Broadband Cable Access Networks

Chapter 11. Emerging Architectures

11.1. Introduction

This chapter covers binary (digital) modulation of a fiber-optic cable as well as deep-fiber architectures. The two are covered together because binary optical transmission is frequently used in last-mile (to the home and/or business) applications. In addition, binary optical transmission is used extensively in metropolitan loops and in intercity trunks. An advantage of digital modulation is that it can operate with much lower signal-to-noise ratio than can analog modulation, as shown in Figure 4.13. Also, output level is not dependent on optical level, and there is no degradation of signals through the system (to the point that they go away, of course). We compare digital optical transmission ...