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COMPARATIVE ANALYSIS OF PLASTIC
OPTICAL FIBER AND GLASS OPTICAL FIBER
FOR HOME NETWORKS
Amevi Acakpovi and Paule Leyola Murielle Voumbo Matoumona
Abstract—This paper presents a comparative analysis between
plastic and glass multimode fiber in order to determine the
most convenient and adequate to deploy Fiber-To-The-Home
(FTTH) technology. FTTH is a promising technology capable
of meeting the on-going increase of bandwidth request. The
main objective of this comparison analysis is to determine the
advantages and disadvantages of plastic to glass fiber and be
able to advise confidently on the most reliable, efficient and cost
effective for FTTH. The work consists of high simulation covered
with Optiwave OptiSystem 7 software. A passive Optical Network
for FTTH has been designed and simulated. The performance
parameters studied are: bandwidth, bit rate and attenuation.
Results showed that the Q factor for the network using plastic
fiber is higher than the one of glass fiber. This makes the plastic
fiber better than the glass fiber in terms of transmission losses
or attenuation. Furthermore, analysis carried on with a BER
analyzer and eye diagram showed that the signal is more distorted
and more affected by noise in the case of the glass fiber. The same
result is also proved by the use of optical signal to noise ratio
which gives higher result in the case of the plastic fiber than the
glass one. In total, plastic fiber is more efficient and reliable for
FTTH.
Index Terms—Plastic fiber, Glass fiber, FTTH, Bandwith,
Attenuation, BER.
I. INTRODUCTION
TECHNOLOGICAL changes and innovations in
telecommunications are causing subscriber’s to
demand for more multimedia services in their homes. To
improve network capacity for indoor environment, various
techniques have been used to increase data rates and
enhance data transmission. These techniques involve several
transmission media which also have their advantages and
disadvantages. Fiber-To-The-Home appears to be an emerging
technology that could enable optimum broadband service
delivery up to the end users. [1] FTTH allows for larger
bandwidth and faster delivery speeds, which are essential for
modern triple-play deliveries in which access providers offer
video, data, and telephony services. Figure 1 shows an optical
distribution network.
Initially, cable modem was the first broadband option avail-
able to many, but only a few hundred thousand subscribed to
Internet cable at first. In 1999, competition from DSL (digital
subscriber line) kicked in, but DSL availability remained
A. Acakpovi is with the Department of Electrical/Electronic, Accra Poly-
technic, Accra, Ghana, e-mail: acakpovia@gmail.com.
P.L.M. Voumbo Matoumona is with the Department of Telecommuni-
cation, Ghana Telecom University College, Accra, Ghana, e-mail: vmley-
ola@yahoo.fr.
Figure 1. Optical Distribution Network
quite limited. The expected competition from satellite services
did not emerge until later, and even today, satellite services
remain a distant third in the home broadband market [2].
As subscriber’s applications are becoming more complex, the
demand for higher bandwidth, higher speed and reliability
also increases. Cable technologies were no more the best
to meet demands. Fiber optics took over and has become
one of the most popular and most reliable technologies.
Optical fiber is the medium in which communication signals
are transmitted from one location to another in the form of
light guided through thin fibers of glass or plastic. Optical
fibers are made of glass, although some are made of plastic.
Glass optical fiber comprises of three layers: the centre core
that carries the light, the cladding layer that covers the core
which confines the light to the core, and the coating that
provides protection for the cladding. The core and cladding are
commonly made from pure silica glass, while the coating is a
plastic or acrylate cover. Plastic optical fiber (POF) also called
polymer optical fiber, uses PMMA (acrylic) which consists of
a general purpose resin as the core material and fluorinated
polymer for the clad material. In large diameter fibers, 96%
of the cross section is the core that allows the transmission
of light. The fiber diameter of most POF in use today is
1000μm, with a core diameter of 980μm. POF is universally
applicable for voice, video as well as data transmission in
building service management, controls, bus systems, circuits
or lightning. From the central office (CO), the content mixed
in the form of electrical signals is converted to optical pulses
before being transmitted over the Optical Distribution Network
(ODN) toward subscriber homes. At each subscriber home,
a Customer Premises Equipment (CPE) converts the optical
154
978-1-4673-4788-4 c
2012 IEEE
pulses back to electrical signals [3,4].
Despite optical fiber gives numerous advantages over the
various electrical cables for home networks it still remains
difficult to choose between types of fiber adequate for home
networking. Two fundamental types can be identified for home
networking: Glass Optical fiber and Plastic Optical Fiber.
The Glass Optical Fiber is the most used, while the Plastic
Optical Fiber can also provide excellent result or even better.
Transmission through both media comes with some advantages
and disadvantages which this paper is investigating into.
The main objective of this paper is thus, to do a comparative
analysis between glass and optical fiber for FTTH. This will
be achieved through the design and the simulation of an FTTH
network architecture using both glass fiber or optical fiber.
II. METHODOLOGY
The design consists of an optical network architecture which
comprises of four main blocks, namely: video transmitter, data
and VoIP transmitter, optical transmitter link, video VoIP and
data receiver. The design is done with Optiwaves Optisystem
software. The next paragraphs discuss each of these blocs
in details, their assembling and the simulation of the whole
design.
Video transmitter: The video transmitter consists of two sine
wave generator having different frequencies which go to the
input of a summer block. One of these frequencies has a value
in video band and the other belong to audio band.
Figure 2. Video Transmitter
The adder mixes the two signals to produce our model of
composite signal which is normally supposed to contain both
audio and video signals. To modulate the electrical signal
coming from the combination of the first two waves, the
Match-Zender modulator block is used with an optical carrier
signal been generated using a CW Laser block. The signal is
later amplified using the EDFA blocks and monitored with an
Optical Spectrum Analyzer as illustrated in figure 2.
Data and VoIP transmitter: It consists of a Pseudo Random
Bit Sequence (PRBS) generator which produces bit streams
and is directly fed to a NRZ electrical encoder. The output of
the encoder goes into the Mach-Zender modulator which uses
another optical carrier wave with the CW Laser block. Finally
an EDFA block amplifies the signal as shown in figure 3.
For the optical transmission link design, we need to mul-
tiplex [5] the video signal created with the data by using a
WDM multiplexer. The video and the voice/data combined is
transferred on a linear multimode optical fiber which takes
the signal to the power splitter and finally, to the receivers as
shown in figure 4.
Figure 3. Data and VoIP Transmitter
Figure 4. OpticalTransmitting Link
Finally, the receiver stage [6] starts with a power splitter
which splits the transmitted signal back into video and data
signals.
The ONU that follows the splitter are provided with two
receivers; one for the reception of the video and another one
for voice/data. The signals are re-sampled using regenerators
and the outputs are monitored with Bit Error Rate analyzers.
Next figure is the diagram of the full design which consists
of a combination of all the stages discussed above.
Figure 5. Full design
III. RESULTS
Simulation results are shown in the figures below. First,
figure 6 show the output of the optical spectrum analyzer for
2012 IEEE 4th International Conference on Adaptive Science & Technology (ICAST) 155
data and VoIP generation model presented in figure 3. There
if a frequency component appearing in red color at the various
carrier frequencies adopted,192 THz and 200 THz respectively
for the Glass and Plastic fiber.
Figure 6. Data and VoIP signal at the EDFA output
Another spectrum was placed just after the WDM multi-
plexer to check on the effective multiplexing of the initial
sources. Figure 7 shows a perfect multiplexing of both the
video signals and the VoIP and data signal. As an illustration,
the two different frequencies can be seen on the spectrum
analyzer.
Figure 7. Multiplexed Signals
Further analysis carrried out with a Bit Error Rate (BER)
analyzer, help to analyze the following parameters: maximum
Q factor, minimum Bit Error Rate, eye height and thresholds.
All these parameters are considered for both Glass and Plastic
Optical fiber. Figure 8 and 9 show respectively, the Q factor
curve for both channels and the eye diagrams.
Figure 8. Q Factor for the received data and VoIP signal
The data resultiing from figure 8 and 9 is summarized in
table 1 and discussed in the next paragraph.
Figure 9. Eye diagram for the received data and VoIP signal
Table I
COMPARATIVE A NALYSIS OF THE RESULTS BETWEEN GLASS AND
PLASTIC OPTICAL FIBER
PARAMETERS Glass Optical Fiber Plastic Optical Fiber
Max. Q factor 48.96 49.1767
Min. BER 0 0
Eye height 1.77e-005 1.78e-005
Threshold 5.79e-006 5.72e-006
Dispersion 193 THz -1.24e007 ps/nm 1.44e006 ps/nm
Dispersion 200 THz 1.16e007 ps/nm 1.16e001 ps/nm
Noise 193 THz -5.37e001 dB/m -5.4e001 dB/m
Noise 200 THz -1.00e002dB/m -1.00e002 dB/m
OSNR 193 THz 5.98e001dB 5.98e001 dB
OSNR 200 THz 2.28e001dB 2.28e001 dB
Power 193 THz 6.7e000dB/m 6.13e000 dB/m
Power 200 THz -7.72e001dB/m -7.72e001dB/m
The results summarized above were taken at different fre-
quencies (192THz and 200THz) in the fiber with a bandwidth
set at 1GHz. Most of the quality parameters including maxi-
mum Q factor, minimum Bit Error Rate and Eye height have
given similar results.
Q factor analysis: The Q factor deals with energy loss
during the transmission; the higher the Q factor the lower
the energy loss; In the table above the Q factor of the glass
fiber is smaller than that of the plastic fiber. Consequently,
the signal transmitted with the plastic fiber is less affected by
transmission losses.
BER: it is the probability made of the ratio of errors bits
over the total number of bits transmitted. BER is measured in
the simulation with the help of an eye diagram analyzer. The
minimum BER is 0 for both the plastic fiber and the glass
fiber. This is due to the fact that the simulated scenario do not
involve noise generation.
Eye height: It provides visual information on the assessment
and troubleshooting of digital transmission systems. The more
opened the eye is, the better the signal quality becomes.
The individual curves forming the eye pattern informs on
the amount of additive noise to the signal. The wider they
are, the more closed the eye and the system immunity to
noise decreases. From the table 1, the value of the eye height
using the plastic is greater than the one using the glass. This
difference implies that the signal transmitted through glass
fiber is the most affected by distortions and additive noise.
Dispersion: It deals with the spreading of the optical pulse
as it travels along the fiber. This spreading of the signal pulse
uses the system bandwidth of the fiber and limits the speed
156 2012 IEEE 4th International Conference on Adaptive Science & Technology (ICAST)
at which information is transferred. Out of the simulation, the
plastic fiber has a lower distortion than the glass fiber. It can be
deduced that information is transferred faster with the plastic
fiber than the glass fiber.
Optical Signal to Noise Ratio (OSNR) [dB]:It is the measure
of signal power to noise power in an optical channel. OSNR
is important because it informs on the degree of impairment
affecting the optical signal. Both channels had a constant
OSNR because the simulation scenario was the same.
IV. CONCLUSIONS
In summary, this article carried out a passive optical fiber
link simulation work with Optiwaves OptiSystem software in
order to compare delivery performances between optical glass
fiber and optical plastic fiber for FTTH. Results shows that
the two fiber are very efficient and enough satisfactory for
indoor communication. However the plastic fiber provides a
higher immunity to noise and also provides a better speed.
Further researches can investigate the cost effectiveness of the
implementation of plastic fiber compared to glass fiber.
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