Hello learners, welcome to this topic on Fiber Optics, a detailed study. Fiber Optic technology, was first used in the 1970s, between the United States and Europe. Fiber Optic Cables were laid in the year 1988, these were laid below the ocean. As many more cables were laid under the sea over a period, your worst network of Fiber Optic cable is available around the world. The main reasons for the remarkable progress, in fiber network, in the telecom fields are, it is still growing, one, high speed capabilities, and two, reliable transmission of data. In a nutshell, it is stated, that the information age is possible, only because of the Fiber optic network. Fiber optic networks have become, more cost effective, when compared with the copper ones, it's the backbone of the present internet networks. Fiber optics, is a technology, in which information is transmitted, as pulses, through Strands made of glass or plastic, over a long distance. Few to hundred optical fibers, can be made available within a plastic casing, in one cable. The data signals are transferred by them, in the form of light, these signals can travel hundreds of kilometers. These signals will be traveling faster than, those signals transmitted through traditional electrical cables. As the fiber optic cables are non metallic, they are not disturbed by electromagnetic interferences. Electromagnetic interference, generally, reduces the speed of the signals, which are transmitted. Fiber optic cables carry only data signals, they carry pulses of laser or LED light, transmit data in binary form. So there is no current carried by them, hence they are safer, no spark is produced, no heat is generated. The thickness of the optic fiber is almost equivalent to, or slightly higher than human hair, they are tiny, its diameter is around 125 microns. When these optic fibers are bonded like a cable, they can transmit more data, for longer distances, with high speed, in comparison to any other medium. This technology provides, the following services, with fiber optic network, homes, business, phones, and televisions. Typically, your fiber optic cable contains, three basic companies, the core which carries the light signals. The cladding which surrounds the core with a lower refractive index and contains the light, and the coating, which protects the fragile core ,and cladding within it. There are two primary types of fiber, multi-mode and single mode, multi-mode fiber can carry multiple light rays at the same time, by having varying optical properties at the core. Essentially, light traveling the shortest part, that is, down the middle, travels the slowest. To get the fiber optic internet connection to home or business establishment, from the network hub, fiber optic cables are laid to the curb near the home or establishment. They are called Fiber To the Home or FTTH or Fiber to the Premises or FTTP. It is called so, as because, the fiber optic cables are installed, between these two points directly and connected. The other way of connectivity is called, Fiber to the Curb or FTTC, in this type, fiber optic cables are laid between your network curb, and the curb near a home, or apartment, or business establishment. From the curbs to the home, or apartment, or business establishment, copper cables carry the signals. We have one more thing called Fiber to The Budding, that is FTTB, in this system, Fiber Cable is installed between the HUB, and the point on the shared property. And the other cabling provides the connection to the offices, or other spaces. The technology used in fiber optic internet is a complex one, this permits the transmission of information in the form of light, not in the form of electricity. Though there are many pieces are involved in this advanced technology, let us understand the important two components of the fiber optic network which are, optical fiber, and lost mile. We have already studied this, these are not copper cables or coaxial cables, the optical fibers carry pulses of laser or LED light down the line, transmitting the information in binary form. As soon as the faster signals reach the destination, they get converted into electrical signals, which are understood by the devices and the users. This job of conversion of the pulses, into electrical signals, is performed by the optical network terminal. After the conversion, these signals are sent through an internet connection to the user. Last mile is the stretch, between the main fiber network line and the end-user. Last mile connectivity has two options, the fiber cable that is laid between, from the hub to the consumer's home, business, or desktop computer is called, pure fiber. This is the costliest mode, at the same time, this is the fastest mode, this will provide you with optimum speed and reliability of fiber, straight to the consumer. The alternative method is to have, connectivity from the street cabinet, generally located at the housing block, or campus, or residential buildings, and from there, to the consumer end. That is, fiber optic cables are terminated at the street cabinet, and from there, consumer ends are connected using copper cables, though this method is less expensive, we lose the speed to some extent. The following is the process to be followed, when we try to install the fiber optic cables through ducts. We have two different methods for pulling the cable through ducts, either we can blow the cable through the ducts, that is a mechanized system, or we can pull the cables through the duct, which is a manual system. Depending upon the length of the route, site condition, accessibility to mobilize the machinery, the method of pulling needs to be selected. After completion of the route survey and finalizing the same, execution planning need to be commenced and completed. The final survey decides the methods of installation, the selection of the method is extremely important, as it saves cost and time. Completing installation of duct cables typically involves the following process, pre installation, route survey, and arrangements. Preparation of cable trench in line with the requirements that is for underground routes. Installation of high density poly ethylene or HDP ducts of suitable diameter including installation of accessories. Pulling up the cables through ducts or blowing up the cable in the duct. Straight through jointing or splicing of the cables, termination of cables, documentation of all the installation data. There are possibilities to come across problems in certain areas of the route where decisions are to be taken to proceed further. Such decisions may involve third parties or other government authorities etc. For such problems, getting the solutions may take more time, so to identify such problems and take necessary actions. The pre installation survey of the route is recommended, so that these problems can be fixed. The following may be the objective of pre installation route survey. To finalize the location for fiber optic cable drum storage. To fix the locations where splicing is to be carried out. To fix the blowing points or the pulling point locations. To identify the requirement of any special equipment or tools or work permission etc. To fulfill the same that execution goes on smoothly without disturbance. These are all the arrangements minimum are not limited to have a smooth execution of the tasks. Necessary arrangements of tools and tackles, machinery, materials ducts, fiber optic cable drums, consumables, templates for measuring with depth of the trench, etc. Management crew to analyze the route and manpower are to be made available. On receipt of the drums at the site, proper inspection to identify physical damages. To ascertain the healthiness of the cables are to be carried out. Without the positive inspection reports work must not be started. Bottom end of the cable must be fixed properly to avoid the damage and to enable comfortable drum rolling. Keep the paved cables in such a way that the cable is not getting rubbed on the ground. Proper pulling grip with the swivel between pulling rope and cable is to be used. Inspect all cable pathways are completely and thoroughly cleaned prior to start cable installation. Pulling or blowing is the most important step in the installation process. Special attention is to be provided in both the cases. Proper instruction must be available with regard to the following. Applicable minimum bending radius, applicable tensile laws, importance of avoiding twisting or squeezing or pinching of the cable. Educate the persons involved about the consequence of not following the above. Let us now look at the consequences of deviating from the laid down conditions. Usage of proper lubrication, compatible with the cable jacket and ducts. This is to prevent twisting while taking the loose from the drum for longer length, keep the cable in form of 8 underground. Minimum bending radius, if bending radius is not maintained as per the stipulated parameter, the damages to fiber may occur, which are not visible. The cable may not serve for the period it is intended to. Such damages will cause expensive repair works and longer downtime. Cable twisting, the most problematic result of twisting is the breakage of fiber. Pulling method, this method is a, used when blowing machine or facility is not available or b, when the route length is very small. If we intends to use this method, your pilot rope must be there In the duct. Blowing method, blowing is used for longer route length. Blowing machine have access to duct or chamber points. Pulling slightly differs from power, control, or instrumentation cable pulling. Fiber optic cable is to be pulled by hand or using a cable pulling winch at every chamber location. The pulling procedure. First note the length of the drum. Identify the pulling chambers between which the distance is almost equal to the drum length, including the required allowances to be provided. Shift the drum to the central point of the identified length nearer to the pulling point, this is to enable bidirectional pulling. Pave fiber optic cable in the form of 8 after taking loose from the drum. That's it could be fed from the center towards both the ends for both directions. Alternatively, keep the drum at a comfortable position almost along the central line of the duct. Provide suitable jacks on either side of the drum. Provide a shaft from one side of the drum on the jack to another side of the drum through a drum center. Raise the jack until it is getting loaded fully, check for stability of the drum. Check for sufficient clearance while rotating the drum. Let the fiber optic cable be unwound from the drum through the top of the drum. Check the cable upper layer for any cross winding and before starting pulling. Fix the cable pulling grip end with an anti twisting device, connect this pulling grip to the pre installed rope. Now start pulling and keep a vigil on the entry and exit point of the ducts for correctness of pulling parameters. Keep a person at every chamber or at the point at which the tension may increase, so that the pulling tension will not exceed rated strength. Take extreme care while making figure eight and pulling it for the next span. This is the most sensitive place for cable bending. Always pull the cable in straight direction. This technique is the most advanced one. This is suitable for cable installation in the duct when compared with the conventional system. That time saving using the blowing system is approximately 80% of the time consumed by the cooling system will be saved. The duct installation is 100% completed including the installation of accessories. Installation to be leakproof, these are the conditions to be fulfilled before initiating the blowing activity. The process is to inject compressed air into the duct along with the fiber optic cable. Both compress the air there and cable move through the duct smoothly with good speed. A cable drum is to be loaded on jacks and shaft to enable blowing up the cable from the top of the drum. The arrangement of drum on jacks and chef to be in such a way that there should not be any inconvenience for drum rotation. The presence of cross winding in the drum is to be checked in case if its presence is noted, remove the same, bring it back to normalcy without any whipping and jerks to the drums start blowing very slowly increase the blowing speed gradually and steadily as per the requirements. Set the blowing pressure considering the requirements of machine cable and that's during the blowing operation through the ducks. Keep an eye on the cable entry point. This is to avoid keeping the bending radius within the permissible limit. Otherwise it may cause permanent damage to the cable and fibers are pressure. Is to be kept in such a way that it does not damage cable or duct or duct accessories during blowing the cable may get struck. This may be due to the bench and undulation in the ducks. In these circumstances, pressure is not to be increased. The best thing to do is to find the reason and rectify the problem. Take extreme care to avoid bending while blowing. Yeah, the process followed. In giant In the fiber optic cables are the fusion splicing process in this process they follow either a color code are a sequence of buffer tubes and fibers After joining, they keep it securely in a giant closure box at every giant location. The connection between the optical fibers may be carried out either using connectors, optical fibers may be connected to each other by connectors or by splicing that is joining two fibers together to form a continuous optical wave gate. The normally accepted splicing method. These are fusion splicing in this, an electric arc melts toward the ends together of the fiber. In this process, that will be a last, which is called splice loss. This is being measured by directing the light on the cladding on one side and measuring the leakage light from the cladding on the other side. Yes, place loss should be under .1 decibels is typical. The following are the important requirements while carrying out splicing, careful stripping, careful cleaning and precision cleaving precision made sleeves keep the phi brains aligned and held together yet clear index matching gel to announce the transmission of light across the giant is utilized. These giants have more optical laws and they are not robust. These prices are protected by an enclosure on either side of the link. The fibers are terminated at connectors, connectors hold the fiber precisely and securely. These connectors are fixed in F. D. M. S. That is fiber distribution management system are worthy of optical distribution frame using a specialist the instrument called splicing machine. These placing activities are being carried out. That operation is explained here below the k billions of the two cables, which are to be joined. Our souls are kept inside the splicing enclosure of the instrument and fastened. This is to protect these places protective polymer coating over the fiber ends are cleaved using a precision cleaver and made perpendicular. They are placed inside the special holders meant for them in displeasure. Yet thorough inspection is carried out using a magnified viewing screen. This is to check this place. This inspection is carried out before and after this place, utilizing the tiny motors alignment in the faces of the places are done display asians are brought together and the small spark is emitted between the electrodes at the gap. This is to burn out the dust and moisture. Next larger spark is generated by the laser which raises the temperature above the melting point of the glass. This process is to fuse the ends together permanently. The energy level of this part and the place where it is located needs to be controlled with a calf in such a way the molten core and cladding Do not mix. This reduces the optical losses. If you need to measure displays loss, then direct light through the cladding on one side and measure the lightly caging from the Cladding on the other side, displays loss for individuals placing can lay between .1 decib and point to disable. However, in a link, the average displaced loss is to be limited to .1 visible. That means in a link Let us assume that there are 20 places numbered from 1 to 20. Though the individuals place losses vary between find one visible to find two. Divisible. The average loss of all the 20s places Should be limited to .1 visible. Because of this complex process involved in fiber splicing, it becomes more difficult than compared with copper splicing the design of the mechanical spices. Eel, quicker and easier installation. Despite this, the activities like stripping, careful cleaning and perfect leaving are required to be carried out. The losses are due to giants made by aligning and holding the ends together using perfectly made sleeve, which generally uses an index matching gel. This gel increased the late transmission across the giant. It is noted that these type of giants have higher optical losses and are not robust when compared with fusions. Places here are few images of mechanicals placing. Figure one shows the various parts. While the Figure two shows all parts together. Data recording is a very important activity that needs to be started on day one of the execution of fiber optic cable project continues to exist still handing over the system to operation and maintenance department. The expected life of the cable is approximately 25 years. The chances of getting damaged are bright during this period. The cable is also very sensitive to damage is generally the selection of the cable plays an important role aerial installation decreases the risk of damage. Data about the installation is very vital in locating the false, easily locating the false in a speedy way saves time of cable, maintenance and restoration. Let us understand what and how to carry out in documentation. The following information minimum required but not limited to, is to be recorded geographical map of cable route at his **** built table with the following information area name, permanent sign at different places. Cable code number giant or termination dropping details, events on what did they are at the time of acceptance test, manhole stroke pool number and location meter marking at each manhole pool joint termination and miscellaneous information shown here is the typical example of optic fiber cable. With this, we come to the end of this topic. Thank you.
