Broadband Cable Access Networks

Chapter 4. Linear Fiber-Optic Signal Transportation

4.1. Introduction

Although coaxial cable is used for the “last-mile” delivery of broadband services to subscribers, other technologies are frequently used to cover most of the physical distance between headend and tap. One reason for this is that the interrelationship among bandwidth, signal levels, number of cascaded devices, noise, and distortion (discussed in Chapter 3) limits the reach of purely coaxial systems. Second, large coaxial systems are best suited to delivery of a common spectrum of signals to all parts of the network, whereas many services, such as data communications, interactive video, and telephony, require a bidirectional bandwidth allocation to every customer. In order to ...