As countries continue to develop networks for global communication.Fiber optic offers a method of transmission that allows for clearer, faster, more efficient communication than copper.A number of characteristics make optical fiber well-suited to video transmission.This chapter discusses the basics behind optical fiber transmission.

Optical Cables

Usually, manufacturers construct optical cables to the customer's specific application.However, all types of fiber optic cables contain common elements: the fiber housing, number of fiber's per cable, cable strength elements, etc.The fiber housing construction techniques include loose-tube or tight-buffer configurations.

Types of Fiber Optic Cables

The simplex cable contains a single fiber in the center. Duplex Fiber Optic Cable may appear circular, oval, or arranged zip cord fashion like an electrical cable.

Complex cable assemblies include breakout cables, composite cables, and hybrid cables.Breakout cables contain single-fiber or emulsified substrates, allowing access to individual fiber without the need for terminating patch panels.The cable industry disagrees about the exact definitions of composite cables and industry disagree about the exact definitions of composite cables and hybrid cables.For the sake of this discussion,composite cables mix both single-mode and multimode optical fiber in a single cable assembly,while hybrid cable describes a hybrid fiber cable that includes both optical fiber and copper cable in one cable assembly.

Both composite cables and Hybrid Cables offer the advantage of installation time and cost savings.However,these cables require application specific custom manufacturing.Still,the increase in demand for the convergence of video, audio, and data transmission makes these types of cable very attractive.Hybrid cables can also carry electrical signals, gaining them wide use in broadband CATV networks.

Fiber To The Home

The technological benefits of fiber to the home (FTTH) include its well-known capacity for transmitting incredibly high bandwidths at relatively negligible losses.This "future-proofs" the resulting network against demands for rising bandwidths,which shows will indeed be done only once because on electronics are installed in the outside plant between office a home.Upgrades are held on the premises of the service provider and the customer.Nearer-term benefits of fiber include its small size and weight compared with metallic cable,especially coaxial cable;its total immunity to both inward and outward leakage of electromagnetic interference,and its resistance to corrosion systems with active components at only the ends of the network ensure high validity.As important and practical as these advantages are more practical benefits may help drive fiber to the home now.These include solving the high costs of Ftth Drop Cable maintenance and electrical powering.

Clearly,optical fiber offers a number of characteristics that make it naturally suitable to fiber optic video transmissions.But as bandwidth and data rates continue to climb,some of fiber shortcoming become notice able.The next chapter describes the effects that limit optical fiber performance.

In recent years, the trend has been to replace all copper communications cable will optical fiber cable.Fiber optic cable communicates using light energy, not electrons.The advantages of using light can be summed up in five categories: speed, bandwidth, distance, resistance, and maintenance.You will see after filling out this chapter that all five categories optical fiber cable can simply outperform copper in every instance.The physical construction of the optical cable can take on many forms, including: Simplex Fiber Optic Cable, Ftth,Drop Cable, Hybrid or composite cables

Simplex Fiber Optic is a jacketed,single-fiber, tight-buffered cable that uses Kevlar for strength and reinforcement.Simplex Fiber Optic Cables typically are used as patch cords and in backplane applications.The backplane refers to the socketed interconnection of multiple cables circuit cards for the purpose of expansion.

Ftth Drop Cable distribution technology has gained in acceptance in many parts of the world as the technology direction for distribution networks.Legacy telephone and cable networks still have the ability to deliver today's services and for a time technology can be utilized to extend their service life.But FTTH is attractive for Greenfield starts and selected overbuild or rehab situations.In the US, about 21 million homes are passed with Ftth networks and about 7 million homes are connected as of March of 2011.There are over 40 million homes connected outside of the US, with Asia Pacific statistics,but the designs can be quite different.Nearly all are based on a pons for service delivery to the customer premises.

Hybrid Cables come in one of two varieties: those that contain both optical fibers and copper conductors under a single jacket, and those that contain multimode and single mode optical fiber under a single jacket.In either case, the different varieties are insulated separately, as required, because they are bundled together as s single cable.When producing such cables, a manufacturer must take into account the requirements and classifications of differing electrical circuits using copper conductors, as well as the insulation barrier and separation requirements.Composite cable over multiple types of cable between systems.

Typical applications for optical fibre cable include communications, data transmission, instrumentation, process, and industrial control.Fiber optic cables are lightweight and unable to spark,shor-circuit,or ignite combustible materials, making them an outstanding option for hazardous locations where gaseous or chemically explosive environments may exist.

Fiber optic cable is becoming increasing popular for data transmission in industrial enviroments.Fiber optic cable has multiple advantages over copper wire for transmission of data.Copper wire is very susceptible to electromagnetic inference caused by electrical devices that draw large amounts of current.Such as motors,transformers.And variable frequency drives.Fiber optic cable is completely immune to electromagnetic interference.Due to the high frequency of light.Fiber optic cable has a very wide bandwidth as compared with copper wire.The bandwidth of fiber optic cable is about million times that of fiber optic cable is about a million times that of copper wire.Fiber optic cables are much lower and lighter in weight than copper cables.A single fiber is about 0.001 in.In diameter and can carry five times more information than a telephone cables containing 900 pairs of 22 AWG twisted conductors.Single and Duplex Fiber Optic Cable are shown in figure 1-1.

Ftth Drop Cable

"Fttp also makes sense on a number of levels,such as system durability and lower maintenance costs,but especially when it comes to quality of service.For instance, the IP video service provided by the last mile link is truly impressive and I know our customers are going to love it. "Certified tap members receive all inclusive access to core's innovative and reliable FTTH solution, after completing specialize training in the design and installation of optical access networks.TAP members are able to offer their customers up to a 10-year extended product warrantly on complete coring FTTH solutions(drop cables and assemblies carry a 3-year warranty).

Hybrid Cables

Fiber optic cables sometimes also contain copper conductors, such as twisted pairs, although the conductors can be used for routine communications, they have two other popular uses.One is to allow customers to communicate with each other during installation of the fiber, especially with long-distances telephone.A technician performing a splice in a manhole must often be in communication with a switching office several miles away.The office contains the test equipment, operated by another technician. That tests the quality of the splice. The other use is to power remote electronic equipment such as repeaters.

Fiber optic cable is typically offered with standard-grade and premium grade fibers.Many applications standards specify performance that is met by standard-grad cables.In most cases, the cable performance is a minimum, the cable may exceed the stated performance of a requirement such as bandwidth.

Most often ,an optical fiber must be packaged before it is used is used Packaging involves cabling the fiber,Cabling is an outer protective structure surrounding one or more fibers.It is analogous to the insulation or other materials surrounding a copper wire.Cabling protects copper and fibers environmentally and mechanically from being damaged or degraded in performance.(The additional protection against electrical shock,shorts,and the possibility of fire important to copper is not an issue with dielectric fibers.) The purpose of this chapter is to describe some typical cable structures.

Like their copper counterparts,fiber-optic cables come in a great variety of configurations.Important considerations in any cable are tensile strength,ruggedness,durability,flexibility,environmental resistance,temperature extremes,and even appearance.

The figure shows the main parts of a simplex single-fiber cable.Even though cables come in many varieties,most have the following parts in common:optical fiber; strength member;jacket.

Number Of Optical Fibers

Yet another difference between fiber optic cables is the number of individual optical fibers within them.The number depends on the intended used of the cable and can increase the cable's size,cost and capacity.because the focus of this book is network cabling and the majority of fiber optic cables you will encounter for networking are tight buffered,we will limit our discussions here to tight buffered cables.These cables can be divided into three categories based on the number of optical fibers: simplex cables;duplex cables;multifiber cables.

A Simplex Fiber Optic Cables has only one tight -buffered optical fiber inside cable jacket.An example of a simplex cable was shown earlier in this chapter in figure 8.8 becayse simplex cables have only one fiber inside them,only aramid yarn is used for strength and flexibility;the crimped directly to a mechanical connector.simplex fiber optic cables are typically categorized as interconnect cables and are used to make interconnections in front of the patch panel.

Duplex cables,in contrast,have two tight buffered optical fibers inside a single jacket.The most popular use for Duplex Fiber Optic Cable is as a fiber optic LAN backone cable,because all LAN connections need a transmission fiber and a reception fiber.Duplex cable have both inside a Single cable,and running a single cable is of course easier than running two.

Outdoor Fiber Optic Cables

Cables used outside a building must withstand harsher environmental conditions than most indoor cables,outdoor cables are used in applications such as the following:

Overhead:cable are strung from telephone poles.

Direct burial:cables are placed directly in a trench dug in the ground and covered

Indirect burial:this is similar to direct burial,but the cable is inside a duct or conduit.

Submarine:the cable is underwater,including transoceanic applications.

Such cables must obviously be rugged and durable,since they will be exposed to various extremes.Most cables have additional protective sheaths,for example,a layer of steel armoring protects against rodents that might chew through plastic jackets and into the fiber.Other constructions use a gel compound to fill the cables and eliminate air within the cable.Loose tube buffers,for example ,are so filled to prevent water from seeping into the cable, where it will freeze,expand,and damage the cable.The fibers "float " in the gel that will not freeze and damage the fiber.

1.Introduction

Fiber to the home (Ftth) is one of the latest information infrastructures and has attracted the interest of telecom carries throughout the word (1) -(4).An urgent concern in terms of realizing the FTTH network is to distribute the optical fiber efficiently and economically.This is especially so in dropping and internal wiring section for a customer's house, where low cost and speedy fiber constructing technologies are strongly required.This is because the facilities in this section cannot be shared but must be individually installed for each customer.

This paper presents technologies for cables and associated hardware that have just been developed in order to reduce costs for dropping and internal wiring to a client's hours.By using these technologies, hardware and construction costs in dropping and internal wiring section for a customer's house,are simultaneously reduced and,as a result,we believe the Ftth Drop Cable will become practical

2.Configuration of dropping and internal wiring for customer's house

Figure 1 shows a typical configuration of the dropping and internal wiring for a customer's house.It has been recently proposed that a distribution method based on the integrated access point is effective for improving facility utilization.This distribution method requires several kinds of cable and associated hardware.These include:Cluster-type optical drop cable; Drop Cable; Indoor Cable; Accsss point the Closure; Drop point closure; Cabinnet on the outside walls of customer's houses; Cabinet inside the customer; s houses.We describe the structure and performance of the above cables, closures and cabinet.Moreover, we report on the design of staples for fixing the cable.

3.Technologies of cable and associated hardware

Our key design concept is to use 0.2mm diameter mono -coated fiber in dropping and internal wiring section for a customer's house.This design can provide small,lightweight cable which means we can reduce the cost o f both the cable itself and it's installation.In this section, we describe the structure and features of newly developed cables and associated hardware in detail.

3.1 Cable

Figure 2 shows the structure of our new drop cable and cluster-type drop cable.The drop cable combines the self -supporting wire section with the fiber insertion section,help to reduce the manufacturing process.At the same time, cable is provided with notch to improve the separability of these two sections during fixing operations on a telephone pole, and the removability of optical fiber during connection work.In general,indoor cable is deployed through a pipe inside a wall.Cable for indoor applications includes the following:Simplex Fiber Optic Cables; heavy--light-and Plenum-duty cable; breakout cables; ribbon cables, multiplier cables and Duplex Fiber Optic Cable, measurements of the transmission and mechanical properties of this cable showed them to be stable with little loss.In addition, we confirmed that there no problems with the workability of the cable, the removability of the optical fibers.