September 7, 2011

Evolution of wireless communication,electromagnetic waves, mobile phones, satellites, telecommunication


Evolution of wireless communication

Communication between two  communications devices   can basically classified as   follows
a. wired communication
b. wireless communication
          Our   focus is on only mobile phone and cell phone. Before mobile phone [wireless communication],   telephone came into existence.
1876 -telephone was invented by Alexander Graham bell 1881-in   Berlin   public telephone service was started [wired circuit switching network]. In early 18 century wireless communication was existing through optical medium. The wireless communication boomed only after invention of electromagnetic waves by Michael Farady.
1907-the first commercial transatlantic connection were setup using huge base stations. On both side.
1920-marconi discovery of short waves gets reflected ionosphere. This helps to sent wireless messages around the world bouncing at the ionosphere.
1926-the first telephone in a train was available on the Berlin Hamburg line.
1927-radio for cars was commercially come into existence.
1958-first network was the analog a-netz using a carrier frequency of 160MHz. [with no handover].
1979-during 1979 Nordic mobile telephone system [cradle of modern mobile communication] with carrier frequency of 450MHz.
1982-GSM [group  special Mobile] using 900Mhz was development, this was initial used throughout Europe.
1983-united states came with advanced mobile phone system, analog mobile system with 850 MHz.
1990-Marked the beginning of fully digital system.
1991-digital European cordless telephone system came into existence, with work spectrum 1880-1900 MHz with range.
1991-finally GSM was standardized it is called as Global system for mobile communication.
                  GSM 900
                  GSM 1800
                  GSM 1900
1998- Mobile communication using satellites.
1998-universal mobile telecommunications system was developed.

2000-international mobile telecommunication system was developed with is combination of units and gms.

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