The Physical Construction Of The Optical Cable

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.

Cost Reduction Technologies of Optical Drop Cable and Indoor Cable

1.Introduction

Fiber to the home (Ftth) is one of the latestinformation 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.

The Common Ways Of Referring To Fibers

The cable buffer is one of two types:loose buffer or tight buffer.The loose buffer uses a hard plastic tube being in an inside diameter several times that of the fiber.One or more fibers lie within the buffer tube.The tube isolates the fiber from the rest of the cable and the mechanical forces operating in it.The tight buffer has a plastic directly applied over the fiber coating.This construction provides better crush and impact resistance.It does not,however,protect the fibre as well from the stresses of temperature variations.

When a table contains several layers of jacketing and protective material,the outer layers are often called the sheath.The jacket becomes the layer directly protecting fibers,and the sheath refers to additional layers.This terminology is particularly common in the telephone industry.

INDOOR CABLES

Cables for indoor applications include the following:

Simplex cables

Duplex cables

Multiplier cables

Hey-,light-,and plenum-duty cables

Breakout cables

Ribbon cables

Although these categories overlap,they represent the common ways of referring to fibers.Figure 7-5 shows cross sections of several typical cable types.

Simplex Fiber Optic Cables

Simplex cables contain single fiber. "Simplex"is a term used in electronics to indicate one-way transmission.Since a fiber carries signals in only one direction,from transmitter to receiver,a simplex cable allows only one-way communication.

Duplex Fiber Optic Cable

Duplex cables contain two optical two optical fibers.Duplex relates to two-way communication.One fiber carries signals in one direction;the other fiber carries signals in the other direction.(Of course,duplex operation is possible with two simplex cables.) Figure compares simplex and duplex operations.

In appearance,duplex cables resemble two simplex cables whose jackets have been bonded together,similar to the jacket of common lamp cords.Ripcord constructions,which allows the two cables to be easily separated,are popular.

Duplex cable is used instead of two simplex cables for aesthetics and convenience, it is easier to handle a single duplex cable,there is less chance of the two channels becoming confused,and the appearance is more pleasing.Remember,the power cord from your lamps is a duplex cable that could easily be two separate wires.Make a single duplex cord in the lamp not make better sense? The same reasoning prevails with fiber optic cables.

Most Outdoor Fiber Optic Cables contain many fibers.The strength member is usually a large steel or fiberglass rod in the center,although small steel strands in the outer sheath are also used, most high-fiber count cables divide the fibers among several buffer tubes.

In cables containing many fibers,not all the fibers are always used at first.Some are kept as spares to replace fibers that fail in the future.Others are saved for future expansion,as the demands for additional capacity dictate,In stalling a cable can be expensive.Having extra fibers in place when they are needed saves future installation costs of additional fibers and cables.It pays to think ahead.