gsm簡介畢業(yè)論文外文翻譯-其他專業(yè)(編輯修改稿)
2025-02-24 06:28 本頁面
【文章內(nèi)容簡介】 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。s maximum work rate is 1W. GSM900/DCS1800/PCS1900 difference: GSM900 i s the initial GSM system, the MOBILE power from outputs 1W~8W, the GSM900 channel from 1~124, DCS1800 channel from 512~885。 DCS1800 is the low power, highest is 1W。 GSM frequency band: GSM900 plot radius 35km upward 880~915MHz downward 925~960MHz. PHASE2: 890~925MHz and 935~960MHz。 Channel number 1~124. SM1800 plot radius is 2Km (because 1800 MHz handset39。s low power) upward 1710~1785MHz downward 1805~1880MHz. PHASE2: SAME。 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。 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 relations each BTS will have set of transceivers. b) BTS covers a plot。 BTS transmits the BCH signal in the RF channel39。s 0 time slots. BCH helps the Mobile recognition/to seek for the work. 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。 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 work core, the call setup, maintains, and the release。 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 work heart. Is and other GSM work, the nonGSM work 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 user 4. TRANTrans coding/rate adapter unit rate adapter. a) TRAN transforms 13KB/S the GSM speed into standard 64KB/S。 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 locatio
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