PowerPoint Presentation

APRACTICAL TRANING SEMINAR ON Optical Fiber CommunicationPURSUEDAT Aksh Optifibre Ltd.

2016-2017 Guided by:- Submitted by:- Mr. Dinesh Bhatia Huzaifa Bohra (Asst. Prof., ECE Dept.) (PIET/EC/13/521)

Department of Electronics and Communication Engineering Poornima Institute of Engineering and Technology, Jaipur

107-12-2016PLCC

Introduction of company Brief introduction of training Technologies learnt Technical terminologies Types of Equipments Working Applications Limitations Future Scope References Conclusion Table of Contents:-

Company Profile :-

Company Name AKSH OPTIFIBRE LIMITEDAKSHwas founded in 1986 with major focus on manufacturing of Optical Fibre Cables.It is a 31 year old company which started manufacturing of optical fibreandoptical fibre cables (OFC)in 1994. In 1996-97 Aksh acquiredFibre Reinforced Plastic Rods (FRP)business which is a key raw material for Optical Fibre Cables. Aksh went Public in the year 2000 and is listed onNational Stock Exchange (NSE) and Bombay Stock Exchange (BSE).Aksh specialize in manufacturing of various optical fibre cables like aerial, duct, armoured, indoor and outdoor FTTH drop cables.AKSH has two plants atBhiwadi, Rajasthanfor Fibre & Optical Fibre Cables, and one plant atReengus, Rajasthan for Fibre Reinforced Plastic Rods (FRP).

Company Vision

"To become a global leaderin enabling simple innovative smart living"

The International turnkey projects: Bhutan: Aksh Optifibre Limited has been successfully completed the assignment installing of 2600 Km of All Dielectric Self Supporting (ADSS) optical fibre cable under Bhutan Power Corporation Limited. Mauritius : In Mauritius, Aksh has received contract from BTL Mauritius to supply and install FTTH triple play equipment.In 2002,AKSHstarted its 1stFibre to the Home (FTTH)in Jaipur and later collaborated with MTNL & BSNL in Jan 2010 to launch FTTH triple play service in Rajasthan.I have done my training from Aksh Optifibre Ltd. Jaipur, Service Division, Sitapura ,Jaipur.Aksh Optifibre Limited reports strong financial results for Q4 FY16 & FY 2015-16. Revenue increased by 23% to Rs. 462 crores, New Delhi, May 30, 2016

Fig. 1: Aksh Products & Services [ 1 ]

Brief Introduction of Training :-The training is all about optical fibre technician.History of optical fibre and basics of optical fibre communication.Introspection of various types of optical fibre.Optical Networking.Surveying and making area root map for laying of fibre.It includes various functions like trenching and laying of duct and blowing the optical fibre in it.Splicing done with fusion splicing tool and mechanical splicing tool.Splicing of Ribbon fibre.Stripping of optical fibre.Colour coding of cladding and outer jacket.Calculation of power loss through power meter.Calculation of power loss and finding fault in cable through Optical Time Domain Reflectometer (OTDR).

Brief history of OFC :-In the late 19th and early 20th centuries, light was guided through bent glass rods to illuminate body cavities. Alexander Graham Bell invented a 'Photo-phone' to transmit voice signals over an optical beam.By 1964, a critical and theoretical specification was identified by Dr. Charles K. Kao for long-range communication devices, the 10 or 20 dB of light loss per kilometre standard. The first challenge undertaken by scientists was to develop a glass so pure that one percent of the light would be retained at the end of one kilometre (km), the existing unrepeated transmission distance for copper-based telephone systems. In terms of attenuation, this one-percent of light retention translated to 20 decibels per kilometre (dB/km) of glass material.Glass researchers all over the world worked on the challenge in the 1960s, but the breakthrough came in 1970, when Corning Incorporated scientists Dr. Robert Maurer, Donald Keck, and Peter Schultz created a fiber with a measured attenuation of less than 20 dB per km. It was the purest glass ever made.In April 1977, General Telephone and Electronics tested and deployed the world's first live telephone traffic through a fiber-optic system running at 6 Mbps, in Long Beach, California.They were soon followed by Bell in May 1977, with an optical telephone communication system installed in the downtown Chicago area, covering a distance of 1.5 miles.

Basics of OFC :-

An optical fibre is a thin, flexible, transparent fiber that acts as a waveguide, or "light pipe", to transmit light between the two ends of the fiber. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communication. Fibers are used instead of metal wires because signals travel along them with less lossand are also immune to electromagnetic interference.

Fig. 2: Cross Section of Optical Fiber & Schematic of OFC [ 2 ]

How Fiber Works :-

The operation of an optical fiber is based on the principle of total internal reflection. Light reflects (bounces back) or refracts (alters its direction while penetrating a different medium), depending on the angle at which it strikes a surface.The angle of refraction at the interface between two media is governed by Snells law:

Fig. 3 :Total Internal Reflection [2]

The Design of Fiber :-

The composition of the cladding glass relative to the core glass determines the fibre's ability to reflect light.That reflection is usually caused by creating a higher refractive index in the core of the glass than in the surrounding cladding glass.The refractive index of the core is increased by slightly modifying the composition of the core glass, generally by adding small amounts of a dopant.

Fig. 4 :TIR In Optical Fibre [2]

Construction of Optical Fibre :-There are two main types of fiber optic cables :--> Single Mode Fiber (SMF)-> Multi-Mode Fiber (MMF)Multi-Mode Fiber -> The wide core allows multiple modes of light to propagate. -> MMF has a much wider core (typically 62.5m or 50m), allowing multiple modes (or rays) of light to propagate. -> Uses aqua coloured cables, rather than the traditional orange.-> Designed to achieve 10Gbps up to 300 meters.Single-Mode Fiber-> SMF has a very narrow core (typically around 9m), which allows only single mode of light to propagate.-> Can support distances of up to several thousand kilometres, with appropriate amplification and dispersion compensation.

Fig. 5: SMF & MMF [3]

Colour Coding :-The type of fiber can be identified by use the of standardized colours on the outer jacket. As shown in the given figure 6(a).

Now to define the position of further fibre hair, there is an another colour code for the positioning of fiber. As shown in the figure 6(b).

Fig. 6 (a. Colour code for outer jacket)

(b. Colour code for fiber hair) [4]

Optical Networks :- Passive Optical Network (PON) -> Fiber-to-the-home (FTTH) :- Each subscriber is connected by a dedicated fibre to a port on the equipment in the PON, or to the passive optical splitter, using shared feeder fibre to the PON. -> Fiber to the Distribution Point (FTTDp) :- This solution has been proposed in the last two years. Connecting the POP to the Distribution Point via the optical cable and then from the Distribution Point to the end-user premises via existing copper infrastructure.

Fig. 7: Different types of FTTx networks. [4]

Installation & Commissioning of Optical Fiber Cables :-This unit is about supporting the Optical Technician in installation and commissioning of optical fiber cables as per route plan. The various steps involved are as follows :--> Surveying and preparing the root area map.-> Trenching-> Laying of duct-> Blowing of cables-> Splicing-> Power Loss-> Power meter measurement-> OTDR measurement

Surveying & preparing area root map :-It is the first and most significant step of optical fiber installation.Here, first a survey team is sent to the targeted area, where they do a survey on number of customers interested and how the fibre will be laded.The task of the optical engineer is to draw an root map according to the requirement, in such way that minimum of resources used.Then the engineer makes a rough sketch of fibre laying root, and then sent it to service division for other formalities.

Fig. 8 :(a) Desktop Survey using Google Street View [4]Fig. 8 :(b) High-level planning colour-coded distribution locations and areas [4]

Trenching & Laying of duct :-Atrenchis a type of excavation or depression in the ground that is generally deeper than it is wide (as opposed to a widergully, orditch), and narrow compared to its length.The advantages of this technique over conventional cable laying technologies lie essentially in its speed of execution, lower cost, significantly lower environmental impact and limited disruption to road traffic and, as a consequence of the previous items, easiness in obtaining permits for the taking over of public area. Trenching is carried out by labour workers as per the route plan requirements and site terrain.

Fig. 9 : Trenching Process [5]

After trenching, the next step is laying of duct in trench.Duct is that pipe in which fibre cables are going to blown.They are made up of hard plastic.The another method of laying duct is through HDD.HDD :- HDD stands for Horizontal Directional Drilling , it is used to lay duct without trenching the ground. It has a flexible drilling bid which drills under ground up to 1-3 Km.

Fig. 10: HDD Machine [5]

Cable Jetting :-

Fig. 11: Blowing of Optical fibre in duct [5]Traditionally fibre optic cables were pulled through cable ducts in the same way as other cables, via a winch line.The technique of installing flexible and lightweightfibre opticunits using compressed air was developed during the 1980s byBritish Telecom. This early version of jetting did not use additional pushing. True cable jetting was invented by Willem Griffioen ofKPN Researchin the late 1980s.Cable jetting is the process of blowing a cable through a duct while simultaneously pushing the cable into the duct.Compressed airis injected at the duct inlet and flows through the duct and along the cable at high speed.

Splicing of Optical Fiber :- Fiber optic splicing involves joining two fiber optic cables together. The other, more common, method of joining fibers is called termination or connectorization.Fiber splicing typically results in lower light loss and back reflection than termination making it the preferred method when the cable runs are too long for a single length of fiber or when joining two different types of cable together, such as a 48-fiber cable to four 12-fiber cables. Splicing is also used to restore fiber optic cables when a buried cable is accidentally severed.There are two methods of fiber optic splicing, -> Fusion splicing -> Mechanical splicing

Fig. 12: A technician doing fusion splicing [6]

1. Fusion Splicing :-Fusion splicing is the process of fusing or welding two fibers together usually by an electric arc. Fusion splicing is the most widely used method of splicing as it provides for the lowest loss and least reflectance, as well as providing the strongest and most reliable joint between two fibers.Fusion splicing may be done one fiber at a time or a complete fiber ribbon from ribbon cable at one time. First we'll look at single fiber splicing and then ribbon splicing.Fusion splicing machines are mostly automated tools that require you pre-set the splicing parameters or choose factory recommended settings that will control the splicing process itself.

Fig. 13: Fusion Arc Principle & Fusion Splicing Tool [7]

-> Steps involved in fusion splicing :-First of all the jacket and cladding of two fibre ends which are to be joined, are removed with the help of a special tool, Stripper.After stripping the cladding, the glass core is cleaned with ethyl alcohol.Now, for an efficient splicing, it is require that the both ends are at 90 deg. finish.For this, a special precision diamond cutter is used, which is known as Cleaver.A precision fiber cleaver that scribes and breaks (cleaves) the fibers to be spliced precisely, as the quality of the splice will depend on the quality of the cleave. Most splicing machines come with a recommended cleaver.

Fig. 14: Cleaver & Various types of Strippers [7]

-> Fuse the fiber - There are two steps within this step, alignment and heating.

Automatic Fiber AlignmentThe ends of the fibers are on moveable stages which are used to align the fibers and set the end gap automatically.Heating Now, an electric arc is produce within the splicer and then two fibres are fused together.

Splicing machines also generally have a heating device for heat shrinking a protective sleeve over the finished splice to protect it from moisture or other environmental hazards.

Fig. 15: Automatic fiber alignment & wrapping of protective sleeve [7]

2. Mechanical Splicing :- In mechanical splicing the fibers are precisely aligned and held in place by a self-contained assembly, not a permanent bond. This method aligns the two fiber ends to a common centre line, aligning their cores so the light can pass from one fiber to another.

Four steps to performing a mechanical splice:Step 1: Preparing the fiber - Strip the protective coatings, jackets, tubes, strength members, etc. leaving only the bare fiber showing. The main concern here is cleanliness.Step 2: Cleave the fiber - The process is identical to the cleaving for fusion splicing but the cleave precision is not as critical.Step 3: Mechanically join the fibers - There is no heat used in this method. Simply position the fiber ends together inside the mechanical splice unit. The index matching gel inside the mechanical splice apparatus will help couple the light from one fiber end to the other. Older apparatus will have an epoxy rather than the index matching gel holding the cores together.Step 4: Protect the fiber - the completed mechanical splice provides its own protection for the splice.

Fig. 16: Mechanical Splicing [7]

Comparison between Fusion & Mechanical Splicing :-Sr. No. Fusion Splicing Mechanical Splicing1.Two fibre end are aligned and then fused together. Just a mechanical alignment device.2.Fused with the help of electric arc.Splice with the help of index matching gel.3.Still, two separated fibres are not continuous.The joint is continuous.5.Due to electric arc, the strength of glass core is weaken at the point of splicing, which cause losses.No such problem is encountered in mechanical splicing.

Table :- 1 (Difference between fusion and mechanical splicing)

Power Losses :-Attenuation or loss in optical fibers basically refers to the loss of power. During transit, light pulse loses some of their photons, thus reducing their amplitude. Attenuation for a fiber is usually specified in decibels per kilometre. The degree of attenuation depends on the wavelength of light transmitted.Types of losses :- Material absorption losses- It is a loss mechanism related to the material composition and fabrication process of the fiber which results in the dissipation of some of the transmitted optical power as heat in waveguide. The absorption of light may be intrinsic (caused by one or more major components of glass) or extrinsic (caused by impurities within the glass). Linear scattering losses-Linear scattering mechanisms cause the transfer of some or all of the optical power contained within one propagating mode to be transferred linearly(proportionally) into a different mode. This process tends to result in attenuation of the transmitted light as the transfer may be to a leaky or radiation mode which does not continue to propagate within the fiber core, but is radiated from the fiber. It is mainly of two types:a)Rayleigh scattering(b) Mie scattering Bending loss- Radiative losses occur whenever an optical fiber undergoes a bend of finite radius of curvature.

Power Meter :-The most basic fiber optic measurement is optical power from the end of a fiber. This measurement is the basis for loss measurements as well as the power from a source or presented at a receiver. Measurement of the power of a transmitter is done by attaching a test cable to the source and measuring the power at the other end. For receivers, one disconnects the cable attached to the receiver receptacle and measures the output with the meter.Optical power meters typically use semiconductor detectors since they are sensitive to light in the wavelengths and power levels common to fiber optics. Most fiber optic power meters are available with a choice of 3 different detectors, silicon (Si), Germanium (Ge), or Indium-Gallium-Arsenide (In GaAs).

Fig. 17: Power Meter Principle & Measurement [8]

OTDR Measurement :-The OTDR is the most important investigation tool for optical fibres, which is applicable forthe measurement of fibre loss, connector loss and for the determination of the exact place and the value of cable discontinuities.

Fig. 18: The structure of the OTDR instrument [8]

The principal of the OTDR analyser is the following: a short light pulse is transmitted into thefibre under test and the time of the incidence and the amplitude of the reflected pulses are measured. The resolution of the OTDR the dead zoneThe resolution of the OTDR system is the distance of two reflecting points that still can bedistinguished by the instrument. This depends on the width of the transmitted impulse, sincethe impulse must not overlap.

Fig. 19: The information in the OTDR trace & A typical OTDR [9]

Applications of OFC :-Fiber optic cables find many uses in a wide variety of industries and applications. Some uses of fiber optic cables include:Medical :- Used as light guides, imaging tools and also as lasers for surgeriesDefence/Government :- Used as hydrophones for seismic and SONAR uses, as wiring in aircraft, submarines and other vehicles and also for field networkingData Storage :- Used for data transmissionTelecommunications :- Fiber is laid and used for transmitting and receiving purposesNetworking :- Used to connect users and servers in a variety of network settings and help increase the speed and accuracy of data transmission.

Industrial/Commercial :- Used for imaging in hard to reach areas, as wiring where EMI is an issue, as sensory devices to make temperature, pressure and other measurements, and as wiring in automobiles and in industrial settings.

Broadcast/CATV :- Broadcast/cable companies are using fiber optic cables for wiring CATV, HDTV, internet, video on-demand and other applicationsFiber optic cables are used for lighting and imaging and as sensors to measure and monitor a vast array of variables. Fiber optic cables are also used in research and development and testing across all the above mentioned industries.

Advantages of Optical Fiber :-

Fig. 20: Comparison between wireless, ADSL & fibre [10]

References :-Ref. No. 1, www.akshoptifibre.comRef. No. 2, -- Electronics & Communication System,2nd edition, by Roy BlackRef. No. 3 fibersystems.netRef. No. 4 www.ftth.euRef. No. 5 www.apollotechno.inRef. No. 6 www.fujikara.comRef. No. 7 www.thefoa.orgRef. No. 8 www.flukenetworks.comRef. No. 9 www.techoptics.comRef. No. 10 www.miniphysics.com

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