-106-

LI NI UTrong cuc sng hng ngy, thng tin lin lc ng vai tr rt quan trng v khng th thiu. N quyt nh nhiu mt hot ng x hi, gip con ngi nm bt nhanh chng cc thng tin c gi tr kinh t, vn ha, xa hi, khoa hc k thut mt cch rt a dng v phong ph.Ngy nay vi nhng nhu cu v v s lng v cht lng ca khch hng s dng dch v vin thng ngy cng cao, i hi phi c nhng phng tin thng tin hiu i nhm p ng cc nhu cu a dng ca khch hng. Thng tin di ng ngy nay tr thnh mt dch v kinh doanh khng th thiu c ca tt c c nh khai thc vin thng trn ton th gii. i vi cc khch hng ca vin thng c bit l cc doanh nghip th thng tin di ng tr thnh phng tin lin lc quen thuc v khng th thiu c. Trong nhng nm gn y, lnh vc thng tin di ng trong nc c nhng bc pht trin vt bc c v c s h tng v cht lng dch v. Vi vic thng tin di ng ngy nay tr thnh dch v bnh dn thu ht c rt nhiu khch hng ng k s dng.Nm 2009 l nm thng tin di dng th h 3 c chnh thc khai thc Vit Nam, cho n nay sau 5 nm khai thc sau nhiu phin bn nng cp v k thut cng nh tc nhu cu s dng cc dch v trn nn cng ngh 3G l rt ln. Vn t ra cho cc nh khai thc l m bo v nng cao cht lng dch v. Chnh v vy, cng tc ti u mng l cng tc rt cn thit v mang ngha rt ln trong vn m bo cht lng mngTrn c s nhng kin thc tch ly trong nhng nm hc tp chuyn ngnh K thut vin thng ti trng i hc Giao thng Vn Ti v sau qu trnh thc tp ti phng Thit k ti u thuc trung tm KVI tng cng ty Viettel Network cng vi s hng dn ca TS. Trn Hoi Trung em tm hiu, nghin cu v hon thnh n tt nghip vi ti Ti u ch s KPI mng v tuyn 3G WCDMA. H ni, ngy 2 thng 4 nm 2014Sinh vin thc hinTrn nh Phc

LI CM NEm xin gi li cm n chn thnh n thy gio TS. Trn Hoi Trung v cc thy c trong b mn K thut vin thng nhit tnh ging dy, quan tm gip em trong sut 4 nm hc tp ti trng, c bit l trong qu trnh thc tp v lm n tt nghip cui kha.Em xin cm n chn thnh n anh Phng Vn Nam Trng phng Thit k ti u, cng trng ban ti u 3G anh inh Vn Doanh v cc cn b phng Thit k ti u trung tm KVI thuc tng cng ty Viettel Network trc tip hng dn v gip em hon thnh n tt nghip ny.

MC LCLI NI U1LI CM N3MC LC4DANH MC CC K HIU, CC T VIT TT7DANH MC HNH V13CHNG I:TNG QUAN V MNG 3G WCDMA161.1.Tng quan v mng 3G WCDMA161.1.1.Gii thiu chung v WCDMA161.1.2.Cp pht ph tn trong mng 3G201.2.Kin trc mng221.2.1.Kin trc tng quan ca UMTS/WCDMA221.2.2.Kin trc mng truy nhp v tuyn UTRAN271.3.Cc knh v tuyn trong WCDMA301.3.1.Cc knh vt l301.3.1.1.Cc knh vt l ng ln301.3.1.2.Cc knh vt l ng xung321.3.2.Cc knh truyn ti371.3.2.1.Cc knh truyn ti dnh ring371.3.2.2.Cc knh truyn ti chung371.3.3.Cc knh Logic391.4.Trng thi cell401.5.Kt lun chng:42CHNG II:CC K THUT CHNH TRONG WCDMA432.1.Gii thiu chng432.2.Cc k thut chnh s dng trong mng 3G WCDMA432.2.1.K thut tri ph v gii tri ph432.2.2.K thut a truy nhp CDMA442.2.3.iu khin cng sut WCDMA462.2.3.1.iu khin cng sut vng h (OLPC)462.2.3.2.iu khin cng sut vng lp ng (CLPC)482.2.4.Chuyn giao v la chn li Cell trong WCDMA492.2.4.1.Chuyn giao492.2.4.2.Cc loi chuyn giao v la chn li Cell502.2.4.3.Cc th tc chuyn giao502.3.Tng kt chng52CHNG III:KPI MNG 3G WCDMA V PHNG PHP TI U533.1.Gii thiu chung533.2.Khi qut v KPI mng 3G533.2.1.nh ngha KPI533.2.2.Mc ch s dng KPI543.2.3.Khi no th s dng KPI553.2.4.Phn loi cc lp KPI553.2.5.Cc ngun d liu phc v tnh ton KPI573.2.5.1.Driving Test.573.2.5.2.D liu t counter phn t mng.603.2.6.KPI v cm nhn ca khch hng603.3.Cc vn c bn ca cng tc ti u mng v tuyn623.3.1.Mc ch, l do, li ch ca vic ti u.623.3.2.Th tc ti u mng v tuyn.633.4.Quy trnh ti u mng da trn ch s KPI653.4.1.Cng tc chun b653.4.2.Thu thp d liu phc v ti u663.4.3.Phn tch cht lng mng phc v ti u.673.4.4.Tin hnh thit k ti u713.4.5.Cng nhn thit k ti u.733.5.Kt lun chng.73CHNG IV:PHN TCH MT S KPI MNG 3G WCDMA744.1.Mt s KPI v nguyn nhn nh hng ti chng.744.1.1.T l rt cuc gi (CDR)744.1.1.1.T l rt cuc gi trn min CS754.1.1.2.T l rt trn min PS764.1.1.3.Hng dn thc hin ti u764.1.2.T l thit lp cuc gi thnh cng804.1.3.T l chuyn giao mm thnh cng (SHOSR)844.2.Mt s trng hp thng gp trong ti u mng 3G UMTS854.2.1.Khu vc c vng ph km854.2.1.1.Tiu chun854.2.1.2.Kho st vng ph ti khu vc thnh ph Tam K, Qung Nam854.2.1.3.Phn tch vng ph khu vc Tam K914.2.1.4.Kt qu sau ti u944.2.2.Khu vc c rt cuc gi (calldrop)974.2.2.1.Phn tch nguyn nhn974.2.2.2.Gii php994.2.2.3.Kt qu sau ti u994.3.Kt lun chng100KT LUN V HNG PHT TRIN TI101PH LC103TI LIU THAM KHO106

DANH MC CC K HIU, CC T VIT TT

ACCHAssociated Control ChannelsKnh iu khin lin kt.

AICHAcquisition Indicator channelKnh ch th bt

AMPSAdvanced Mobile Phone SystemH thng in thoi di ng tin tin.

ARQAutomatic Repeat RequestYu cu lp li t ng.

ASAccess StratumTng truy nhp.

BCCHBroadcast Control ChannelKnh qung b iu khin.

BCHBroadcast ChannelKnh qung b.

BERBit Error RatioT s bit li.

BSCBase Station ControlerB iu khin trm gc.

BSSBase Station SubsystemPhn h trm gc.

BTSBase Tranceiver StationTrm v tuyn thu pht gc.

BPSKBinary Phase Shift KeyingKha dch pha nh phn.

CCCHCommon Control ChannelKnh iu khin chung.

CDMACode Division Multiple Accessa truy cp chia theo m.

C/ICarrier to Interference ratioT s sng mang trn nhiu.

CCCHCommon Control ChanelKnh iu khin chung.

CCPCHCommon Control Physical ChanelKnh vt l iu khin chung.

CPCHCommon Packet Chanel.Knh gi chung.

CPICHCommon Pilot ChanelKnh hoa tiu chung

CRChip RateTc chip (tng ng vi tc tri ph ca knh).

CRNC Controlling RNCRNC iu khin

CSCircuit SwitchChuyn mch knh

DCADynamic Chanel AllocationPhn b knh ng.

DCCHDedicated Control ChannelKnh iu khin dnh ring.

DPCCHDedicated Physical Control ChanelKnh iu khin vt l ring.

DPCHDedicated Physical ChanelKnh vt l ring.

DPDCHDedicated Physical Data ChanelKnh s liu vt l ring.

DTCHDedicated Traffic ChanelKnh lu lng ring.

DTEData Terminal EquipmentThit b u cui s liu.

DSCHDownlink Shared ChanelKnh dng chung ng xung.

Ec/NoEnergy per chip over total received power spectral density

EDGEEnhanced Data rate for GSM Evolution.Tng tc truyn dn

ETSIEuropean Telecommunications Standards InstituteVin Tiu chun vin thng chu u.

FACCHFast Associated Control ChannelKnh iu khin lin kt nhanh.

FACHForward Access ChanelKnh truy nhp ng xung.

FAUSCHFast Uplink Signalling ChanelKnh bo hiu ng ln nhanh.

FCCCHForward Common Control ChanelKnh iu khin chung ng xung.

FCCHFrequency Correction ChannelKnh hiu chnh tn s.

FDDFrequency Division DuplexGhp knh song cng phn chia theo tn s.

FDMAFrequence Division Multiple Accessa truy cp phn chia theo tn s

FDCCHForward Dedicated Control ChanelKnh iu khin ring ng xung.

FSKFrequency Shift KeyingKho iu ch dch tn.

GoSGrade Of ServiceCp phc v.

GSMGlobal System for Mobile CommunicationThng tin di ng ton cu

GPSGlobal Position SystemH thng nh v ton cu

GPRSGeneral Packet Radio ServicesDch v v tuyn gi chung.

HSCSDHight Speed Circuit Switched DataH thng chuyn mch knh tc cao.

HS-PDSCHHigh Speech Physical Downlink Shared ChannelKnh chia s ng xung vt l tc cao

IMT-2000International Mobile TelecommunicationTiu chun thng tin di ng ton cu.

IMSIInternational Mobile Subscriber IdentityS nhn dng thu bao di ng quc t.

IPInternet ProtocolGiao thc Internet.

ISDNIntegrated Servive Digital NetworkMng s a dch v.

ITU-RInternational Mobile Telecommunication Union Radio SectorLin minh vin thng quc t - b phn v tuyn.

IWFInterWorking FunctionChc nng tng tc mng

KPIKey Performance Indicator

LACLink Access Controliu khin truy nhp lin kt.

LAILocation Area IndentifyNhn dng vng v tr.

MEMobile EquipmentThit b di ng.

MSMobile StationTrm di ng.

MTPMessage Transfer PartPhn truyn bn tin.

MSCMobile Service Switching CenterTng i di ng.

NASNon-Access StratumTng khng truy nhp.

Node BL nt logic kt cui giao din IuB vi RNC.

NSSNetwork and Switching SubsystemH thng chuyn mch

ODMAOpportunity Driven Multiplex Accessa truy cp theo c hi.

OMOperation and ManagementKhai thc v bo dng.

PAGCHPaging and AccessKnh chp nhn truy cp v nhn tin.

PCCHPaging Contrlo ChanelKnh iu khin tm gi.

PCHPaging ChannelKnh nhn tin.

PCPCHPhysical Common Packet ChanelKnh gi chung vt l.

PCSPersonal Communication ServicesDch v thng tin c nhn.

PICHPaging Indicator ChannelKnh ch th tm gi

PLMNPublic Land Mobile NetworkMng di ng mt t cng cng.

PSTNPublic Switched Telephone NetworkMng chuyn mch thoi cng cng.

PRACHPhysical Random Access ChannelKnh truy nhp ngu nhin vt l

PS Packet switchedChuyn mch gi

RACHRandom Access ChannelKnh truy cp ngu nhin.

RNC Radio network controllerB iu khin mng v tuyn

RNS Radio network subsystem

RSCPReceive signal code powerCng sut m tn hiu thu

RRCRadio Resource Controliu khin ti nguyn v tuyn.

S-CCPCHSecondary Common Control Physical ChannelKnh vt l iu khin chung th cp

SCHSynchronous ChannelKnh ng b

SRNC Serving RNCRNC phc v

SRNSServing RNS

TDMATime Division Multiple Accessa truy cp phn chia theo thi gian

TDDTime Division DuplexGhp song cng phn chia thi gian.

UE User equipmentThit b ngi s dng

USIM UMTS subscriber identity moduleModule nhn dng thu bao UMTS

UTRANUniversal Terrestrial Radio Access NetworkMng truy nhp v tuyn mt t ton cu.

UMTSUniversal Mobile Telecommunnication System

WCDMAWideband Code Division Multiplex Accessa truy cp phn chia theo m bng rng.

DANH MC HNH VHnh 1.1. Cc tn hiu a ng17Hnh 1.2. Cc tn hiu nhiu giao thoa18Hnh 1.3. Di tn UMTS-WCDMA22Hnh 1.4. Kin trc h thng UMTS mc cao23Hnh 1.5. Kin trc mng UMTS24Hnh 1.6. Kin trc UTRAN27Hnh 1.7. Cu trc khung knh vt l ring DPDCH/DPCCH31Hnh 1.8. Cu trc khung cho knh hoa tiu chung32Hnh 1.9. Dng iu ch cho knh hoa tiu chung33Hnh 1.10. Cu trc khung ca Knh vt l iu khin chung s cp34Hnh 1.12. Cu trc khung cho PDSCH36Hnh 1.13. Cc ch ca UE v cc trng thi iu khin ti nguyn v tuyn41

Hnh 2.1. Qu trnh tri ph v gii tri ph44Hnh 2.2. Cc cng ngh a truy nhp44Hnh 2.3. Nguyn l a truy nhp tri ph45Hnh 2.4. Th t cc loi iu khin cng sut46Hnh 2.5. Cc c ch iu khin cng sut trong W-CDMA48Hnh 2.6. Th tc iu khin cng sut vng trong v vng ngoi49Hnh 2.7. Cc loi chuyn giao trong W-CDMA51

Hnh 3.1. Phn loi cc lp KPI56Hnh 3.2. Giao din s dng ca TEMS Investigation59Hnh 3.3. V tr t cc counter60Hnh 3.4. Quy trnh qun l cht lng mng61Hnh 3.5. Th tc ti u mng64Hnh 3.6. Cc tham s iu chnh72

Hnh 4.1. V tr thc t Node B ti thnh ph Tam K86Hnh 4.2. Cng trng RSCP ca thnh ph Tam K87Hnh 4.3. Legend ca RSCP CPICH88Hnh 4.4. Cht lng tn hiu Ec/No ca thnh ph Tam K88Hnh 4.5. Legend ca Ec/No CPICH89Hnh 4.6. Khu vc c vng ph km91Hnh 4.7. WCDMA Pilot92Hnh 4.8. Weak coverage do pilot pollution93Hnh 4.9. Phn b RSCP sau khi thi hnh ti u94Hnh 4.10. Phn b Ec/No sau khi ti u95Hnh 4.11. Khu vc sau ti u96Hnh 4.12. Khu vc c rt cuc gi98Hnh 4.13. Tn hiu v kh nng chuyn giao thnh cng98Hnh 4.14. Calldrop c gii quyt99

DANH MC BNG BIUBng 1.1. Bng tn c trin khai vo thng 11/200720Bng 1.2. Cc c im ch yu ca cc knh truyn ti chung38

Bng 4.1. Tiu chun vng ph tt85Bng 4.2. Thng k mu RSCP CPICH trc ti u88Bng 4.3. Thng k mu Ec/No CPICH trc ti u89Bng 4.4. Kt qu o lng CSSR, CDR, SHOSR trc ti u90Bng 4.5. Chnh tilt v azimuth93Bng 4.6. Thng k mu RSCP CPICH sau ti u94Bng 4.7. Thng k mu Ec/No CPICH sau ti u95Bng 4.8. RSCP CPICH trc v sau ti u96Bng 4.9. Ec/No CPICH trc v sau ti u96Bng 4.10. CSR, CDR, HOSR trc v sau ti u97Bng 4.11. Thng k cc KPI sau khi ti u99

TNG QUAN V MNG 3G WCDMA1.1. Tng quan v mng 3G WCDMA1.1.1. Gii thiu chung v WCDMAWCDMA (Wideband Code Division Multiple Access: a truy cp phn chia theo m bng rng) l mt trong nhng cng ngh a truy nhp c la chn xy dng ln phn truy nhp v tuyn ca h thng thng tin di ng th h th 3. Cc c im chnh ca WCDMA: WCDMA l mt h thng a truy nhp phn chia theo m tri ph chui trc tip (DS-CDMA) ngha l cc bit thng tin ngi dng c tri ph ti mt tn s rt rng bng cch nhn cc bit d liu ny vi mt chui cc bit gi ngu nhiu cn c gi l cc chip. Tc chip c s dng c nh l 3,84Mcps dn ti rng bng ti thiu cho mt knh trong WCDMA l 5MHz. WCDMA cho php thay i tc d liu ca user theo ngha Bng thng theo yu cu. Tc ny thay i theo mc khung 10ms. WCDMA h tr 2 c ch hot ng: FDD v TDD. Vi FDD cn ti thiu 2 sng mang, mi sng mang 5MHz, mt cho ng ln v mt cho ng xung. Nh vy vi FDD, mt mng ch c th trin khai ti thiu 10MHx bng tn c cp pht. Trong c ch TDD do phn chia theo thi gian nn ng ln v ng xung c th s dng chung mt sng mang c rng bng tn 5MHz. C ch ny ph hp vi cc quc gia di tn quanh 2GHz c cp cho nhiu cc h thng khc. WCDMA cho php cc trm gc BS hot ng ch khng ng b, ngha l khng cn ly tn hiu ng h t GPS ging nh cc h thng CDMA khc nh IS-95. c im ny thch hp cho cc indoor v micro BS ni kh c th thu c tn hiu GPS. WCDMA s dng cng ngh pht hin phi logic d liu trn c ng ln v ng xung trn c s knh hoa tiu chung. Cng ngh ny c s dng trong IS-95 trn ng xung, vi WCDMA cng ngh ny c p dng c ng ln gip tng cng vng ph v dung lng knh trn ng ln.nh hng ca nhiu ln h thng WCDMATrong knh thng tin v tuyn l tng, tn hiu thu c ch bao gm mt tn hiu n trc tip. Song, trong thc t iu l khng th xy ra, tn hiu s b thay i trong sut qu trnh truyn, tn hiu thu c s l s kt hp cc thnh phn khc nhau: tn hiu suy gim, khc x, nhiu x ca cc tn hiu khcWCDMA l h thng di ng v tuyn nn s b nh hng bi iu . Sau y l m hnh ca hai loi nhiu chnh, l nhiu fadinh nhiu tia v nhiu giao thoa.

Hnh 1.1. Cc tn hiu a ng

Hnh 1.2. Cc tn hiu nhiu giao thoa lm gim cc nh hng ca cc loi nhiu trn, trong WCDMA c nhiu k thut x l l: m ho knh, iu ch, tri ph, phn tpTnh a dng phn tp trong WCDMATrong h thng iu ch bng hp nh iu ch FM tng t ,s dng trong h thng thng tin di ng t ong u tin th tnh a ng to nn fading nghim trng. Tnh nghim trng ca a ng fading c gim i trong iu ch CDMA bng rng, v cc tn hiu qua cc ng khc nhau c thu nhn mt cch c lp. Nhng hin tng a ng xy ra mt cch lin tc trong h thng ny do fading a ng khng th loi tr hon ton c v vi cc hin tng fading xy ra mt cch lin tc th b iu ch khng th x l tn hiu thu mt cch c lp c. Phn tp l mt hnh thc tt lm gim fading, c 3 loi phn tp l theo tn s, theo thi gian v theo khong cch. Phn tp theo thi gian t c nh s dng vic chn v m sa sai. Phn tp theo thi gian c th c p dng cho tt c cc h thng c tc m truyn dn cao m th tc sa sai yu cu. H thng CDMA bng rng ng dng vic phn tp theo tn s nh vic m rng kh nng bo hiu trong mt bng tn rng v fading lin hp vi tn s thng c nh hng n bng tn bo hiu(200-300kHz). Nhng vi mt bng tn rng th fading t nh hng n tn hiu hn. Phn tp theo khong cch hay ng truyn thng t c theo 3 phng php sau: Thit lp nhiu ng bo hiu (chuyn vng mm) kt ni my di ng vi 2 hoc nhiu trm gc BTS. S dng mi trng a ng qua chc nng tri ph ging nh b thu qut thu nhn v t hp cc tn hiu pht vi cc tn hiu pht khc tr thi gian. t nhiu anten ti BS (anten mng).Phn tp theo khong cch c th d dng c p dng i vi h thng TDMA v FDMA. Phn tp theo thi gian c th c p dng cho tt c cc h thng s c tc m truyn dn cao m th tc sa sai yu cu. Phn tp theo tn s c th d dng c p dng cho h thng CDMA. B iu khin a ng tch dng sng nh s dng b tng quan song song. My di ng s dng 3 b tng quan, BTS s dng 4 b tng quan. My thu c b tng quan song song gi l my thu qut (Rake), n xc nh tn hiu thu theo mi ng v t hp, gii iu ch tt c cc tn hiu thu c. Fading c th xut hin cc ng tn hiu thu nhng khng c s tng quan gia cc ng tn hiu thu.V vy tng cc tnh hiu thu c c tin cy cao v rt t c fading ng thi gia cc ng tn hiu thu c. Nhiu b tch tng quan c th p dng mt cch ng thi cho h thng thng tin c 2 BTS sao cho c th thc hin chuyn vng mm cho thu bao di ng. Cc k thut phn tp: Phn tp thi gian: y l phng php phn tp c bn nht, dng nhng khe thi gian ti nhng thi im khc nhau truyn cng mt tn hiu ban u, nh vy ti u thu ta c th nhn c nhiu bn sao ca mt tn hiu ti nhiu thi im. Hoc cng mt tn hiu thu, c th c thu theo nhiu khong thi gian tr khc nhau chn ra c tn hiu thu tt nht. Phn tp tn s: Nguyn l c bn ca bt k loi sng no (c sng c v sng in t ) th ch giao thoa vi nhau khi c cng tn s hay vng tn s ln cn. Phn tp tn s da vo c tnh ny, dng nhiu tn s khc nhau truyn cng mt tn hiu, nh vy ti u thu s thu c cng mt tn hiu ti nhiu tn s khc nhau. Phn tp khng gian ( hay phn tp anten ): Trong kiu phn tp ny chng ta dng nhiu anten t ti nhiu v tr khc nhau, c phn cc khc nhau truyn hay thu cng mt tn hiu. Phng php ny s khng lm mt rng bng thng ca h thng.1.1.2. Cp pht ph tn trong mng 3GBng 1.1. Bng tn c trin khai vo thng 11/2007Tn bngS bngKchthcDi ng lnDi ngxungPhncch

Cc vng khc (trong c Vit Nam)

UMTS-2100I2x601920-19802110-2170190 Mhz

UMTS-2600VII2x702500-25702620-2690120 Mhz

Chu u/GSM

UMTS-1800III2x751710-17851805-188095 Mhz

UMTS-900VIII2x35880-915925-96045 Mhz

Hoa K

UMTS-1900II2x601850-19101930-199080 Mhz

UMTS-1700-2100IV2x451710-17552110-2155400 Mhz

UMTS-850V2x25824-849869-89445 Mhz

Nht Bn

UMTS-800VI2x10830-840875-88545 Mhz

UMTS-1700IX2X351749.9-1784.91844.9-1879.995 Mhz

S rt tt nu c mt s cp pht tn s ton cu cho tt c cc h thng 3G. Tuy nhin, s cp pht ph tn do cc c quan qun l ring r v vy khng c ph tn 3G chung cho ton cu. Cc bng tn s khc nhau c gn cho UMTS ti cc vng v cho cc nc khc nhau. Cc h thng UMTS FDD hin nay c d kin vn hnh trn cc bng tn nu trong bng 1.1, mc d ch c mt vi bng tn l hin c trin khai. UMTS-900 c d nh trin khai ti Chu u vo nm 2008. Ti Vit Nam, cng ngh 3G UMTS s dng bng tn s theo chun IMT- 2000 trong bng tn s 1900-2200 Mhz. C th n c bng tn c cp ca Viettel l UL: 1935 1950MHz v DL: 2125 - 2140MHz. Di tn UMTS-WCDMAHnh 1.3 minh ho di tn s ca h thng UMTS.

Hnh 1.3. Di tn UMTS-WCDMAKhong cch knh: Khong cch knh danh nh l 5 Mhz, nhng c th c iu chnh ti u cht lng trong mi hon cnh trin khai ring.Mnh knh: d Khz, c ngha l tn s trung tm phi l mt s nguyn ln ca 200 Khz.S knh: Tn s sng mang c ch inh bi s knh tn s v tuyn tuyt i (UARFCN). Fcenter= URAFCN200 Khz.Phn cch ng ln vi ng xung: phn cch tn s ng ln v ng xung tu theo cc bng tn nh c ch ra trong hnh 1.1.1.2. Kin trc mngKin trc tng quan ca UMTS/WCDMA H thng UMTS bao gm mt s cc phn t mng logic, mi phn t c mt c mt chc nng xc nh. Theo tiu chun, cc phn t mng c nh ngha ti mc logic, nhng c th li lin quan n vic thc thi mc vt l. c bit l khi c mt s cc giao din m. Cc phn t mng c th c nhm li nu c cc chc nng ging nhau, hay da vo cc mng con cha chng. Theo chc nng th cc phn t mng c nhm thnh cc nhm: Mng truy nhp v tuyn RAN (Mng truy nhp v tuyn mt t UMTS l UTRAN). Mng ny thit lp tt c cc chc nng lin quan n v tuyn. Mng li (CN): Thc hin chc nng chuyn mch v nh tuyn cuc gi v kt ni d liu n cc mng ngoi. Thit b ngi s dng (UE) giao tip vi ngi s dng v giao din v tuyn. Kin trc h thng mc cao c ch ra trong hnh 1-4

Hnh 1.4. Kin trc h thng UMTS mc cao H thng UMTS c th chia thnh cc mng con c th hot ng c lp hoc hot ng lin kt cc mng con khc v n phn bit vi nhau bi s nhn dng duy nht. Mng con nh vy gi l mng di ng mt t UMTS (PLMN), cc thnh phn ca PLMN c ch ra trong hnh 1-5.

Hnh 1.5. Kin trc mng UMTS Thit b ngi s dng (UE) bao gm 2 phn: Thit b di ng (ME) l u cui v tuyn s dng giao tip v tuyn qua giao din Uu. Modul nhn dng thu bao UMTS (USIM) l mt th thng minh m nhn vic xc nhn thu bao, thc hin thut ton nhn thc, v lu gi kho m mt, kho nhn thc v mt s cc thng tin v thu bao cn thit ti u cui. UTRAN cng bao gm 2 phn t: Nt B: chuyn i d liu truyn gia giao din Iub v Uu. N cng tham gia vo qun l ti nguyn v tuyn. B iu khin mng v tuyn (RNC) s hu v iu khin ngun ti nguyn v tuyn trong vng ca n (gm cc Nt B ni vi n). RNC l im truy cp dch v cho tt c cc dch v m UTRAN cung cp cho mng li. Cc phn t chnh ca mng li: HLR (B ng k thng tr) l mt c s d liu trong h thng thng tr ca ngi s dng, lu tr cc bn gc cc thng tin hin trng dch v ngi s dng, hin trng v dch v bao gm: thng tin v dch v c php s dng, cc vng roaming b cm, thng tin cc dch v b sung nh: trng thi cc cuc gi i, s cc cuc gi i N c to ra khi ngi s dng mi ng k thu bao vi h thng, v c lu khi thu bao cn thi hn. Vi mc ch nh tuyn cc giao dch ti UE (cc cuc gi v cc dch v nhn tin ngn), HLR cn lu tr cc thng tin v tr ca UE trong phm vi MSC/VLR hoc SGSN. MSC/VLR (Trung tm chuyn mch dch v di ng/B ng k tm tr) l mt b chuyn mch(MSC) v c s d liu(VLR) phc v cho UE v tr tm thi ca n cho cc dch v chuyn mch knh. Chc nng MSC c s dng chuyn mch cc giao dch s dng chuyn mch knh, chc nng VLR l lu tr bn sao v hin trng dch v ngi s dng l khch v thng tin chnh xc v v tr ca thu bao khch trong ton h thng. Phn ca h thng c truy nhp thng qua MSC/VLR thng l chuyn mch knh. GMSC (MSC cng): l mt b chuyn mch ti v tr m mng di ng mt t cng cng UMTS kt ni vi mng ngoi. Tt cc kt ni chuyn mch knh n v i u phi qua GMSC. SGSN (Nt h tr GPRS phc v) c chc nng tng t nh MSC/VLR nhng thng c s dng cho cc dch v chuyn mch gi. GGSN (Node cng h tr GPRS) c chc nng gn ging GMSC nhng phc v cc dch v chuyn mch gi. Mng ngoi c th chia thnh 2 nhm: Cc mng chuyn mch knh: Cc mng ny cung cp cc kt ni chuyn mch knh, ging nh dch v in thoi ang tn ti V d nh ISDN v PSTN. Cc mng chuyn mch gi: Cc mng ny cung cp cc kt ni cho cc dch v d liu gi, chng hn nh mng Internet. Cc giao din m c bn ca UMTS: Giao din Cu: y l giao din gia th thng minh USIM v ME. Giao din ny tun theo tiu chun cho cc th thng minh. Giao din Uu: y l giao din v tuyn WCDMA. Uu l giao din nh UE truy cp c vi phn c nh ca h thng, v v th c th l phn giao din m quan trng nht trong UMTS. Giao din Iu: Giao din ny kt ni UTRAN ti mng li, giao din ny em li cho cc b iu khin UMTS kh nng xy dng c UTRAN v CN t cc nh sn xut khc nhau. Giao din Iur: Giao din m Iur h tr chuyn giao mm gia cc RNC t cc nh sn xut khc nhau, v v th b sung cho giao din m Iu. Giao din Iub: Iub kt ni mt Nt B v mt RNC. UMTS l mt h thng in thoi di ng mang tnh thng mi u tin m giao din gia b iu khin v trm gc c chun ho nh l mt giao din m hon thin. Kin trc mng truy nhp v tuyn UTRAN Kin trc UTRAN c m t nh hnh 1-6.

Hnh 1.6. Kin trc UTRANUTRAN bao gm mt hay nhiu phn h mng v tuyn (RNS). Mt RNS l mt mng con trong UTRAN v bao gm mt B iu khin mng v tuyn (RNC) v mt hay nhiu Nt B. Cc RNC c th c kt ni vi nhau thng qua mt giao din Iur. Cc RNC v Nt B c kt ni vi nhau qua giao din Iub. Cc yu cu chnh thit k kin trc, giao thc v chc nng UTRAN: Tnh h tr ca UTRAN v cc chc nng lin quan: Yu cu tc ng ti thit k ca UTRAN l cc yu cu h tr chuyn giao mm (mt thit b u cui kt ni ti mng thng qua 2 hay nhiu cell ang hot ng) v cc thut ton qun l ngun ti nguyn v tuyn c bit ca WCDMA. Lm tng s tng ng trong vic iu khin d liu chuyn mch gi v chuyn mch knh, vi mt ngn xp giao thc giao din v tuyn duy nht v vi vic s dng cng mt giao din cho cc kt ni t UTRA n min chuyn mch gi v chuyn mch knh ca mng li. Lm tng tnh tng ng vi GSM. S dng phng thc vn chuyn ATM nh l c cu chuyn vn chnh trong UTRA. S dng kiu chuyn vn trn c s IP nh l c cu chuyn vn thay th trong UTRAN k t Release 5 tr i.a. RNCB iu khin mng v tuyn (RNC) l phn t mng chu trch nhim iu khin ngun ti nguyn v tuyn ca UTRAN. N giao tip vi mng li (thng l vi mt MSC v mt SGSN) v cng l phn t cui cng ca giao thc iu khin ngun ti nguyn v tuyn m xc nh cc thng ip v th tc gia my di ng v UTRAN. V mt logic, n tng ng vi BSC trong GSM. RNC iu khin mt Nt B c coi nh l b RNC iu khin (CRNC) ca Nt. B iu khin CRNC chu trch nhim iu khin ti v iu khin nghn cho cell ca n, v iu khin thu nhn v phn b m cho lin kt v tuyn c thit lp trong cc cell. Trong trng hp mt kt ni UTRAN, my di ng s dng ngun ti nguyn t nhiu phn h mng v tuyn RNS, th cc RNS bao gm 2 chc nng logic ring bit (v phng din kt ni my di ng - UTRAN ny).RNC phc v (SRNC): RNC cho mi my di ng l mt RNC m xc nh bin gii c lin kt Iu cho s vn chuyn d liu ngi s dng v bo hiu RANAP tng thch qua mng li (kt ni ny c gi l kt ni RANAP). SRNC cng xc nh bin gii ca Bo hiu iu khin ngun ti nguyn v tuyn, n l giao thc bo hiu gia UE v UTRAN. N thc hin x l lp 2 cho cc d liu chuyn qua giao din v tuyn. Hot ng Qun l ngun ti nguyn v tuyn c bn, nh l nh x cc thng s mang thng tin truy nhp v tuyn thnh cc thng s knh chuyn vn giao din v tuyn, quyt nh chuyn giao, v iu khin cng sut vng bn ngoi. Cc hot ng ny c thc thi trong SNRC. SRNC cng c th l CRNC ca mt s Nt B s dng bi my di ng cho kt ni vi UTRAN. Mt UE kt ni vi UTRAN th ch c duy nht mt SRNC.DRNC: DRNC c th l bt c RNC no ngoi SRNC, n iu khin cc cell s dng bi my di ng. Nu cn thit, DRNC c th thc hin kt hp hay chia nh phn tp macro. DRNC khng thc hin x l d liu ngi s dng lp 2, nhng nh tuyn mt cch trong sut d liu gia giao din Iub v Iur, ngoi tr khi UE ang s dng mt knh chuyn vn dng chung. Mt UE c th khng c, c mt hoc c nhiu DRNC. Chc nng ca RNC iu khin ti nguyn v tuyn Cp pht knh Thit lp iu khin cng sut iu khin chuyn giao Phn tp Macro Mt m ha Bo hiu qung b iu khin cng sut vng h Lin kt vi cc RNC ln cn qua giao din Iur

b. Nt B (Trm gc)Chc nng chnh ca Nt B l thc hin x l lp 1 giao din v tuyn (ghp xen v m ho knh, thch ng tc , tri ph ...). N cng thc hin mt s hot ng qun l ti nguyn v tuyn nh l iu khin cng sut vng bn trong. 1.3. Cc knh v tuyn trong WCDMACc knh vt l Cc knh vt l c xc nh bi cc tn s sng mang c th, m ngu nhin, m nh knh, thi gian bt u v dng, trn ng ln, pha tng i (0 hoc /2). Cc khong thi gian c xc nh bi cc khong u v cui, c o trong cc chip gi tr nguyn. Khung v tuyn l khong thi gian x l gm 15 khe. di ca 1 khung v tuyn tng ng vi 38400 chip. Khe l khong thi gian bao gm cc trng cha bit. di ca 1 khe tng ng vi 2560 chip. Khong thi gian mc nh cho 1 knh vt l l lin lc t khong bt u ti khong kt thc. 1.3.1.1. Cc knh vt l ng ln Cc knh vt l ng ln dnh ringC 2 loi knh vt l dnh ring ng ln, knh d liu vt l ring ng ln (uplink DPDCH) v knh iu khin vt l dnh ring (uplink DPCCH). DPDCH ng ln c s dng mang knh truyn ti DCH. C th c 1 hoc vi knh ng ln DPDCH trn mi lin kt v tuyn. Knh DPDCH ng ln c s dng mang thng tin iu khin ly t lp 1. Thng tin iu khin lp 1 bao gm cc bit hoa tiu bit h tr c tnh knh cho tch sng nht qun, cc lnh iu khin cng sut pht (TPC), cc thng tin phn hi (FBI) v ch th ghp nh dng truyn dn (TFCI). Ch th ghp nh dng truyn dn ny thng bo cho b thu v ch th nh dng truyn dn tc thi ca cc knh truyn ti c ghp ti khung v tuyn DPDCH ng ln c pht tc thi. Ch c 1 v ch 1 knh ng ln DPCCH trn mi lin kt v tuyn.Hnh 1.7 ch ra cu trc khung ca cc knh vt l dnh ring ng ln. Mi khung v tuyn c chiu di 10ms c chia thnh 15 khe, mi khe c chiu di Tslot = 2560 chip, tng ng vi 1 chu k iu khin cng sut.

Hnh 1.7. Cu trc khung knh vt l ring DPDCH/DPCCHC hai kiu knh vt l dnh ring ng ln, v th mt knh c cha trng TFCI v mt knh khng cha TFCI, ch nn, cc khe DPCCH c nh dng vi cc trng TFCI b thay i. Cc knh chung vt l ng lnKnh vt l chung ng ln c chia lm 2 loi: Knh truy nhp ngu nhin vt l PRACH: mang thng tin ca knh giao vn RACH. Knh gi chung vt l PCPCH: mang thng tin ca knh giao vn CPCH.1.3.1.2. Cc knh vt l ng xungCc knh vt l ng xung bao gm: 1 knh vt l dnh ring, 1 knh phn chia v 5 knh iu khin chung l. Cc knh vt l ng xung ringCh c knh vt l dnh ring ng xung (DPCH ng xung) pht s liu dnh ring c to ra t lp 2 v lp cao hn trong b ghp trung gian vi thng tin iu khin to ra ti lp 1. Cc knh vt l ng xung chungKnh hoa tiu chung (CPICH)CPICH l knh vt l ng xung c tc c nh (30kbps, SF = 256) mang chui bit c nh ngha trc. Hnh 1.8 ch ra cu trc khung ca CPICH.

Hnh 1.8. Cu trc khung cho knh hoa tiu chung Trong trng hp phn tp pht (vng h hoc ng) c s dng trn bt k knh ng xung no trong cell, CPICH s c truyn t c 2 antenna s dng m nh knh v m ngu nhin. Trong trng hp ny, cc chui bit c nh trc ca CPICH l khc nhau i vi Antenna 1 v Antenna 2, xem hnh 1.9. Trong trng hp khng c phn tp pht, chui bit ca Antenna 1 trong hnh 1.9 c s dng.

Hnh 1.9. Dng iu ch cho knh hoa tiu chung C 2 loi knh hoa tiu chung, CPICH s cp v th cp. Chng khc nhau trong vic s dng v nhng hn ch t ln cc c im vt l ca chng. Knh hoa tiu chung s cp (P-CPICH)Knh hoa tiu chung s cp (P-CPICH) c cc c im sau:-M nh knh ging nhau lung c s dng cho P-CPICH-P-CPICH c ngu nhin ha bng m ngu nhin ha s cp.-Ch c 1 v ch mt knh P-CPICH mi cell-Knh P-CPICH c qung b trong ton cell.Knh CPICH s cp l tham chiu pha cho cc knh ng xung sau: SCH, CCPCH s cp, AICH, PICH, AP-AICH, CD/CA-ICH, CSICH, DL-DPCCH cho CPCH v CCPCH th cp. Theo mc nh, CPICH s cp cng l 1 tham chiu pha cho DPCH ng xung v bt k knh PDSCH lin kt no. UE c thng bo bi bo hiu lp cao hn nu P-CPICH khng l 1 tham chiu pha cho ng xung DPCH v bt k knh PDSCH lin kt no.CPICH s cp lun lun l tham chiu pha cho knh vt l ng xung s dng phn tp pht vng kn. Knh hoa tiu chung th cp (S-CPICH)Knh hoa tiu chung s cp (S-CPICH) c cc c im sau:- M nh knh bt k c h s tri ph l 256 c s dng cho S-CPICH.- S-CPICH c ngu nhin ha bi c m ngu nhin s cp v th cp.- C th khng c, c 1 hoc 1 vi S-CPICH mi cell.- S-CPICH c th c truyn trong ton b cell hoc ch 1 phn ca cell. CPICH th cp c th l tham chiu pha cho knh DPCH ng xung. Nu iu ny ng, UE c thng bo v iu ny bng cc bo hiu lp cao. CPICH th cp c th l tham chiu pha cho knh vt l ng xung s dng phn tp pht vng h, thay v knh CPICH s cp l tham chiu pha. Knh vt l iu khin chung s cp (P-CCPCH)CCPCH s cp l knh vt l ng xung tc c nh (30 kbps, SF = 256) c s dng mang knh truyn ti BCH.

Hnh 1.10. Cu trc khung ca Knh vt l iu khin chung s cpHnh 1.10 ch ra cu trc khung ca knh CCPCH s cp. Cu trc khung khc vi knh ng xung DPCH m trong khng c m TPC, khng c bit TFCI v hoa tiu c truyn i. Knh CCPCH s cp khng c truyn trong sut 256 chip u tin ca mi khe. Thay vo , SCH s cp v th cp c truyn trong sut khong thi gian ny. Knh ng b (SCH)Knh ng b (SCH) l tn hiu ng xung c s dng cho tm kim cell. SCH bao gm 2 knh ph, s cp v th cp. Cc khung v tuyn 10ms s cp v th cp c chia thnh 15 khe, mi khe c di l 2560 chip. Hnh 1.11 minh ha cu trc ca khung v tuyn SCH.Hnh 1.11. Cu trc knh ng b (SCH) Knh s cp SCH bao gm 1 m c iu ch c di l 256 chip, m ng b s cp (PSC) c th hin bng cp trong hnh 1.12, c truyn 1 ln trong mi khe. PSC l ging nhau trong mi cell trong h thng.Cc m nh knh s cp v th cp c iu ch bi k t a trong hnh 1.11, m ch ra s c mt hay thiu ca m ha STTD trn knh P-CCPCH v c a ra bi bng sau:P-CCPCH STTD encodeda = +1

P-CCPCH not STTD encodeda = -1

Knh chia s ng xung vt l (PDSCH)1 knh PDSCH tng ng vi 1 m nh knh di hoc ti m nh knh gc PDSCH. 1 knh PDSCH c cp pht trn khung v tuyn ti 1 UE. Trong 1 khung v tuyn, UTRAN c th cp pht nhng PDSCH khc nhau di m nh knh gc PDSCH ging nhau ti cc UE khc nhau da trn ghp m. Trong cng 1 khung v tuyn, cc knh PDSCH song song, vi cng 1 m tri ph, c th c cp pht ti 1 UE. y l trng hp c bit ca truyn dn a m. Tt c PDSCH hot ng vi ng b khung v tuyn. PDSCH c cp pht ti cng UE trn cc khung v tuyn khc nhau c th c nhiu h s tri ph khc nhau.

Hnh 1.12. Cu trc khung cho PDSCH i vi mi khung v tuyn, mi PDSCH c lin kt vi 1 knh DPCH ng xung. PDSCH v PDCH lin kt khng cn thit phi c cng h s tri ph khc nhau v khng cn thit phi cn chnh khung.Tt c thng tin iu khin lp 1 c lin quan c truyn trn 1 phn DPCCH ca knh lin kt DPCH, v d nh PDSCH khng mang thng tin lp 1. ch ra cho UE rng d liu gii m trn DSCH, trng TFCI ca knh DPCH lin kt s c s dng. TFCI thng bo cho UE v cc thng s nh dng truyn dn tc thi lin quan ti PDSCH cng nh l m nh knh ca PDSCH. Knh ch th bt (AICH)Knh ch th bt (AICH) l knh vt l tc c nh (SF=256) c s dng mang cc ch th tm gi (AI). Cc ch th tm gi AI tng ng vi k hiu s trn PRACH.Cc knh truyn tiCc knh truyn ti c nhim v truyn thng tin gia phn lp MAC v lp vt l. Cc knh truyn ti c phn loi chung hoc thnh hai nhm: Cc knh ring v cc knh chung.1.3.1.3. Cc knh truyn ti dnh ringCc knh truyn ti dnh ring (DCH) l mt knh thc hin vic truyn thng tin iu khin v thng tin thu bao gia UTRAN v UE. DCH c truyn trn ton b hoc ch truyn trn mt phn ang s dng. Thng thng ch c mt knh truyn dnh ring s dng cho ng ln hoc ng xung ch TDD hoc FDD.1.3.1.4. Cc knh truyn ti chungMc d chc nng ch yu ca tng knh truyn ti chung c th khng nht thit l phi ging nhau hai ch FDD v TDD nhng chng c cng mt vi chc nng v du hiu c bn.C FDD v TDD u c mt s knh truyn ti ging nhau, tuy nhin FDD khng c knh dng chung ng ln (USCH) v T khng c knh gi chung (CPCH). Knh truyn ti CPCH FDD thc hin cc lnh iu khin cng sut cn thit, cc lnh ny khng c yu cu TDD. Ngc li USCH thc hin cc lnh cn thit TDD m khng c yu cu FDD. Bng 1.8 khi qut c im ch yu hai ch FDD v TDD nh sau:Bng 1.2. Cc c im ch yu ca cc knh truyn ti chung FDDTDD

BCH-Knh qung bBCH- Knh qung b

Knh truyn ti ng xung c dng cho h thng qung b v thng tin c th v BCH thng c truyn trn ton b .

FACH- Knh truy nhp ng xungFACH- Knh truy nhp ng xung

Knh truyn ti ng xung truyn thng tin iu khin ti trm di ng khi h thng bit c nh v ca trm di ng. FDD, FACH c th c truyn trn ton b hoc ch trn mt phn ang s dng v n c th c s dng truyn lnh iu khin cng sut chm. TDD, n c th truyn cc gi tin ngn ca ngi s dng.

PCH- Knh tm giPCH- Knh tm gi

Knh truyn ti ng xung thng c truyn trn ton b , c dng truyn thng tin iu khin ti trm di ng khi h thng khng bit v tr ca trm di ng. FDD qu trnh truyn PCH c kt hp vi qu trnh truyn cc ch th tm gi ca lp vt l h tr cc quy trnh ch ch mt cch c hiu qu.

RACH- Knh truy nhp ngu nhinRACH- Knh truy nhp ngu nhin

Knh truyn ti ng ln, thng thu c t ton b , thc hin truyn thng tin iu khin t trm di ng, FDD, RACH c c trng bi nguy c xung t v bi vic s dng iu khin cng sut vng m s dng cho vic truyn dn. TDD, n cng c th truyn cc gi tin ngn ca ngi s dng.

CPCH- Knh gi chungCPCH- Knh gi chung

Knh truyn ti ng ln kt hp vi mt knh ring ng xung to ra cc lnh iu khin CPCH (v d dng khn cp). N c c trng bi nguy c xung t ban u v vic s dng iu khin cng sut vng trong cho vic truyn dnKnh truyn ti ng ln c dng chung bi mt vi UE thc hin truyn s liu iu khin dnh ring hoc lu lng.

DSCH- Knh dng chung ng xungDSCH- Knh dng chung ng xung

Knh truyn ti ng xung c dng chung bi mt vi UE, thc hin truyn s liu iu khin dnh ring hoc lu lng. FDD n c kt hp vi mt vi knh DCH ng xung. N c th c truyn trn ton b hoc ch trn mt phn ang s dng.

Cc knh LogicCc knh logic c th c chia lm hai nhm ch yu l: nhm knh iu khin v nhm knh lu lng. Nhm knh iu khin bao gm: Knh iu khin qung b BCCH: L knh ng xung pht qung b thng tin h thng. Knh iu khin tm gi PCCH: Knh ng xung pht qung b thng tin tm gi. Knh iu khin dnh ring DCCH: Knh hai chiu im n im pht thng tin iu khin ring gia UE v mng. c thit lp bi thit lp kt ni ca RRC. Knh iu khin chung CCCH: Knh hai chiu pht thng tin iu khin gia mng v cc UE. c s dng khi khng c kt ni RRC hoc khi truy nhp mt mi. Knh iu khin phn chia knh SHCCH Knh iu khin ring cho ODMA- OCCH Knh iu khin chung cho ODMA-OCCCH. Nhm knh lu lng bao gm: Knh lu lng dnh ring DTCH: Knh hai chiu im n im ring cho mt UE truyn thng tin ca ngi s dng. DTCH c th tn ti c ng ln v ng xung. Knh lu lng chung CTCH: Knh mt chiu im a im truyn thng tin ca mt ngi s dng cho tt c hay mt nhm ngi s dng quy nh hoc ch cho mt ngi s dng. Knh ny ch c ng xung.1.4. Trng thi cell UE c th ch ri hoc ch kt ni. Trong ch ri, my di ng c bt v bt c knh iu khin ca mt cell no , nhng phn UTRAN ca mng khng c thng tin no v UE. UE ch c th c nh a ch bi mt thng ip (chng hn nh thng bo tm gi) c pht qung b n tt c ngi s dng trong mt cell. Trng thi ch ri cng c gi l trng thi ngh trong cell. UE c th chuyn sang ch kt ni bng cch yu cu thit lp mt kt ni RRC. Hnh v sau y ch ra cc trng thi v s chuyn tip cc trng thi cho mt UE bao gm c cc ch GSM/GPRS.

Hnh 1.13. Cc ch ca UE v cc trng thi iu khin ti nguyn v tuyn Nhn chung vic n nh cc knh khc nhau cho mt ngi s dng v vic iu khin ti nguyn v tuyn c thc hin bi giao thc Qun l ti nguyn v tuyn. Trong ch kt ni ca UTRA, c 4 trng thi RRC m UE c th chuyn i gia chng: Cell DCH, Cell FACH, Cell PCH v URA PCH.Trong trng thi Cell DCH, UE c cp pht mt knh vt l ring trn ng ln v ng xung, trong 3 trng thi khc UE khng c cp pht knh ring. Trong trng thi Cell FACH, UE gim st mt knh ng xung v c cp pht mt knh FACH trn ng ln. Trong trng thi ny, UE thc hin vic chn la li cell. Bng cch gi thng ip cp nht cell, RNC bit c v tr ca UE mc cell.Trong trng thi Cell PCH v URA PCH, UE chn la knh tm gi (PCH) v s dng vic tip nhn khng lin tc (DRX) gim st knh PCH chn la thng qua mt knh lin kt PICH. Trn ng ln khng c hot ng no lin quan n trng thi ny. S khc nhau gia 2 trng thi ny nh sau: Trong trng thi Cell PCH v tr ca UE c nhn bit mc cell tu theo vic thc hin cp nht cell cui cng. Trong trng thi URA PCH, v tr ca UE c nhn bit mc vng ng k UTRAN (URA) tu theo vic thc hin cp nht URA cui cng trong trng thi Cell FACH.1.5. Kt lun chng:Trong chng ny, chng ta cp n vn tng quan mng thng tin di dng WCDMA, cc c im c bn ca mng thng tin di dng WCDMA nh cu trc mng, cc thnh phn mng, knh trong mng WCDMA, trng thi UE trong cell. V mt cu trc 3G khc vi 2G ch yu phn giao din v tuyn UTRAN

CC K THUT CHNH TRONG WCDMA2.1. Gii thiu chngSo vi h thng 2G, h thng 3G c nhiu im ni tri, th hin qua cc cng ngh m n s dng, nh cc k thut tri ph, chuyn giao hay iu khin cng sut,v.vy l nhng k thut ht sc quan trng, ng vai tr ch yu vo nhng ci tin ca h thng 3G so vi 2G. Chng ny s cp n cc k thut ny mt cch tng i chi tit, qua c ci nhn tng th v cc k thut trong h thng UMTS.2.2. Cc k thut chnh s dng trong mng 3G WCDMA0. K thut tri ph v gii tri phTri ph v gii tri ph l hot ng c bn nht trong cc h thng DS- CDMA. D liu ngi s dng gi s l chui bit c iu ch BPSK c tc l R. Hot ng tri ph chnh l nhn mi bit d liu ngi s dng vi mt chui n bit m, c gi cc chip. y, ta ly n=8 th h s tri ph l 8, ngha l khi thc hin iu ch tri ph BPSK th kt qu tc d liu s l 8xR v c dng xut hin ngu nhin nh l m tri ph. Vic tng tc d liu ln 8 ln p ng vic m rng (vi h s l 8) ph ca tn hiu d liu ngi s dng c tri ra. Tn hiu bng rng ny s c truyn qua cc knh v tuyn n u cui thu.

Hnh 2.1. Qu trnh tri ph v gii tri phTrong qu trnh tri ph, cc chui chip/d liu ngi s dng tri ph c nhn tng bit vi cng cc chip m 8 c s dng trong qu trnh tri ph. Nh hnh 2.1 tn hiu ngi s dng ban u c khi phc hon ton.0. K thut a truy nhp CDMAMt mng thng tin di dng l mt h thng nhiu ngi s dng, trong mt s lng ln ngi s dng chia s ngun ti nguyn vt l chung truyn v nhn thng tin. Dung lng a truy nhp l mt trong nhng yu t c bn ca h thng. Trong lch s thng tin di ng tn ti cc cng ngh a truy nhp khc nhau: TDMA, FDMA v CDMA. S khc nhau ca chng c ch ra hnh 2.2

Hnh 2.2. Cc cng ngh a truy nhpTrong h thng CDMA, cc tn hiu cho ngi s dng khc nhau c truyn i trong cng mt bng tn trong mt thi im. Mi tn hiu ngi s dng lc ny ng vai tr nh nhiu i vi tn hiu ca ngi s dng khc, do dung lng h thng CDMA gn nh l mc nhiu v khng c con s ln nht c nh nn dung lng ca h thng CDMA c gi l dung lng mm.Hnh 2.3 ch ra v d lm th no 3 ngi s dng c th truy nhp ng thi trong h thng CDMA

Hnh 2.3. Nguyn l a truy nhp tri phTi bn thu, ngi s dng 2 s gii tri ph tn hiu thng tin ca minh tr li tn hiu bng hp, ch khng phi tn hiu ca bt k ngi no khc. Bi v s tng quan cho gia m ca ngi s dng mong mun v m ca ngi s dng khc l rt nh. li x l v c im bng rng ca qu trnh x l em li nhiu li ch cho h thng CDMA nh hiu sut s dng ph cao v dung lng mm. Tuy nhin, tt c cc li ch u yu cu s dng k thut iu khin cng sut mt cc nghim ngt v chuyn giao mm nhm trnh tn hiu ca ngi s dng ny nh hng n tn hiu ca ngi s dng khc.0. iu khin cng sut WCDMAH thng WCDMA mun hot ng tt u c yu cu rt cao v vn iu khin cng sut. iu khin cng sut (PC) ti thiu ho cng sut pht ca c UE v mng. V cc h thng WCDMA b hn ch bi nhiu, nn gim cng sut t tt c ngi dng s lm tng dung lng. Vn c bn nht trong iu khin cng sut l vn gn-xa. Yu cu ca iu khin cng sut l mc cng sut m cc UE to ra NodeB cn phi bng nhau. WCDMA s dng cc phng php iu khin cng sut sau:

Hnh 2.4. Th t cc loi iu khin cng sut2.2.3.1. iu khin cng sut vng h (OLPC)c s dng khi UE ln u tin truy cp h thng. Ti thi im UE c lng cng sut c yu cu nh nht cn cho mng thu c tn hiu ca n trong iu kin khng c phn hi UE tng hoc gim cng sut. iu khin cng sut vng h da trn cc tnh ton tn hao ng truyn trn ng xung v t s tn hiu trn nhiu yu cu.Trong th tc truy cp ngu nhin, UE thit lp cng sut pht tin t u tin:Pr ea mb le_ In itia l_ po wer = C PICH _ Tx_ po wer CPIC H_ RS C P+ U L _ in t e r f e r e n c e + U L _ r e q u i r e d _ C ITrong CPICH_Tx_Power CPICH_RSCP: l c tnh suy hao ng truyn t Node B n UE.CPICH_Tx_power: l cng sut pht ca P_CPICH; CPICH_RSCP: l cng sut P_CPICH thu ti UEUL_interference (gi l tng cng sut thu bng rng): c o ti NodeB v c pht qung b trn BCH; UL_required_CI: l hng s tng ng vi t s tn hiu trn nhiu c thit lp trong qu trnh quy hoch mng v tuyn.Nhc im ca phng php ny l iu kin truyn sng ca ng xung khc vi ng ln nht l pha inh nhanh nn s thiu chnh xc.

Hnh 2.5. Cc c ch iu khin cng sut trong W-CDMA2.2.3.2. iu khin cng sut vng lp ng (CLPC)c thc hin khi MS kt ni vi h thng. N thc hin iu khin cng sut pht trn c ng ln v ng xung. CLPC da trn ba bc c bn l thc hin vic truyn dn, o lng pha thu v c phn hi c cung cp cho pha pht xem c nn tng hay gim cng sut hay khng.iu khin cng sut vng kn gm c hai phn:- iu khin cng sut nhanh vng trong tc 1500 Hz- iu khin cng sut chm vng ngoi tc 10-100Hz iu khin cng sut vng ngoi (Chm): c thit lp trn RNC v UE, thc hin nh gi di hn cht lng ng truyn trn c s FER hoc BER quyt nh t s tn hiu trn nhiu (SIR) ch cho iu khin cng sut vng trong, duy tr c QoS dch v. Thc hin iu khin cng sut vng ngoi, mi khung s liu ca ngi s dng c gn ch th cht lng khung l CRC. Vic kim tra ch th cht lng ny s thng bo cho RNC v vic gim cht lng v RNC s ra lnh cho NodeB tng SIR ch. iu khin cng sut vng trong (Nhanh)c lng SIR phi c tnh sau mi khe thi gian, t khi hoa tiu ca DPCCH xut hin trong mi khe thi gian. Vng lp trong c cho SIR ch v n thc hin so snh SIR c lng vi SIR ch. Nu SIR c lng nh hn SIR ch, vng lp trong s bo hiu cho my pht tng cng sut xung v ngc li. Vic ny din ra rt nhanh 1500 ln/s, b tr cho cc iu kin fadinh thay i nhanh. PC ng ln vt qua nh hng ca hiu ng near-far, tit kim cng sut UE. PC ng xung tit kim cng sut NodeB v gim nhiu cho cc NodeB khc.

Hnh 2.6. Th tc iu khin cng sut vng trong v vng ngoi2.2.4. Chuyn giao v la chn li Cell trong WCDMA2.2.4.1. Chuyn giaoL qu trnh b sung hoc loi b i cc lin kt vi cc cell m UE ang lin lc trn mt knh dnh ring. UE h tr qu trnh ny bng vic thc hin cc o lng cng tn hiu ca cc cell ln cn v bo co ti UTRAN, v cui cng th UTRAN s quyt nh khi no thc hin chuyn giao.La chn li Cell: l qu trnh la chn mt cell mi khi UE ang nmtrong ch ri (Idle). UE la chn mt cell mi mt cch c lp m khng yu cu s can thip t UTRAN. Tuy nhin UTRAN cung cp cc tham s trong cc bn tin thng tin h thng m n nh hng ti quyt nh la chn li Cell ca UE.2.2.4.2. Cc loi chuyn giao v la chn li CellChuyn giao cng tn s: xy ra gia cc cell c cng tn s v tuyn. UE c th o lng cng tn hiu ca cc cell khc m khng gy gin on kt ni vi cell hin ti. Chuyn giao c th l mm hoc mm hn.Chuyn giao gia cc tn s: xy ra gia cc cell trn cc tn s v tuyn khc nhau. o lng cng tn hiu ca mt cell ln cn gia cc tn s, UE phi iu chnh khi tn s ca cell ang phc v v iu chnh ti tn s ca cell ln cn.Chuyn giao gia cc h thng (IS-HO): gia cc t bo thuc hai cng ngh truy cp v tuyn (RAT) hay hai ch truy cp v tuyn (RAM) khc nhau. Trng hp thng xuyn xy ra nht l chuyn giao gia cc h thng WCDMA v GSM.2.2.4.3. Cc th tc chuyn giao

Hnh 2.7. Cc loi chuyn giao trong W-CDMAChuyn giao cng (Hard handOver-HO) l cc th tc trong tt c cc ng truyn v tuyn c ca mt UE c gii phng trc khi thit lp cc ng truyn v tuyn mi.Chuyn giao mm (Soft HandOver-SHO) v chuyn giao mm hn (Softer Handover): l cc th tc trong UE lun duy tr t nht mt ng v tuyn ni n UTRAN. Trong chuyn giao mm UE ng thi c ni n mt hay nhiu cell thuc cc NodeB khc nhau ca cng mt RNC (chuyn giao mm ni RNC) hay thuc cc RNC khc nhau (chuyn giao mm gia cc RNC). Trong chuyn giao mm hn UE c kt ni n t nht l hai cell ca cng mt NodeB. Soft HO v Softer HO ch c th xy ra trn cng mt tn s sng mang v trong cng mt h thng.Ph thuc vo s tham gia trong chuyn giao mm, cc cell trong mt h thng WCDMA c chia thnh cc tp sau y:Trong ch kt ni, UE lin tc o cc phc v v cc ln cn (do RNC ch dn) trn tn s sng mang hin thi. UE so snh cc kt qu o vi ngng HO do RNC cung cp v gi bo co kt qu o n RNC. V th SHO l kiu chuyn giao c nh gi bi u cui di ng (MEHO).2.3. Tng kt chngiu khin cng sut v chuyn giao trong h thng thng tin di ng UMTS l nhng khu quan trng ca h thng. iu khin cng sut hn ch c nh hng ca hiu ng gn xa n cht lng dch v thoi, dung lng ca h thng v kh nng chng li fading vn l c trng ca mi trng di ng. Trong khi iu khin chuyn giao m bo tnh lin tc ca dch v pht huy th mnh di ng ca h thng 3G. Tm hiu c k iu khin cng sut v chuyn giao trong mng WCDMA l rt cn thit, qua lm tin ti u v tuyn v t a ra cc gii php ti u cc thng s ca mng sau ny

KPI MNG 3G WCDMA V PHNG PHP TI U3.1. Gii thiu chungChng 2 cp n cc k thut quan trng c s dng trong h thng 3G-UMTS. y l nhng tin ht sc cn thit, gip cho ngi lm ti u hiu su v h thng, t c th a ra c cc gii php ti u khi mng 3G gp s c. C rt nhiu tiu ch nh gi hiu nng ca mng, trong ni ln l ch s KPI Key Performance Indicator. Mc ch ch yu ca vic s dng KPI l o lng cht lng ca dch v theo mt cch ph hp v duy nht. Qua vic kim sot s thay i ca cc KPI ta c th pht hin cc vn ca mng nhanh nht c th. Chng ny s cp n cc phng php ti u mng 3G ni chung v mng v tuyn ni ring. Ngoi ra, cc ch s KPI ch yu cng c gii thiu mt cch chi tit.3.2. Khi qut v KPI mng 3G3.2.1. nh ngha KPIKPI Key Performance Indicator l cc ch s th hin cht lng mng, l tiu ch nh gi cht lng mng tt hay xu. Vic phn tch, nh gi cc ch s KPI a ra quyt nh hnh ng nng cao cht lng mng. Vic s dng KPI gip cc nh vn hnh c th theo di trng thi v cht lng dch v mng mt cc ton din m bo cc tha thun vi khc hngKPI phi c nh ngha r rng v o kim d dng. Khi so snh cc KPI rt cn thit phi c nh ngha chnh xc c bit l cc ch tiu lc la chn u vo, cc mc tha thun v cc lin h v tham s.Cc nh ngha v cc phng n o kim thng khng thay i v c xy dng cho mc tiu di hn.Hin ti cc KPI cha c chun ha gia cc vendor. V vy, nh ngha v biu thc tnh ton mt KPI c th c th khc nhau gia cac vendor khc nhau.Cc KPI cn phi c phn tch mt cc chi tit cho cc dch v, cho mi phn t mng, cho mi loi thu bao. Vic ny gip nh gi cht lng mng mt cch ton din trong cng tc nng cao cht lng mng.KPIs Target c nh ngha l thc o cht lng c s dng th hin cht lng mng m nh iu hnh mong mun. Vic ti u mng nhm mc ch chnh l t c mc tiu KPI. Cc KPI target cn phi c cp nht lin tc ph hp vi cc cng ngh mi, dch v mi3.2.2. Mc ch s dng KPIMc ch chnh ca vic s dng KPI l o lng cht lng dch v mng mt cch ng b. Qua kim sot s thay di ca cc KPI ta c th ch ra cc vn ca mng mt cch nhanh nht.Vic kim tra cc KPI cho mt mng l cha nng cng vic qun l cht lng mng hng ngy. Vic kim tra ny s cho cc nh vn hnh cc thng tin lin quan n vic mng thc hin cc chc nng ca n nh th no.Mng c p ng y cc yu cu cht lng khng?Cht lng mng c thay i khng? Tt ln hay ti i?Khu vc no c vn ?Nhng loi vn no mng gp phi?

3.2.3. Khi no th s dng KPI S dng khi quy hoch mng: xy dng ch tiu tn s v tuyn Khi trin khai mng v ti u ban u: Tp trung vo ti u mc tiu tn s v tuyn KPI dch v c th c thu thp nh gi tc ng ca s ci thin tn s v tuyn trn cht lng dch v KPI dch v cn phi c xem st sau khi mc tiu ti u tn s v tuyn c hon thnh S dng cc mc tiu cao hn v ti m phng trong mng H thng KPI khng th c thu thp v s lng ngi s dng ban u cha nh gi chi tit lu lng truy cp S dng khi ti u mng v thng mi ha: tp trung vo ti u KPI dch v3.2.4. Phn loi cc lp KPI Phn loi theo nhm cht lng dch v.Theo ITU-T E800, cc KPI dch v c chia thnh 4 nhm sau:Nhm KPI v lu lngNhm KPI v kh nng truy cp dch vNhm KPI v kh nng duy tr dch vNhm KPI v tnh di ng.Nhm KPI v lu lng: ch ra cht lng ca mng, s thay i ca lu lng mng theo thi gian v s phn b theo khu vc. Cc KPI lu lng c s dng kim sot ti nguyn, ti ca cc cell cc khu vc im nng v ca ton mng. Cc KPI ny l tham chiu phn tch v nh gi phc v cho pht trin lu lng mng.Nhm KPI v kh nng truy cp dch v: l kh nng sn sng cung cp dch v m khch hng yu cu. Hiu n gi l cc nh mng phi theo di t l thnh cng thit lp cc dch v m khch hng yu cu.Nhm KPI kh nng duy tr dch v: l kh nng gi cho mt dch v c thng sut di cc iu kin khc nhau trong mt khong thi gia c yu cu. v d cc nh vn hnh phi theo di t l rt cuc gi (CDR)Nhm KPI tnh di dng: ch ra kh nng cung cp cc dch v mt cc lin tuc khng ph thuc vo trng thi ca thu bao. V d nh iu hnh mng phi theo di t l chuyn giao thnh cng.

Hnh 3.1. Phn loi cc lp KPI Phn loi theo i tng o lng.Theo loi ny, cc KPI c chia thnh 2 nhm:KPI mc RNCKPI mc cell.Nhm KPI mc RNC c s dng gim st trng thi vn hnh v cht lng trn ton mngNhm KPI mc cell c s dng gim st trng thi vn hng v cht lng mng ca mi cell trong mng.3.2.5. Cc ngun d liu phc v tnh ton KPICc ngun c s dng theo di cht lng mng nh sau:Thng tin t cc b m thng k trn cc phn t mng.Cc bn ghi lu lng chi tit (v d: UETR, CTR, GPEH)D liu t Driving TestD liu phn nh ca khch hng. Driving Test v cc thng tin c ly t cc counter thuc cc phn t mng l 2 ngun d liu chnh c s dng trong qu trnh ti u nng cao cht lng mng.3.2.5.1. Driving Test.Vic thu thp d liu l rt cn thit. Do cc c s d liu ny c thu thp t cc kt ni ang hot ng v vy nu nh s thu bao hin c hoc dung lng mng rt thp th cc mu ny li qu nh s dng cho vic phn tch thng k v c th nh gi mt cch chnh xc hn cc vn th cn phi tin hnh o c thc am chnh l qu trnh Driving Test.Driving test l mt bc khng th thiu c trong qu trnh ti u, thit b s dng hin ti l: Mapinfo, Laptop c ci t phn mm Tems Investigation 9.1, b cng c TEMS INVESTIGATION (Bao gm my Tems investigation 9.1, GPS- USB), y l mt cng c mnh do Ericson cung cp, vi thit b o ny chng ta c th xc nh c vng ph ca mt hay nhiu cell, cht lng cuc gi ca cell phc v v c th pht hin ra c nhng thiu xt trong khi khai bo neighbor cng nh tn s.S dng bi o Idle o vng ph v pht hin li, thc hin kt ni MS ch Idle, o theo route i qua tt c cc cell thuc Cluster pht hin cc vn li v vng ph, li lp t (nh sai feeder,) v li khai bo tham s. Sau lu li ton b cc vn li pht hin tin hnh x l, v tin hnh so snh vi kt qu sau ti u

y l phng n chung nht phn tch cht lng mng trong mt khu vc nht nh thng qua cc phn tch vng ph, dung lng, trng thi mng, kh nng duy tr dch v. Khng nhng th DT cn gii thch cc vn , cung cp khc khuyn ngh cho k s a ra hnh ng x l khc phc cc vn m mng gp phi. Tuy nhin, Driving Test l phng n tn nhn lc, thit b v c gi thnh cao. Mt s cng c phc v Driving Test.Cng c, dng c:Laptop ci t sn TEMS Investigation, My Term Pocket ci dt term softwareCap kt ni may Tems pocket vi may tinh.GPS kt ni c vi may tinh.Inverter (dung trong trng hp i o route, convert ngun DC c-quy t thanh ngun AC cho may tinh). D liu. Ban s khu vc cn o kim (trong trng hp ko co ban s thi dung ban t tao bng Mapinfo)Cellfile (mang thng tin v cell data, t tao cell file t CDD).Route o ve trc bng Mapinfo thun tin trong qua trinh o.ia chi im o hoc toa , co th show trc trn map (trong trng hp o im).

Hnh 3.2. Giao din s dng ca TEMS Investigation

3.2.5.2. D liu t counter phn t mng.Phn ln cc thng tin v qun l cht lng mng c sn mng li (CN), v mng truy nhp v tuyn UTRAN. C nhng thng tin khng c sn t mng, cc thng tin ny c th thng xuyn c nh gi bi cc thng tin khc c thu thp t cc phn t mng.

Hnh 3.3. V tr t cc counterCc counter c lp t cc phn t mng nh Radio Network Controller(RNC), Radio Base Station (RBS) v Radio Access Network Aggregator (RANAG) c m t nh hnh trn. Cc d liu thng k bi cc phn t mng c lu tr c s d liu ca OSS Operation Support System mt cng c cn thit h tr vn hnh, phn tch d liu v bo co d liu3.2.6. KPI v cm nhn ca khch hngYu t chnh quyt nh thnh cng ca dch v (di ng cng nh vi bt k dch v no) l mc hi lng ca khc hng i vi dch v. Do vy nh vn hnh phi o kim, nh gi cht lng dch v theo cm nhn ca khch hng (QoS). Nh vy mt cu hi c t ra l khi s dng dch v, khch hng cm nhn c iu g?. Khi khch hng s dng in thoi di dng, h ch cn bt my, thc hin cuc gi thoi, thc hin kt ni d liu, tt my. Nu mi th u tt h cm thy dch v m bo. Cc s c c th xy ra s ri vo mt trong nm nhm sau:Thu bao khng th ng k vi mngThu bao khng th thit lp cuc giRt cuc gi trc khi bn ch gi hoc b gi gc myTc ti d liu km, nh hng n dch v s liuCht lng thng tin truyn km, nh hng n cc cuc m thoiTrong khi khch hng khng bao gi quan tm n cc vn xy ra trong mng, nh vn hng mng phi tm c nguyn nhn gy ra s c v nh gi c mc nh hng ca s c n cht lng dch vQuy trnh qun l cht lng mng c ch ra hnh

Hnh 3.4. Quy trnh qun l cht lng mngTin trnh bt u vi nh ngha cht lng. Mc tiu cht lng tng th end to end c nh ngha v cho mi loi dch v c cc tiu chun xc nh khc nhau. Cc gi tr gii hn c thit lp cho mi chi s nh gi hiu sut mng c lin quan.3.3. Cc vn c bn ca cng tc ti u mng v tuyn3.3.1. Mc ch, l do, li ch ca vic ti u. Mc ch:Mc ch quan trng ca vic ti u l ci thin ton b cht lng hin thi ca mt mng di ng. lm c iu ny cn phi kt hp cc yu t sau:Xc nh chnh xc nhng li, d l li nh trong qu trnh hot ng. Nhng li ny c xc nh thng qua vic gim st lin tc cc tham s cht lng quan trng ca mng (KPIs: Key Performance Indicators), thng qua qu trnh Driving Test, v s phn nh ca khch hng.Cn m bo cho mng hot ng hiu qu nht trong khi tha mn s rng buc ca cht lng dch v. L do ti uSau khi hon thnh vic trin khai mng, thng qua qu trnh Driving Test v gim st cc KPIs s gip ta pht hin ra cc vn ca mng do cc gi thit v thit k, nh c ban u cha chnh xc. Hin nay, ngy cng c nhiu mng di ng ra i, nn s cnh tranh v thu ht khch hng rt gay gt. Cht lng dch v (QoS: Quality Of Service) l ch tiu m khch hng quan tm khi ng k mng. Do vic ci thin cht lng mng, a ra nhiu dch v mi thu ht khch hng l rt quan trng. lm iu ny th ti u l mt cng vic khng th thiu i vi mi mng di ng. Qu trnh ti u phi c thc hin mt cch thng xuyn, lin tc, ko di cng vi s pht trin ca mng cht lng dch v ngy cng c nng cao Li ch ca vic ti u.Ti u ha thnh cng s em li rt nhiu li ch cho nh cung cp. Cht lng dch v s c ci thin, b sung thm nhiu dch v mi, tha mn nhu cu ca khch hng, lm tng li nhun ca nh cung cp. Mc tiu ca cc nh cung cp l tm kim nhng cch pht sinh li nhun ln nht vi chi ph u t b sung nh nht. Mt cch t c iu ny l xc nh nhng vng m mng hot ng cha hiu qu tm ra nguyn nhn v ci thin chng. chnh l cng vic ti u ha.Nh vy, ti u l mt cng vic cc k quan trng, khng th thiu c i vi s pht trin ca mng. Cc nh cung cp mng vin thng thng xuyn tin hnh ti u mng mng lun hot ng n nh, hiu qu vi cht lng dch v cao tha mn nhu cu ca khch hng.3.3.2. Th tc ti u mng v tuyn.Cc th tc ti u mng v tuyn l qu trnh cn c p dng trong cc giai on ti u mng v tuyn.Cc th tc ti u mng v tuyn gm 6 bc nh sau

Hnh 3.5. Th tc ti u mng1. Cng tc chun bC nhim v xc nh cc tham s k thut thc t v cc tham s mng. Nghin cu mi trng v tuyn trong khu vc v im nng lu lng v tm hiu cc kin phn nh ca khch hng.2. Thu thp d liuC nhim v thu thp cc d liu thng k cht lng mng, d liu cnh bo, d liu Drive Test v phn nh khch hng qua MS 3. Phn tch d liu.C nhim v nh gi, phn tch d liu thu thp c nhm tm ra cc vn ca mng4. Tin hnh ti uT cc nh gi v phn tch bc 4 a ra cc phng n ti u, thay i tham s k thut v cc tham s chc nng mng5. Thm tra ti u mng.C nhim v kim tra xem cc KPI t ch tiu cha sau khi tin hnh ti u6. Bo co ti u mngMt bo co ti u phi bao gm cch d lng v thi hnh ti u, thng k cc KPI tha mn ch tiu cht lng mng, v cc khuyn ngh cho vic pht trin sau ny3.4. Quy trnh ti u mng da trn ch s KPI3.4.1. Cng tc chun b Mc tiu: Xc nh nhim v ti u v mc ch ti u l g, chun b v phi hp cc cng c ti u, t chc nhn s v phn cng nhim v. Xc nh mc tiu yu cu v ln k hoch hnh ng. Ni dung cng vicPhn tch yu cu: phn tch cc yu cu ca khch hng vi vic ti u cht lng mng, bao gm: vng ph, lu lng, QoS ca mngXc nh ch tiu, v thi gian thc hin nhim viu tra v tp hp cc ti liu h tr nhim v: bao gm cc bo co m phng mng v tuyn WCDMA khu vc cn ti u giai on quy hoch mng, thng tin cu hnh phn cng, cc vn tn ti trong mngChun b cng c ti u: 3.4.2. Thu thp d liu phc v ti u Mc tiuThu thp tt c d liu thng k cht lng mng t cc ngun. Ni dung cng vic:Thu thp d liu thng k cht lng mngThu thp d liu CQT, Drive TestThu thp phn nh khch hngThu thp d liu cnh boThu thp cc d liu cnh bo v tuyn c 2 pha UE v RNCThu thp d liu v tham s k thut v cc thng tin bn D liu thng k cht lng bao gm: cc file thng k cht lng RNC, cc file thng k cht lng Node B v cc file thng k cuc gi (CHR)CHR Call history c cung cp bi thit b mng ghi li cc bn tin bo hiu cuc gi c xc nh trc. CHR c th gip xc nh c cc cuc gi b li bng vic ghi li thng ti li, gip nng cao kh nng duy tr v kh nng sa cha bng vic ghi li thng tin x l chi tit. CHR c phn loi thnh: d liu thit lp cuc gi, d liu kt ni cuc gi, d liu chuyn giao cng v chuyn giao mm, d liu chuyn giao lin h thng..Thu thp phn nh khch hng: c s dng giai on ti u sau khai trng. Cc d liu ny l nhng tri nghim ca chnh h v cht lng mng, d liu ny c b sung thm cc d liu v v tr a l v c x l cn thn.Thu thp d liu bo hiu: l phng php thng c s dng trong qu trnh ti u c thc hin trn c UE v RNC. D liu thu thp UE l d liu bo hiu giao din v tuyn phm vi hp, i vi RNC l phm vi rng hn.3.4.3. Phn tch cht lng mng phc v ti u. Mc tiu`Mc tiu ca giai on ny l phn tch, nh gi d liu thc t t phng on, xc nh cc vn a ra phng n ti u mng Ni dung thc hinVic phn tch cht lng mng c phn thnh cc mc khc nhau ty trng trng hp c th Phn tch KPI mc mngCc KPI mc mng l cc KPI mc RNC, thng c s dng gim st trng thi vn hnh chung ca mng, cc phn tch KPI mng da trn phn tch cc d liu o lng cht lng theo ngy, theo tun, thng Quy trnh thc hin gim st cht lng mng l khi theo di thy mt KPI mc RNC l khng bnh thng, th thc hin phn tch tip N cell nh xc nh cell c vn ang tn ti, cn c vo d liu ca cc b m v cc KPI mc cell xc nh li v nguyn nhn gy li trong cell. Cc phn tch da trn bo co ngyCc bo co ngy th hin trong bng thng k cc KPI c nh vn hnh cung cp hng ngy kim sot trng thi vn hnh ca mng. Mc ch ca vic phn tch hng ngy l kim tra xem c KPI no vt qu bnh thng hoc t n ngng hay khng t xc nh cc li v nguyn nhn li trong cell mt cch sm nht lm c s cho vic thc hin cc hiu chnh cn thit vi thi gian tr nh nht. Phn tch da trn bo co ngy ch yu tp trung vo phn tch cc KPI mc cell. Cc phn tch da trn bo co tun v thngCc phn tch da trn bo co tun v thng tp trung vo s bin i ca cc KPI, cng nh l phn tch v ti u cc KPI theo xu hng suy gim ca chng. Vic phn tch bo co tun v thng c bit c ch cho vic nh gi s ci thin ca cc KPI sau khi thc hin cc iu chnh ti u hng ngy. im khc nhau chnh gia chng l phn tch da trn bo co tun tp trung vo xu hng bin i ca cc KPI mc cell, cn cc phn tch da trn bo co thng tp trung vo vic x l cc KPI mc RNC Xc nh cc nguyn nhn c thSau khi phn tch cc KPI mc mng v cc KPI mc cell ta c th xc nh c c vn g ang tn ti trong mng v xc nh c ngay nguyn nhn tng qut ca vn nh li phn cng, li phn truyn dn hay li phn v tuyn. xc nh nguyn nhn c th ta cn thc hin cc phn tch chi tit hn da vo cc d liu cnh bo ca h thng, d liu drive test v CQT, d liu phn nh khch hng, d liu bo hiu v d liu cu hnh ca thit b mng. y ta c th a ra mt s vn thng gp trong ti u mng 3GVi cc vn v phn cng thit b mng nh RNC, hay Node B ta cn kim tra thng tin cnh bo ca thit b. Nu khng c cc cnh bo hoc sau khi loi b cc cnh bo m cc ch th vn khng bnh thng ta cn thc hin cc phn tch v ti v lu lng ca cell.Vic phn tch lu lng c th gip kim sot v pht hin cc khu vc im nng, tm ra cc cell c lu lng cao bng vic so snh cc thng k cht lng, phn tch s thay i ca lu lng trong mt chu k o lng, v thc hin o lng trn cc cell vt qu ngng cnh bo lu lng.Phn tch vn v nhiu: H thng WCDMA l mt h thng t gy nhiu.Nhiu c nh hng r rt n vng ph, dung lng, iu khin ti v l nguyn nhn trc tip dn n li truy cp v rt cuc gi. Cc phn tch nhiu gm phn tch nhiu ng ln v phn tch nhiu ng xung.Phn tch nhiu ng xung: Nu Ec/No hoa tiu CPICH thp hn mt gi tr ngng (thng l -14 dB) v cng sut m tn hiu thu (RSCP) cao hn mt gi tr ngng (thng l -95dBm) iu chng t tn ti nhiu ng xung.Cc phn tch nhiu ng ln: Nu cng sut bng rng tng cng thu c (RTWP) cao trong khi lu lng thp chng t c nhiu ng ln.Phn tch vn v vng ph: Vng ph mng km c th dn n t l thnh cng thit lp cuc gi thp, t l rt cuc gi cao, t l thnh cng chuyn giao thp. Phn tch vng ph tp trung vo s phn b ca tn hiu v bao gm phn tch vng ph ng ln v vng ph ng xungPhn tch vn nhim hoa tiu (pilot pollution). nhim hoa tiu ngha l c qu nhiu hoa tiu thu c ti mt im nhng khng c hoa tiu no kho tr thnh hoa tiu ch yu. nhim hoa tiu s gy nh hng xu ti qu trnh la chn li cell trong ch ri v gy nhiu trong ch knh dnh ring (ch vn hnh).Vi Nth l gi tr cu hnh h thng quy nh s hoa tiu ti a tho mn iu kiu RSCP ln hn mt ngng cho trc ti mt khu vc khng xy ra nhim hoa tiu. nhim hoa tiu tn ti nu c 2 iu kin sau: S lng hoa tiu tho mn RSCP CPICH > -95dBm l ln hn Nth (RSCP hoa tiu CPICH th 1 RSCP CPICH th (Nth+1)) < 5 db Phn tch vn mt cu hnh cell ln cn. Mt cu hnh cell ln cn l vic khai thiu danh sch cell ln cn ca mt cell ang phc v khin cho khi UE dch chuyn ra xa khi cell phc v nhng vn khng chn c cell cht lng tt tin hnh chuyn giao dn ti rt cuc gi. Danh sch cell ln cn ca Node B phc v cng c thnh phn ging vi tp c kim sot (Active set) ca UE.T vic phn tch nguyn nhn nh trnh by trn s gip xc nh c nguyn nhn ca cc vn tn ti trong mng v gip xy dng c thit k ti u chnh xc v ph hp phc v cho qu trnh thi hnh thit k ti u mng.

3.4.4. Tin hnh thit k ti u Mc chTin hnh trin khai ti u da trn thit k ti u Ni dung cng vic:Tu theo tng vn tn ti trong mng m vic thi hnh ti u cng s din ra khc nhau. Di y s trnh by mt s phng php thi hnh ti u tng ng vi cc tnh hung khc nhau. i vi li phn cng: Li phn cng l nhng li lin quan n Node B v truyn dn vo trm, nhng li ny c th sinh ra do tc ng ca cc yu t khch quan nh thi tit, hoc do yu t ch quan do trong qu trnh vn hnh v lp t khng ng quy tc. Li phn cng ca trm nh hng rt nhiu n cht lng ca mng li, vic ti u tham s khng th a li mt ch tiu KPI tt nu nh phn cng khng c m bo hot ng tt. Mt s li phn cng thng gp khi ti u. Lp sai feeder, dy TX, dy RX, u sai cu hnh. Feeder b mp hoc nc vo trong anten, feeder. u conector tip xc khng tt. Truyn dn khng m bo, chp chn do im tip xc cha chun hoc do tuyn vi ba thit k khng tt, hoc do nh hng ca ma bo dn n cho vi ba b lch so vi thit ktCc dng c c th h tr kim tra li phn cng ca trm l: My tnh c ci t phn mm OMT My o Site Analyser dng xc nh v tr ca li feeder.H thng OMC R dng xc nh li trc tip trn h thng Vi cc vn v nhiu v vng ph: c th x l bng vic iu chnh cc tham s k thut nh downtilt, gc phng v (azimuth), chiu cao v tr v loi anten,

Hnh 3.6. Cc tham s iu chnh x l vn v nhim hoa tiu (pilot pollution) ti mt khu vc nht nh, ta cn to ra mt hoa tiu tri cho khu vc bng vic nng cao mc tn hiu thu (RSCP) ca mt cell v iu chnh cc tham s k thut i vi anten ca cell khc (cp downtilt, thay i gc phng v) tn hiu t cc anten cell khc yu i v s hoa tiu ti khu vc gim xung. Cn vi cc vn v chuyn giao th cn iu chnh cc tham s cu hnh v tuyn: cc tham s chuyn giao mm, nh ngng chuyn giao mm, tr thi gian kch hot chuyn giao, dch cell (CO) v h s lc. Cc tham s chuyn giao cng nh ngng chuyn giao lin h thng. Ta cn khai b sung cc quan h ln cn b thiu cho NodeB ti trung tm vn hnh RNC nu pht hin thy vn mt cell ln cn. Ch khi thc hin iu chnh cn xem xt nhiu phng hng iu chnh khc nhau v la chn phng php t gy tc ng xu cho cc cell khc ca cng h thng nht nh t hiu qu ti u cao nht.3.4.5. Cng nhn thit k ti u. Mc chSau khi thc hin ti u, cng nhn kt qu ti u bng cc phng php kim tra khc nhau Ni dung cng vicSau khi thc hin ti u, da trn cc bn ghi iu chnh ti u v d liu cht lng mng trc ti u, t so snh cht lng mng trc v sau ti u.Tu theo s tng phn d liu ca cht lng mng trc v sau khi iu chnh cn chc chn rng cc vn mng c gii quyt v cht lng mng c cao hn yu cu hay khng. iu c th hin c th bng vic cc KPI c p ng cc gi tr tham chiu do nh vn hnh mng a ra khng. 3.5. Kt lun chng.Cng tc ti u l cng tc v cng quan trng trong vic m bo cht lng mng. Ni dung chng ny cp n vic nh ngha th no l cht lng mng v cc tham s phn nh cht lng mng, t xy dng cc quy trnh thc hin chun ha cng tc ti u PHN TCH MT S KPI MNG 3G WCDMA4.1. Mt s KPI v nguyn nhn nh hng ti chng.Mc ny tp trung nh ngha 3 KPI chnh c s dng trong cng tc ti u mng v tuyn 3G WCDMA CDR Call Drop Rate: t l rt cuc gi CSSR Call Setup Success Rate: t l thit lp cuc gi thnh cng SHOSR Soft HO Success Rate: t l chuyn giao mm thnh cngHin cc KPI ny ang c Viettel s dng gim st cht lng mng 3G s dng cc thit b ca vendor Ericsson, Huawei, ZTE. Cc KPI ny c tnh da theo gi tr ca cc b m (counter). ph hp vi thc t s liu c ly ra t h thng.4.1.1. T l rt cuc gi (CDR) nghaKPI ny nh gi kh nng cung cp dch v mt cch lin tc ca mng do n s trc tip ch ra cht lng mng.T l rt cuc gi c chia thnh 2 loi l rt trn min CS v rt trn min PS. Nguyn nhn dn n rt cuc gi Rt do mt ng b ng ln v ng xung: l du hiu cho cc vn v vng ph,, nhiu ng ln, mt cell ln cn Rt do nghn: Cuc gi c th b rt do chc nng iu khin nghn ca mng UMTS. Rt cuc gi xy ra khi ti ca cell tr nn qu cao trn ng ln c pht hin khi RTWP vt qu mt ngng c cu hnh trc trong mt khong thi gian di hn thi gian tr. Rt do xung t m xo trn (SC): UE c th thy 2 cell trong cng mt tp hot ng (AS), cng tp ln cn c kim sot (MN) hoc ln cn c pht hin (DN) c cng SC, iu ny dn n gim Ec/No, tng BLER v cui cng dn n rt cuc gi. Rt cuc gi do chc nng chuyn giao mm v chuyn giao mm khng thc hin c. Rt cuc gi do chc nng chuyn giao lin tn s v chuyn giao RAT khng thc hin c Ngoi nhng nguyn nhn trn th c gi l cc nguyn nhn khc (other reason): bao gm cc nguyn nhn nh li phn cng, li truyn dn, li anten, feeder4.1.1.1. T l rt cuc gi trn min CSCc dch v trn min CS bao gm: thoi AMR, thoi truyn hnh, d liu tc thp. KPI ny nh gi t l rt cuc gi trn min CS chung cho c 3 dch v trn

a. Cng thc tnh (c tnh da trn cc counter Ericsson)CS CDR = x100Trong :CS Drop = pmNoSystemRabReleaseSpeech CS Att=pmNoSystemRabReleaseSpeech+pmNoNormalRabReleaseSpeechGii thch cc b m:pmNoSystemRabReleaseSpeech: tng s cuc gi trn min CS b rtpmNoNormalRabReleaseSpeech: Tng s cuc gi kt ni bnh thng

b. Phn loiKPI ny thuc nhm duy tr dch vc. Gi tr tham chiuCS CDR 0.38% (gi tr tham chiu hin ti ca Viettel)4.1.1.2. T l rt trn min PSKPI ny nh gi t l rt cuc g trn min PS a. Cng thc tnhPS CDR = x 100Trong : PSRABAbnormalRelease: tng s cuc gi rt trn min PSPSRABRelease: tng cc cuc gi gii phng knh c bnh thng v rtb. Gi tr tham chiuPS CDR 0.75% (gi tr tham chiu hin ti ca Viettel)4.1.1.3. Hng dn thc hin ti uBc 1: Ly d liu thng k. Thc hin ly y cc d liu thng k phc v phn tch cuc rt bao gm: D liu gi peak, d liu gi normal 7 ngy lin tip, d liu theo gi. CDD full tham s, phn mm Winfiol check tham s online. Map Info, plancheck dng check relation, tn s, PSC.Bc 2: Phn tch s b d liu bit c cell c b rt t bin so vi ngy trc khng. Nu rt t bin, kim tra nhanh mt s vn nh sau: Kim tra li phn cng ca trm cn kim tra v cc trm ln cn qua winfiol v phi hp cc n v sa li nu c. Kim tra cht lng lung truyn dn xem lung c b chp chn khng. Tng t vi cc trm ln cn. Phi hp cc n v sa li nu c. Kim tra xem c trm no mi active, khai thiu relation gy rt cuc gi cuc Kim tra cc tc ng vo mng c phn cng v mm: iu chnh phn cng, Add remove relation, chuyn trm, thay tn 2G Nu khng gp nhng li trn chuyn Bc 3. Nu khng t bin chuyn Bc 3.Bc 3: Xc nh nguyn nhn rt v cch x l. Nu nguyn nhn no chim > 30% tng s cuc rt ca cell th coi l nguyn nhn rt chnh. Rt do missing neighbor. Kim tra relation cng tn s c thiu khng bng cch check trn Map, plancheck. Kim tra tham s selectionpriority ng cha. Mc u tin selectionpriority khai bo t 1 ->32, gi tr cng nh c mc u tin cng cao. Hin ti ang khai 9 cell relation mnh nht u tin 1, 6 cell tip theo u tin 2, cn li u tin 3. Cn m bo cc cell relation quan trong (lp 1 va 2) c mc u tin l 1. Kim tra cc relation v External 3G khai bo ng cha. i vi trng hp relation khai bo v ng, cn c vo bn ghi NSC xc nh cell gy ra missing neighbor. nh gi xem cell b missing hay cell gy missing c vn v vng ph. Rt do Soft Handover khng bao gm missing neighbor. Cn c vao d liu Ho cell to cell xac inh xem cell ich nao ti (co ti l handover failure cao nht). Kim tra cell ich ti co bi sai external khng (nu cell ich ti nm khac RNC). Kim tra cell ich c b li khng: Kim tra relation cua cell co bi trung tn va PSC khng. Rt do mt ng b ng ln (Rt do sng yu UL v DL, nhiu UL v DL) Ti u relation cung tn s: Vic thiu relation gy nhiu c ng ln v ng xung. m bo relation cung tn s khong 20->25 relation. Ti u da vo map v NSC. Ti u relation 3G 2G Ti u relation khc tn i vi cell tn F2, F3, F4. m bo khong 15-20 relation. Kim tra xem cell c b overshooting khng Cng sut CPICH ca cell ti a cha. Kim tra pilot polution Kim tra xem tram bi co li co song khng goi c khng Mt s tham s mc cell dng ti u nguyn nhn ny l: Minpwrmax, MinPwrRl, nOutSyncInd, nInSyncInd, rlFailureT, maxTxPowerUl: Tng gia tri Minpwrmax, MinPwrRl, tng cng sut cho mi kt ni thoai giam rt do song yu. Tuy nhin khai tng tham s nay cn anh gia xem CSSR co bi suy giam do nghen cng sut khng. Tng gia tri tham s nOutSyncInd, giam gia tri nInSyncInd, tng gia tri tham s rlFailureT giup cai thin rt cuc goi do song yu. Check tham s mc RNC xem khai ng cha: Kim tra nhiu ng ln: Rt do nghn. Kim tra v ti u cc tham s mc cell: Thay i tham s releaseAseDl t 1->0, releaseAseDlNg t 3->10 disable tinh nng reject cuc goi thoai khi tai cao. Thc hin share ti, nng cp chng nghn cho cell, y tai sang 2G bng tinh nng directed retry. Rt trong qua trinh chuyn giao InRAT HO, khac tn s. Ti u relation 3G - 2G: m bo s lng khong 15, hn ch relation cng tn, khai bo ext, outer LAI ng. Thc hin t mc u tin relation. Ti u relation khc tn i vi cell tn F2. m bo khong 15-20 relation. S lng relation cang it, thi gian o ac cang nhanh, han ch rt cuc goi. Thc hin t mc u tin relation. iu chnh ngng 2d cho hp l (chu y vic tng giam nay anh hng n vung phu cua 3G).

Rt do other reason Kim tra li truyn dn, li trm khng Kim tra xem c trng PSC relation khng (check PSC, tn s ca cc relation c b trng khng). Mt s trng hp rt khng y cnh bo thng gp nh sau: Trm b ch rt cao 1 cell, mi ln reset cell ti chuyn sang cell khc cng trm. Trm b li 06. Hin tng: CS CDR suy gim t bin t 0.3% -> 1.5%, CS CSSR suy gim t 99%- > 95%. Reset trm4.1.2. T l thit lp cuc gi thnh cng nghanh gi t l thit lp dch v thnh cng, gm c 2 phn: thit lp phn v tuyn RRC v thit lp dch v RAB.RAB gm 3 loi dch v: thoi AMR, video call v dch v nn PS, do s c 3 gi tr khc nhau cho 3 RAB ny, tng ng c 3 t l thit lp dch v thnh cng cho tng dch v. Cc nguyn nhn dn n t l thnh cng thit lp cuc gi thpT l thnh cng thit lp cuc gi thp tng ng vi vic li truy cp xy ra cao. Mt s nguyn nhn gy ra li truy cp l: Nghn trn knh PCH do ti tm gi cao, cng sut pht PCH thp gy ra li tm gi. Cu hnh cc tham s la chn li cell nh ngng v tr la chn li cell, dch cell khng ph hp. Bn cnh , mt cell ln cn, vng ph km, v nhiu u dn n vic UE khi u truy cp ngu nhin trong mt cell c cht lng tn hiu km (Ec/No thp) nn d UE tng cng sut ti ti a vn khng thc hin c truy cp ngu nhin thnh cng. Nghn iu khin chp nhn. Khi ti h thng cao do chc nng iu khin chp nhn s khng cho php s dng ti nguyn b sung (m knh, ti nguyn truyn dn). Ngoi ra vn mt ng b gia UE v UTRAN, cng sut pht knh FACH thp dn n vic UE khng gi c bn tin hon thnh thit lp kt ni RRC cng dn n li thit lp kt ni RRC Cu hnh tham s cho vic thit lp RAB khng ph hp, chc nng iu khin nghn v vn v dung lng gy ra li thit lp RAB. Vn xung t m xo trn SC cng l nguyn nhn gy ra li truy cp Cc vn v li thit b.a. Cng thc tnhCSSR= (RRC Setup Success rate)(RAB Setup Success rate)100%

Trong : T l thnh cng thit lp kt ni RRC (RRC Setup Success rate) RRC Setup Success rate= (RRC setup success)/(RRC Attempt) T l thnh cng thit lp RAB (RAB Setup Success rate) RAB Setup Success rate tnh ring cho mi loi dch v:- T l thnh cng thit lp RAB dch v thoi AMR (AMR RAB_SR)

- T l thnh cng thit lp RAB dch v thoi truyn hnh (Video phone)

- T l thnh cng thit lp RAB dch v PS

Trong :RRC settup success: tng s thit lp RRC thnh cngRRC attempt: tng s ln c gng thit lt RRCAMRRABSetupsuccess: tng s thit lp RAB thnh cng cho thoi AMRAMRRABSetupAttempt: tng s ln c gng thit lp RAB cho thoiVPRABSetupsuccess: Tng s ln thit lp RAB thnh cng cho VPVPRABSetupAttempt: Tng s ln c gng thit lp RAB cho VPPSRABSetupsuccess: Tng s thit RAB thnh cng cho dch v PSPSRABSetupAttempt: Tng s ln c gng thit lp RAB cho dch v PSb. Phn loiKPI ny thuc nhm kh nng truy cp dch vc. Gi tr tham chiuCS CSSR 99.9%PS CSSR 99.5% Hng dn ti u CSSR ti do nghn, lu lng cao.Hin tng: Cell c lu lng cao tp trung ch yu cc trng i hc v khu vc ng dn, c im lu lng data cao. Cc cell ny thng xc nh thng qua t l PS RAB CR > target, Hiu sut s dng code gi peak > 70%Cch x l: thc hin theo trnh t t trn xung Nng cp cu hnh Cn ti gia 2 cell o kim iu chnh vng ph nh gi a ra gii php quay cell ( hiu l u cu hnh cao) nu vng ph m bo Gii php ln trm share ti, lp cosite thm t CSSR ti do tham s t sai: trng hp ny ch cn iu chnh li cc tham s theo GL nh mng CSSR ti do trm liTt c cc trng hp li trm c th kim tra c trn h thng h tr vn hnh do cc trm s y li cnh bo. Cch khc phc: Yu cu i xung kim tra xem c card khng hay do cm lng. Tin hnh cm li card, nu vn khng c th thay th. Cn ch n yu t nhit nh trm. Nu nhit cao gy ln hin tng lc nhn card lc khng CSSR ti do li truyn dn: Truyn dn c nh hng ln n KPI CSSR v CDR. Do c hin tng SHO nn khi 1 trm pht chp chn gy nh hng ln n cc cell xung quanh, c bit l trong thnh ph.Cch khc phc: ly KPI h thng, phn tch nguyn nhn, phi hp vi b phn truyn dn v tng trm khc phc4.1.3. T l chuyn giao mm thnh cng (SHOSR) nghaKPI ny nh gi kh nng chuyn giao mm trong qu trnh vn hnh mng, KPI ny c lin quan n cc KPI ni trn. Nguyn nhn t l chuyn giao mm thnh cng thp Mt cell ln cn ( nu trong phn trn) Pilot pollution ( nu trong phn trn) Cu hnh cc tham s thut ton chuyn giao mm khng chnh xc dn n hin tng: chuyn giao b tr nguyn nhn l do cu hnh cc tham s v tr v ngng chuyn giao mm qu su, dn n UE giao khng thu c lnh cp nht tp hot ng nn gy li chuyn giao mm khi xy ra tnh hung Ec/No ca cell gc gim t ngt khi Ec/No ca cell mc tiu tng ln mnh trong mt khong thi gian ngn lm cho UE mt ng b v khng thu c bn tin cp nht tp hot ng t RNC. Cc nguyn nhn v li thit b. nh ngha t l thnh cng chuyn giao mm (SHOSR)a. Cng thc Mc RNC

Trong :SHOASSuccess: l tng cc ln chuyn giao mm thnh cngSHOASUAttempt: m tng s ln chuyn giao c RNC quyt nhb. Phn loiKPI ny thuc nhm tnh di ng ca dch v Hng ti u: nu trong phn ti u t l rt cuc gi4.2. Mt s trng hp thng gp trong ti u mng 3G UMTS4.2.1. Khu vc c vng ph km4.2.1.1. Tiu chun nh gi khu vc c vng ph km th i vi mi khu vc s c mt tiu chun ring v cc ch s (RSCP, Ec/No) nh gi.Bng 4.1 m t mc tiu nh gi cht lng vng ph ca Viettel vi cc khu vc khc nhau (y l mc thu trong xe khi tin hnh drive test khng c anten gn ngoi). Cc khu vc tng ng trong qu trnh o nu c cc ch s cao hn cc ch s mc tiu l khu vc c vng ph tt. Khu vc no c RSCP thp hn ch tiu l khu vc vng ph km.Bng 4.1. Tiu chun vng ph ttKhu vcThnh ph mt dn c caoThnh ph mt dn c trung bnhNgoi Nng thn

RSCP (dBm)-88-93-100-105

Ec/No (dB)-12-12-12-12

4.2.1.2. Kho st vng ph ti khu vc thnh ph Tam K, Qung NamV tr lp t cc Node B c s dng chung c s h tng vi mng GSM c sn c nn cch b tr trm cn nhiu hn ch. Hnh 4.1 ch ra v tr cc Node B trong thnh ph Tam K.

Hnh 4.1. V tr thc t Node B ti thnh ph Tam K Tiu chun vng ph cho vng:- Khu vc tin hnh drive test thuc khu vc ni thnh. Tiu chun vng ph cho khu vc ny l RSCP -95 dBm, Ec/No -12 dB.- Hnh 4.2 m t phn b RSCP knh hoa tiu CPICH trong vng thc hin drive test.Nhn vo hnh 4.2, ta c th thy cng trng ti khu vc ny tng i tt, th hin qua s tn hiu c mu xanh tng i nhiu. Duy ch c khu vc mu c khoanh trn l c vn cn gii quyt c th ci thin tn hiu.

Hnh 4.2. Cng trng RSCP ca thnh ph Tam KRSCP(dBm)The color of LegendResult

RSCP-105Very bad, No coverage

-105RSCP-95Bad, Outdoor coverage cant be guaranteed.

-95RSCP-85Normal, Indoor coverage cant be guaranteed.

-85RSCP-75Better, Indoor coverage can be partly guaranteed.

-75RSCP-65Good, Indoor coverage can be guaranteed.

RSCP-65Excellent.

Hnh 4.3. Legend ca RSCP CPICHBng 4.2. Thng k mu RSCP CPICH trc ti uRSCP (dBm)x < -95x -95

S mu tn hiu256925167

T l %9,2690,74

Qua bng 4.2, ta c th d dng nhn ra vng ny cha t v ch s RSCP v s mu c ch s RSCP ln hn -95 dBm chim 90.74%, trong khi ch tiu cn t l t l RSCP ln hn -95dBm l t 95% tr ln.Hnh 4.4 th hin ch s cht lng tn hiu Ec/No.

Hnh 4.4. Cht lng tn hiu Ec/No ca thnh ph Tam KEc/No(dB)The color of LegendResult

Ec/No-14Very bad, No coverage

-14Ec/No-12Bad coverage, The bit rate ofPS service is low, the communication quality cant be guaranteed.

-12Ec/No-8Normal coverage for voice call,The bit rate of PS Service cant be guaranteed.

-8Ec/No-6Video call cant be guaranteed,The higher speed PS Service can be partly guaranteed.

-6Ec/No-4Good coverage for all service

Ec/No-4Excellent

Hnh 4.5. Legend ca Ec/No CPICHBng 4.3. Thng k mu Ec/No CPICH trc ti uEc/No (dB)x < -12x -12

S mu tn hiu189822489

T l %7.892.2

o kim ti u ch voice trc khi thi thc hin ti uYu cu:- o theo cluster- 3 cuc/cell- Thit lp 60s (gi) + 5s (Idle)- Mc tiu: CSSR > 99,9%, CDR < 0,38%, SHOSR = 100 %- CSSR= (s cuc gi c thit lp/s c gng thit lp)x100%- CDR= (s cuc gi rt/s cuc gi c thit lp)x100%- SHOSR= (b sung lin kt v tuyn + loi b lin kt v tuyn + thay th lin kt v tuyn)/(b sung lin kt v tuyn + loi b lin kt v tuyn + thay th lin kt v tuyn + li b sung lin kt v tuyn + li loi b lin kt v tuyn + li thay th lin kt v tuyn) Kt qu Bng 4-4 th hin kt qu o lng cc KPI CSSR, CDR, SHOSR trc khi thi hnh ti u ti khu vc thnh ph Tam K Kt qu trc ti u CDR= 9.66%, CSSR= 98.64%, SHOSR= 100%Bng 4.4. Kt qu o lng CSSR, CDR, SHOSR trc ti uS kinS lngCDRSHOSRCSSR

C gng thit lp147

5,5%

9.66%

100%

100%

98,64%

98.64%

Cuc gi c thit lp

Cuc gi c thit lp145

Cuc gi b rtCuc gi b rt8

B sng lin kt v tuynB sung lin kt v tuyn786

Li b sung lin kt v tuynLi b sung lin kt v tuyn0

Loi b lin kt v tuynLoi b lin kt v tuyn708

Li loi b lin kt v tuynLi loi b lin kt v tuyn0

Thay th lin kt v tuynThay th lin kt v tuyn228

Li thay th lin kt v tuynLi thay th lin kt v tuyn0

4.2.1.3. Phn tch vng ph khu vc Tam K V cc ch tiu RSCP v Ec/NoT bng 4.2 ta thy rng t l s mu RSCP CPICH c gi tr cao hn -95 dBm khng cao (ch l 90.74 %), trong khi ch tiu l trn 95% s mu RSCP CPICH c gi tr ln hn -95 dBm. T l s mu Ec/No CPICH c gi tr cao hn -12dB l 92.2% cng thp hn ch tiu l 95% s mu Ec/No CPICH c gi tr ln hn - 12 dB. Khu vc ny cn khc phc vn vng ph km. Bng gii php tng gim gc tilt, azimuth ca cc cell, ta c th ci thin vng ph ca khu vc ny. Hnh 4.6 m t khu vc c vng ph km

Hnh 4.6. Khu vc c vng ph kmHnh 4.7 l gi tr ca RSCP CPICH ti im c vng ph km

Hnh 4.7. WCDMA PilotC nhiu nguyn nhn khin cho vng ph yu nh pilot pollution, overshooting,Trong , pilot pollution l nguyn nhn chnh trong trng hp ang xt (Hnh 4.8). y, ta c th thy cell 1 ca site 3024 (PSC=24) l cell ch o ti v tr ang xt. Ngoi ra th n cn bt c tn hiu t cc cell khc nh trn hnh v vi cc gi tr chnh lch nhau khng nhiu v cng trng RSCP, t gy ra hin tng pilot pollution, lm cho tn hiu khu vc ny xu i.

Hnh 4.8. Weak coverage do pilot pollutionGii phpThay i gc tilt v azimuth ca cc cell c lin quan.Chnh tilt v azimuth cho cell ca 5 trm nh m t trong bng 4.5Bng 4.5. Chnh tilt v azimuthTn CellAzimuth cTilt cAzimuth miTilt mi

50211541103

7211041305

30241063507

3025132063405

3033323062305

4.2.1.4. Kt qu sau ti u Hnh 4.9 biu din phn b RSCP CPICH sau khi thi hnh ti u

Hnh 4.9. Phn b RSCP sau khi thi hnh ti uBn g 4.6 b iu din thng k mu bin ca ch s RSCP CPICH sau khi ti u.Bng 4.6. Thng k mu RSCP CPICH sau ti uRSCP (dBm)x < -95x -95

S mu tn hiu2524563

T l %0.1199.89

Phn b Ec/No CPICHHnh 4.10 biu din phn b Ec/No CPICH sau ti u

Hnh 4.10. Phn b Ec/No sau khi ti uBng 4.7 biu din thng k mu gi tr ca ch s Ec/No CPICH sau khi thi hnh ti u.Bng 4.7. Thng k mu Ec/No CPICH sau ti uEc/No (dB)x < -12x -12

S mu tn hiu40624182

T l %1.6598.35

o kim ch voice sau khi thc hin ti u KPI t c sau khi thc hin ti u nh sau: CDR= 0.35 % CSSR= 99.9 % SHOSR= 100 %

Hnh 4.11. Khu vc sau ti u nh gi kt qu ti u Mc ci thin RSCP CPICH vng ph c th hin trong bng 4.8.Bng 4.8. RSCP CPICH trc v sau ti uRSCPx < -95x -95

Trc ti uS mu tn hiu228222306

T l %9.2690.74

Sau ti uS mu tn hiu2524563

T l %0.1199.89

Ci thin %98.8%10%

Mc ci thin Ec/No CPICH vng ph c th hin trong bng 4.9Bng 4.9. Ec/No CPICH trc v sau ti uEc/Nox < -12x -12

Trc ti uS mu tn hiu189822489

T l %7,892.2

Sau ti uS mu tn hiu40624182

T l %1.6598.35

Ci thin %78.85%6,7%

Mc ci thin ca cc KPI CDR, CSSR v SHOSR c th hin trong bng 4.10.Bng 4.10. CSR, CDR, HOSR trc v sau ti uCDRCSSRSHOSR

Trc ti u5,5%98.64%100%

Sau ti u0.35 %99.9%100 %

Ci thin %93.64%1,3%0%

Lu : Cng thc tnh ci thin= (ch s sau ti u - ch s trc ti u)/(ch s trc ti u)x100% (ly gi tr dng)4.2.2. Khu vc c rt cuc gi (calldrop)4.2.2.1. Phn tch nguyn nhnVi bi o ch Voice, ta thy rng t l rt cuc gi CDR cao (9,66%), v khng p ng c ch tiu (CDR < 1%). Da vo phn tch d liu logfile ta c th thy rng nguyn nhn gy rt cuc gi khu vc ny do cc hin tng ping- pong handover hay vng chuyn giao qu nh nn khi UE di chuyn ra xa trm, sng yu m khng chuyn giao c dn n rt cuc gi. Hnh 4.12 ch ra vng c cuc gi b rt.

Hnh 4.12. Khu vc c rt cuc giTrong qu trnh chuyn giao khi UE o c c cng ca cc tn hiu tu thuc vo cng ny th UE s gi cc bn tin measurement report ln RNC yu cu c chuyn giao. Khi gi cc bn tin ny th n c tr cng vi thi gian ch RNC x l v gi lnh xung l mt khong thi gian kh di. V vy nu tn hiu bin i 1 cch t t th s chuyn giao hnh cng ngc li tn hiu bin i qu nhanh trong thi gian ngn th vic chuyn giao s khng kp gy rt cuc gi (hnh 4.13). Trong hnh 4.12 trn, tn hiu ca 2 cell 30331(PSC=36) v 30333(PSC=38) bin i qu t ngt gy ra rt cuc gi.

Hnh 4.13. Tn hiu v kh nng chuyn giao thnh cng4.2.2.2. Gii phpM rng vng chuyn giao nhm mc ch lm cho tn hiu 2 cell ny bin i 1 cch t t, bng cch thay i azimuth v gc tilt ca chng.4.2.2.3. Kt qu sau ti uHnh 4.14 cho thy khng cn call drop sau khi ti u

Hnh 4.14. Calldrop c gii quytNhn xt:Sau khi ti u, ta thy cc ch tiu ny u c ci thin ng k. Mc p ng cc ch tiu ca cc KPI ny c th hin trong bng 4.11.Bng 4.11. Thng k cc KPI sau khi ti uTn bi oSau ti uCh tiuKt lun

Bi o IdleCPICH RSCP > -95 dBm99.89% 95%t

CPICH Ec/No > -12 dB98.35%95%t

Bi o VoiceCSSR99.9% 99,9%t

Bi o VoiceCDR0.35 % 0,38%t

Bi o VoiceSHOSR100%98.5%t

4.3. Kt lun chngThng qua bng thng k cc KPI sau ti u, chng ta c th thy cht lng tn hiu, cng nh cc ch s c ci thin mt cch ng k. Nh vo d liu Drive test, chng ta c th thy c phn no thc trng ca mng kho st. T , bng nhng kin thc c lin quan, chng ta s c nhng phng n ti u thch hp cho tng trng hp c th. y chng ta khc phc c hn ch v mt vng ph v gii quyt c tnh trng rt cuc gi. Qua qu trnh ti u th cht lng mng Viettel 3G Tam K ni ring, v Qung Nam ni chung tng i n nh tuy nhin do cc bin ng v s lng ngi dng v a hnh che chn nn qu trnh ti u ny cn tip tc m bo cung cp cht lng dch v tt nht cho ngi dng.

KT LUN V HNG PHT TRIN TI Hin nay cng ngh thng tin di dng trn th gii pht triu ln th h 4G, 5G, trong nc cc nh khai thc cng c l trnh nng cp h thng ln 4G. Mc d vy cng ngh 3G ti Vit Nam trin khai t nm 2009 n nay nhng vn c coi l kh khn trong cng tc ti u i vi cc cn b k thut. Do vy, vi vic la chn n vi n ti Ti u ch s KPI mng v tuyn 3G WCDMA em hiu c cc c im chnh ca cng ngh WCDMA ng thi cng hiu c cc vn v thit k ti u trong cng tc nng cao cht lng mng ca cc nh khai thc mng ti Vit Nam, c bit l Viettel ni to iu kin cho em c thc tp v tm hiu cc cng tc ti u trong thc t ti phng thit k ti u.Do kin thc bn thn cn hn ch, trong tng lai c c hi nghin cu v lm vic trong lnh vc vin thng mng thng tin di dng em s tm hiu v i su hn na vo vn ti

NHN XT CA GIO VIN HNG DN............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ N T LOI ....................................................................................................Ngy 7 thng 4 nm 2014 TS. Trn Hoi TrungNHN XT CA GIO VIN C DUYT............................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................ N T LOI .................................................................................................... Ngy thng nm 2014

.....................................................PH LCCc counter lin quan n rt cuc gi CDRKPICounter ngha

CS droppmNoSystemRabReleaseSpeechS cuc rt thoi

Cs AttpmNoSystemRabReleaseSpeech + pmNoNormalRabReleaseSpeechS cuc att thoi

CS CDRCS drop/Cs Att *100T l rt cuc gi thoi

Drop due SHO LostpmNoSysRelSpeechSoHo Rt do SHO (bao gm rt missing neighbor)

Drop due Missing neigborpmNoSysRelSpeechNeighbrRt do missing neighbor

Drop due SHO Lost exclude Missing neighborpmNoSysRelSpeechSoHo - pmNoSysRelSpeechNeighbrRt do SHO khng bao gm missing neighbor

Drop due ULSynchpmNoSysRelSpeechUlSynchRt do mt ng b ng ln

Drop due CongpmNoOfTermSpeechCongRt do nghn

Drop due CSinRAT HO Lost (Speech only)pmNoAttOutIratHoSpeech - SpeechUeRejection - pmNoSuccessOutIratHoSpeech - SpeechReturnOldChPhyChFail - SpeechReturnOldChNotPhyChFailRt trong qu trnh chuyn giao t 3G sang 2G dch v thoi only

Drop due CSinRAT HO Lost (MultiRAB)pmNoAttOutIratHoMulti - MultiUeRejection - pmNoSuccessOutIratHoMulti - MultiReturnOldChPhyChFail - MultiReturnOldChNotPhyChFailRt trong qu trnh chuyn giao t 3G sang 2G dch v multi RAB ( thoi + data)

Drop due CSinRAT HO LostDrop due CSinRAT HO Lost (Speech only) + Drop due CSinRAT HO Lost (MultiRAB)Rt trong qu trnh chuyn giao t 3G sang 2G ( bao gm thoi only + MultiRAB

Drop due IF HO LostFailRevertCsSpeech12 Rt trong qu trnh chuyn giao khc tn s

Drop due Other ReasonCS drop - Drop due SHO Lost - Drop due ULSynch - Drop due Cong - Drop due CSinRAT HO Lost - Drop due IF HO LostRt do other reason

Tt c cc counter ny c s dng trong cc h thng ca vendor Ericsson

B counter SHO cell to cell:Countery nghia

pmRlAddAttemptsBestCellSpeechS cuc SHO att cho dich vu thoai

pmRlAddAttemptsBestCellCsConversS cuc SHO att cho dich vu video call

pmRlAddAttemptsBestCellPacketLowS cuc SHO att cho data R99 tc =128 kbps

pmRlAddAttemptsBestCellStreamS cuc SHO att cho dich vu stream

pmRlAddAttemptsBestCellStandAloneS cuc SHO att cho dich vu RRC only

pmRlAddSuccessBestCellSpeechS cuc SHO succ cho dich vu thoai

pmRlAddSuccessBestCellCsConversS cuc SHO succ cho dich vu video call

pmRlAddSuccessBestCellPacketLowS cuc SHO succ cho data R99 tc =128 kbps

pmRlAddSuccessBestCellStreamS cuc SHO succ cho dich vu stream

pmRlAddSuccessBestCellStandAloneS cuc SHO succ cho dich vu RRC only

B counter chuyn giao khac tn s cell to cell:Countery nghia

CsSpeech12S cuc yu cu chuyn giao khac tn s cho dich vu thoai

CsConversationalS cuc yu cu chuyn giao khac tn s cho dich vu video cell

PsInteractiveLess64S cuc yu cu chuyn giao khac tn s cho dich vu data 64 kbps

InterFreqHoCsSpeech12S cuc chuyn giao khac tn s thanh cng cho dich vu thoai

InterFreqHoCsConversationalS cuc chuyn giao khac tn s thanh cng cho dich vu video cell

InterFreqHoPsInteractiveLess64S cuc chuyn giao khac tn s thanh cng cho dich vu data 64 kbps

RevertCsSpeech12S cuc chuyn giao khac tn s failure cho dich vu thoai, tuy nhin return v knh cu

RevertCsConversationalS cuc chuyn giao khac tn s failurecho dich vu video cell, tuy nhin return v knh cu

RevertPsInteractiveGreater64S cuc chuyn giao khac tn s failure cho dich vu data 64 kbps, tuy nhin return v knh cu

FailRevertCsConversationalS cuc chuyn giao khac tn s failure cho dich vu thoai, khng return v knh cu, rt cuc goi

FailRevertCsSpeech12S cuc chuyn giao khac tn s failurecho dich vu video cell, khng return v knh cu, rt cuc goi

FailRevertPsInteractiveGreater64S cuc chuyn giao khac tn s failure cho dich vu data 64 kbps, khng return v knh cu, rt cuc goi

TI LIU THAM KHOTi liu ting vit1. Nguyn Phm Anh Dng (2003), Gio trnh thng tin di dng th h 3, NXB Bu inTi liu ting anh1. Qalcomm (2009), Viettel Network optimization, Viettel2. Viettel (2009), Viettel callflow, Viettel3. Ericsson (2009), WCDMA RAN P7 optimization, Ericsson4. Ericsson, Th vin Alex, EricssonWebsite1. http://vntelecom.org2. http://tongquanvienthong.blogspot.com

CNUuIuUEUTRANtext

Iu PS

UE

UTRAN

CN

Uu

Iu CS

USIM

ME

Cu

Nt B

Nt B

Nt B

Nt B

RNC

RNC

MSC/VLR

SGSN

Iur

Iub

RNS

RNS

Cell DCH

Cell FACH

Cell PCH

URA PCH

Ch kt ni GSM

Ch kt ni GPRS

Ngh trong cell UTRAN

Ngh trong cell GSM/GPRS

Ch kt ni UTRA RRC

Ch Ri