cac ky thuat trong optima zit ion trong 3g2

8/8/2019 Cac Ky Thuat Trong Optima Zit Ion Trong 3G2

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Ti u ha ... Ti u ha mng di ng l cng 1 ti nguyn nh nhau s trm nh nhau,bn cn phi lm cho mng tt hn.

Tt hn theo 1 trong 3 tiu ch sau:

1. Ti u vng ph sngm bo cho sng ph tt u cc khu vc khc nhau.Da vo phn nh ca khch hng ni sng km, hoc kt qu i o sng, C th l chnhantenna, iu chnh cc thng s khai bo cho trm2. Ti u cht lng cuc giDa vo phn nh ca khch hng v cht lng cuc gi, hoc da trn thng k cht lngmng t h thng.3. Ti u dung lngTnh ton lu lng cho tng sector iu chnh ngun ti nguyn, hoc c k hoch thmtrm.

-Tng ln 2 tn s tc l tng s cy m OVFS --> tng s code --> tng dung lngc th p ng...

-Hin ti theo mnh hiu, S CE m BBU ca NodeB chtng quan vi nng lc xl. 3 Cell/NodeB cn khong 30CE dng cho cc knh iu khin chung (ty hng sc con s chnh xc ring), s CE cn li phc v x l cc knh dnh ring, nichung 1 user AMR cn 1CE UL (SF64) v 1 CE DL (SF128), 1 user PS 384kbps cn12CE UL (SF4) v 12 CE DL (SF8) ... (Ty hng s c s khc bit i cht) nh vynu NodeB c 512CE (UL + DL) th c kh nng x l khong 19 n 20 user PS

384kbps hoc chkhong 256 user AMR cng 1 lc. Tuy nhin cn ph thuc vo SFna cho nn cp c 20 user PS 384kbps trn cng hot ng cn khong 5 n6 RRU (hoc 3 RRU, NodeB cu hnh 2/2/2 chng hn) khi NodeB s qun l 6primary scrambling code, NodeB c 6 cy m OVFS phc v. Ngoi ra cn phthuc vo cng sut ca RRU cng nh khong cch ca user m NodeB c thphc v c ti a 20 user PS ny hay khng ... vi NodeB c 512CE (UL+DL) phcv c 256 AMR 12.2kbps cn khong 256/63 = 4 cy OVSF => NodeB ny chcn 4RRU l ... lp lun tng t vi cc dch v khc, vi HSDPA th cn phi ch thm NodeB c cp bao nhiu code na, cc bn khc ng gp thm nha

Dung lng ca Node BPh thuc vo 5 th:1. Conga suet: Nu cc thu bao gin, thong b nhiu, mi thu bao s dng t cngsut > dung lng tng. Vng ph rng c th gim dung lng.2. Signal quality (Ec/No, RxQuality): Nu dch v yu cu cht lng cao th dunglng ca cell cng gim. Cell b nhiu (bao gm nhiu cng cell, nhiu t cell khc,
http://tudiencongnghe.com/Special:Search/cellhttp://tudiencongnghe.com/Special:Search/cell


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v nhiu t ngun khc) cng lm gim dung lng. Ci ny vi cng sut thonglin quan n nhau nn tch ra lm 2 ci.3. Code OVFS: ci ny l gii hn cng ca 3G. Ht OVFS th thong nng cp c.(cn bn mun hiu n th phi t tm hiu). Chc cch thm cell.4. Channal Element: thnh phn x l Baseband. Ci ny chia s cho cc cell ca

cng 1 node B. Tc l 3 cell (hoc 4, 5 , 6 cell) c th s dng chung.5. Iub bandwidth: bng thng t Node B v RNC.Ngoi ra cn c cc gii hn khc t pha thit b nh: Liscense, gii hn ca thitb,... nhng my ci ny thong nh hng lm. Khng quan tm.

Trong 5 th trn:Power l thnh phn quan trng nht quyt nh dung lng.OVFS l phn code, gii hn ca cng ngh 3G WCDMA (WCDMA l code m)Channel Element l gii hn phn cng.Cu hi: Power l thnh phn chnh quyt nh dung lng ca cell. Vy ta c th

dng cc thit b c cng sut cao tng dung lng cho 3G c thong. V d40W, 60W.

Tr li: Di th, tng cng sut ln th nhiu cng tng ln, Ec/No c ci thin um tng dung lng. Ci ny l c bn ca 3G m hi z.>>> Tng cng sut chtng vng ph cho cell thi, cn dung lng u c tng,c khi gim na y ch, nhiu lung tung. Cng sut ch cell t n dung lnggii hn ca cy m OVFS thi.

Phn bin: Tng cng sut c th tng dung lng bn, vi iu kin l cell chc 1 ngi xi. Lc No khng thay i do chc 1 ch u c ai gy nhiu u m

. (Ci ny l thm vo cho vui thi nghe, nhng m ng !)

Cu 2:Dung lng cell 3G thc t ph thuc Power & Signal Qual (Ec/No, RSCP) nnmun tnh dung lng ca cell bn phi c nhng tham s ny. Tuy nhin tnhdung lng 3G rt phc tp v n a dch v, v khi ni n dung lng ngi tathng phi c cc thng s v tl nghn chp nhn c (GoS Grade of Service).V d trong 2G, mt trm c 4 tn s vi 32 TS, c 28 TS cho TCH th n c th phcv c 20 Erlang vi GoS = 2% chng hn. Cn 3G l dung lng mm nn rt khtnh ton.

Tuy nhin h thng no cng c gii hn trn ca n. Bn c th tnh dung lnggii hn ca 3G da vo cy m OVFS.Nu mt thu bao cn dch v 384kbps th n cn 1 m OVFG SF8. Nh vy c 8 mSF8 nn cell c th phc v c 7 thu bao s dng dch v 384kbps. Cn dch v128 th ln n 14 thu bao.i vi HSDPA th MS s dng kiu iu ch 16QAM nn dung lng cell c kh nngphc v l ln n 14.4Mbps.
http://tudiencongnghe.com/Special:Search/3Ghttp://tudiencongnghe.com/Special:Search/2Ghttp://tudiencongnghe.com/Special:Search/HSDPAhttp://tudiencongnghe.com/Special:Search/MShttp://tudiencongnghe.com/Special:Search/3Ghttp://tudiencongnghe.com/Special:Search/2Ghttp://tudiencongnghe.com/Special:Search/HSDPAhttp://tudiencongnghe.com/Special:Search/MS


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So snh vi 2G: Nu 1 trm c 4 tn s, tng ng vi 32 TS, th bn c th phc vti a c 31 thu bao (loi tr knh bo hiu).

Thng thng cc bn ni tnh dung lng chung chung, khng hiu cc bn

mun tnh dung lng loi g, nhng theo mnh bit, hu ht cc bn mun tnhduong lng gii hn trn ca3G. Ch dung lng thc t c nghn nh 2G th chckhng c bao nhiu ngi bit tnh u.

UMTS-Power Controlng ngy: 01:05 05-01-2010

Th mc: Networking

bi ny, chng ta cng xem xt mt t tnh quan trng ca h thng thng tin di ng s dngcng ngh phn chia theo m (CDMA, UMTS) l t tnh iu khin cng sut. Nh ta bit trong h thng phn chia theo m, cc users s dng chung bng tn truyn tn hiu, vvy vic gy ra nhiu ln nhau l iu ng quan tm. Mc d, vi k thut s dng cc m trcgiao vi nhau, s giao thoa nhiu gia cc tn hiu c trnh khi. Tuy nhin, vn cn s nhhng ca nhiu mi trng tc ng ln mc tn hiu nhn c ti u thu lm suy gim chtlng tn hiu v c th khng th gii m c. Tht khng may, vi h thng m trc giao, cctn hiu khng giao thoa ln nhau, nhng tn hiu ny li tr thnh nhiu mi trng vi tn hiu

khc. Nu khng c thut tan iu khin cng sut th tn hiu gn thit b thu s khin cho tnhiu cn nhn c pht xa b ln lt han tan v khng gii m c.

Mt v d thc t in hnh cho vn ny : Gi s trong phng rng c nhiu ngi ni ccting khc nhau Anh, Php, Vit, Nga .. R rng ch nhng ngi ni ting Vit vi nhau mic th hiu c thng ip bng ting Vit (vi iu kin l cc ngi khc khng bit tingVit :D). By gi tng tng tnh hung, ngi u phng trao i vi ngi cui phng bngting Vit. Tuy nhin, cui phng c rt nhiu ngi ang trao i vi nhau bng ting Anh,Php, Nga ; v rt ln. Trong trng hp ny, rt kh (nu khng mun ni l khng th) chongi nghe hiu c ngi u phng ni ci g. gii quyt tnh trng ny, bt buc ngini phi ni ln hn v mi ngi ang trao i pha cui phng bng th ting khc phi ni

nh li.iu tng t cng xy ra trong h thng UMTS khi xem xt n vn nng lng. Mt giithut tng t c p dng trong UMTS, nhm m bo tt c cc tn hiu ti c u thu cmc tn hiu gn bng nhau. lm c iu ny, trong h thng UMTS, t s tn hiu trnnhiu c quan tm mt cch t bit. y cng chnh l thng s gip h thng t iu chnhcng sut m bo tiu ch ra. Ta s thy t s ny c s dng nh th no trong cc thtc iu khin cng sut Inner Loop, Open Loop, Outer Loop c UE, Node B v RNC thc
http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/bomcuoi/article?mid=300http://vn.360plus.yahoo.com/bomcuoi?l=f&id=4http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/bomcuoi/article?mid=300http://vn.360plus.yahoo.com/bomcuoi?l=f&id=4


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hin trong c hai hng Uplink v DownLink trong bi tip theo. iu cui cng chng ta cn thm lin quan ti vn ny l : Thng s tn hiu trn nhiu ca cell thng l mt tiuchun c nh. V vy khi c cng nhiu cuc gi trong cng mt cell, th t l ny cng nh (dotn hiu nhiu tng ln trong khi mc cng sut hu nh c nh), n mt lc no cuc gi skhng c chp nhn. Tng t khi ta ni, cng nhiu users trong mt cell th rng vng

ph sng ca cell cng nh li. Cc bn hy t l gii xem sao nh ! Hn gp li trong bi ti.trng: Vui v

UMTS-Power Control (Part 2)ng ngy: 16:43 10-01-2010

Th mc: Networking

Hm nay chng ta i su vo cac thut tan iu khin cn bng cng sut c cp bitrc. M hnh trnh by c thng nht gia UE, Node B v RNC :

UE --------------------------------- Node B -------------------------------- RNC

u tin, l th tc Uplink Inner Loop Power Control, y l th tc xy ra ch yu gia UE vnode B (Node B yu cu UE cn chnh cng sut). Ti mi Node B lun c thng s chun v tl tn hiu trn nhiu (ta gi l SIR_target), SIR_target c RNC gi xung cho Node B. Nh ta bit, cc UE gi cc thng ip DPCCH n Node B, trong thng ip DPCCH mang thngtin Pilot, thng tin ny cho ta bit mc tn hiu trn nhiu hin ti c nh gi ti UE (ta gi lSIR_estimated). Khi Node B nhn c thng ip DPCCH, s tin hnh so snh gi tr gia

SIR_target v SIR_estimated. Nu SIR_estimated ln hn, Node B s gi thng ip DPCCHvi gi tr trng TPC=0 yu cu UE gim cng sut mt lng delta (Ngha l ln sau UE spht tn hiu vi cng sut Pw=Pw-delta). Ngc li nu SIR_estimated nh hn, Node B s githng ip tng cng sut mt lng delta vi trng TPC=1 trong DPCCH.

Nh vy ta s t ra cu hi, trong trng hp cng sut UE qu nh Node B khng th phthin c th nh th no (mt ng b vi Node B). Trong trng hp ny, UE s t ng tngcng sut sau mi ln pht d tn hiu. Qu trnh lp li cho n khi UE ly c ng b tNode B. y chnh l th tc Uplink Open Loop Power Control c thc hin gia UE v

Node B, trong UE nm phn ch ng.

Vy tgi s UE pht ti a cng sut, m tn hin Node B nhn c vn b li (trong trnghp ny Node B pht hin CRC trong thng tin nhn c), th nh th no ? Cuc gi b rt ?May mn l UMTS c h tr th tc khc hn ch nhng bt li trong trng hp ny, cgi l Uplink Outer Loop Power Control c thc hin gia Node B v RNC nhm iu chnh
http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/bomcuoi/article?mid=304http://vn.360plus.yahoo.com/bomcuoi?l=f&id=4http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/bomcuoi/article?mid=304http://vn.360plus.yahoo.com/bomcuoi?l=f&id=4


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li mc SIR_target ti RNC (nu c). Thng thng ngi vn hnh mng s khai bo thngtin BER_target, t RNC tnh tan mc SIR_target gi xung cho Node B. Trong trng hpNode B pht hin CRC, n s gi thng tin cho RNC ; RNC so snh hai mc BER, nuBER_estimated > BER_target, RNC s tin hnh tnh tan li SIR_target ri gi li thng tinmi cho Node B.

Ti y ta thy hat ng iu khin cng sut hng Uplink, vy cn hng Downlink ? UEc ng vai tr tch cc no trong qu trnh iu khin cng sut. Cu tr li l c, cng chnhl ni dung ca th tc Dowlink Inner Loop Power Control gia UE v Node B, trong NodeB t cn chnh cng sut da vo tn hiu DPCCH nhn c t UE. Thng qua u trnh thit lpcuc gi, RNC gi thng tin BER_target cho UE thng qua tn hiu thit lp RRC (Th tc nycn c gi l Downlink Outer Loop Control). Khi UE nhn c gi tin DPDCH t Node B,n s thc hin php so snh BER_estimated vi BER_target quyt nh thng ip DPCCHtip theo gi cho Node B c trng TPC mang gi tr 0 hoc 1. Khi node B nhn c thng

ip DPCCH t UE, ty vo gi tr ca trng TPC n quyt nh tng hay gim cng sut mtkhang delta.

Tuy theo thit b v nh sn xut, gi tr delta c th l 0.5dB, 1dB, 1.5dB hoc 2dB, cng nhngi vn hnh c c can thip vo cc thng s trong cc u trnh ny hay khng! Nh vy lchng ta xem qua t tnh iu khin cng sut trong UMTS. Kt thc bi ny, ch lu thmvi cc bn tn ca th tc Inner, Open hay Outer u c ngha ca chng y, gip chng tad nh v khng b ln ln.

u im ca WCDMA

1) Bng thng rng hn, t cc i l 5 MHz , vi tc chip 3,81 GHz, 1 khung vtuyn 10ms, c 15 khe thi gian , 1 khe c 2500 chip.

2) Khc vi IS 95, cc trm gc trong UMTS khng cn tham chiu thi gian GPDS,mi trm gc c th vn hnh d b vi nhau nhng mi trm gc c 1 m ngu

nhin ha c trng , ngi ta ni UTMS vn hnh d b.

3) Ty thuc ng dng , ty thuc mi trng truyn dn m ng s liu c th cm ha sa li hay khng, v c th chn cc s MH s li khc nhau, c thdng m vng xon, c th dng m turbo.

4) Tri ph vi tc kh bin. ( trong IS 95 c nh)
http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/leminhabe/article?mid=152http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/leminhabe/article?mid=152http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/leminhabe/article?mid=152http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/leminhabe/article?mid=152http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/leminhabe/article?mid=152http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/leminhabe/article?mid=152http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/leminhabe/article?mid=152http://vn.rd.yahoo.com/blog/mod/art_title/*http:/vn.360plus.yahoo.com/leminhabe/article?mid=152


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5) M ngu nhin ha: c m di , m ngn , phn bit cho hng ln v xung, mny l m phc.

6) Tri ph phc: lm gim di ng ca tn hiu, do ph hp vi b khuch icng sut phi tuyn c hiu sut cao.

7) Mng c th cp pht 1 hay nhiu khe thi gian, 1 hay nhiu knh dnh ring tytheo nhu cu lu lng ca lin lc.

8) UMTS h tr dch v s liu gi 1 cch linh hot.

9) p dng cc cng ngh tin tin, v d: k thut thu tng can, s dng mnganten thch ng, k thut pht hin phn bit nhiu ngi dng.

10) Cht lng truyn n c ci thin nh p dng pht phn tp i vi knh

hng xung.

11) iu khin cng sut 1500 ln/s , cng sut pht ca trm gc cng c iukhin theo nguyn tc mch vng kn.

Ngun trch dn (0)

2.TNG QUAN V GSM

TNG QUAN V GSM1.1 Gii thiuCung cp cu trc tng quan v mng GSM, bao gm cc gii thch ngn gn v cc h thngcon (subsystem) v m t chc nng ca cc thnh phn trong mi h thng con. Chng nybao gm: Cu trc tng quan Mobile Station (MS) Subsystem v cc thnh phn Base Station Subsystem (BSS) v cc thnh phn Network Switching Subsystem (NSS) v cc thnh phn Gii thiu v cc giao din

1.2 Cc s nhn dng trong GSM1.2.1 IMEI - International Mobile Equipment IdentifierIMEI l thng s duy nht xc nh phn cng MS. N c ng k bi nh khai khc mng v(ty chn) c lu trong AuC cho cc mc ch xc nhn hp l.1.2.2 IMSI - International Mobile Subcriber IdentifierKhi mt thu bao ng k vi nh khai thc mng, thng s IMSI duy nht c to ra v lu trtrn SIM ca MS. Mt MS ch c th hot ng vi SIM hp l v IMEI hp l.1.2.3 TMSI - Temporary Mobile Subcriber Identifier


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TMSI c s dng bo v s nhn dng thc (IMSI) ca mt thu bao. N c to ra vlu tr trong VLR khi qu trnh IMSI attach din ra hay cp nht Location Area (LA) din ra.Ti MS, n c lu trong SIM ca MS. TMSI ny ch hp l trong LA xc nh.1.2.4 MSISDN Mobile Subscriber ISDN NumberMSISDN l s thu bao di ng. N c gn cho thu bao bi nh khai thc mng khi ng k

v c lu trong SIM. C th mt MS c nhiu MSISDN, mi MSISDN lin i vi mi dchv khc nhau.1.2.5 MSRN Mobile Station Roaming NumberMSRN l s ISDN tm, ph thuc vo v tr c to ra bi VLR cho tt c cc MS trong khuvc phc v ca n. N c lu tr trong VLR v HLR nhng khng lu trong MS. MSRNc s dng bi MSC/VLR cho mc ch nh tuyn cuc gi.1.2.6 LAI Location Area IdentityMi LA trong PLMN c mt s nhn dng duy nht (LAI). LAI c qung b u n bi ccBTS trn knh BCCH (Broadcast Control Channel),1.2.7 CI Cell IdentifierCI l mt s nhn dng c gn cho mi cell trong mng. Tuy nhin, CI ch duy nht trong LA

xc nh. Khi kt hp vi LAI trong LA tng ng, GCI (Global Cell Identity) c to ra vmang tnh duy nht.1.2.8 BSIC Base Station Identity CodeMi BTS c mt s nhn dng duy nht l BSIC v n c s dng phn bit cc BTS lncn (neighbour).

1.3 Cu trc tng quan

Hnh 1.1 Cu trc tng quan mng GSM
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Ch thch:MSC Mobile Switching CentreBSC Base Station ControllerBTS Base Transceiver Station

TRX TransceiverMS Mobile StationOMC Operation and Maintenance CentrePSTN Public Switched Telephone NetworkHLR Home Location RegisterVLR Visitor Location RegisterAuC Authentication CentreEIR Equipment Identity Register

Mt mng GSM bao gm ba h thng con: Mobile Station (MS)

Base Station Subsystem (BSS) bao gm BSC v cc BTS Network Switching Subsystem (NSS) bao gm MSC v cc thanh ghi tng ngCc giao din c xc nh gia cc h thng con ny bao gm: Giao din A gia NSS v BSS Giao din Abis gia BSC v BTS (trong BSS) Giao din Um v tuyn gia BSS v MS

1.4 Mobile Station (MS)MS bao gm mt thit b vt l c s dng bi thu bao PLMN kt ni vi mng. N baogm Mobile Equipment (ME) v Subcriber Identity Module (SIM). SIM lu tr IMSI, MSISDN, kha xc thc Ki v gii thut dng cho kim tra xc thc. ME c s xc nhn IMEI duy nht, c s dng bi EIR.

1.5 Base Station Subsystem (BSS)BSS bao gm cc thit b trm gc (transceivers, controllers) c nhn thy bi MSC thngqua giao din A. Thit b v tuyn ca mt BSS c th h tr mt hay nhiu cell.BSS c th bao gm mt hay nhiu trm gc, ti giao tip Abis c thc thi. BSS bao gmmt BSC v mt hay nhiu BTS.Chc nng ca BTS: Cung cp truy cp v tuyn cho cc MS Qun l cc mt v truy cp v tuyn ca h thngBTS bao gm: Thu pht v tuyn (TRX) Cc thit b x l v iu khin tn hiu Cc Antenna v cp feederChc nng BSC: Cp pht 1 knh cho sut mt cuc gi Duy tr cuc gi:o Gim st cht lng


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o iu khin cng sut truyn t BTS hay MSo Quyt nh handover sang mt cell khc khi cn thit

Tm hnh ny c thu nh. Click vo y thy ton b tm hnh. Kch thc tht l756x175.

Hnh 1.2 S u ni BSS

Cc kiu u ni BSS:

Mt xch Vng Sao

1.6 Network Switching Subsystem (NSS)1.6.1 Tng quan v NSSCc thnh phn chnh ca NSS: MSC/VLR, HLR/AuC, EIR, GMSC.Cc thnh phn ny lin kt vi nhau s dng bo hiu s 7 (SS7).
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Hnh 1.3 Tng quan v NSS

1.6.2 Mobile Switching Centre (MSC)Chc nng ca MSC: Chuyn mch cuc gi, iu khin cuc gi v ghi nht k cuc gi Giao tip vi PSTN, ISDN, PSPDN Qun l di ng (Mobility Management) thng qua mng v tuyn v cc mng khc Qun l ti nguyn v tuyn (Radio Resource Management) handover gia cc BSC Thng tin tnh cc1.6.3 Visitor Location Register (VLR)VLR l mt c s d liu cha cc thng tin tm ca thu bao trong mt MSC area. Mi MSCtrong mng c mt VLR lin i nhng mt VLR c th phc v nhiu MSC.Khi MS di chuyn vo LA mi, n s bt u qu trnh ng k. MSC c nhim v thng bovic ng k ny v chuyn s xc nh LA cho VLR. Nu MS cha c ng k trc ,

VLR v HLR trao i thng tin cho php vic qun l cuc gi thch hp cho MS .VLR cng bao gm cc thng tin cn thit qun l vic thit lp hay nhn cuc gi bi ccMS ng k trong c s d liu ca n. Cc thnh phn ny bao gm: IMSI MSISDN MSRN TMSI LMSI


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LA, ti MS tin hnh ng k1.6.4 Home Location Register (HLR)HLR l mt c s d liu c trch nhim qun l cc thu bao di ng. PLMN c th c mt hayvi HLR ph thuc vo s lng thu bao, dung lng ca thit b ny v vic t chc trongmng.

C 2 nhm thng tin c lu tr ti y: Thng tin thu bao Thng tin v tr cho php vic tnh cc v nh tuyn ti MSC vi MS c xc nh ti y(v d MSRN, a ch ca VLR, a ch ca MSC, LMSI)Hai kiu s nhn dng c attach cho mi thu bao di ng v c lu trong HLR: IMSI Mt hay nhiu s MSISDNIMSI hay MSISDN c th c dng nh l kha truy cp thng tin trong c s d liu chomt thu bao di ng.1.6.5 Authencation Centre (AuC)AuC c kt hp vi HLR, v lu tr kha xc nhn cho mi thu bao c ng k vi

HLR.Kha ny dng to ra: D liu c s dng xc thc IMSI Mt kha c s dng bo mt thng tin qua knh v tuyn gia MS v mng1.6.6 Gateway Mobile Switching Centre (GMSC)GMSC nh tuyn cc cuc gi ra ngoi mng v l mt im truy cp cho cc cuc gi vomng t bn ngoi.1.6.7 Equipment Identity Register (EIR)EIR l mt c s d liu lu tr s nhn dng IMEI cho ME.EIR iu khin truy cp vo mng bng cch tr v trng thi ca MS tr li cho IMEI querytng ng.Cc mc trng thi: White-listed: Thit b u cui c cho php kt ni vi mng Grey-listed: Thit b u cui ang c quan st bi mng bi cc vn c th xy ra Black-listed: Thit b u cui c bo mt hay khng phi l loi c ph chun cho mngGSM, do thit b u cui khng th kt ni vi mng



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Hnh 1.4 Cc giao din trong mng GSM

1.7 Cc giao din trong GSM1.7.1 Giao din A (MSC-BSS)Giao din gia BSS-MSC c dng mang cc thng tin lin quan n: Qun l BSS Qun l cuc gi Qun l di ng1.7.2 Giao din Abis (BSC-BTS)

Giao din ny c s dng gia BSC v BTS h tr cc dch v cho ngi dng v thu baoGSM. Giao din ny cng cho php vic iu khin cc thit b v tuyn v tn s v tuyn cppht cho BTS.1.7.3 Giao din B (MSC-VLR)Bt c khi no MSC cn d liu lin quan ti mt MS ang trong khu vc ca n, n s hi VLRthng qua giao din ny. Th d khi m MS bt u th tc cp nht v tr vi mt MSC, MSCthng bo cho VLR ca n cc thng tin lin quan.1.7.4 Giao din D (HLR-VLR)Giao din ny c s dng trao i d liu lin quan n v tr ca MS v vic qun l thubao. Dch v chnh c cung cp cho thu bao di ng l kh nng thit lp hay nhn cc cucgi trong ton b service area. h tr iu ny, cc thanh ghi v tr phi trao i d liu.

Trao i d liu xy ra khi thu bao di ng i hi dch v c th, khi mun thay i d liuattach trong thng tin thu bao.1.7.6 Giao din E (MSC-MSC)Khi MS di chuyn t MSC area sang MSC area khc trong sut cuc gi, th tc handover phic tin hnh c th duy tr lin lc. Bi mc ch cc MSC phi trao i d liu btu v thc hin vic nySau khi handover hon tt, cc MSC s trao i thng tin truyn ti bo hiu giao din A nucn thit. Khi m mt thng ip ngn c truyn gia MS v SMC (Short Message Service


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Centre), c 2 chiu, giao din ny c dng truyn thng ip gia MSC phc v MS vMSC c giao din vi SC.1.7.7 Giao din F (MSC-EIR)Giao din ny dng cho trao i d liu gia MSC v EIR, mc ch EIR c th xc nhntrng thi khi nhn c IMEI t MS,

1.7.8 Giao din G (VLR-VLR)Khi MS di chuyn t VLR area ny sang VLR area khc, th tc ng k v tr s xy ra. Th tcny c th bao gm vic ly IMSI v cc thng s xc thc trong VLR c.1.7.9 Giao din H (HLR-AuC)Khi HLR nhn yu cu xc thc v m ha d liu cho MS, HLR yu cu d liu t AuC. Giaothc c s dng truyn d liu thng qua giao din ny khng c chun ha.1.7.10 Giao din Um (MS-BTS)Giao din ny l giao din v tuyn.

1. Cu trc cc knh Logic ca h thng GSM.Trong h thng knh Logic ca GSM chia lm 2 loi nhm knh: Nhm knh bo hiu v nhmknh lu lng.*Nhm knh lu lng: ch yu dng phc v cho ch thoi ( khi bn v u bn kia nichuyn thng sut vi nhau y), trong mt s ch d c bit khc th knh lu lng cng bchim dng phc v cho cc nhu cu khn cp khc nh HandOver (chuyn giao cell phcv) chng hn. Nhm knh ny gi chung l TCH (Traffic Channel). C 2 loi vi tc truynkhc nhau:-Knh lu lng ton tc ( Fullrate TCH or TCH/F): Mt knh TCH/F s chim trn mt TS( Timeslot) ca khung TDMA. Tc truyn l 13kb/s cho thoi v 9.6 kb/s cho data.-Knh lu lng bn tc ( Halfrate TCH or TCH/H): 2 knh TCH/F s cng chim mt TS cakhung TDMA. Tc truyn b gim i mt na: 6.5kb/s cho thoi v 4.8kb/s cho data.Nu h thng kch hot ch HR ( halfrate) th cht lng thoi ca cuc gi s b gim, nhngb li s thu bao phc v c ca Cell s tng ln. Dng ng ph trong trng hp lulng tng t bin v khng thng xuyn, khng tin hnh nng cp h thng kp. Khi lulng gim xung ngi ta li b ch HR. Thng th HR c s dng km vi mt c chna l AMR s ni sau).*Nhm knh bo hiu: Cc nhm knh ny ng nh t gi s m bo cho cc bo hiu ca hthng nh: ng b,qung b,cp knh ,thit lp cuc gi, ....c chia lm 3 nhm chnh sau:-Nhm knh qung b: Broadcast Channel ( BCH)y l knh mt chiu, theo ng xung, c n nh trn TS0 ca khung TDMA. Gm ccc knh:FCCH: Knh iu khin tn s gi ti MS (Mobile Station): gm mt cm ton bit 0, MSda vo hiu chnh tn s pht.SCH: Knh ng b cho MS kh nng ng b vi trm BTS( nhn bit cc thng s nhn dngtrn h thng (BSIC)ca BTS), bit c s khung TDMA.BCCH:gi cc thng tin c th v mng, nh qun l ti nguyn v tuyn v cc bn tin iukhin, v d: m nhn din mng MNC, LAI,.-Nhm knh iu khin chung: Common Control Channel (CCCH)Bao gm tt c cc knh ng xung im ti a im (BTS ti mt nhiu MS) v knh truynhp ngu nhin ng ln:


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AGCH: c s dng n nh 1 knh dnh ring (SDCCH) ti MS.PCH: knh tm gi(pagging) gi tn hiu thng bo ti MS v 1 cuc gi n.CBCH: l 1 ty chn (c th c hoc ko) cho bn tin qung b SMS.NCH: l 1 ty chn (c th c hoc ko) dng cho dch v qung b thoi (VBS).Trong 2 knh quan trng nht l AGCH v PCH. Knh AGCH s c gi cho MS c yu

cu cp knh iu khin ring sau khi h thng kim tra thy ti nguyn cn trng, v yu cuca MS l hp l. Cn knh PCH s c gi cho tt c cc MS trong vng phc v khi c mts thu bao no c gi. Tt c cc MS s nhn v gii m bn tin ny, nhng ch c MS bgi mi tr li cho h thng tm gi v chung.-Nhm knh iu khin ring: Delicated Control Channel. (DCCH)Bao gm cc knh iu khim im- im, gm c 2 hng (uplink/downlink). Cc nhm knhny dng thit lp mt lin lc ring gia mt MS v h thng, qua h thng s lng nghev thc hin yu cu hp l ca MS .SDCCH: Knh iu khin dnh ring c s dng cho thit lp cuc gi, LU v SMS.SACCH: Knh iu khin lin kt chm c s dng cho bo co o v bo hiu trong 1 cucgi.

FACCH: Knh iu khin lin kt nhanh c s dng (khi cn) cho bo hiu trong 1cuc gi,ch yu cho phn pht bn tin Handover v cho hi bo khi TCH c gn.Trong SACCH v FCCH c xem l ch chim knh, do n ly cc TS l ra dnh choknh lu lng gi nhng thng tin khn cp cn thit cho vic duy tr cuc gi. V ch chims t TS v ko lin tc nn hu nh ngi s dng cng ko cm nhn c s thay i cht lngthoi ti thi im b chim knh.

TNG QUAN V CC TRAFFIC CASE1. IDLE Mode


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Hnh 1 Cc Traffic Case khi MS trong IDLE Mode

1.1 IMSI AttachKhi MS m my, qu trnh IMSI attach din ra. Bao gm cc bc sau:1. MS gi thng ip IMSI ti mng bo rng n chuyn sang trng thi idle.2. VLR xc nh rng c bn ghi d liu (record) cho thu bao hay cha. Nu cha c, VLRlin h vi HLR ly mt bn sao v thng tin thu bao.3. VLR cp nht trng thi ca MS l idle.

4. ACK c gi ti MS.


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Hnh 2 IMSI Attach

1.2 Cp nht v tr dng IMSI attachTrong qu trnh IMSI attach, VLR c th xc nh LAI hin ti ca MS khc vi LAI lutrong thng tin thu bao ca MS. Do , VLR cp nht LAI ca MS.

1.3 Thay i cell trong cng LAMS lin tc di chuyn trong mng. Thng tin v tr ca MS c lu trong VLR l LA. Nu MSthay i cell trong cng LA th khng cn phi cp nht. MS bit rng cell mi thuc cng LA

bng cch lng nghe knh BCCH (qung b LAI ca cell). MS so snh LAI trc v LAI minhn c. Nu ging nhau ngha l MS khng thay i LA v khng cn thng bo cho mng.

1.4 Cp nht v tr trong cng MSC/VLRNu MS pht hin c thay i LAI trn BCCH, n s thng bo ti mng. khi MS gi thng ipcp nht v tr, MSC/VLR xc nh l MS c ng k hay MS di chuyn t MSC/VLRkhc.

Tm hnh ny c thu nh. Click vo y thy ton b tm hnh. Kch thc tht l768x250


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.

Hnh 3 Cp nht v tr trong cng MSC/VLR

1. MS lng nghe knh BCCH trong cell mi xc nh LAI. LAI mi c so snh vi LAI c.Nu khc nhau, cp nht v tr l cn thit.2. MS thit lp kt ni vi mng qua knh SDCCH. Qu trnh xc thc c thc hin.3. Nu qu trnh xc thc thnh cng, MS gi yu cu cp nht v tr ln h thng.4. H thng tr v ACK v yu cu BTS v MS gii phng knh bo hiu.

1.5 Cp nht v tr khc MSC/VLRKhi MS chuyn sang LA mi, cp nht v tr c thc hin. Tuy nhin, LA c th thucMSC/VLR mi. Khi yu cu cp nht v tr c nhn bi VLR mi, cc qu trnh sau y sc thc hin.1. Qu trnh xc thc c thc hin. Nu xc thc thnh cng, VLR kim tra c s d liu can xc nh n c bn ghi d liu cho MS hay cha.2. Khi VLR khng tm thy bn ghi d liu cho MS, n gi ti HLR yu cu bn sao thng tinthu bao ca MS.3. HLR gi thng tin cho VLR v cp nht thng tin ca n v v tr cho thu bao. HLR yu cuVLR c xa thng tin v MS ca n.4. VLR lu tr thng tin thu bao ca MS, bao gm v tr mi nht v trng thi (idle). VLR giACK ti MS.


Hnh 4 Cp nht v tr khc MSC/VLR


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1.6 Cp nht v tr dng ng k theo chu kng k theo chu k l mt tnh nng bt buc MS gi bn tin ng k vi mng ti cc thiim xc nh trc. Nu MS khng thc hin vic ny, mng s xem nh MS ri mng(detach). iu ny c th xy ra khi MS ra ngoi vng ph v bo m khng cn phi paging

n MS ny.Nu mng s dng ng k theo chu k, MS s c thng bo trn BCCH rng vic ng ktheo chu k din ra thng xuyn nh th no. ng k theo chu k c mt thng ip ACK.MS c gng thc hin vic ng k cho ti khi nhn c thng ip ny.

1.7 IMSI DetachIMSI detach cho php MS bo cho mng rng n tt my. Khi tt my, MS gi thng ipIMSI Detach ti mng. Khi nhn c thng ip ny, VLR nh du IMSI ny detach. HLRkhng c thng bo. Khng c ACK c gi ti MS.

1.8 Detach ngm

Nu MS gi thng ip IMSI detach ti mng nhng cht lng kt ni v tuyn xu, h thngkhng th gii m thng tin ny. Bi khng c ACK c gi ti MS, nn s khng c qu trnhthc hin li. Trong trng hp ny, h thng vn xem MS l attach. Nu ng k theo chu kc s dng, h thng s sm pht hin MS detach. VLR thc hin vic detach ngm, nhdu MS detach.

2. Active Mode


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Hnh 5 Cc Traffic Case khi MS trong Active Mode

2.1 Cuc gi t MSV d mt cuc gi c thc hin t MS n mt thu bao trong PSTN. Qu trnh xy ra nhsau:1. MS dng RACH yu cu knh bo hiu.2. BSC/TRC cp pht knh bo hiu, dng AGCH.

3. MS gi yu cu thit lp cuc gi qua knh SDCCH n MSC/VLR. Qua SDCCH, cc th tcbo hiu cho cuc gi c thc hin. Bao gm: nh du MS trong trng thi active trong d liu ca VLR Qu trnh chng thc Bt u qu trnh bo mt (ciphering) Xc nh thit b Gi s thu bao B ti mng Kim tra thu bao c dch v Chn chiu gi i hay khng
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4. MSC/VLR yu cu BSC/TRC cp pht knh TCH rnh cho MS. BTS v MS c iu chnhn knh TCH ny.5. MSC/VLR chuyn s thu bao c gi (B-number) n tng i ca PSTN thit lp ktni.6. Nu thu bao tr li, kt ni c thit lp.


Hnh 6 Cuc gi t MS ti PSTN

2.2 Cuc gi n MSS khc bit gia cuc gi ti MS v cuc gi t MS l trong cuc gi ti MS, v tr chnh xcca thu bao di ng l cha bit. Do , MS phi c xc nh v tr bng cch s dng pagingtrc khi kt ni c thit lp.

Hnh 3.7 m t th tc thit lp cuc gi t thu bao PSTN n MS. Cuc gi t MS n mtthu bao di ng khc cng c qu trnh tng t ch khc l GMSC s c kt ni viMSC/VLR khc thay v l PSTN node.



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Hnh 7 Cuc gi t PSTN ti MS

1. PSTN phn tch s MSISDN ca MS v xc nh cuc gi l ti thu bao mng di ng. Mtkt ni c thit lp n GMSC ca MS .2. GMSC phn tch MSISDN xc nh HLR m MS ng k v hi HLR thng tin nh tuyncuc gi n MSC/VLR phc v.3. HLR chuyn i MSISDN thnh IMSI v xc nh MSC/VLR ang phc v MS. HLR cngkim tra dch v chuyn cuc gi n s C. Nu c dch v ny, cuc gi s c nh tuynbi GMSC n s ny.4. HLR yu cu MSRN t MSC/VLR phc v.5. MSC/VLR tr v MSRN thng qua HLR n GMSC.6. GMSC phn tch MSRN v nh tuyn cuc gi n MSC/VLR.

7. MSC/VLR bit LA ca MS. Mt thng ip paging c gi cho tt c cc BSC trong LA .8. BSC phn pht thng ip ny n cc BTS trong LA. BTS gi thng ip ny trn knhPCH. tm gi (page) mt MS, mng dng IMSI hoc TMSI (ch hp l trong vng phc vMSC/VLR).9. Khi MS pht hin thng ip paging, n s yu cu cp knh SDCCH trn knh RACH.10. BSC cp pht knh SDCCH, dng AGCH.11. SDCCH c s dng thit lp cuc gi: nh du MS trong trng thi active trong d liu ca VLR


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Qu trnh chng thc Bt u qu trnh bo mt (ciphering) Xc nh thit bMSC/VLR ch th cho BSC/BTS cp pht knh TCH rnh. BTS v MS c iu chnh nknh TCH ny.

12. MS chung. Nu thu bao tr li, kt ni c thit lp.2.3 Handover trong cng BSCKhi thc hin handover gia 2 cell trong cng BSC, s khng lin quan ti MSC/VLR. Tuynhin, MSC/VLR s c thng bo khi handover tin hnh xong. Nu handover gia cc LAkhc nhau, cp nht v tr c thc hin sau khi cuc gi hon tt.1. BSC yu cu BTS mi kch hot knh TCH2. BSC gi thng ip cho MS bao gm thng tin v tn s v time slot v mc cng sut ti MSthng qua BTS c bng cch s dng knh FACCH.3. MS chuyn sang tn s mi v truyn burst truy cp handover trong time slot ng. Bi v MScha c cc thng tin TA, cc burt handover rt ngn (khong 8bit).

4. Khi BTS mi pht hin cc burst handover, n gi thng tin v TA trn knh FACCH.5. MS gi thng ip hon thnh handover ti BSC thng qua BTS mi.6. BSC yu cu RBS c gii phng TCH c.


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Hnh 8 Handover trong cng BSC

2.4 Handover khc BSC, cng MSCKhi BSC khc lin quan trong handover, MSC/VLR phi lin quan thit lp kt ni gia 2BSC.1. BSC c gi tin nhn yu cu handover ti MSC cha nhn dng ca cell mi.2. MSC bit BSC no iu khin cell mi ny v gi yu cu handover ti BSC ny.3. BSC mi yu cu BTS mi kch hot knh TCH.4. BSC mi gi thng ip ti MS thng qua MSC v BTS c.

5. MS chuyn sang tn s mi v truyn burst truy cp handover trong time slot ng.6. Khi BTS mi gi thng tin v TA7. MS gi thng ip hon thnh handover ti MSC qua BSC mi8. MSC yu cu BSC gii phng TCH c.9. BSC c yu cu BTS c gii phng TCH.

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Hnh 9 Handover khc BSC, cng MSC

2.5 Handover khc MSCHandover gia cc cell c iu khin bi cc MSC/VLR khc nhau ch c th thc hin trongmt PLMN. Cc cell c iu khin bi cc MSC/VLR khc nhau cng c ngha l chngthuc cc BSC khc nhau.1. BSC c gi thng ip yu cu handover ti MSC phc v (MSC-A), vi nhn dng ca cellmi.2. MSC-A nhn dng cell mi ny thuc MSC khc (MSC-B) v yu cu tr gip.3. MSB-B cp s handover ti nh tuyn cuc gi. Sau gi yu cu handover ti BSCmi.4. BSC mi yu cu BTS mi kch hot TCH.5. MSC-B nhn thng tin, v chuyn n ti MSC-A cng vi s handover.

6. Mt kt ni c thit lp ti MSC-B, c th thng qua PLMN.7. MSC-A gi lnh handover ti MS, thng qua BSC c.8. MS chuyn sang tn s mi v truyn burst truy cp handover trong time slot ng.9. Khi BTS mi pht hin cc burst handover ny, n gi thng tin v TA.10. MS gi tin nhn hon thnh handover ti MSC c thng qua BSC mi v MSC/VLR mi.11. Mt ng mi trong groupswitch trong MSC-A c thit lp v cuc gi c chuynmch sang ng ny.12. TCH c c gii phng bi BSC c.


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MSC c (MSC-A) gi chc nng iu khin cuc gi n khi cuc gi kt thc. l bi v ncha thng tin v thu bao cng nh tnh ccSau khi cuc gi c gii phng, MS phi thc hin cp nht v tr bi v mt LA khng baogi thuc v nhiu hn 1 MSC/VLR. HLR c cp nht bi VLR-B v s thng bo cho VLR-A xa tt c cc thng tin v thu bao ny.


Hnh 10 Handover khc MSC

THIT LP CUC GI (CALL SETUP)1.Mc ch : Thit lp cuc gi c yu cu thit lp ng truyn giaMS v NSS. NSSc nhim v thit lp kt ni vi thu bao tng ng. Cc loi cuc gi khc nhau yu cu dch

v thoi khc nhau.C 3 kiu cuc gi c bn :-Cc cuc gi qun l tnh di ng : dng tp hp cc thng tin MS, vd: cp nht v tr. Chtrao i cc bn tin giao thc (protocol), do ch s dng 1 knh bo hiu.-Cc cuc gi dch v : cc cuc gi ny ch chuyn mt lng thng tin nh, nh cuc giSMS haySS, nn cng ch dng 1 knh bo hiu.-Cc cuc gi lu lng ca khch hng : cc cuc gi ny c th chuyn mt lng thng tinln, nh cuc gi thoi hay d liu n ch tng ng, do cn bng thng ln hn 1 knh
http://tudiencongnghe.com/Special:Search/MShttp://tudiencongnghe.com/Special:Search/MShttp://tudiencongnghe.com/Special:Search/SMShttp://tudiencongnghe.com/Special:Search/SShttp://tudiencongnghe.com/Special:Search/SShttp://tudiencongnghe.com/Special:Search/MShttp://tudiencongnghe.com/Special:Search/SMShttp://tudiencongnghe.com/Special:Search/SS


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bo hiu. Nhng cuc gi ny dng knh lu lng.(Knh dng cho bo hiu l SDCCH, dng cho lu lng l TCH.)

2.Cc giai on ca thit lp cuc gi :

-Thit lp kt ni v tuyn.*Tm gi (paging) (i vi my c gi) ch ra MS c gi.*Nu attach_detach_allowed c kch hot, bn tin IMSI_detach MS c th loi tr nhu cu tmgi.*Qu trnh n nh tc thi s cp 1 ti nguyn cho MS v thit lp 1 kt ni bo hiu v tuyngia BSS v MS.*Mt kt ni giao din n nh 1 knh bo hiu SCCP gia BSC v MSC.*n nh ng chuyn mch xuyn qua BSC.-Nhn thc v mt m .*Classmark handling (X l mt n).*Nhn thc.

*Mt m.-n nh thng thng.*Tho thun dch vu Teleservice/bearer.*n nh knh.*Qu trnh context vt l.*n nh knh lu lng, nu c yu cu.*Kt ni cuc gi.3. Qu trnh thit lp cuc gi cho cc thu bao cng mng : ( qu trnh gm 25 bc)

Bc 1 : Yu cu cp knh :

MS khi u cuc gi bng vic gi bn tin channel-request trn knh RACH vi ni dung:nguyn nhn thit lp cuc gi + 1 REF (Random Access Information Value) + 1 RAND (cdng cho nhn thc).Cc l do thit lp c th c trong REF (7 trng hp):* Cuc gi khn.* Cuc gi yu cu ti thit lp.* Tr li bn tin tm gi.* Cuc gi thoi ca thu bao ch gi.* Cuc gi d liu ca thu bao ch gi.* Cp nht v tr.* Cuc gi dch v (vd SMS )

Trong mi bn tin channel-request, MS cn gi km s ngu nhin v s khung. Nhng s nygip MS nhn ra bn tin c phc p t BSS trn knh AGCH knh c gim st bi nhiuMS. MS s gii m tt c nhng bn tin trn knh ny, v ch nhn mt bn tin c s ngu nhinv s khung ph hp vi mt trong 3 bn tin yu cu c gi i ngay trc .MS s tip tc gi bn tin channel-request cho n khi no nhn c phc p. Nu khng nhnc phc p no trc khi truyn mt s Retries,MS s :Hin th mt bn tin bo li mng cho tt c cc loi cuc gi ngoi tr cuc gi cp nht v tr.Tin hnh chn t ng li cc cuc gi cp nht v tr. C ngha l MS n lc truy nhp ngu
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nhin mt cell khc.

Bc 2: Khi nhn bn tin channel-request t MS, BTS s gi cho BSC 1 bn tin channel-required. Bn tin ny cha s ngu nhin ca MS v khong nh thi do BTS a ra.BSC skim tra bn tin channel-required m bo n c th chp nhn yu cu hay khng.BSC s

kim tra xem c knh SDCCH no r i hay khng ,nu cn n s cp cho MS mt knhSDCCH . Phn mm qun l ti nguyn ca BSC ch nh knh D trn nn knh lu lng cnhiu knh D ri nht. iu ny nhm m bo ti c tri u trn tt c cc knh lu lng.

Bc 3 : Sau , BSC s gi cho BTS bn tin channel-activation. ng thithit lp mt timer i bo nhn (acknowledgement) t BTS, bo cho bit BTS sn sng kch hot knh. Bn tinchannel-activation bao gm :M t knh D c dng.Khong nh thi.Lnh iu khin cng sut cho MS v BTS. Cng sut MS v BTS t n mc ti a c thtrong cell.

Bc 4: BTS khi to ngun ti nguyn lp vt l v lp gii php tranh chp LAPDm (nhmtrnh trng hp 2 MS kt ni n cng 1 knh D) sn sng cho bn tin MS u tin trn knhD, sau gi BSC bn tin channel_activation_ack . BSC s dng khong thi gian bo v.

Bc 5 : Qu trnh n nh tc th :BSC to v gi BTS bn tin immediate_assign_command tm tt cc thng tin trong bn tinchannel_activation. Bn tin ny cng bao gm s ngu nhin v s khung caMS gi yu cup ng ca BSC. N cng hng dn BTS xc nh (inform) MS yu cu n nh knh D.BSC kch khi khong thi gian ch MS tr li.

Bc 6 : Tip BTS gi cho MS bn tin immediate_assignment trn knh AGCH.MS kim tra s ngu nhin v s khung trong bn tin ny xem c hp vi mt trong 3 bn tinchannel_request m n gi i gn y nht khng, nu ngMS s chuyn sang knh D dnhring ny v t TA ca mnh vo value indicate trong bn tin immediate-assignment.

Bc 7: Thit lp mode cn bng bt ng b (set asynchronous balanced mode)Mng da vo bn tin ny quyt nh cc th tc tho thun cuc gi no c yu cu v cn nh knh lu lng hay khng.

Bc 8: Establish Indication :BTS gi bn tin establish-indication n BSC bo MS kt ni. BSC chm dt khong thigian bo v, trch thng tin trong CM v khi to kt ni SCCP vi MSC.

Bc 9: Kt ni SCCP :BSC gi bn tin SCCP-connection-request n MSC.

Bc 10: MSC tr li bng bn tin SCCP- connection-confirm. Bn tin ny c th cha 1 yucu CM hoc 1 lnh mt m . ng bo hiu c thit lp giaMS v MSC.
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Bc 11: Khi qu trnh thit lp kt ni v tuyn thnh cng, gia MS v mng c 1 ng bohiu. Nu cuc gi yu cu 1 knh lu lng lin lc (communicate) vi thu bao b gi, MSs gi 1 bn tin setup. Bn tin ny s ch ra loi dch v yu cu (tele hay bearer) v s thu bao

b gi. Thng tin ny c truyn xuyn qua BSS. Bn tin ny c th cha nhiu hn 1 thnhphn dch v bearer, v mt thng s cho bit thu bao c th .yu cu thay i yu cu dch v(in-call modification) trong sut cuc gi.

Bc 12: MSC gi MS 1 bn tin call_proceeding. Bn tin ny cho bit MSC nhn cc thngs cuc gi, v cc n lc thit lp kt ni vi called party l under way.

Bc 13: Yu cu knhMSC bt u n nh knh lu lng bng cch gi BSC bn tin assignment-request v lp 1timer gim st p ng t BSC.BSC kim tra bn tin phi cha 1 loi knh (knh lu lng l thoi hay d liu v tc d liu

). Bn tin ny cng cha classmarkMS m BTS dng n trong trng hp cha nhn cclassmark t MS.Bn tin assignment-request c th cha 1 danh sch codec, giving, tnh hp l ca cc mc utin, loi codec hay dng (vd, loi h tr knh thoi ton tc tng cng). Trong trng hpny,BSC s kim tra danh sch c cung cp bi cell v chn ra loi codec u c th dng choc BTS v MS.Nu BSC tm thy 1 li trong bn tin assignment-request, n s gi bn tin assignment-failure.Nu khng pht hin ra li no, n s bt u qu trnh n nh thng thng hng nMS.

Bc 14 : Kch hot knh lu lngBSC gi BTS bn tin physical-context-request ch ra cng sut v timing advance hin thi

ca MS trn knh SDCCH.

Bc 15: BTS p ng bng bn tin physical-context-confirm cha cc thng tin lin quan.Nu khng c sn knh no, hng i c cho php, cuc gi c xp vo hng i.

Bc 16 : BSC gi BTS bn tin channel-activation vi ni dung :M t knh lu lng c s dng.Timing advance MS c p dng.Thut ton mt m v kho mt m (ging nh n nh SDCCH)Ch s truyn gin on cho hng ln (khng sd) v hng xung.Cng sut MS s dng.Cng sut BTS s dng.BSC khi to 1 timer, v i BTS bo (ack) n kch hot knh.

Bc 17a,17b:BTS kch khi ngun ti nguyn knh lu lng, lp m mt, gi TA v thngtin cng sut cho MS trn knh SACCH knh kt hp vi knh TCH v c MS gim stthng xuyn. Cng lc, BTS gi BSC bn tin chanel-activation-acknowledge.
http://tudiencongnghe.com/Special:Search/BTShttp://tudiencongnghe.com/Special:Search/MShttp://tudiencongnghe.com/Special:Search/BSChttp://tudiencongnghe.com/Special:Search/BTShttp://tudiencongnghe.com/Special:Search/MShttp://tudiencongnghe.com/Special:Search/BSC


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Bc 18 : BSC s ngng khong timer ca n v gi MS bn tin assignment-command trnknh SD. Bn tin ny hng dn MS chuyn sang knh lu lng.

Bc 19 : Khi nhn bn tin assignment-command, MS s khng kt ni lp vt l v thc hingii phng kt ni LAPDm ca knh SD.

Sau MS thit lp kt ni LAPDm (qua SABMtrn knh FACCH) cho knh lu lng.

Bc 20,21 : BTS gi BSC bn tin establish-indication. ng thi cng lp chuyn m(transcoder) v thut ton pht hin li kt ni v tuyn ca n. BTS gi MS 1 bo nhn lp 2.

Bc 22: MS gi BSC bn tin assignment-complete.Khi nhn bn tin establish-indication, BSC thit lp ng chuyn mch ti nguyn gia giaodin Abis c n nh v trn giao din A. Khi nhn bn tin assignment-complete,BSC s giMSC bn tin assignment-complete v bt u gii phng knh SD.

Bc 23: Kt ni cuc gi :Khi vic kt ni vi thu bao b gi c thit lp (nhng trc khi thu bao b gi tr li), MSCs gi MS 1 bn tin alerting. MS s pht ra 1 ring tone (hi m chung).

Bc 25: Khi thu bao b gi tr li, MSC gi MS bn tin connect. MS p ng bng bn tinconnect-acknowledgement. Cuc gi c thit lp.

http://dtvtbk.com/forum/showthread.php?t=4428Ngun trch dn (0)--------------------------------------------------------------------------------------------------------------------

Nguyn vn bi nvqthinh

C ti liu th gi khc i mt t v 3 bc m bc khoalv ni trn:- nominal planning --> mc ch l tnh xem s cn bao nhiu BS, bao nhiuBSC/RNC..- detailed planning --> mt khi dimensionning xong, "kho st a hnh", s dngn cc cng c planning tool tnh ton cc v tr s t cc BS.- network operation and optimization--> Mt khi t BS ri th s tin hnh cc oc, kim tra s vn hnh, v s c cc iu chnh cn thit v cc thng s, v trBS, hng... ti u mng.

Nhn qua th thy cng ging vi 3 bc bc khoalv cp .

Nu bc khoalv c bit ch no c th ly c ci planning tool th chcho mnhvi. Tm mi m chng thy ci no free c.

Xin chnh lai mt t:1. nh c mng ( xc nh s lng cc tramh BTS, Cu hnh - theo s lng thubao cn phc v, S lng MSC, BSC...)2. Nomirnal Plan ( xc nh cc v tr cc trm BTS d kin quy hoch trn bn s
http://tudiencongnghe.com/Special:Search/SABMhttp://tudiencongnghe.com/Special:Search/SABMhttp://vntelecom.org/diendan/showthread.php?p=2499#post2499http://tudiencongnghe.com/Special:Search/SABM


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v bn giy)3. Site Survey ( Hay gi l Detail Plan cng c - Kim tra tnh kh thi v tr t trmtrong xc nh - To chun , Azimuth, tilt, Tower, Mt bng, Cc phng ntruyn dn)4. Thit k cc tham s( sau mi lp t tch hp v pht sng)

vic thit k s dng cc tool nhng m t khi thy cc tool free lm( Hin c Mcomfor Ericson , RNP Ca alcatel ...l ang dng crack thoai )

ring phn Ti u ni th c v tru tng nhng m thc ra cng vic ch yu l:Thu thp cc thng tin :1. Ly d liu v phn tch t h thng.2. Ly d liu t kt qu o Driving test ( trc y dng Antenna mi khi i onhng thc ra th khch hng h ngi trong xe u c cm antenna ra bn ngoi

nn o khng cho n ng thc t vi khch hng - tr khi o kim chnh xc hocbenmarking)3. Ly d liu phn nh t khch hng

Trong vic ly d liu v phn tch t h thng kh quan trng n i hi ta phinm vng l thuyt cng nh cc tham s trn h thng. Mt s cc tham s chtiucht lng mng chn nh sau:1) T l thit lp cuc gi thnh cng CSSRCall_Setup_Success_Rate2) T l rt cuc gi CDRCall_Drop_Rate

3) T l cuc gi thnh cng CSRCall_Success_Rate4) T l chuyn giao cuc gi thnh cng HOSRHand_Over_Success_Rate5) T l mc tn hiu thu t yu cuRXLEV6) T l cht lng tn hiu thu t yu cuRXQUAL = 0..4

Kt hp vi kt qu o kim t a ra cc tc ng thay i n h thng nhm

nng cao cht lng mng li.( bi sau em s ni r hn v cc tham s trn v c nguyn nhn)

CALL DROPBt k ch ri hay ch thoi th gia MS v h thng cng lun c s trao i


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thng tin hai chiu vi nhau. Mt phn thng tin lin quan n cng tn hiu,cht lng tn hiu v v tr tng i ca MS so vi trm BTS. Cc thng tin ny baogm c thng tin v ng xung ln ng ln, nhng c thng tin v ng xungv ng ln u c MS gi ln h thng gip h thng c c s tnh ton vquyt nh cch hnh x ca MS i vi cc cell.

C mt s nguyn nhn dn n vic mt cuc gi b rt, tn gi ca cc nguynnhn c chr phn trn. ng vi mi nguyn nhn rt, h thng c mt bm xc nh, cc b m ny c p dng n mc cell. Ngha l h thng sthng k trn mi cell c bao nhiu cuc gi b rt ng vi tng nguyn nhn trn.C s h thng phn chia c s ln rt do tng nguyn nhn l da vo thngtin m MS gi ln v cng tn hiu, cht lng tn hiu v v tr tng i ca nso vi trm BTS. Sau y l cc thng tin lin quan n cc nguyn nhn rt cp.1. Rt do vt nh thi TA:chun GSM a ra khi nim Timing Advance dng thi gian xc nh tng i

khong cch t MS n trm BTS da trn c s vn tc truyn sng l khng itrong cng mt mi trng. Ngha l MS o c thi gian tr ca sng di ngtruyn t BTS n MS th s xc nh c khong cch t n n BTS. Trong chunGSM, TA c gi tr t 0 n 63, xc nh mt khong cch ti a t MS n BTSl 35 km (vi iu kin sng truyn thng). Khi MS vt ra ngoi khong cch xcnh bi gi tr TALIM l gi tr cc i cho php ca TA c khai trn h thng mkhng kp chuyn giao sang cell khc th cuc gi s b rt v h thng s tng gi trca b m TFDISTA ln 1 n v. Nh vy rt do vt inh thi thc cht l do MSvt ra ngoi bn knh cho php ca trm v khng th chuyn giao c sang cellkhc. V sng di ng khng chtruyn thng m cn truyn theo phn x, nhiu xhay khc x nn khong cch t MS n BTS chl tng i. Nu nh mt cell c s

cuc rt do vt nh thi cao th trc ht phi kim tra xem tham s TALIM c khai gi tr ln nht hay cha (i khi TALIM c khai nh i hn ch rtdo cc nguyn nhn khc hoc hn ch vng phc v ca cell).

Rt do cng tn hiu thp (Low SS):Khi ang thc hin cuc gi th MS vn u n gi cc bn tin v cng tn hiu,cht lng tn hiu v khong cch t MS n BTS cho h thng. Nh cc bn tin nym h thng bit c rng kt ni ang c thc hn vi cng tn hiu ngln v ng xung l bao nhiu. Gi tr ca cng tn hiu ng ln v ng

xung ny s c so snh vi cc gi tr ngng xc nh c thit lp trn hthng cho mi ng.C rt nhiu nguyn nhn gy ra rt:c th do vng ph ca cell qu rng dn n MS pht khng mnh c th nc BTS mc d BTS c th pht mnh n MS (v tuy suy hao ng truyn haing ln xung l nh nhau nhng cng sut pht v nhy ca hai thit b lkhc nhau. khc phc hin tng ny chc cch gim vng ph ca trm (cp


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tilt hay h cao hoc gim cng sut hoc mt bin php hn chu tin cell phcv khu vc xa) nhng li cn c mt trm khc h tr cho vng ph ca cell bhn ch vng ph

Hoc c th trong qu trnh lp t xy ra hin tng Swap feeder t cell ny vo

cell kia, Hoc do cp tilt qu thp,...phn cng ri connector b suy hao lm suy gimcng sut..Cch khc phc kim tra ti tram, o kim,....

Rt do cht lng tn hiu ti (Bad Quality):Cng tng t nh trng hp rt do cng tn hiu thp, h thng cng cc kt ni ang c thc hin mc cht lng tn hiu l bao nhiu v cng ccc gi tr ngng cho cht lng tn hiu mi ng. V ng ln v ng

xung u s dng chung mt knh (mc d khong cch gia knh tn ng lnv knh tn ng xung l 20 MHz) nn thng thng, nu nhnh hng t cccell i vi nhau th s c nh hng c hai ng. Tuy nhin, c th do vng phca mt cell ln cn l qu rng nn s gy ra nhiu ng ln nhiu hn so ving xung i vi mt cell khc. Hin tng nhiu chr rt khi cc cell chng lnvng ph ca nhau c s dng tn s ging nhau hay ln cn nhau.

Rt t ngt (Suddenly drop):y c th l mt trong cc nguyn nhn trn, nhng v h thng khng kp nhn

c bn tin gi v t MS nn khng xc nh c chnh xc tham s no dingng (cng , cht lng hay khong cch). C th thi im trc MS vnhot ng vi iu kin tt (c cng ln cht lng v iu kin v TA) nhng vmt s thay i t ngt no m n khng kp gi bn tin v cho h thng, v bntin c gi mang tnh cht chu k. C th k ra mt s nguyn nhn gy rt tngt nh: MS i vo hm ngm, thang my, hay t ngt b mt ngun nhiu no tc ng, cng c th do my MS ht pin gia chng cuc hi thoi v.vRt do cc l do khc (Other reason):l nhng cuc gi b rt m khng thuc tt c cc l do trn. Cell no c s rtOther reason cao thng l nhng cell c truyn dn chp chn hay c li phn

cng.


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Cm n bn Namdq chia s nhng thng tin b chV nguyn nhn rt cuc gi ng nh bn Namdq ni trn. Trong thng k OMC c th cho ta bit c cc nguyn nhn dn n rt cuc gi thng qua vicphn tch cc Counter v Measurement Report. V bn cht th tt c cc nguynnhn dn n rt cuc gi c th phn loi nh trn. Mnh b xung mt cch phn

loi khc v cc nguyn nhn dn n rt cuc gi nh sau:- Rt do RxLev thp- Rt do TA vt qu gii hn cho php- Rt do HO khng thnh cng- Rt do nhiu- Rt do h thng anten, feeder (Mt cn bng gia downlink v uplink, chofeeder...)- Rt do mt truyn dn- Cc nguyn nhn khcRt cuc gi c th xy ra c trn TCH v SDCCH

B con khc tip tc ch ny nh

Cheer

Ln sa cui bi khoalv; 02/08/2008 lc 02:50

namdq

Nguyn vn bi khoalv

Nm nay, MIC s cp php cho 4 operator trin khai 3G da trn chun cngngh WCDMA, i vi cc operator ang s hu mng GSM th qu trnh s l

upgrade, nu l CDMA s l mt s trin khai hon ton mi. Tuy nhin ngay c ivi cc operator ang c mng GSM th vic nng cp thnh 3G khng chn ginl b xung thm cho phn radio access network (Node B, RNC) v core network(SGSN,GGSN) l thnh 3G. Trong qu trnh trin khai, operator vn phi m bophc v tt cc existing user, ng thi pht trin thm cc ng dng mi ca 3G.Vy khi , planning hin ti s c thay i nh th no ? v l 3G, mt lotcc features hon ton khc vi GSM hin c nh mode packet,RRA, cell load, QoSRequirement, coverage ca GSM v WCDMA rt khc nhau, nu l co-located th sra sao...ni chung cn rt nhiu vn .Rt mong mi ngi chia s quan im v kinh nghim v vn ny, chng hn

nh kinh nghim ca cc nc trin khai WCDMA, t l ph sng caWCDMA/GSM ra lm sao.... ?...Thanks a lot
http://vntelecom.org/diendan/showthread.php?p=2857#post2857

cac ky thuat trong optima zit ion trong 3g2

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