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This article introduces wireless communications systems and explains the different products and standards related to wireless communications. The article is divided into five main sections. A brief introduction in Section 1 offers a perspective of the evolution of wireless communications systems and introduces a useful classification. After this introduction, Section 2 is devoted to the explanation of basic concepts and fundamentals of the different wireless products, while Section 3 explains the related technology. Sections 2 and 3 both make it easy to understand Section 4, in which five wireless products and related standards are detailed: cellular, cordless, trunking, paging, WLAN, and WPAN systems. Finally, Section 5 offers a brief vision of the future evolution of wireless systems, introducing advanced technologies such as “smart” antennas and spacetime transmission diversity (STTD), and research, towards the fourth generation of mobile communications. Keywords: wireless communications; personal communications services; wireless products; cellular communication; portable phone; cordless phone; cellular system; vehicle; WPBX; wireless local access; WCDMA; OFDM; cellular frequency band; cellular service; PCS; GSM; UMTS; multimedia communications |
