ng Visit us on the web: www.LLH-Publishing.com For revisions and updates, check www.telecommunicationsdemystified.com 1 Introducing Telecommunications Communication Systems Definition The Parts of a Communication System An Example of a Communication System The Transmitter The Channel The Receiver Telecommunication Systems Definition Four Examples and an Erratic History Lesson Analog and Digital Communication Systems Some Introductory Definitions Definitions And Digital Became the Favorite Making It Digital Congrats and Conclusion Problems 2 Telecommunication Networks Telecommunication Network Basics Connecting People with Telephones Connecting More People, Farther Apart Multiplexing An Alternative to a Lot of Wire First There Was FDM Along Came TDM POTS: Plain Old Telephone System Local Calls Long Distance Calls Connecting the Call The Signals Sent from Switching Center to Switching Center Class 5 to Class 4 Other Signals between Switching Centers Communication Channels Transmission Lines (Wires) Terrestrial Microwave Satellite Connections Fiber-optic Links Data Communication Networks Mobile Communications Local Area Networks (LANs) Conclusion Problems 3 A Review of Some Important Math, Stats, and Systems Random Variables Definitions The Distribution Function: One Way to Describe X The Density Function: A Second Way to Describe X The Mean and the Variance Example 3.1 Multiple Random Variables Random Processes A Definition Expressing Yourself, or a Complete Statistical Description Expressing Some of Yourself, or a Partial Description And in Telecommunications Example 3.2 Signals and Systems: A Quick Peek A Few Signals Another Way to Represent a Signal: The Fourier Transform Example 3.3 Bandwidth A Linear Time Invariant (LTI) System Some Special Linear Time Invariant (LTI) Systems Onward Problems 4 Source Coding and Decoding: Sampling Ideal Sampling The Sampling The Information in the Samples Getting Back All the Information from the Samples Some Commonly Used Words Example 4.1 Zero-order Hold Sampling The Informat