agnetic Fields A.6.2 Electromagnetism Inductance and Capacitance A.7.1 What Happens When We Close a Switch on an Inductive Circuit? A.7.2 RC Circuits and the Time Constant A.8 Alternating Currents A.8.1 Calculating Power in ac Circuits A.8.2 Ohm's Law Applied to ac Circuits A.8.3 Calculating Impedance A.9 Resistance in ac Circuits Resonance [Refs. 1 and 4] References Appendix B A Review of Mathematics for Telecommunication Applications Objective and Scope Introduction B.2.1 Symbols and Notation B.2.2 The Function Concept B.2.3 Using the Sigma Notation B.3 Introductory Algebra B.3.1 Review of the Laws of Signs B.3.2 Conventions with Factors and Parentheses B.3.3 Simple Linear Algebraic Equations B.3.4 Quadratic Equations B.3.5 Solving Two Simultaneous Linear Equations with Two Unknowns CONTENTS Logarithms to the Base 10 B.4.1 Definition of Logarithm B.4.2 Laws of Logarithms Appendix C Learning Decibels and Their Applications Learning Decibel Basics dBm and dBW Volume Unit (VU) Using Decibels with Signal Currents and Voltages Calculating a Numeric Value Given a dB Value C.5.1 Calculating Watt and Milliwatt Values When Given dBW and dBm Values Addition of dBs and Derived Units dB Applied to the Voice Channel Insertion Loss and Insertion Gain Return Loss C.10 Relative Power Level: dBm0, pWp0, etc. C.10.1 Definition of Relative Power Level C.10.2 Definition of Transmission Reference Point C.11.1 References Appendix D Acronyms and Abbreviations Index PREFACE This book is an entry-level text on the technology of telecommunications. It has been crafted with the newcomer in mind. The twenty-one chapters of text have been prepared for high-school graduates who understand algebra, logarithms, and the basic principles of electricity such as Ohm's law. However, it is appreciated that many readers require support in these areas. Appendices A and B review the essentials of electricity and mathematics up through logarithms. This material was placed in the appendices SO as not to distract from the main theme, the technology of te