【正文】 tem, the popular name the whole world passes, is one kind stems from Europe39。s 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 American persontoperson munication is using GSM to take one kind of wide band persontoperson munication service the technology. This kind of persontoperson munication service finally for Ericsson, Motorola as well as Nokia the handset which produces is establishing more than 400 base depots now. Handset includes telephone, short note beeper and inter.GSM and other technologies are the wireless mobile munication evolutions, wireless mobile munication including highspeed circuit exchange data, general packet radio system, based on GSM network data enlargement mode mobile munication technology as well as general mobile munication service.二、 GSM histories In 1998, the goal replaced GSM for the making the third generation mobile phone (3G) the standard 3GPP start. 3GPP also accepted has maintained and continues to develop the GSM standard the work. ETSI is one of 3GPP members. In the development process, the GSM system39。s frequency multiplying pattern may reduce to 4/12 or 3/9 even is small (analogous system is 7/21)。s introduction and the automatic traffic distribution reduce the skip zone cut the number of times, causes the GSM system39。s use, serves the safe purpose. The authentication uses for to confirm the user to enter the net right. The encryption uses in the space connector, by the SIM card and network AUC key decision. TMSI is one by the service network the temporary identification number which assigns to the user, prevents some people to track divulges its geographical position.6. Realizes roaming in the SIM card foundation. Roaming is the mobile munication key character, it symbolizes that the user may enter another network automatically from a network. The GSM system may provide global roaming, certainly also needs the network operation between certain agreements, for example cost. 四、 GSM principle GSM is the Global System for Mobile Communication abbreviation. The meaning is the whole world mobile munication system. Divides GSM900, DCS1800 and PCS1900SAN a frequency band, the mon socalled dualfrequency handset is in GSM900 and the DCS1800 frequency band cut handset. PCS1900 (PCS1900 Personal Communications System operating in the 1,900MHz band.) is other national use frequency band (for example the US). GSM900/1800 respectively is the work in the 890~960mhz/1710~1880MHz frequency band. The GSM900 handset maximum work rate is 8W (actual traveling carriage not such big power, mon handset maximum work rate is 2W, Che Zaitai the function big), but the DCS1800 handset39。 DCS1800 is the low power, highest is 1W。 Channel number 1~124. SM1800 plot radius is 2Km (because 1800 MHz handset39。 Channel number: 512~885.For high density user，GSM1900: 1850~1910MHz 1930~1990MHz upward and downward poses a frequency to be right, upward is the handset launch, machine the station receive。s relations each BTS will have set of transceivers.b) BTS covers a plot。s 0 time slots. BCH helps the Mobile recognition/to seek for the network.c) The plot handset user capacity dependence channel counts. d) The GSM space connector data transfer rate is 13Kbps, namely the BTS receiving and dispatching pronunciation data rate is 13KB/S. e) The BTS order handset to establish its emissive power, moves, the cut. 2. BSC base station controller base station controller:a) Several BTS base depots connect BSC, the base depot arrangement channel disposition, the cut, and BTS connect BSC。 Links BSC and PSTN, the authentication, the call switches over, the short information, the charge and so on. When the user increases to the certain amount, may increase MSC between MSC and MSC uses GMSC to link (GATEWAY). a) Works as the call setup, MSC gets up maintains talks over the telephone and separates the telephone conversation the function. b) Saves all user data and their related characteristic. c) Is situated between MS and PSTN, exchange correspondence data. d) MSC is the GSM network heart. Is and other GSM network, the nonGSM network pany connection. e) MSC major function: The authentication, the position renew, the connection, the charge, the call to switch over, SMS. f), when the user increases, surpasses MSC the　capacity, needs many MSC, doubles user4. TRANTrans coding/rate adapter unit rate adapter. a) TRAN transforms 13KB/S the GSM speed into standard 64KB/S。s expense condition. b) The direct pany arrives at MSC, gives BC by the MSC transmission charge information (when telephone conversation) c) BC processing according to unit cost.9. Operation center: OMCoperation and maintenance center. a) Each GSM network surpasses 100 BTS positions, each entity needs to operate and the maintenance. b) Some remote controls are necessary, the examination and longdistance enters. 10. Short message exchange: The SMSC information sends to the handset which through the short message center assigns.a) The information transmits through SMS the information to be possible (pany to arrive at SMS).b) Through the artificial terminal to transmit.c) Short message exchange SMS.11. Pronunciation service center: a) It has all pronunciation users’ database。我國于20世紀(jì)90年代初引進(jìn)采用此項(xiàng)技術(shù)標(biāo)準(zhǔn)，此前一直是采用蜂窩模擬移動技術(shù)，即第一代GSM技術(shù)；目前，中國移動，中國聯(lián)通的GSM網(wǎng)已經(jīng)分別為世界最大的移動通信網(wǎng)絡(luò)。GSM（全球移動通信系統(tǒng)）是一種廣泛應(yīng)用于歐洲及世界其他地方的數(shù)字移動電話系統(tǒng)。GSM將資料數(shù)字化，并將數(shù)據(jù)進(jìn)行壓縮，然后與其它的兩個用戶數(shù)據(jù)流一起從信道發(fā)送出去，另外的兩個用戶數(shù)據(jù)流都有各自的時隙。因?yàn)樵S多GSM網(wǎng)絡(luò)操作員與其他國外操作員有漫游協(xié)議，因此當(dāng)用戶到其他國家之后，仍然可以繼續(xù)使用他們的移動電話。這種個人通信服務(wù)將最終為愛立信、摩托羅拉以及諾基亞現(xiàn)在正在生產(chǎn)的手持機(jī)建立400多個基站。GSM及其他技術(shù)是無線移動通信的演進(jìn)，無線移動通信包括高速電路交換數(shù)據(jù)、通用無線分組系統(tǒng)、基于GSM網(wǎng)絡(luò)的數(shù)據(jù)增強(qiáng)型移動通信技術(shù)以及通用移動通信服務(wù)。