epts Digital Network 6.12.1 Introduction 6.12.2 Technical Requirements of the Digital Network 6.12.3 Digital Network Performance Requirements Review Exercises References Chapter 7 Signaling What Is the Purpose of Signaling? Defining the Functional Areas 7.2.1 Supervisory Signaling 7.2.2 Address Signaling 7.2.3 Call Progress: Audible-Visual Signaling Techniques 7.3.1 Conveying Signaling Information 7.3.2 Evolution of Signaling 7.3.3 Subscriber Call Progress Tones and Push-Button Codes (North America) 7.4 Compelled Signaling Concepts of Link-by-Link Versus End-to-End Signaling Effects of Numbering on Signaling Associated and Disassociated Channel Signaling Signaling in the Subscriber Loop 7.8.1 Background and Purpose Metallic Trunk Signaling 7.9.1 Basic Loop Signaling CONTENTS 7.9.2 Reverse-Battery Signaling Review Exercises References Chapter 8 Local and Long-Distance Networks Chapter Objective 8.2 Makeup of the PSTN 8.2.1 The Evolving Local Network 8.2.2 What Affects Local Network Design? Design of Long-Distance Networks 8.3.1 Introduction 8.3.2 Three Design Steps 8.3.3 Link Limitation 8.3.4 Numbering Plan Areas 8.3.5 Exchange Location 8.3.6 Hierarchy 8.3.7 Network Design Procedures Traffic Routing in a National Network 8.4.1 New Routing Techniques 8.4.2 Logic of Routing 8.4.3 Call-Control Procedures 8.4.4 Applications Transmission Factors in Long-Distance Telephony 8.5.1 Introduction 8.5.2 Echo 8.5.3 Singing 8.5.4 Causes of Echo and Singing 8.5.5 Transmission Design to Control Echo and Singing 8.5.6 Introduction to Transmission-Loss Engineering 8.5.7 Loss Plan for Digital Networks (United States) Review Exercises References Chapter 9 Concepts in Transmission Transport 9.1 Objective Radio Systems 9.2.1 Scope 9.2.2 Introduction to Radio Transmission 9.2.3 Line-of-Sight Microwave 9.2.4 Fades, Fading, and Fade Margins 9.2.5 Diversity and Hot-Standby 9.2.6 Frequency Planning and Frequency Assignment Satellite Communications 9.3.1 Introduction 9.3.2 The Satellite 9.3.3 Three Basic Technical Problems 9.3.4 Frequency Ba