Fiber Optic Cable Types and Installations

Fiber optic cables are very different from copper cables.Fiber optic cables transmit data through very small cores over long distance at the speed of light.These cables come in a wide variety of configurations.Important considerations in any cable installation and operation are the bending radius; tensile strength; ruggedness; durability; flexibility; environmental conditions, such as temperature extremes; and even appearance.Due to fiber optic cables; lightweight and extreme flexibility, fiber optic cable are more easily installed than their copper counterparts.
Fiber Optic Cable Types and Applications
There are many fiber optic cable types and designs available.Fiber cables can be classified into the following categories: fiber optic cables for indoor applications, those for outdoor applications, and indoor/outdoor applications.The following sections explain each category in detail.
Indoor Fiber optic cable Types and Applications
Indoor cables are generally installed and operated in a controlled,stable environment.The cables must perform with minimal loss.Her factors that generate losses, such as environment and mechanical stresses during and after installation, can cause failure.Outdoor cables have more factors that concern their performance.Indoor fiber cables are divided into the following types:

1.Simplex Fiber Optic Cable contain a single fiber cable, as shown in figure 4.1.They are employed to connections within equipment.They have a thicker outer jacket, which makes the table easier to handle and adds mechanical protection.
2.Duplex Fiber Optic Cable contain two tight-buffered fiber cables inside a single jacket, as showed in figure 4.2 They are used in equipment interconnections within workstations, test equipment, hubs and router,etc.
3.Breakout cables have several individual simplex cables
4.Light cables,heavy cables,and plenum cables are application dependent.
Outdoor Fiber Optic Cable Tyes
Outdoor cables must withstand a variety of enviroment and mechanical stress during and after installation.The cables must perform with minimal losses over a wide range of temperature and humidity changes.The cable must also have waterproof capabilities, have strength to endure the difficult installation conditions, provide protection against ultraviolet radiation, and provide mechanical protection, there are many types and designs, depending on the manufacturer and application.Outdoor fiber cables are divided into the following types:
1.Overhead cables may be stung from telephone poles or along power lines.
2.Direct burial cables placed directly in a trench dug in the ground and then covered with soil.
3.Submarine cables are set underwater.
Ftth Drop Cable
Ftth has already been tried -and it failed miserably.Why should carriers are tested again? With the advent of asymmetric digital subscriber line and cable modems, the need for broadband Internet access has grown.That growth is likely to continue to into the future,and at some point demand will reach a level that can support ftth.The data requirements between the residence and its multiple communities of interest will reach a ftth-sustainable level within a few years, and customers will be willing to pay Ftth prices.Moreover, some carriers's investment strategies will favor Ftth over hybrid fiber because at some point,Hfc becomes too expensive, If Ftth can be delivered at lower cost it will gain a competitive advantage.

Main Parts Of A Fiber Optic Cable

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 disccussions 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.