Teach Yourself Electricity and Electronics, Sixth Edition, 6th Edition

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CHAPTER

Advanced Communications Systems

THE TERM WIRELESS AROSE IN THE EARLY 1900S WHEN INVENTORS AND EXPERIMENTERS BEGAN sending and receiving messages using EM fields. Before long, wireless acquired more specific terminology, such as radio, television, and EM communications. In the 1980s and 1990s, the term wireless emerged again, this time in the consumer context.

Cellular Communications

Wireless telephone sets operate in a specialized communications system called cellular. Originally, the cellular communications network served mainly traveling business people. Nowadays, many (if not most) ordinary folks regard cell phones as necessities, and most cell-phone sets have non-voice features, such as text messaging, Web browsing, video displays, ...