elopment of the Telecommunications Business Introduction to Telecommunications Network Engineering Problems and Review Questions References The Telecommunications Network: An Overview Basic Telecommunications Network 2.1.1 Transmission 2.1.2 Switching 2.1.3 Signaling Operation of a Conventional Telephone 2.2.1 Microphone 2.2.2 Earphone 2.2.3 Signaling Functions Signaling to the Exchange from the Telephone 2.3.1 Setup and Release of a Call 2.3.2 Rotary Dialing 2.3.3 Tone Dialing 2.3.4 Local Loop and 2W/4W Circuits Telephone Numbering 2.5.1 International Prefix 2.5.2 Country Code 2.5.3 Trunk Code, Trunk Prefix, or Area Code 2.5.4 Subscriber Number 2.5.5 Operator Numbers Switching and Signaling 2.6.1 Telephone Exchange 2.6.2 Signaling 2.6.3 Switching Hierarchy 2.6.4 Telephone Call Routing Local-Access Network 2.7.1 Local Exchange 2.7.2 Distribution Frames Trunk Network Contents International Network Telecommunications Networks 2.10.1 Public Networks 2.10.2 Private or Dedicated Networks 2.10.3 Virtual Private Networks 2.10.4 2.10.5 Public Switched Telecommunications Network Today Network Management 2.11.1 Introduction 2.11.2 Who Manages Networks? 2.11.3 2.11.4 Traffic Engineering 2.12.1 Grade of Service 2.12.2 Busy Hour 2.12.3 Traffic Intensity and the Erlang 2.12.4 Probability of Blocking Problems and Review Questions References Signals Carried over the Network Types of Information and Their Requirements Simplex, Half-Duplex, and Full-Duplex Communication Frequency and Bandwidth 3.3.1 Frequency 3.3.2 Bandwidth Analog and Digital Signals and Systems 3.4.1 Analog and Digital Signals 3.4.2 Advantages of Digital Technology 3.4.3 Examples of Messages Introduction to Telecommunications Network Engineering Analog Signals over Digital Networks 3.6.1 Sampling 3.6.2 Quantizing 3.6.3 Quantizing Noise 3.6.4 Nonuniform Quantizing 3.6.5 Companding Algorithms and Performance 3.6.6 Binary Coding 3.6.7 PCM Encoder and Decoder Other Speech-Coding Methods 3.7.1 Adaptive PCM (APCM) 3.7.2 Differential PCM (DPCM) 3.7.3 3.7.4 Adaptive DPC