GSM简介毕业论文外文翻译-其他专业.doc

中文2950字 英文资料原文 INTRODUCTION OF GSM GSM implication The GSM full name is: Global System for Mobile Communications, Chinese as the whole world two-way charges for cellular phones system, the popular name the whole world passes, is one kind stems from Europes mobile communication technical standard, is the second generation of mobile communication technology, its development goal is enables the world to be possible to use a mobile phone network standard together, lets the user use a handset to be able good the whole world. Our country used this technical standard in the early-1990s introduction, before this uses the honeycomb simulation migration technology, namely the first generation of GSM technology (on December 31, 2001 our country has closed simulation migration network). At present, China moves, China Unicom to have a GSM net respectively, for world biggest mobile communication network. GSM system including GSM 900:900 MHz, GSM1800:1800MHz and GSM1900:1900MHz and so on several frequency bands. GSM (whole world mobile communication system) is one kind widely applies in European and the world other place numeric move telephone system. What GSM use is the time division multiple access anomalous form, and it is the present three kind of digital cordless phones technology (TDMA, GSM and CDMA) uses the most widespread one kind. GSM digitizes the material, and carries on the data the compression, then transmits together with other two user data stream from the channel, other two user data stream has the respective time slot. GSM in fact is Europes radio telephone standard, Joint board reported according to GSM the MOU, GSM has 1,200,000,000 users in the whole world, and the user proliferates more than 120 countries. Because many GSM network operator has the roaming agreement with other overseas operators, therefore works as user after other countries, still might continue to use their mobile phone. An American Famous Correspondence Company Sprint Auxiliary unit, the A