【正文】 二、GSM歷史：1998年，目標(biāo)為制訂接替GSM的第三代移動電話（3G）規(guī)范的3GPP啟動。手持機(jī)包括電話、短信尋呼機(jī)和對講機(jī)。美國著名通信公司Sprint的一個輔助部門，美國個人通信正在使用GSM作為一種寬帶個人通信服務(wù)的技術(shù)。GSM實際上是歐洲的無線電話標(biāo)準(zhǔn)，據(jù)GSM MOU聯(lián)合委員會報道，GSM在全球有12億的用戶，并且用戶遍布120多個國家。GSM使用的是時分復(fù)用的特殊形式，并且它是目前三種數(shù)字無線電話技術(shù)（TDMA、GSM和CDMA）中使用最為廣泛的一種。GSM系統(tǒng)包括GSM900：900MHz、GSM1800：1800MHz及GSM1900：1900MHz等幾個頻段。b) It also saved the pronunciation information.譯　文GSM簡介一、GSM的涵義：GSM全名為：Global System for Mobile Communications，中文為全球移動通訊系統(tǒng)，俗稱“全球通”，是一種起源于歐洲的移動通信技術(shù)標(biāo)準(zhǔn)，是第二代移動通信技術(shù)，其開發(fā)目的是讓全球各地可以共同使用一個移動電話網(wǎng)絡(luò)標(biāo)準(zhǔn)，讓用戶使用一部手機(jī)就能行遍全球。 TRAN takes MSC a part. b) Trans coding also uses when downward transforms 16kbps 64kbps. c) Trans coding in MSC \ BSC \ BTS.5. HLR Home location register belongs to the location register. a) Has all user data stock in MSC to lie in HLR. In HLR has the permanent user database. When b) the user sends out the call, MSC obtains the user data from HLR. Is the user core database, the majority may obtain in the SIM card data in HLR.6. VLR visiting location register visits the location register.a) Has in VLR all user number which activates. b) When in other MSC user roams to new MSC, between MSC and HLR corresponds, new MSC will roam the user registers in its VLR.c), When the handset roams, user visit area by other network cover, moreover belongs to the position network to authorize it to use the network which visits, its user information (will be visited from HLR by the copy to VLR location register) to temporarily store. 7. Authentication center AUCAuthentication center a) Is the SIM card proof procedure. b) Each SIM card as IMSI, in IMSI has Canadian password c) To have when HLR IMSI and password d) the handset corresponds, first confirms the SIM card the validity, carries on the confirmation by AUC.8. Charge center BCBilling centera) BC has each user39。 All BSC connection to MSC, b) each BTS links BSC to use the abis connection, is the 2Mbps connection. Uses microwave link, optical fiber, ways and so on coaxial line to connect. c) Microwave link is the best connection mode choice frequently. What d) BSC links the MSC use is A e) may provide services and so on plot broadcast in BSC. 3. MSC mobile switching center is the network core, the call setup, maintains, and the release。 BTS transmits the BCH signal in the RF channel39。 Downward is the base depot to the handset. For example 935~960 and 890~915 differ 45MHz, on the second channel, upward backwardness downward three time departments.Network position:1. BTS base depot: base transceiver the station base depot most important is the transceiver, the transceiver how many decision plot capacity, a transceiver can support 8 users, a plot by 3 antennas.a) Transceiver and antenna39。s low power) upward 1710~1785MHz downward 1805~1880MHz.PHASE2: SAME。 GSM frequency band: GSM900 plot radius 35km upward 880~915MHz downward 925~960MHz.PHASE2: 890~925MHz and 935~960MHz。s maximum work rate is 1W.GSM900/DCS1800/PCS1900 difference: GSM900 is the initial GSM system, the MOBILE power from outputs 1W~8W, the GSM900 channel from 1~124, DCS1800 channel from 512~885。s volumetric efficiency (each megacycle each plot channel number) pared to TACS system high 3~5 times.3. Voice quality.In view of the fact that in digital transmission technology characteristic as well as GSM standard related space connector and voice code definition, when threshold value, the voice quality always achieves the same level, but has nothing to do with the wireless transmission quality.4. Opening connection. The GSM standard provides open connection, is not only restricted in the space connector, moreover the publication network is direct as well as in network between equipment entity, for example A connection and Abis connection.5. Security.Through the authentication, the encryption and the TMSI number39。 In addition the half speed rate voice code39。s function obtains unceasingly richly. It can thus provide a diverse service. The short information service which first introduces by the GSM system (SMS) has provided one kind novel, convenient, the inexpensive munication way. In 1994, GSM has realized based on the circuit switching data traffic and the facsimile service. In 1999, the WAP agreement caused the user to be possible through the handset visit Internet. After 2000, starts the mercial general grouping wireless service (GPRS) to enable the GSM system to be able to provide the data munication by the efficiency higher packet mode. In 2003, the EDGE technology started mercial, has provided the close 3G data munication ability. At present, the 3GPP organization is also developing the GSM standard, with the aim of using already massively deployed the GSM infrastructure, smoothly to 3G technology evolution.三、 GSM characteristics 1. GSM uses the directviewing characteristic: The GSM system has several important characteristics: Security beats ability to be good, the network capacity is big, the handset number fruitful in resources, the telephone conversation are clear, the stability not easily is disturbed, the information to be keen, the telephone conversation dead angle are few, the handset power consumption is low.2. GSM technical Characteristic:1. Frequency spectrum efficiency. Because used the highly effective modulator, the channel coding, to interweave, balanced and the speech coding technology, enabled the system to have the highfrequency spectrum efficiency. 2. Capacity. Because each channel transmission band width increases, causes the frequency multiplying to plant does reduces pared to the request to 9dB, therefore the GSM system39。s mobile munication technical standard, is the second generation of mobile munication 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 early1990s introduction, before this uses the honeyb simulation migration t