GSM原理介绍(英文)(ppt 34页)

. GSM900/DCS1800      
. The GSM Network & Air Interface   
. Technical Basics   
. Speech Coding       
. Types of Channel     
. Making a Phone Call       
GSM Development History
1982 Groupe Special Mobile?is created within CEPT
1986 A Permanent Nucleus is set up
1987  Main radio transmission techniques are chosen,   based on prototype evalution (1986)
1989 GSM becomes an ETSI technical committe
1990 The phase 1 GSM 900 specifications are finalized
1991 First systems are running
1992  All major European GSM 900 operators begin commercial  operator
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