FIBER OPTIC COMMUNICATION
TOPIC 1 :
INTRODUCTION TO FIBER OPTIC
Course Learning Outcome
1. Explain clearly the basic concept of fiber optic
communication system and system
2. Handle systematically the related communication
equipments in performing the assigned practical
3. Perform problem solving skill through end of
chapter question on any given topic(A2)
Fiber To The Home (FTTH)
Fiber optics –
•A means to carry information from one point
to another or serves as transmission medium
•A technology that uses thin strand of glass (or
plastic) threads (fibers) to transmit data.
•A fiber optic cable consists of a bundle of glass
threads, each of which is capable of
transmitting messages modulated onto light
1870 - John Tyndall
2000 and beyond
1970 – Drs. Robert
Keck, and Peter
1966 – Kao and
1880 – Alexander
1960 – Line of sight
Fiber vs Metallic Cables
– Larger bandwidth
– Immune to cross-talk
– Immune to static
– Do not radiate RF
– Spark free
– No corrosion, more
– Initial cost of installation
– Brittle (serpih)
– Maintenance and repair
more difficult and more
The Advantages of Fiber-Optic
• The advantages of fiber-optic systems warrant considerable attention.
• This new technology has clearly affected the telecommunications
industry and will continue to thrive due to the numerous advantages it has
over its copper counterpart.
• The major advantages include.
Low Loss Electromagnetic Immunity
Noise Immunity and Safety Security
• Fiber optic communications can run at
10 Ghz and have the potential to go as high as 1 Thz
• A 10 Ghz capacity can transmit (per second):
– 1000 books
– 130,000 voice channels
– 16 HTDV channels or 100 compressed HDTV channels.
• Separate Voice, data and video channels are transmitted
on a single cable.
• Copper cables can act as an antennae picking
up EMI from power
lines, computers, machinery and other
• Fiber is not susceptible to Electro-Magnetic
Interference and thus no interference allowing
Light Weight and Volume
– Fiber – 9lb per 1000 ft. (due mainly to packaging).
– Coax – 80lb per 1000 ft.
• Fiber optic cables are substantially lighter in weight and
occupy much less volume than copper cables with the same
• Fiber optic cables are being used to relieve congested
underground ducts in metropolitan and suburban areas.
• For example, a 3-in. diameter telephone cable consisting of
900 twisted-pair wires can be replaced with a single fiber
strand 0.005 inch.
• In diameter (approximately the diameter of a hair strand) and
retain the same information carrying capacity.
• Use where space is at a premium:
– Aircraft, submarines
– Underground conduit
– High density cable areas – Computer centers.
Noise Immunity and Safety
• No electricity thus no spark hazards so can be
used through hazardous areas.
• Because fiber is constructed of dielectric
materials, it is immune to inductive coupling
or crosstalk from adjacent copper or fiber
• In other words, it is not affected by
electromagnetic interference (EMI) or
• Since fiber does not carry electricity, it emits no EMI which
could be used for eavesdropping.
• Difficult to 'tap' – cable must be cut and spliced.
• Because light does not radiate from a fiber optic cable, it is
nearly impossible to secretly tap into it without detection.
• For this reason, several applications requiring
communications security employ fiber-optic systems.
• Military information, for example, can be transmitted over
fiber to prevent eavesdropping.
• In addition, metal detectors cannot detect fiber-optic cables
unless they are manufactured with steel reinforcement for
• Presently, since the cost of fiber is
comparable to copper it is expected to drop as
it becomes more widely used.
considerably less than for coaxial cable,
expensive repeaters can be spaced farther
• Fewer repeaters mean a reduction in
overall system costs and enhanced reliability.
• Once installed, a longer life span is
expected with fiber over its metallic
counterparts, because it is more resistant to
corrosion caused by environmental extremes
such as temperatures, corrosive gases, and
Disadvantages of Fiber-Optic System
• In spite of the numerous advantages that fiber-optic systems
have over conventional methods of transmission, there are
some disadvantages, particularly because of its newness.
• Many of these disadvantages are being overcome with new
and competitive technology. The disadvantages include:
Remote powering of devices
Inability to interconnected
• Electronic facilities must be converted in order to
interface to the fiber.
• Often these costs are initially overlooked.
• Fiber-optic transmitters, receivers, couplers, and
connectors, for example, must be employed as part of
the communication system.
• Test and repair equipment is costly.
• If the fiber-optic cable breaks, splicing can be costly
and tedious task.
• Manufacturers in this related field however are
continuously introducing new and improved field repair
• Optical fiber , by itself has a significant lower
tensile strength than coaxial cable.
• Surrounding the fiber with stranded Kevlar (A
nonmetallic, difficult to-stretch, strengthening
material) and a protective PVC jacket can help to
increase the pulling strength.
• Installations requiring greater tensile strengths
can be achieved with steel reinforcement.
Remote Powering Of Devices
• Occasionally, it is necessary to provide
electrical power to a remote device.
• Because this cannot be achieved through the
fiber, metallic conductors are often included in
the cable assembly.
• Several manufacturers now offer a complete
line of cable types, including cables
manufactured with both copper wire and
Inability to interconnect
• Inability to interconnect easily requires that current
communication hardware systems be somewhat retrofitted to
the fiber-optic networks.
• Much of the speed that is gained through optical fiber
transmission can be inhibited at the conversion points of a
• When a portion of the chain experiences heavy use,
information becomes jammed in a bottleneck at the points
where conversion to, or from, electronic signals is taking
• Bottlenecks like this should become less frequent as
microprocessors become more efficient and fiber-optics reach
closer to a direct electronic hardware interface.
· High bandwidth and capacity
· Lower signal attenuation (loss)
Immunity to Electrical Noise,
· Immune to noise (electromagnetic interference
· No crosstalk
· Lower bit error rates
· Difficult to tap
· Nonconductive (does not radiate signals)
Size and Weight
· Reduced size and weight cables
Overall System Economy
· Low overall system cost
· Lower installation cost
· Less restrictive in harsh environments
•High planning, installation, and maintenance
•lower tensile strength than coaxial cable
Remote Powering of Devices
•necessary to provide electrical power
to a remote device.
• Cannot be achieved
through the fiber, metallic conductors are
often included in the cable assembly.
Inability to interconnect
•incompatibility with the electronic hardware
systems that make up today's world.
Block Diagram of Fiber Optic Communications
Light ON/OFF at
Digital data from computer
Fiber Optic cable
Digital data to computer
• The information signals to be transmitted may be
voice, video or computer data.
• The first step is to convert the information into a form
compatible with the communication medium.
• This is usually done by converting the continuous analog
signal such as voice and video(TV) signal into a series of
Coder or converter
• The information at input is converted into
digital signals by coder or converter circuit.
• This circuit is actually ADC (analog to digital
• Thus, it converts analog signals into
proportional digital signals.
• If the input signals are computer signals, they
are directly connected to light source
• The light source block is a powerful light source.
• It is generally a FOCUS type LED (Light Emitting Diode) or low
intensity laser beam source (such as Injection Laser Diodesolid state laser) or in some cases infrared beam of light is also
• The rate, at which light source turns ON/OFF, depends on
frequency of digital pulses.
• Thus, its flashing is proportional to digital input.
• In this way, digital signals are converted into equivalent light
pulses and focused at one end of fiber-optic cable.
• They are then received at its other end.
• Fiber–optic cable – when light pulses are fed
to one end of fiber-optic cable, they are
passed on to other end.
• The cable has VERY LESS attenuation (loss due
to absorption of light waves) over a long
• Its bandwidth is large; hence, its information
carrying capacity is high.
• Light detector or photocell or photodetector is
used to detect light pulses.
• It is a transducer, which converts light signals
into proportional electrical signals.
• These signals are amplified and reshaped into
original digital pulses, (while reshaping,
distortion & noise are filtered out) with the
help of shaper circuit.
ADC circuit (Analog to Digital
Converter)• The signals are connected to decoder. It is
actually ADC circuit (Analog to Digital
Converter), which converts digital signals into
proportional analog signals like voice, video or
• Digital signals for computer can be directly
taken from output of shaper circuit.
Pulses before shaper process
Pulses after shaper process
Application in Communication System
• Analog System
• Undersea cables are laid on the ocean floor and require
several layers of armor to protect the system from
damage due to pressure or shifts along the ocean floor.
• The fibers are single-mode optical light guides
operating at 1.312 mm. The data rate on each fiber pair
is 280Mbps, and repeaters are spaced every 35km.
• Submarine cables are typically buried as they approach
shore. This helps protect submarine cables from fishing
operations from accidently breaking the submarine
High Definition Television (HDTV)
• The high bandwidth provided by fiber makes it
the perfect choice for transmitting broadband
signals, such as high-definition television (HDTV)
• Analog television is a relatively high bandwidth
signal of more than 5 MHz.
• Digital television (in particular HDTV) has bit rates
of more than 1.5Gbps.
• High resolution computer graphics can have a
bandwidth exceeding 500 MHz.
• All of these television and video applications are
ideal for fiber.
Triple Play Technology
• A triple-play network is one in which voice, video
and data are all provided in a single access.
• Most FTTH systems are called "triple play"
systems offering voice (telephone), video (TV)
and data (Internet access).
• To provide all three services over one
fiber, signals are sent bidirectionally over a single
fiber using several wavelengths of light.
Fiber Optic in Local Area Network
– Ethernet is a baseband networking technology that has been defined by
international standards, specifically IEEE 802.3. A baseband technology
devotes the entire bandwidth of the media to one channel
– Is the standard local area network (LAN) access method - used to connect
computers in a company or home network as well as to connect a single
computer to a cable modem or DSL modem for Internet access.
– It enables the connection of
up to 1024 nodes over coax,
twisted-pair, or fiber optic cable.
Types of ethernet:
Twisted pair : 10Base-T, 100Base-T, 1000Base-T, etc
Coax : 10Base5 “thick”, 10Base2 “thin”
Fiber : FOIRL, 10Base-F, 100Base-Fx, 100Base-Fx,
• The 10, 100 or 1000 in the media type
designation refers to the transmission
speed of 10 Mbit/s, 100 Mbit/s or
• The "BASE" refers to baseband signalling,
which means that only Ethernet signals are
carried on the medium.
• The TX, FX refer to the physical medium
that carries the signal.
• Fiber Optic Inter-Repeater Link (FOIRL)
– The most commonly used fiber optic medium type is the link segment.
There are two fiber optic link segments in use today, the original FOIRL
segment, and the newer 10BASE-FL segment.
– The original FOIRL specification provided a link segment of up to 1000
meters between two repeaters only. As the cost of repeaters dropped and
more and more multiport repeater hubs were used, it became costeffective to link individual computers to a fiber optic port on a repeater
• 10BASE-FL (10Mbps, baseband, over fibre optic cable)
– The new Fiber Link specifications which replaces the older FOIRL specifications, and is
designed to interoperate with existing FOIRL-based equipment.
– It provides for a full duplex fiber optic link segment up to 2000 meters long providing that only
10BASE-FL equipment is used in the segment. If 10BASE-FL equipment is mixed with FOIRL
equipment, then the maximum segment length may be 1000 meters.
– A 10BASE-FL segment may be attached between two computers, or two repeaters, or
between a computer and a repeater port.
– The Fiber Backbone link segment system. The 10BASE-FB specifications
describe a special synchronous signaling backbone approach that allows
the limit on the number of repeaters that may be used in a given
Ethernet system to be exceeded. 10BASE-FB links do not attach to
computers or end nodes, and are only used to link special 10BASE-FB
repeater hubs together in a large repeated backbone system. 10BASE-FB
links may be up to 2000 meters in length.
– The 100BaseX (Fast Ethernet) standard is an extension of the existing
Ethernet standard. It runs on UTP Category 5 data grade cable and uses
CSMA/CD in a star wired bus topology, similar to 10BaseT where all
cables are attached to a hub.
– 100BASE-SX standard was released as a low cost upgrade in performance
from 10BASE-FL systems. It utilizes 850nm devices and ST connectors.
Segment length are limited to 300m
– 100BASE-BX10 supports single-mode, single fiber and a signaling
speed of 125 Mbd. It also supports greater than a 10 km span. The
optical output is -14 dBm with a sensitivity of -29.2 dBm.
– 100BASE-LX10 is a version of Fast Ethernet over two single mode
– It has a nominal reach of 10 km and a nominal wavelength of
– The 100BASE-LX10 support is for single-mode, dual fiber connections
at a signaling speed of 125 Mbd.
• Gigabit Ethernet (1 to 100 Gigabit Ethernet)
– Gigabit Ethernet is the latest version of Ethernet and based
on the same Ethernet standard but 10 times faster than Fast
Ethernet and 100 times faster than Ethernet. It also supports
additional features that accommodate today's bandwidthhungry applications and match the increasing power of the
– Gigabit Ethernet requires the use of optical fiber on all
connections beyond 100 meters due to the extreme difficulty
in transmitting very narrow pulses over copper media and
having them recognizable at a receiver.
Example of Gigabit Ethernet Scenario
Existing Ethernet LANs with 10 and 100 Mbps cards can feed
into a Gigabit Ethernet backbone.
• Fiber Distributed Data Interface (FDDI)
– FDDI is a set of ANSI and ISO standards for data transmission
on fiber optic lines in a local area network (LAN) that can
extend in range up to 200 km.
– The FDDI protocol is based on the token ring protocol.
– FDDI local area network can support thousands of users.
– FDDI network contains two token rings, one for possible
backup in case the primary ring fails. The primary ring offers up
to 100 Mbps capacity. If the secondary ring is not needed for
backup, it can also carry data, extending capacity to 200 Mbps.
Application in MAN & WAN
• SONET (Synchronous Optical Networking) and SDH
(Synchronous Digital Hierarchy) are standardized
multiplexing protocols that transfer multiple digital bit
streams over optical fiber using lasers or highly
coherent light from light-emitting diodes (LEDs).
• At low transmission rates data can also be transferred
via an electrical interface.
• The method was developed to replace the
Plesiochronous Digital Hierarchy (PDH) system for
transporting large amounts of telephone calls and data
traffic over the same fiber without synchronization
• SONET and SDH use different terms to describe the
three layers. SDH uses the terms path, multiplex
section, and regenerator section while SONET uses the
terms section, line, and path.
• The Synchronous Optical Network (SONET) and
Synchronous Digital Hierarchy (SDH) are a set of related
standards for synchronous data transmission over fiber
optic networks that are often used for framing and
synchronization at the physical layer.
• SONET is the United States version of the standard
published by the American National Standards Institute
(ANSI). SDH is the international version of the standard
published by the International Telecommunications
• SONET/SDH can be used in an ATM or non-ATM environment. Packet Over
SONET/SDH (POS) maps IP datagrams into the SONET frame payload using
Point-to-Point Protocol (PPP).
• The following table lists the hierarchy of the most common SONET/SDH
Bit Rate (Mbps)
STS - 1, OC - 1
STM - 0
28 DS - 1s or 1 DS - 3
STS - 3, OC - 3
STM - 1
84 DS - 1s or 3 DS - 3s
63 E1s or 1 E4
STS - 12, OC - 12
STM - 4
336 DS - 1s or 12 DS - 3s
252 E1s or 4 E4s
STS - 48, OC - 48
STM - 16
1,344 DS - 1s or 48 DS - 3s
1,008 E1s or 16 E4s
STS - 192, OC - 192
STM - 64
5,376 DS - 1s or 192 DS - 3s
4,032 E1s or 64 E4s
21,504 DS - 1s or 768 DS - 3s
16,128 E1s or 256 E4s
SONET/SDH Designations and bandwidths
Table : SONET/SDH Data Rate
• is a generic term for any network architecture that uses
optical fiber to replace all or part of the usual copper local
loop used for telecommunications.
It describes the fiber optic network for the "last mile" of the
telecom connectivity between the communications
provider and the customer.
The four technologies, in order of an increasingly longer
fiber loop are:
• Fiber‐to‐the‐Node (FTTN) or Fiber‐to‐the‐Cabinet
• Fiber‐to‐the‐Curb (FTTC),
• Fiber‐to‐the‐Building (FTTB)
• Fiber‐to‐the‐Home (FTTH) or Fiber-to-the-Premise
(FTTP). Both are often used interchangeably
FTTN - fiber is terminated in a street cabinet up to several kilometers away from the
customer premises, with the final connection being copper.
FTTCab - this is very similar to FTTN, but the street cabinet is closer to the user's
premises; typically within 300m.
FTTC - fiber running directly from the central Office to the outdoor shelters on curbs
near homes or any business environment.
FTTB - fiber reaches the boundary of the building, such as the basement in a multidwelling unit, with the final connection to the individual living space being made via
FTTH - fiber reaches the boundary of the living space, such as a box on the outside wall
of a home.
FTTP - this term is used in several contexts: as a blanket term for
both FTTH and FTTB, or where the fiber network includes both
homes and small businesses.
New technology of FTTx
• It is not a surprise when came to know from Draka that they
had developed optical fiber cable and connectors that will
take the optical communication signals to the house boats
floating in Amsterdam lakes!
• Before naming that technology we expect the announcement
of a new technology: FTTM – Fiber to the Moon!
If Draka can take fiber to the house
boats and Google can aim moon,
why Fiber to the Moon – FTTM
should remain only as a wild dream?
1. Define fiber optic?
2. The advantages of fiber optic, overcome its
disadvantages. Explain the advantages and
disadvantages of fiber optic.
3. Draw the block diagram of fiber optic
4. State the function of each block in the
• Which of the following answer, describe the
application of fiber optic in communication
Triple Play System
Undersea Communication Cable
Digital Transmission System
Weather forecast System
• State TWO (2) application of fiber optic in
Metropolitan Area Network (MAN)?
• FTTH is the application of fiber optic in
Metropolitan Area Network (MAN). State the
application of FTTH nowadays.