upstream and downstream for both

business and houses.

6. The best choose for large area.

1. Hard to install and

maintain.

2. Bandwidth is shared

with PON.

3. Cost of subscriber

equipment with PON.

4. Cannot upgrade it

easily with PON.


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7. Can do all methodologies to deliver

the signal.

8. The future proof.

FTTC

1. Low cost.

2. Flexible to deploy.

3. The idea is to deliver a high data to

the premises with copper cable

from the cabinet (good for).

1. Less Bandwidth.

2. Take the time to solve

the problem.

3. Requires a lot of

equipment’s, which

are expensive.

4. Can’t upgrade easily.

5. Loss of signal.

6. Needs to Maintain.

FTTB

1. Bandwidth.

2. The data rate.

3. High quality.

1. Need to convert the

optic signal.

2. Loss of signal (in

building area).

10 FTTx issues

FTTx has many benefits and advantages to use, but when establishing the

network of FTTx its must required a lot of thing (issue) to consider about such like

design, installation, testing and safety. These issues are helpful to identify the

problems and solve it. The FTTx issues that most consider about are:

10.1 FTTx design issues

Before the implementing or installing the FTTx technology. FTTx design issues

must consider several requirements, like:

1. Each of FTTx network is different, that’s required to study all factors and the

size of area for designing and installation.

2. Provider must consider about:

a. The geographical area and the current location of each FDH, OLT

and ONT.


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b. The current infrastructure, which kind of FTTx use?

c. Types of premises terminologies.

d. Types of services that have required from the customers, to be

chose which FTTx refer to use.

e. Provider requirements.

10.2 FTTx Installation Issues

There are many issues to consider about FTTx installation must be consider about

like:

1. Termination: The end of fiber cables, connecters, splicing pigtails (cabinet)

and splicing at the customers.

2. Location and cable placemat: is about how far to the customers from CO

(central office) or electronic cabinet and consideration of pulled in cabinet

and buried.

3. Hardware Mounting: the device in CO (central office) for basis, OLT

(optical line terminated) inside the CO.

4. Testing the fiber: testing for each cable for insert loses, testing for each

splicers location and testing in the customer cable.

5. Testing the equipment: Is the fiber work perfectly? Using the equipment to

testing the transmitting and receiving the data, voice and video.

6. Vendors Requirements: here use the specialized vendors to save the time

about the methods of installation and testing to save the design time.

10.3 FTTx Testing Issues

After the design and installation the one of FTTx type, the part of testing issues is

important to know if the job is done perfectly and for sure to keep the testing work

daily when the need of the testing. Here some issues must to considering about

which they are: -

Testing all components from CO to the premises with each equipment’s and

fiber cable flow.

Testing here with the same of old OSP, but the differences with each of

WDM and splitter (became more complex than old OSP, e.g. PONs)


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Intelligent ONT that allow to troubleshooting the easily and located inside

the FITL.

Testing of each splitter, couplers and splicing box cabinet.

The testing device should be operating of each 1310, 1490 and 1550 nm

wavelength.

With the using of optical loss test (EXFO is the best), testing of each OTDR,

insertion losses and reflectance.

Testing the link signal from CO to FDH (fiber distribution hubs) and from

FDH to the ONT, just for FTTP.

After the installation of FTTx make sure they testing of END to END that

include of connecters losses, fiber flow losses in each link and the splicing

box link.

10.4 FTTx Safety issues

Installing or maintaining fiber cables needs specific precautions to avoid

hazardous caused by optical fiber cables. As any other communication system

fiber has several factors, which are taken on consideration when dealing with fiber,

otherwise harmful damages could happen, these factors are:

Laser.

Bare Fibers.

Chemical Materials.

Optical Power.

Laser can damage the worker eyesight when direct views, and reflected lights

beams can cause fire, or skin injury. Therefore, there are several factors can

determine the precautions of optical fiber sources, in order to avoid harmful

damages, as the following:

Wearing safety glassware.

Do not throw fiber debris in the site.

Ethylene chloride.

Acetone.

Isopropyl or denatured alcohol.


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Epoxies.

Gel removers, cable gels.

The worker must turn the power off, whether installing or maintaining the

fiber in the workstation especially with EDFA.

11 Conclusion

Today many service are applied and the problem with the using of copper cable.

But with the capability and the advantages of fiber optic cable the fiber today is the

best solution of transmission media. With the evolution of broadband services,

FTTx methodology is the solution for everything with using the Fiber cable to

transfers the highest bandwidth with minimum losses. FTTx can cover all the

needs of customers and businesses demands from the bandwidth to the speed of

data rate.

The best technology to deliver the highest bandwidth is P2P and AON, but the

AON technology is to serve a small area with limited subscriber. PONs technology

is the best to deliver a high bandwidth with a large area (MAN), GPON today is the

popular network.

All FTTx scenarios can deliver high bandwidth with the speed of data rate, but

each of FTTx types has the own advantages like; FTTH is the best scenarios to

deliver a high bandwidth and the data rate, especially if the customer wants to

upgrade his service. FTTH use a three technology of delivered which they are:

P2P, Active switch and PONs (GPON) FTTH are required from houses or small

businesses. The good technique that’s delivered the fiber to the large area is

FTTP. FTTP is a generic term that’s including the three scenarios of FTTx, which

they are FTTH, FTTB and FTTC. FTTP is required from houses, businesses, and

big institute.

FTTC is good for unstructured area e.g. if the MAN area that’s service use an

Copper cable and the telecoms company are poor to establishing a fiber cable to

each customers then the best solution is to provide a FTTC methods and for FTTB

is same idea of FTTC but the main different with FTTB using an copper cable

inside the building.


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The most important thing in testing part is the designs issues, the question will be

are: -

Which types of network terminologies are?

Which types of premises terminologies are?

How many the customers in one area?

Which methods we used AON or PONs or better P2P?

Which kind of FTTx used?

Provider and customers requirements.


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12 Vocational Pedagogy part: (FTTx Concept 50min)

12.1 Curriculum analysis.

Department Major Course Name Code Prerequisites

Communication

Techniques Communications Fiber Optic Cable COM-240 COM-136

Trimesters 1 2 3 4 5 6

Credit Hours (Hours/Week) 5

Contact Hours

(Hours/Week)

L 4

W 2

T

Table 12.1

Prerequisites of FTTx (Thesis):

A basic knowledge of electric circuit-1 (COM-115) is needed. Also, some subjects those are

relevant to basic communications needed to complete this subject, or as a required in future

semester, as follows:

General Mathematics “MAT-113”

Electric Circuit-1 “COM-115”

Electric Circuit-2 “COM-116”

General Physics “PHY-115”

After finishing this course there’s no required courses for the next trimester.

However, there are some lessons are required before the topic (FTTx Concept), and lessons come

after finishing this topic. They are grouped and organized on the following chart

Course Description:

This course is designed to provide state-of-art information of different types of optical fiber and the new technologies available nowadays in communication system. Considering the broad meaning of FTTx concept including its features, the four scenarios, the installation issues, and the advantages of FTTx types compared to other types of communication network. Also, to deliver the reasons beyond the demands of large bandwidth that requires new loop installation, in order to deliver high-speed Internet services including IPTV, video-conference and voice over IP.


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The following topics will be addressed:

Related

tasks Duties Tasks detail

1A4

2A2

2C4

Knowledge of electrical

characteristics of transmission

lines like characteristic

impedance, propagation constant

and their dependence on

frequency and line length.

The trainees should follow the fault

repair, analyze the fault, and Examine the

devices after repair. And participate in

executing solutions.

1C3

2C3

1D2

Knowledge of Fresnel reflection

and misalignment loss (lateral,

angular).

The trainees should suggest suitable

solutions, and take readings from the

base transmitting stations.

This course will be given on the 5th trimester; it has five credit hours, four hours for lectures

(theories), and two hours for practice. It consists of eleven chapters with fifty-four sub-topics

within thirteen weeks. FTTx is located on the sixth chapter, and the total contact hours are

78hrs. This course has also different tasks “NOSS”, which specific skills, objectives,

knowledge, and duties that are required to complete this subject. These skills have taken

from the book of job analysis timetable, which is made by TVTC organization and published

on 2002.


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1E1

1E2

2E4

2E5

Ability to measure characteristic

impedance of transmission lines,

light source and photo-detector

characteristics and attenuation

for glass and plastic fibers.

The trainees should Collect faulty

information from the faulty controller, and

specify the type and location of faults.

Also, examine the devices after repair to

coordinate with the faults controller to

make sure of clearing all faults.

Table 12.2

12.2 Content analysis

Before we start the lecture, make an overview about the fiber optic (overview in

what we stop in last chapter). Then we start in new chapter.7 we define some

terms such like FTTx concept, why FTTx, FTTx features and benefits, FTTx

scenarios and the FITL functions. First, we define the FTTx in Generally; Fiber to

the x (FTTx) is techniques or methods of fiber installation between central offices

to the customer. FTTx “last mile” is a generic term of network topology that’s most

to replace the copper cable into fiber optic. Second, why we need FTTx today?

With the evolution of communication around the world, Telecom companies now

are suffering from copper cables especially in Saudi Arabia. Last statistics around

the world is said the cable telephone bulk is 10% for long distance (fiber optic

cable) and 10% for a local loop (fiber optic cable) and 80% Subscriber loop

(copper cable) for that the telecoms companies are suffering. Then, the features

and benefits of FTTx todays are with the performance of FTTx comparison with

twisted pair or coaxial cable, Quick to install and easy to maintenance, flexible to

design, Easy to absorb from a new users and technologies with low cost of

building FTTx networks. Last but not least, define the scenarios of FTTX like FTTH,

FTTP, FTTC, FTTB and FTTN. In short definitions of FTTx scenarios are:

FTTH: Fiber to the Home, using fiber optic between central office and customer

FTTB: Fiber to the building or business, Its used a fiber between central office

CO to the entrance of building after that is usually copper cable.to the cabinet,

which is not more than 300m far from the customer. From the cabinet to the

customer is copper cable.


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FTTP: Fiber to the Premises, Generic terms that include both FTTH and FTTB.

FTTN: Fiber to the Node or neighborhood, it’s like FTTC but the different is

how far the cabinet from the user ends.

Finally, with FITL (fiber in the loop) The idea of FITL is to implement and

upgrading the POTS (plain old telephone service) of telephone line in the local

loop to the customer premises by using a components of FITL with a fiber optic

technology. And define the elements that’re between CO to the premsis of all

FTTx senairos.

12.3 Didactic analysis

This is a 50-minute lecture, which is about an overview of FTTx concept to

everyone who would benefit from a broad knowledge of the fundamentals

concepts of FTTx of Fiber Optic Cables. Also, to provide information about how

does fiber cable installation from CO to the premises. Introduction as examples of

reality of all FTTx scenarios would be included that will be delivered in the

classroom. Then, the lesson will be define of FTTx concepts, and what the major

types FTTx. After that, these types will be explained with details including the

Pictures and drawing in the WB telling the different of all FTTX scenarios and fiber

performance.

First, in the opening phase, the trainer will start attracting the trainee's intention by

reviewing the last lecture’s topic to make a connection between them, and simply

explain the definition of FTTX Concept. The method at the beginning will be (in

front of the class), this is the only way to encourage the trainees to be more active.

Also, to motivate them to concentrate as a beginning, the media that the trainer

will use are:

Whiteboard.

Projector (presentation).

Second, in the body phase the social form will be (Demonstration, or in other word

in front of the class). I will explain about one if the all FTTx scenarios such like

FTTH, FTTP, FTTC, FTTB, and which is the important of dominating the telecom

business nowadays. So, it needs to be taken step-by-step to be understandable

from the trainee’s side. The media will be used are (whiteboard, PowerPoint


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slides) besides the trainees will be given handouts to follow the trainer where the

important points are included. Also, useful for the present time and the future as

well, overview and defining FTTx types using the following media:

Whiteboard.


This lecture is seemed to be (deductive approach), because there’s no practical

part it just about architectures.

Then, the important part of the topic is (Why we need FTTx Toady), and the

method the trainer will use is (demonstrating). The media will be used are:

Whiteboard.


After that the trainer will explain the types of FTTx including the effects of labour

marketing today and which is better and the media are:

Whiteboard.


After that, the general and the total formulas of FITL technology and tell what the

function of each elements between central office and the premises. The method

that will be used is (Demonstrating), and the media are:

Whiteboard.


Finally, at the end of the lesson the trainer will give a short explaining of one

example of FTTx, which is FTTH architecture. The suitable methods for this phase

are (in front of the class and classroom conversation). The media that will be used

are (Whiteboard and Projector (presentation).


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12.4 Learning objectives

General objectives:

o Review of last lecture.

o Are encouraged to improve technical English.

o Get further knowledge beyond demands of FTTx Networks.

o Get further knowledge about the benefits and features of FTTx.

o Are getting more proficiency to work in-group.

o Are encouraged to take note with the trainer.

o Finishing the task that’s given on the time.

Specific objectives:

The trainees:

o Are able to define the FTTx Concept. (Reproduction)

o Are able to define the four main Types of FTTx. (Reorganization)

o Are able to compare with different FTTx scenarios. (Transfer).

o Are able o describe the functions of elements in FITL loop.

(Reproduction)

o Are able to distinguish which FTTx methodologies are better.

(Reproduction)

o Are able to identify the FITL network components. (Reproduction)

12.5 Process Overview of a lesson plan

Opening/Entrance/Motivation Methodology Media Time

Expected Trainer-action Expected Trainee-

action

Reviewing in what we

toke the last chapter and

make the link it with this

lesson. Questioning

them about last lecture.

Give the trainees

Motivation And

Expecting form

them some

answers.

Question/Disc

ussion.

WB

3 min.


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Close (Reflection, Exercises, Homework,

Feedback

Methodology Media Time

Expected Trainer-

action

Expected Trainee-

action

Starting on the topic to

define the FTTx concept

and the meaning of last-

mile.

Trainees listen.

Frontal,

Classroom

conversion.

PPT,

WB

5 min.

Explaining Why we

need the FTTx and tells

the benefits and

features. And whose

wants the FTTx?

Trainees listen.

Frontal,

Classroom

conversion.

Work.

PPT,

WB

5 min.

Explaining The main

four types of FTTx and

which the popular and

important. And

explaining the services

of FTTx.

Trainees listen, and

asking some

questions.

Frontal,

Classroom

conversion.

PPT

(PICs),

WB

12 min

Group work; the

questions about “ what

the advantages and

disadvantages of the all

FTTx scenarios and

what the best type?”

Trainees listen. And

accepting from them

some questions.

And they will do

group work

perfectly.

Group Work

PPT,

WB

10 min

Explaining the elements

of FITL loop such like

OLT, ONT and ONU.

And distinguish between

the active and the

passive splitter.

Trainees listen.

Frontal,

Classroom

conversion.

PPT

12 min


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Close (Reflection, Exercises, Homework,

Feedback)

Methodology Media Time

Expected Trainer-

action

Expected Trainee-

action

At the END of the class.

Review What we

learned today. Giving

them as concluding.

Should be

answering, if they

understood the

lesson

Classroom

conversion.

Question/Disc

ussion

----------

---------

Pre-assessment; Which

type of fiber cable use in

FITL.

Trainees listen and

try to answer the

assessment.

Classroom

conversion.

PPT

3 min


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13 Bibliography

Main references Books:

Gerd Keiser, FTTx Concept and application ©2006.

FuruKawa Company, Understanding Fiber Optic ©2007.

Ivan P.Kainow, Tingy Li, Alan Willner, Optical Fiber Telecommunications,

Elsevier Inc. ©2008.

Moh. Yasin, Sulaiiman Harun, Hamszah Arof, Optical Fiber Communcations

and Devices, InTech ©2012.

FTTx System Catalogue, fibreflow System, Emtelle ©2011.

Gwenn AMICE, PPT of FTTx and xDSL testing, EXFO ©2008.

Jim Hayes, FTTx (Current Status of Fiber To The User), Fiber Optic

Association and VDV Academy ©2006.

Andre Girard, FTTx PON Technology and Testing, EXFO Electro-Optical

Engineering ©2005.

PDF project of AON and PONs network, KeyMile company.

List of Figures:

Fig 3.1: (http://olabstech.com/pdf/construction.pdf)

Fig 3.2: (http://nuclearfootprints.com/?attachment_id=1973)

Fig 3.3: (http://science.hq.nasa.gov/kids/imagers/ems/index.html)

Fig 3.4: FTTx concept and Application, Gerd Keiser ©200

Fig 4.1: (http://etd.lib.fsu.edu/theses/available/etd-11202003-

060632/unrestricted/09_psm_Chapter2.pdf)

Fig 4.3: (http://www.sensornet.co.uk/)

Fig 4.4: (http://www4.nau.edu/microanalysis/Microprobe-SEM/Statistics.html)

Fig 4.5: (http://aaronmiemban.blogspot.com/2009/11/basic-block-diagram-of-

communication.html )

Fig 4.6: (http://physicsnet.co.uk/a-level-physics-as-a2/waves/refraction/)

Fig 4.7: (http://physicsnet.co.uk/a-level-physics-as-a2/waves/refraction/)

Fig 4.8: PPT, Partner

Fig 5.1: FuruKawa Company, Understanding Fiber Optic ©2007.

Fig 5.2: FTTx concept and Application, Gerd Keiser ©2006.

Fig 5.3: (http://www.muxtronics.com/pressure-and-level-measurement-


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systems/)

Fig 5.5: (http://www.thefoa.org/tech/)

Fig 5.6: (http://www.fiberoptics4sale.com/wordpress/)

Fig 5.7: (http://www.thefoa.org/tech/)




Fig 7.1: Wikipedia web. FTTx.

Fig 7.2: Course of Advanced comm. System with Dr. Frohberg, TTC.

Fig 8.1: AON Vs. PON Project, KeyMile company, Germany.

(http://www.keymile.com)

Fig 8.2: AON Vs. PON Project, KeyMile company, Germany.

(http://www.keymile.com)

Fig 9.1: Multicomm. Marketing company, America.

(http://www.multicominc.com)







http://www.multicominc.com/


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14 Annex

Glossary

FTTx Fiber to the Terminated x.

OSI Open System Layers interconnect

WAN Wide area network

MAN Metropolitan area network

LAN Local area network

CO Central Office

POP Point of presence

MDF Main distribution frame

EXCH Exchange

DWDM Dense Wave Division Multiplexing

FITL Fiber in the loop

SDU A single dwelling unit

MDU: A multiple dwelling unit

MHU A multiple hospitality unit

MTU: A multiple tenant unit

SFU: A single-family unit

SOHO Small office/home office

AON Active Optical Network

PON Passive optical network

CATV Community access television

VOIP Voice over IP

FTTH Fiber to the home

FTTB Fiber to the building

FTTC Fiber to the curb

FTTP Fiber to the premises

FTTN Fiber to the node

IPTV Internet Protocol television

HDTV High definition television.

OLT Optical line termination

ONT Optical Network termination


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OLD Optical line distributor

SU Service Unit

ATM Asynchronous Transfer Mod

OSP Out side plant

P2P Point to Point

AN Access node

MSAN Multiple service access network

SONET Synchronous Optical Networking

ADM Add-drop multiplexer

DSLAM Digital subscriber line Access network

O-E-O Optical to Electrical to optical

PMP Point to multipoint point

TDM Time division multiplexing

WDM Wavelength division multiplexing

BPON Broadband Passive optical network

EPON Ethernet Passive optical network

APON ATM Asynchronous Transfer Mod -Passive optical network

GPON Gigabit Passive optical network

ITU International telecommunication union

IEEE Institute of Electrical and Electronics Engineers


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15 Statutory declaration

We declare within the meaning of 1.43/1.45 of Examination and Study Regulations and TTC’s Code of Conduct and Honor: This bachelor thesis has been completed by our group independently without outside help and only the defined sources and study aids were used. Sections that reflect the thoughts or works of others are made known through detailed references.

1. Moayad Al Zoghiby:

City, Date Trainee name Trainee ID

Signature

2 0 2 3 0 2 1 0 3

[202302103] [Moayad] [AlZoghiby] [ICT]

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