MC LC

PAGE -i-

MC LC

TrangiMC LC

ivDANH MC K HIU, T VIT TT

viiiDANH MC BNG BIU

viiiDANH MC HNH V TH

xiLI NI U

1CHNG 1: TNG QUAN TNH HNH PHT TRIN CA MNG THNG TIN DI NG

11.1. Thng tin di ng v s lc s pht trin

41.2. H thng thng tin di ng 3G theo 2 nhnh cng ngh chnh

41.2.1. Hng pht trin ln 3G s dng cng ngh WCDMA

51.2.2. Hng pht trin ln 3G s dng cng ngh CDMA 2000

71.3. Mng UMTS 3G v nh hng cng ngh mng 3G ca MOBIFONE

71.3.1. nh hng cng ngh & dch v theo tiu chun chu u do 3GPP qui nh p dng cho mng MobiFone

71.3.2. Ni dung ch yu cc phin bn tiu chun 3GPP

81.3.2.1. GPP R99

101.3.2.2. 3GPP R4

111.3.2.3. 3GPP R5

131.3.2.4. 3GPP R6

141.4. Kt lun chng

15CHNG 2: H THNG TRUY NHP V TUYN UMTS

152.1. Nguyn l CDMA

152.1.1. K thut tri ph v gii tri ph

152.1.2. K thut a truy nhp CDMA

172.2. Mt s c trng lp vt l trong mng truy nhp WCDMA

172.2.1. Phng thc song cng

172.2.2. Dung lng mng

182.2.3. Cc knh giao din v tuyn UTRA FDD

192.2.4. Cu trc Cell

202.3. H thng v tuyn UMTS

202.3.1. Dch v ca h thng UMTS

212.3.2. Cu trc ca h thng UMTS

232.3.2.1. Node-B

232.3.2.2. RNC

242.3.3. Mng li CN

252.3.4. Cc giao din m c bn ca UMTS

262.3.5. Thit b ngi s dng UE

262.4. Kt lun chng

27CHNG 3: QUN L TI NGUYN MNG UMTS

273.1. Cc chc nng trong qun l ti nguyn v tuyn

273.1.1. Mc ch chung ca qun l ti nguyn v tuyn

273.1.2. Cc chc nng ca qun l ti nguyn v tuyn RRM

303.1.3. iu khin cng sut

323.1.4. iu khin chuyn giao

363.1.5. iu khin thu np

373.1.6. iu khin ti (iu khin nghn)

383.2. Cc th tc lp vt l

383.2.1. Th tc tm

393.2.2. o lng trong mng UMTS

413.2.3. Thit lp cuc gi

433.2.4. Thit lp kt ni

453.3. Kt lun chng

47CHNG 4: TI U HA MNG UMTS

474.1. Khi qut v l thuyt ti u ha

474.1.1. Mc ch ti u ha

474.1.2. Nhng iu cn bit trong vic ti u ho h thng

484.1.3. o kim cc ch s KPI trong mng UMTS

504.1.3.1. Cm nhn ca khch hng v tham s o kim nng lc KPI theo 3GPP

514.1.3.2. Phn truy nhp v tuyn UMTS

514.1.3.3. Phn li

524.1.3.4. Phn mng ngoi

4.2. Cc tham s o kim nng lc KPI mng li 534.2.1. Vng ph

544.2.2. Cht lng dch v

544.2.2.1. T l kt ni bo hiu RRC thnh cng

554.2.2.2. T l thit lp thnh cng knh mng v tuyn RAB

574.2.2.3. T l thit lp cuc gi thnh cng

584.2.2.4. T l rt cuc gi

594.2.3. Di chuyn

594.2.3.1. T l chuyn giao mm thnh cng ca RNC

614.2.3.2. T l chuyn giao cng thnh cng gia cc tn s

634.2.3.3. T l chuyn giao gia cc h thng CS

644.2.3.4. T l chuyn giao gia cc h thng PS thnh cng

664.2.3.5. T l chuyn giao gia cc h thng PS thnh cng

674.2.4. Dung lng

674.2.4.1. Thi gian truy nhp dch v CS 12.2K

684.2.4.2. Thi gian truy nhp dch v CS 64K

694.2.4.3. Tc download d liu PS trung bnh

694.2.4.4. Lu lng Erlang dch v CS

704.2.4.5. Lu lng dch v PS

714.2.4.6. Ch s nhiu ca ti ng ln

714.2.4.7. Ch s ti ng xung

714.2.5. S dng ti nguyn

714.2.5.1. T l Cell b s c

724.2.5.2. T l Cell bn

724.2.5.3. T l cell trng thi ch

724.3. Kt lun chng

74CHNG 5: MT S MINH HA CNG TC TI U HA MNG UMTS CA VMS_MOBIFONE KV III

745.1. Cc ch tiu cht lng thc t mng UMTS ca VMS MOBIFONE KV III

745.1.1. Cc ch tiu thc t mng UMTS

785.1.2. S liu thng k cht lng mng hin ti

795.1.3. S liu thng k cht lng mng hin ti TP Nng

805.2. Cng c ti u mng

805.2.1. S tng quan cu trc ca h thng Nemo Outdoor

805.2.2. S tng quan cu trc ca h thng Nemo Outdoor vi ty chn o kim cht lng thoi

815.2.3. Cc thnh phn thit b trong h thng Nemo Outdoor Multi

825.2.4. M hnh nguyn l o kim cht lng thoi vi h thng Nemo Outdoor

825.2.4.1. Cu trc h thng o kim cht lng thoi

835.2.4.2. H thng o kim cht lng thoi Mobile ti Mobile

855.2.4.3. H thng o kim cht lng thoi Mobile ti Fixed

885.3. Minh ha cng tc ti u ha mng UMTS

885.3.1. X l vn Handover li t vng WCDMA qua GSM

895.3.2. S tro i sector

905.3.3. iu chnh vng ph

935.4. Kt lun chng

95KT LUN

96TI LIU THAM KHO

DANH MC K HIU, T VIT TT

1xEV- DO

3G

3GPP

3GPP21x Evolution Data Optimized

Third Generation

Third Generation Global Partnership Project

Third Generation Global Partnership Project 2Pha 1- Ti u d liu

Th h 3

D n hi nhp ton cu th h 3

A.

AGC

AMR

AMPSAutomatic Gain Control

Adaptive Multi-Rate codec

Advanced Mobile Phone System

B iu khin tng ch t ng

B m ho v gii m a tc thch nghi

H thng in thoi di ng tin tin (M)

B.

BHCA

BER

BLER

BPSK

BSIC

BTSBusy Hour Call AttemptsBit Error Rate

Block Error Rate

Binary Phase Shift Keying

Base station identity code

Base Tranceiver Station S cuc gi trong gi bn

Tc li bitTc li Block

Kho dch pha nh phnM nhn dng trm gc

Trm gc

C.

CDG

CDMA

CN

CRCThe CDMA Development Group

Code Division Multiple Access

Core Network

Cylic Redundancy Check Nhm pht trin CDMA

Truy nhp phn chia theo m

Mng li

M vng kim tra d tha

D.

DL

DSSSDownlink

Direct Sequence Spread Spectrum ng xung

H thng tri ph chui trc tip

E.

EDGE

EIRP

ETSIEnhanced Data Rates for Evolution

Equivalent Isotropic Radiated Power

European Telecommunication Standard Institute Cc tc d liu tng cng cho s tin ho

Cng sut bc x ng hng tng ng

Vin chun ho vin thng Chu u

F.

FDD

FDMA

FERFrequency Division Duplex

Frequency Division Multiple Access

Frame Error Rate Phng thc song cng phn chia theo tn s

a truy nhp phn chia theo tn s

T s li khung

G.

GGSN

GPRS

GP

GPS

GSM

Gateway GPRS Support Node

General Packet Radio Service

Gain Processer

Global Positioning System

Global System for Mobile Telecommunication Nt h tr cng GPRS

Dch v v tuyn gi chung li x l

H thng nh v ton cuH thng vin thng di ng ton cu

H.

HLR

HSDPA

HSUPA

HOHome Location Registor

High Speed Downlink Packet Access

High Speed Uplink Packet Access

Handover B ng k thng tr

Truy nhp gi ng xung tc cao

Truy nhp gi ln xung tc cao

Chuyn giao

I.

IMT-2000

IMT- MC

IP

ITU

Iub

IurInternational Mobile Telecommunication 2000

IMT- Multicarrier

Internet Protocol

International Telecommunication Union

Thng tin di ng ton cu 2000

IMT a sng mangGiao thc Internet

Lin hp vin thng quc t

Giao din gia RNC v nt B

Giao din gia 2 RNC

K.

KPIKey performace Indicator B ch th hiu nng chnh.

L.

LOSLine of sightTm nhn thng

M.

ME

MMS

MGW

MPLS

MIMO

MSC

MSSMobile Equipment

Multimedia Messaging Service

Media Gateway

Multiprotocol Label Switching

Multi input multi output

Mobile Service Switching Centre

MSC server Thit b di ng

Dch v nhn tin a phng tin

Nt cng ca Softswitch

Chuyn mch nhn a giao thc

a phn tp Anten In/Out

Trung tm chuyn mch dch v di ngNt chuyn mch ca Softswitch

O.

OFDM

OMCOrthogonal frequency-division multiplexing

Operation Mainternance CenterGhp knh phn chia theo tn s trc giao

Trung tm iu hnh qun l khai thc

P.

PCU

PN

PPS-INPacket Control Unit

Pseudo Noise

Prepaid System - Interligent Networkn v iu khin gi

Gi tp m

H thng iu khin thu bao tr trc IN

Q.

QPSKQuardrature Phase Phase Shift Keying Kho dch pha cu phng

R.RAM

RAT

RNC

RNS

RRC

RRMRadio Access Mode

Radio Access Technology

Radio Network Controller

Radio Network subsystem

Radio Resoure Control protocol

Radio Resouse Management Ch truy nhp v tuynCng ngh truy nhp v tuynB iu khin mng v tuyn

Phn h mng v tuyn

Giao thc iu khin ti nguyn v tuyn

Thut ton qun l ti nguyn v tuyn

S.

SFN

SCP

SDP

SGSN

SHO

SIP

SIR

SMS

SNR

STPSystem Frame Number

Service Control Point

Service Data Point

Serving GPRS Support Node.

Soft Handover

Session Initiation Protocol

Signal to Interference Ratio

Short Messaging Service

Signal to Noise Ratio

Signaling Transfer PointS hiu khung h thngNt h tr iu khin dch v trong PPS-IN

Nt h tr iu khin d liu trong PPS-IN

Nt h tr GPRS phc v

Chuyn giao mmGiao thc khi to phin

T s tn hiu trn nhiu

Dch v nhn tin ngnT s tn hiu trn tp m

im chuyn tip bo hiu

T.

TDD

TDMA

TPC

TSCTime Division Duplex

Time Division Multiple Access

Transmission Power Control

Trantsit/Gateway CenterPhng thc song cng phn chia theo thi gian

a truy nhp phn chia theo thi gian

iu khin cng sut pht

Trung tm chuyn tip cuc gi

U.

UE

UL

UMTS

USIM

UTRANUser Equipment

Uplink

Universal Mobile Telecommunication System

UMTS Subscriber Identify Module UMTS Terrestrial Radio Access Network Thit b ngi s dng

ng xung

H thng vin thng di ng ton cuModul nhn dng thu bao UMTS

Mng truy nhp v tuyn mt t UMTS

V.

VLR

VOIPVisitor Location Registor

Voice Over Internet Protocol B ng k tm tr

Truyn thoi qua giao thc Internet

W.

WCDMA Wideband Code Division Multiple Access a truy nhp phn chia theo m bng rng

DANH MC BNG BIU S hiu bngTn bngTrang

1.1Cc loi QoS ca h thng UMTS21

4.1Tham s nh gi nng lc mng IP cho cc loi dch v khc nhau52

5.1Bng phn b SITE VMS MOBIFONE khu vc III74

5.2Cc ch tiu KPI thc t VMS III77

5.3Kt qu o kim ti KVIII thng 3/ 201078

5.4S liu thng k cht lng mng hin ti TP Nng79

DANH MC HNH V THS hiu hnh vTn hnh vTrang

1.1Cc gii php nng cp h thng 2G ln 3G4

1.2Qu trnh pht trin ln 3G theo nhnh s dng cng ngh WCDMA4

1.3Qu trnh pht trin ln 3G theo nhnh CDMA 20006

1.4Cu trc mng 3G theo tiu chun 3GPP R999

1.5Cu trc mng 3G theo tiu chun 3GPP R411

1.6Cu trc mng 3G theo tiu chun 3GPP R512

1.7M hnh cung cp dch v s dng giao thc SIP trn IMS13

2.1Qu trnh tri ph v gii tri ph15

2.2Cc cng ngh a truy nhp16

2.3Nguyn l ca a truy nhp tri ph16

2.4Phn b ph tn cho UMTS chu u17

2.5S nh x gia cc knh khc nhau18

2.6Cu trc cell UMTS19

2.7Cu trc tng th h thng UMTS/GSM21

2.8Cu trc ca UTRAN22

3.1Cc v tr in hnh ca cc chc nng RRM trong mng WCDMA28

3.2S so snh gia chuyn giao cng v chuyn giao mm 33

3.3Chuyn giao gia cc h thng GSM v WCDMA.34

3.4Th tc chuyn giao gia cc h thng34

3.5Nhu cu chuyn giao gia cc tn s sng mang WCDMA35

3.6Th tc chuyn giao gia cc tn s.35

3.7ng cong ti37

3.8o lng trong mng UMTS40

3.9Thit lp cuc gi42

3.10Thit lp kt ni44

4.1Quy trnh qun l cht lng mng51

4.2Phn loi cc lp KPI53

4.3S tn hiu bo hiu RRC54

4.4S tn hiu knh mang v tuyn RAB56

4.5S tn hiu kt ni cuc gi57

4.6S yu cu gii phng knh RAB t RNC n CN59

4.7S tn hiu yu cu chuyn giao60

4.8S chuyn giao gia cc h thng trong RNC61

4.9S chuyn giao gia cc h thng ca cc RNC62

4.10S chuyn giao gia cc h thng CS63

4.11S chuyn giao gia cc h thng PS65

4.12S chuyn giao gia cc h thng khc nhau (GPRS -> WCDMA)67

4.13S truy nhp dich v CS 12.2K68

4.14S truy nhp dich v CS 64K69

5.1Phn b SITE ti Thnh ph Nng75

5.2Phn b SITE ti khu vc trung tm Thnh ph Nng76

5.3S tng quan cu trc ca h thng Nemo Outdoor80

5.4S tng quan cu trc ca h thng Nemo Outdoor vi ty chn o kim cht lng thoi80

5.5Cc thnh phn thit b trong h thng Nemo Outdoor Multi81

5.6Cu trc h thng o kim cht lng thoi82

5.7H thng o kim cht lng thoi Mobile ti Mobile83

5.8Gi tr MOS kim tra c cho 2 ng downlink ca 2 MS84

5.9H thng o kim cht lng thoi Mobile ti Fixed85

5.10Thng tin v ng Line in thoi86

5.11Gi tr MOS kim tra c cho ng downlink ca MS v Server87

5.12Chuyn giao gia cc h thng ( t drivetest) 88

5.13Tn hiu chuyn giao b li RNC Qung Bnh89

5.14Tn hiu chuyn giao thnh cng sau khi khc phc li89

5.15Sector b tro i v khc phc90

5.16Vng ph mc khng t yu cu90

5.17Vng ph sau khi iu chnh92

5.18Tn hiu b che lp bi cng trnh mi xy dng v sau khi khc phc93

LI NI U

***

Trong cuc sng hng ngy thng tin lin lc ng mt vai tr rt quan trng v khng th thiu c. N quyt nh nhiu mt hot ng ca x hi, gip con ngi nm bt nhanh chng cc thng tin c gi tr vn ho, kinh t, khoa hc k thut rt a dng v phong ph.

Ngy nay vi nhng nhu cu c v s lng v cht lng ca khch hng s dng cc dch v vin thng ngy cng cao, i hi phi c nhng phng tin thng tin hin i nhm p ng cc nhu cu a dng ca khch hng mi lc, mi ni m h cn.

Thng tin di ng ngy nay tr thnh mt dch v kinh doanh khng th thiu c ca tt c cc nh khai thc vin thng trn th gii. i vi cc khch hng vin thng, nht l cc nh doanh nghip th thng tin di ng tr thnh phng tin lin lc quen thuc v khng th thiu c. Dch v thng tin di ng ngy nay khng ch hn ch cho cc khch hng giu c na m n ang dn tr thnh dch v ph cp cho mi i tng vin thng.

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 ln cht lng phc v. Vi s hnh thnh nhiu nh cung cp dch v vin thng mi to ra s cnh tranh thu ht th phn thu bao gia cc nh cung cp dch v. Cc nh cung cp dch v lin tc a ra cc chnh sch khuyn mi, gim gi v thu ht c rt nhiu khch hng s dng dch v. Cng vi , mc sng chung ca ton x hi ngy cng c nng cao khin cho s lng cc thu bao s dng dch v di ng tng t bin trong cc nm gn y.Nm 2009 l nm thng tin di ng th h th 3 chnh thc a vo phc v ti Vit Nam. Vi cng ngh WCDMA c kh nng cung cp dung lng d liu ln, tc cao em n cho ngi s dng nhng tin ch a phng tin, cng nh nhng ng dng hon ton mi m m cng ngh 2G cha c c. Mt khc s ra i ca h thng thng tin di ng th h 3 Vit Nam cng to ra s cnh tranh gia cc nh cung cp dch v thng tin di ng, c bit l ba nh mng vin thng hng u hin nay : MobiFone, Vinaphone, Viettel. Cnh tranh khng ch v c s h tng, s lng thu bao, m quan trng cn l cht lng dch v. Chnh v vy vic ti u ha mng di ng 3G UMTS l vic lm rt cn thit v mang mt ngha thc t cao.

Trn c s nhng kin thc tch lu trong nhng nm hc tp chuyn ngnh in T - Vin Thng ti trng i hc Quy Nhn v sau thi gian thc tp ti phng K thut_Khai thc thuc Trung tm di ng KVIII cng ty VMS-MobiFone cng vi s hng dn ca C L Th Cm H, em tm hiu, nghin cu v hon thnh n tt nghip vi ti Ti u ha mng UMTS. Em xin gi li cm n chn thnh ti C L Th Cm H v cc thy c Khoa K thut v cng ngh nhit tnh ging dy, quan tm gip em trong sut 5 nm em hc tp ti trng, c bit l trong qu trnh thc tp v lm n tt nghip cui kha.Em xin chn thnh cm n Trng phng Cao Vn Tun_ Phng K thut Khai thc, ng thi cng vi t trng t ti u ha anh Trn Vit Dng v cc cn b phng K thut_Khai thc thuc cng ty thng tin di ng VMS_MobiFone khu vc III trc tip hng dn v gip em hon thnh n tt nghip ny. Quy Nhn, ngy 10 thng 6 nm 2010

Sinh vin thc hin

Phan Th Hnh Dung

CHNG 1TNG QUAN TNH HNH PHT TRIN CA MNG THNG TIN DI NG

1.1. Thng tin di ng v s lc s pht trin

Trong nhng nm gn y, cng ngh khng dy l ch c nhiu chuyn gia quan tm trong lnh vc my tnh v truyn thng. Trong thi gian ny cng ngh ny c rt nhiu ngi s dng v tri qua rt nhiu thay i. Qu trnh thay i th hin qua cc th h :* Th h th nht (1G)

H thng thng tin di ng th h 1 ch h tr cc dch v thoi tng t v s dng k thut iu ch tng t mang d liu thoi ca mi ngi, v s dng phng php a truy cp phn chia theo tn s (FDMA). Vi FDMA, khch hng c cp pht mt knh trong tp hp c trt t cc knh trong lnh vc tn s. S bo hiu ca h thng FDMA kh phc tp, khi MS bt ngun hot ng th n d sng tm n knh iu khin dnh ring cho n. Nh knh ny, MS nhn c d liu bo hiu gm cc lnh v knh tn s dnh ring cho lu lng ngi dng. Trong trng hp s thu bao nhiu hn s lng knh tn s c th, th mt s ngi b chn li khng c truy cp.

c im: Mi MS c cp pht mt i knh lin lc trong sut thi gian thng tuyn. Nhiu giao thoa do cc knh ln cn l ng k. BTS phi c b thu pht ring lm vic vi mi MS.H thng FDMA in hnh l h thng in thoi di ng AMPS (Advanced Mobile Phone System). H thng di ng ny s dng phng php a truy cp n gin. Tuy nhin, h thng khng tho mn nhu cu ngy cng tng ca ngi dng v c dung lng v tc . V th, h thng di ng th 2 ra i c ci thin v c dung lng v tc .* Th h th hai (2G) Vi s pht trin nhanh chng ca thu bao, h thng thng tin di ng th h 2 c a ra p ng kp thi s lng ln cc thu bao di ng da trn cng ngh s.

Tt c h thng thng tin di ng th h 2 s dng phng php iu ch s v 2 phng php a truy cp :

a truy cp phn chia theo thi gian TDMA a truy cp phn chia theo m CDMAa truy cp phn chia theo thi gian TDMAPh quy nh cho lin lc di ng c chia thnh cc di tn lin lc, mi di tn lin lc ny c dng cho N knh lin lc, mi knh lin lc l mt khe thi gian trong chu k mt khung. Cc thu bao khc nhau dng chung knh nh ci xen khe thi gian, mi thu bao c cp pht mt khe thi gian trong cu trc khung.

c im:

Tn hiu ca thu bao c truyn dn s

Lin lc song cng mi hng thuc cc di tn lin lc khc nhau, trong mt bng tn c s dng truyn tn hiu t trm gc n cc my di ng v mt bng tn c s dng truyn tn hiu t my di ng n trm gc. Vic phn chia tn s nh vy cho php cc my thu v my pht c th hot ng cng mt lc m khng c s can nhiu ln nhau Gim s my thu BTS Gim nhiu giao thoaH thng TDMA in hnh l h thng di ng ton cu GSM. My di ng k thut s TDMA phc tp hn FDMA. H thng x l s i vi tn hiu trong MS tng t c kh nng x l khng qu 106 lnh trong 1 giy, cn trong MS s TDMA phi c kh nng x l 50x106 lnh trong 1 giy.

a truy cp phn chia theo m CDMATrong thng tin di ng CDMA s dng k thut tri ph cho nn nhiu ngi s dng c th chim cng knh v tuyn ng thi tin hnh cc cuc gi m khng s gy nhiu ln nhau. Nhng ngi s dng ni trn c phn bit vi nhau nh m tri ph gi ngu nhin PN, c cp pht khc nhau cho mi ngi s dng.

c im: Di tn tn hiu rng S dng k thut tri ph phc tp K thut tri ph cho php tn hiu v tuyn s dng c cng trng rt nh v chng fading hiu qu hn TDMA v FDMAVic cc thu bao trong cng cell dng chung tn s khin cho thit b truyn dn n gin v vic thay i , chuyn giao, iu khin dung lng cell thc hin rt linh hot* Th h th ba (3G) p ng kp thi cc dch v ngy cng phong ph v a dng ca ngi s dng, t u thp nin 90 ngi ta a ra h thng thng tin di ng t ong th h th 3. H thng thng tin di ng th h 3 vi tn gi ITM-2000 a ra cc muc tiu chnh sau:

Tc truy nhp cao m bo cc dch v bng rng nh truy cp Internet nhanh hoc cc dch v a phng tin Linh hot m bo cc dch v mi nh nh s c nhn v in thoi v tinh. Cc tnh nng ny s cho php m rng ng k tm ph sng ca cc h thng thng tin di ng Tng thch vi cc h thng thng tin di ng hin c m bo s pht trin lin tc ca thng tin di ng3G ha hn tc truyn dn ln ti 2.05 Mbps cho ngi dng tnh , 384 Kbps cho ngi dng di chuyn chm v 128 Kbps cho ngi dng trn moto. Cng ngh 3G dng sng mang 5MHz ch khng phi l sng mang 200KHz nh ca CDMA nn 3G nhanh hn rt nhiu so vi cng ngh 2G v 2,5G. Nhiu tiu chun cho h thng thng tin di ng th h 3 ITM-2000 c xut, trong 2 h thng WCDMA v cdma-2000 c ITU chp thun v ang c p dng trong nhng nm gn y. Cc h thng ny u s dng cng ngh CDMA, iu ny cho php thc hin tiu chun ton th gii cho giao din thng tin v tuyn.

Hnh 1.1 Cc gii php nng cp h thng 2G ln 3G

* Th h th t (4G)Cc nh cung cp dch v v ngi dng u lun mong mun v hng ti cc cng ngh khng dy c th cung cp c nhiu loi hnh dch v hn vi tnh nng v cht lng dch v cao hn. Vi cch nhn nhn ny, Lin minh Vin thng quc t (ITU) v ang lm vic hng ti mt chun cho mng di ng t bo mi th h th t 4G. ITU ln k hoch c th cho ra i chun ny mt vi nm ti. Cng ngh ny s cho php thoi da trn IP, truyn s liu v a phng tin vi tc cao hn rt nhiu so vi cc cng ngh ca mng di ng hin nay. V l thuyt, theo tnh ton d kin tc truyn d liu c th ln ti 288 Mb/s.1.2. H thng thng tin di ng 3G theo 2 nhnh cng ngh chnh

1.2.1. Hng pht trin ln 3G s dng cng ngh WCDMA

WCDMA l mt tiu chun thng tin di ng 3G ca IMT-2000 c pht trin ch yu Chu u vi mc ch cho php cc mng cung cp kh nng chuyn vng ton cu v h tr nhiu dch v thoi, dch v a phng tin. Cc mng WCDMA c xy dng da trn c s mng GSM, tn dng c s h tng sn c ca cc nh khai thc mng GSM. Qu trnh pht trin t GSM ln WCDMA qua cc giai on trung gian, c th c tm tt nh hnh 1.2:

Hnh 1.2 Qu trnh pht trin ln 3G theo nhnh s dng cng ngh WCDMA

GPRS: GPRS cung cp cc kt ni s liu chuyn mch gi vi tc truyn ln ti 171,2Kbps (tc s liu nh) v h tr giao thc Internet TCP/IP v X25, nh vy tng cng ng k cc dch v s liu ca GSM.

Cng vic tch hp GPRS vo mng GSM hin ti l mt qu trnh n gin. Mt phn cc khe trn giao din v tuyn dnh cho GPRS, cho php ghp knh s liu gi c lp lch trnh trc i vi mt s trm di ng. Cn mng li GSM c to thnh t cc kt ni chuyn mch knh c m rng bng cch thm vo cc nt chuyn mch s liu Gateway mi, c gi l GGSN v SGSN. GPRS l mt gii php c chun ho hon ton vi cc giao din m rng v c th chuyn thng ln 3G v cu trc mng li.

EDGE: H thng 2,5G tip theo i vi GSM l EDGE. EDGE p dng phng php iu ch 8PSK, iu ny lm tng tc ca GSM ln 3 ln. EDGE l l tng i vi pht trin GSM, n ch cn nng cp phn mm trm gc. Nu EDGE c kt hp cng vi GPRS th khi c gi l EGPRS. Tc ti a i vi EGPRS khi s dng c 8 khe thi gian l 384kbps.

WCDMA: WCDMA (Wideband Code Division Multiple Access) l mt cng ngh truy nhp v tuyn c pht trin mnh Chu u. H thng ny hot ng ch FDD & TDD v da trn k thut tri ph chui trc tip (DSSS- Direct Sequence Spectrum) s dng tc chip 3,84Mcps bn trong bng tn 5MHz. WCDMA h tr trn vn c dch v chuyn mch knh v chuyn mch gi tc cao v m bo s hot ng ng thi cc dch v hn hp vi ch gi hot ng mc hiu qu cao nht. Hn na WCDMA c th h tr cc tc s liu khc nhau, da trn th tc iu chnh tc .1.2.2. Hng pht trin ln 3G s dng cng ngh CDMA 2000

H thng CDMA 2000 gm mt s nhnh hoc giai on pht trin khc nhau h tr cc dch v ph c tng cng. Ni chung CDMA 2000 l mt cch tip cn a sng mang cho cc sng c rng n ln 1,25MHz hot ng ch FDD. Nhng cng vic chun ho tp trung vo gii php mt sng mang n 1,25MHz (1x) vi tc chip gn ging IS-95. CDMA 2000 c pht trin t cc mng IS-95 ca h thng thng tin di ng 2G, c th m t qu trnh pht trin nh hnh 1.3:

Hnh 1.3 Qu trnh pht trin ln 3G theo nhnh CDMA 2000

IS-95B: IS-95B hay CDMA One c coi l cng ngh thng tin di ng 2,5G thuc nhnh pht trin CDMA 2000, l mt tiu chun kh linh hot cho php cung cp dch v s liu tc ln n 115Kbps. CDMA 2000 1xRTT: Giai on u ca CDMA2000 c gi l 1xRTT hay ch l 1xEV-DO, c thit k nhm ci thin dung lng thoi ca IS-95B v h tr kh nng truyn s liu tc nh ln ti 307,2Kbps. Tuy nhin, cc thit b u cui thng mi ca 1x mi ch cho php tc s liu nh ln ti 153,6kbps. -CDMA 2000 1xEV-DO: 1xEV-DO c hnh thnh t cng ngh HDR (High Data Rate) ca Qualcomm v c chp nhn vi tn ny nh l mt tiu chun thng tin di ng 3G vo thng 8 nm 2001 v bo hiu cho s pht trin ca gii php n sng mang i vi truyn s liu gi ring bit.

Nguyn l c bn ca h thng ny l chia cc dch v thoi v dch v s liu tc cao vo cc sng mang khc nhau. 1xEV-DO c th c xem nh mt mng s liu xp chng, yu cu mt sng mang ring. tin hnh cc cuc gi va c thoi, va c s liu trn cu trc xp chng ny cn c cc thit b hot ng 2 ch 1x v 1xEV-DO. CDMA 2000 1xEV-DV: Trong cng ngh 1xEV-DO c s d tha v ti nguyn do s phn bit c nh ti nguyn dnh cho thoi v ti nguyn dnh cho s liu. Do CDG (nhm pht trin CDMA) khi u pha th ba ca CDMA 2000 bng cc a cc dch v thoi v s liu quay v ch dng mt sng mang 1,25MHz v tip tc duy tr s tng thch ngc vi 1xRTT. Tc s liu cc i ca ngi s dng ln ti 3,1Mbps tng ng vi kch thc gi d liu 3.940 bit trong khong thi gian 1,25ms. CDMA 2000 3x(MC- CDMA): CDMA 2000 3x hay 3xRTT cp n s la chn a sng mang ban u trong cu hnh v tuyn CDMA 2000 v c gi l MC-CDMA (Multi carrier) thuc IMT-MC trong IMT-2000. Cng ngh ny lin quan n vic s dng 3 sng mang 1x tng tc s liu v c thit k cho di tn 5MHz (gm 3 knh 1,25Mhz). S la chn a sng mang ny ch p dng c trong truyn dn ng xung. ng ln tri ph trc tip, ging nh WCDMA vi tc chip hi thp hn mt t 3,6864Mcps (3 ln 1,2288Mcps).1.3. Mng UMTS 3G v nh hng cng ngh mng 3G ca MOBIFONE

1.3.1. nh hng cng ngh & dch v theo tiu chun chu u do 3GPP qui nh p dng cho mng MobiFone

Chun 3GPP qui nh pht trin cng ngh v cu trc mng GSM 2G truyn thng pht trin ln UMTS 3G theo nhnh s dng cng ngh WCDMA vi xu hng s dng truyn ti TDM tin n mt mng "All IP" theo trnh t phin bn: 3GPP R99, 3GPP R4, 3GPP R5 v 3GPP R6. Mng Mobifone trong giai on hn 15 nm qua u t tr thnh mng GSM 2,5G v l phn u trong qu trnh chun ho 3 GPP. V vy, la chn nh hng tin trin thng tin di ng ln 3G cho mng Mobifone theo tiu chun chu u do 3GPP khuyn ngh v:

Chun ETSI cho thng tin di ng GSM ng nht cho cc nc chu u c th s dng ton cu ha thng tin di ng nh hng 3G

Mng MOBIFONE ang theo chun GSM/ETSI chu u l GSM 900/1800. UMTS tha hng nhiu phn t chc nng t GSM hin ti. Nn vic tn dng cc thit b ang c trn mng s em li nhiu thun li ln cho Mobifone. 1.3.2. Ni dung ch yu cc phin bn tiu chun 3GPP

ETSI l t chc tiu chun thng tin di ng GSM trong nhng nm 1980 v 1990. ETSI cn xy dng cu trc chun ha mng GPRS. Chun cui cng ETSI xy dng nm 1998.

3GPP thnh lp nm 1998 l t chc kt hp ca cc t chc tiu chun ha: chu u, Nht, Nam Triu tin, M v Trung quc. Mc ch chun ha h thng thng tin di ng 3G theo nh hng:

Phn truy nhp v tuyn s dng WCDMA v TD-CDMA. Phn mng li pht trin t GSM, k tha nhng nhng tiu chun ETSI do SMG xy dng.

n nm 2001, sau khi hon thnh phin bn 3GPP R99, 3GPP chia thnh hai t chc:

3GPP: xy dng cc tiu chun pht trin mng li, dch v, cu trc h thng, truy cp radio WCDMA v TD-CDMA. ETSI SMG: pht trin truy nhp radio GSM v EDGE.

Trong 3GPP xy dng cc b tiu chun trn c s nm. Phin bn u tin l 3GPP Release 99 (3GPP R99). n nay 3GPP c 04 phin bn v ang c cc nh khai thc trn th gii p dng:

3GPP release 99 (3GPP R99): chnh thc c p dng t thng 3/2001. 3GPP release 4 (3GPP R4): chnh thc c p dng t thng 9/2002. 3GPP release 5 (3GPP R5): thng 12/2003 ang c p dng. 3GPP release 6 (3GPP R6): b sung nhng im thiu trong IMS 3GPP R5 v a thm vo mt s features mi; tin ti mt mng truyn ti All IP.

Ni dung c bn tng phin bn 3GPP qui nh nh sau:

1.3.2.1. GPP R99Nhng yu cu chnh:Tp trung vo s ang hin din ca mng GSM, c 2 yu cu t ra l:

Mng UMTS phi tng thch vi mng GSM ang tn ti. Hai mng UMTS v GSM phi c kh nng lm vic tng tc.

Truy nhp v tuyn WCDMA l im mu cht nht m 3GPP R99 gii quyt. Thm vo , UTRAN cng c a ra vi giao din Iu.

So snh vi cc giao din A v Gb trong GSM, 3GPP R99 t c hai im c bn:

Chuyn i m tn kiu thoi trn Iu c mng li m nhim thay cho BTS trong GSM. M ha s liu di ng mc cell trn giao din Iu c RNC m nhn thay cho SGSN i vi GPRS.

Vy n gin, mng 3G R99 l h thng mng GSM-based. l mt mng GSM c hai mng truy cp v hai mng truy cp cung cp lu lng c tc khc nhau cho c hai min core CS v PS.

Cu hnh k thut

3GPP a ra mt phng php truy nhp v tuyn mi WCDMA. Thit b v tuyn WCDMA khng tng thch vi thit b v tuyn GSM nn phi a b sung mt h thng thit b mi l RNC v Node-B. Phn mng v tuyn WCDMA gi l UTRAN.

Mt yu cu chnh cho UMTS l hot ng tng tc GSM/UMTS. V d handover t GERAN sang UTRAN v ngc li. Yu cu ny c thc hin bi:

Th nht: hng downlink, giao din air GSM c c pht trin c th qung b thng tin sng WCDMA. Cng nh vy downlink ca radio WCDMA cng qung b thng tin v sng GSM. Th hai: nhm gim thiu u t, cc chun 3GPP yu cu 2G MSC/VLR GSM phi lm vic c vi UTRAN.

Hnh 1.4 Cu trc mng 3G theo tiu chun 3GPP R99

Cc im quan trng ca phn Core trong 3GPP R99, gm:

Cc node core trong min CS nh MSC/VLR v HLR/AuC/EIR phi thay i v phi s l ng thi c thu bao 2G v 3G.

Vi min PS: tn v s lng cc node mng GPRS ging trong 2G, nhng chc nng SGSN th rt khc. Trong 2G, SGSN m nhim chc nng qun l di ng (MM) cho ni mch gi s liu. Trong 3G chc nng MM c RNC v SGSN san s. Ngha l min PS khng qun l s thay i cell ca thu bao trong UTRAN m l RNC.1.3.2.2. 3GPP R4

Nhng yu cu chnh:Cha c IMS, ch n nh nhng thay i trong min CS core UMTS tch lung d liu ngi dng ra khi cc c ch iu khin cng mt s kha cnh khc, ch yu nh sau:

Chc nng iu khin s dng MSC Server. Chc nng chuyn mch d liu ngi s dng dng MGW. IP transport cho cc giao thc mng core. IP ha cho giao din Gb min PS.Cu hnh k thut: MSC min CS trong GSM truyn thng c 3GPP R4 tch ring chc nng iu khin s dng MSC Server vi chc nng ni mch vn chuyn lu lng s dng MGW.

MSC Server v MGW c quan h mt-nhiu. Mt MSC Server c th iu khin nhiu MGW.

V c bn 3GPP R4 khng cung cp, ci thin thm dch v.

Cu trc 3GPP R4 bt u a IP vo h thng Core CS. Cu trc softwsitch to bi MSC Server MGW to tin nh hng transport All IP. Gim chi ph truyn dn, phn lp cu trc chc nng; nh hng pht trin dch v c lp vi h tng mng.

Hnh 1.5 Cu trc mng 3G theo tiu chun 3GPP R4

im quan trng nht trong 3G R4 l: 3G R4 l ng thi IP ha ton b min CS. Truyn ti cng IP/ATM, chuyn mch cng IP/ATM. Cng ngh SOFTSWITCH c a vo nhm mc ch ny. Cng ngh SOFTSWITCH tch MSC c in thnh:

MSC-Server l phn t iu khin, ni IP giao thc MEGACO n

Media Gateway l phn t chuyn mch dch v ngi dng. Dch v ngi dng l dch v c trn min chuyn mch knh CS truyn thng, nhng li dng chuyn mch IP/ATM.1.3.2.3. 3GPP R5

Nhng yu cu chnh: a IMS vo mng UMTS, cung cp c ch v t chc multimedia. IP v cc giao thc trn IP cng s c s dng lm c ch iu khin. D liu ngi dng v c bn cng da trn IP. IP cng c s dng lm giao thc truyn thay th SS7, mt giao thc chnh ang dng trong dch v chuyn mch knh.

3GPP R5 a IMS vo tiu chun ha. IMS c h tr bi cu trc tiu chun c lp da trn IP v c ni vi cc mng thoi v s liu hin ti cho c ngi s dng mng c nh (nh PSTN, ISDN, Internet) v mobile (nh GSM, CDMA).

Kin trc IMS c kh nng thit lp truyn thng IP peer-to-peer vi tt c cc lient vi yu cu cht lng dch v. Thm vo kh nng qun l phin lm vic, kin trc IMS cng c cc chc nng a ch, m l iu cn thit t chc dch v (nh ng k, bo mt, cc, iu khin truyn thng, roaming). IMS s to nn tri tim ca mng core.

3GPP R5 cng chun ha c ch dch v IP multimedia da trn SIP. SIP cha cc chc nng phn t logic, m t phng cch ni cc phn t, a ra cc giao thc v cc th tc.

Cu hnh k thut:

Hnh 1.6 Cu trc mng 3G theo tiu chun 3GPP R5

Nhng im chnh tp trung vo:

Vn chuyn IP trn ton b h thng mng t BS n network border gateway. a IMS vo bt u ng dng cc dch v multimedia. Hp nht giao din m gia cc mng truy cp v mng core khc nhau. t c nng lc cao trn giao din v tuyn UTRAN hng downlink.

3G R5 n gin ha cu trc mng cho php cc giao thc truyn ti s dng hiu qu hn so vi 3G R4, IP ha ton b truyn ti lm n gin ha cu trc truyn ti.

V dch v, IMS ng vai tr chnh trong 3G R5 v trong c nhng pht trin dch v tng lai.

Trong pha ny, 3GPP khuyn ngh v tuyn UTRAN trin khai cng ngh HSDPA tng tc s liu downlink nhm cung cp hiu qu cc dch v khng i xng (ti s liu downlink ln hn uplink nhiu). IMS

Mt mng 3G UMTS hon thin qua 3G R99, R4 cung cp c mt h tng mng truyn ti IP linh hot cho cc terminal s dng GPRS, EDGE, v WCDMA cho cc dch v s liu.

IMS l mt gii php pht trin tch bit nhng IMS lm h tng cho php trin khai cung cp dch v trn nhiu h tng mng khc nhau. Mt trong s l mng 3G UMTS.

Hnh 1.7 M hnh cung cp dch v s dng giao thc SIP trn IMS

IMS cung cp mt c ch ni mch ni cc terminal s dng IP. Hnh 1.5, IMS dng giao thc SIP trn min PS iu khin phin cung cp cc dch v multimedia. Qua IP v qua IMS , ngi dng s dng terminal IP thit lp cc ni mch vi cc Server Dch v khc nhau nhn dch v, v c bit, dng cc dch v IP gia cc my u cui.1.3.2.4. 3GPP R6

3GPP R6 b xung nhng im thiu trong IMS 3GPP R5 v a thm vo mt s c im mi c nh hnh r rng.

Nhng ni dung khc ch l xu hng. Xu hng pht trin cc phin bn 3GPP cao hn R5 bao gm:

Hon thin IP ha ton mng UMTS Trin khai cng ngh truy cp HSUPA cho WCDMA nhm nng kh nng uplink cho cc dch dng IP Nghin cu a truy nhp v cc mng hot ng tng tc nh hng hi t1.4. Kt lun chng

Mi thc s pht trin trong vng 20 nm, nhng nhng bc tin trong cng ngh cng nh trong s pht trin th trng ca mng di ng cho thy thng tin di ng l mt nhu cu thit yu v quan trng i vi ngi dng. n nay, in thoi di khng ch dng gi in, nhn tin SMS m cn c th gi v nhn MMS, email; lu cc tp m thanh, hnh nh, d liu cng chc nng nghe nhc, gii tr; lt web, xem TV trc tuyn

Cc nh cung cp dch v v ngi dng u lun mong mun v hng ti cc cng ngh khng dy c th cung cp c nhiu loi hnh dch v hn vi tnh nng v cht lng dch v cao hn. Qua cc giai on pht trin cc th h thng tin di ng t 1G, 2G, 3G v 4G trong tng lai u gn cht vi nhu cu ca ngi dng thng qua cc tc dch v ca cc th h.

Hin nay, phn ln cc nh khai thc vin thng ln trn th gii u ln k hoch thc hin 4G cho cc vng th, ni m c nhiu cc t chc, cng ty cng nh s lng khch hng ln - cc i tng m lun mong mun cc dch v cht lng tt v tc truyn d liu cao. Tuy nhin, trc mt cc nh u t s tip tc cung cp cc dch v 3G cng nh 3,5G v n c xem nh l qu trnh thc hin tng bc cho 4G. iu ny khng ch gip h tip tc m rng vng ph sng, gia tng s lng khch hng v gip thu hi vn u t cho 3G. Vi ngi dng, h c th chuyn d dng sang cng ngh 4G, bi n gin vi h ch l s m rng cc ng dng ca mng 3G hay 3,5G m h ang dng.

CHNG 2H THNG TRUY NHP V TUYN UMTS

2.1. Nguyn l CDMA

2.1.1. K thut tri ph v gii tri ph

Tri 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 l 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 ph

Trong qu trnh gii 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 trn hnh 2.1 tn hiu ngi s dng ban u c khi phc hon ton.2.1.2. K thut a truy nhp CDMA

Mt mng thng tin di ng 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 cc 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 gia chng c ch ra hnh 2.2.

Hnh 2.2 Cc cng ngh a truy nhp

Trong h thng CDMA, cc tn hiu cho ngi s dng khc nhau c truyn i trong cng mt bng tn ti cng mt thi im. Mi tn hiu ngi s dng ng vai tr nh l nhiu i vi tn hiu ca ngi s dng khc, do dung lng ca 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 mt v dlm th no 3 ngi s dng c th truy nhp ng thi trong mt h thng CDMA.

Hnh 2.3 Nguyn l ca a truy nhp tri ph

Ti bn thu, ngi s dng 2 s gii tri ph tn hiu thng tin ca n tr li tn hiu bng hp, ch khng phi tn hiu ca bt c ngi no khc. Bi v s tng quan cho gia m ca ngi s dng mong mun v cc 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 cc h thng CDMA, nh hiu sut ph cao v dung lng mm. Tuy nhin, tt c nhng li ch yu cu vic s dng k thut iu khin cng sut mt cch nghim ngt v chuyn giao mm nhm trnh cho tn hiu ca ngi s dng ny che thng tin ca ngi s dng khc. 2.2. Mt s c trng lp vt l trong mng truy nhp WCDMA2.2.1. Phng thc song cng

Hai phng thc song cng c s dng trong kin trc WCDMA: Song cng phn chia theo thi gian (TDD) v song cng phn chia theo tn s (FDD). Phng php FDD cn hai bng tn cho ng ln v ng xung. Phng thc TDD ch cn mt bng tn. Thng thng ph tn s c bn cho cc nh khai thc theo cc di c th bng 2x10MHz hoc 2x15MHz cho mi b iu khin. Mc d c mt s c im khc nhau nhng c hai phng thc u c tng hiu sut gn ging nhau. Ch TDD khng cho php gia my di ng v trm gc c tr truyn ln, bi v s gy ra ng gia cc khe thi gian thu v pht. V vy m ch TDD ph hp vi cc mi trng c tr truyn thp, cho nn ch TDD vn hnh cc pico cell. Mt u im ca TDD l tc d liu ng ln v ng xung c th rt khc nhau, v vy m ph hp cho cc ng dng c c tnh bt i xng gia ng ln v ng xung, chng hn nh Web browsing. Trong qu trnh hoch nh mng, cc u im v nhc im ca hai phng php ny c th b tr. n ny ch tp trung nghin cu ch FDD.

Hnh 2.4 ch ra s phn b ph tn s ca h thng UMTS Chu u.

Hnh 2.4 Phn b ph tn cho UMTS chu u

2.2.2. Dung lng mng

Kt qu ca vic s dng cng ngh a truy nhp tri ph CDMA l dung lng ca cc h thng UMTS khng b gii hn cng, c ngha l mt ngi s dng c th b sung m khng gy ra nghn bi s lng phn cng hn ch. H thng GSM c s lng cc lin kt v cc knh c nh ch cho php mt lu lng ln nht c tnh ton v hoch nh trc nh s dng cc m hnh thng k. Trong h thng UMTS bt c ngi s dng mi no s gy ra mt lng nhiu b sung cho nhng ngi s dng ang c mt trong h thng, nh hng n ti ca h thng. Nu c s m th mc tng nhiu do tng ti l c cu gii hn dung lng chnh trong mng. Vic cc cell b co hp li do ti cao v vic tng dung lng ca cc cell m cc cell ln cn n c mc nhiu thp l cc hiu ng th hin c im dung lng xc nh nhiu trong cc mng CDMA. Chnh v th m trong cc mng CDMA c c im dung lng mm. c bit, khi quan tm n chuyn giao mm th cc c cu ny lm cho vic hoch nh mng tr nn phc tp.2.2.3. Cc knh giao din v tuyn UTRA FDD

Giao din v tuyn UTRA FDD c cc knh logic, chng c nh x vo cc knh chuyn vn, cc knh chuyn vn li nh x vo knh vt l. Hnh v 2.5 ch ra s cc knh v s nh x ca chng vo cc knh khc.

Hnh 2.5 S nh x gia cc knh khc nhau

2.2.4. Cu trc Cell

Trong sut qu trnh thit k ca h thng UMTS cn phi ch nhiu hn n s phn tp mi trng ca ngi s dng. Cc mi trng nng thn ngoi tri, th ngoi tri, hay th trong nh c h tr bn cnh cc m hnh di ng khc nhau gm ngi s dng tnh, ngi i b n ngi s dng trong mi trng xe c ang chuyn ng vi vn tc rt cao. yu cu mt vng ph sng rng khp v kh nng roaming ton cu, UMTS pht trin cu trc lp cc min phn cp vi kh nng ph sng khc nhau. Lp cao nht bao gm cc v tinh bao ph ton b tri t; Lp thp hn hnh thnh nn mng truy nhp v tuyn mt t UTRAN. Mi lp c xy dng t cc cell, cc lp cng thp cc vng a l bao ph bi cc cell cng nh. V vy cc cell nh c xy dng h tr mt ngi s dng cao hn. Cc cell macro ngh cho vng ph mt t rng kt hp vi cc micro cell tng dung lng cho cc vng mt dn s cao. Cc cell pico c dng cho cc vng c coi nh l cc im nng yu cu dung lng cao trong cc vng hp (v d nh sn bay). Nhng iu ny tun theo 2 nguyn l thit k bit trong vic trin khai cc mng t bo: cc cell nh hn c th c s dng tng dung lng trn mt vng a l, cc cell ln hn c th m rng vng ph sng.

Hnh 2.6 Cu trc cell UMTS

2.3. H thng v tuyn UMTS2.3.1. Dch v ca h thng UMTS

3 GPP xy dng tiu chun cho cc dch v ca h thng UMTS nhm p ng: nh ngha v cc c im yu cu ca dch v

Pht trin dung lng v cu trc dch v cho cc ng dng mng t ong, mng c nh v mng di ng

Thu bao v tnh cc

UMTS cung cp cc loi dch v xa (teleservices) nh thoi hoc bn tin ngn (SMS) v cc loi dch v mang (bearer services: mt dch v vin thng cung cp kh nng truyn tn hiu gia hai giao din ngi s dngmng). Cc mng c cc tham s Q0S (Quality of Service: cht lng dch v) khc nhau cho tr truyn dn ti a, tr truyn bin thin v t l li bit (BER). Nhng tc d liu c yu cu l :

144 Kbps cho mi trng v tinh v nng thn 384 Kbps cho mi trng thnh ph (ngoi tri)

2084 Kbps cho mi trng trong nh v ngoi tri vi khong cch gn

H thng UMTS c 4 loi QoS sau:

Loi hi thoi (thoi, thoi thy hnh, tr chi)

Loi lung (a phng tin, video theo yu cu)

Loi tng tc (duyt web, tr chi qua mng, truy nhp c s d liu)

Loi c bn (th in t, SMS, ti d liu xung)

Yu t ch yu phn bit cc loi ny l nhy cm vi tr, v d nh hi thoi rt nhy vi tr cn loi c bn th t nhy cm vi tr nht.Bng 1.1 Cc loi Q0S ca h thng UMTS

Loi lu lngLoi hi thoiLoi lungLoi tng tcLoi c bn

Cc c tnh c bnDnh trc quan h thi gian gia cc thc th thng tin ca lung .

Mu hi thoi (cht ch v tr nh)Dnh trc quan h thi gian gia cc thc th thng tin ca lungYu cu mu tr li trc

Dnh trc s liu ton vn Ni nhn khng i s liu trong khong thi gian nht nh

Dnh trc s liu ton vn

Th d v ng dng- Thoi

- Thoi thy hnhLung a phng tin- Duyt Web

- Cc tr chi qua mng- Ti d liu xung

- Email

2.3.2. Cu trc ca h thng UMTS

Mt h thng UMTS sau khi c nng cp v m rng t h thng GSM hin c th cu trc h thng c th c m t tng quan nh hnh 2.7:

Hnh 2.7 Cu trc tng th h thng UMTS/GSM

Trong UTRAN 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 Node-B.

Cc yu cu chnh thit k kin trc, giao thc v chc nng UTRAN:

Hnh 2.8 Cu trc ca UTRAN Tnh h tr ca UTRAN v cc chc nng lin quan: Yu cu tc ng n 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 UTRAN n min chuyn mch gi v chuyn mch knh ca mng li.

Lm tng tnh tng ng vi GSM.

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.

Cc thit b UTRAN vi chi ph CAPEX v OPEX c tit kim ti a. ng thi cc thit b UTRAN c thit k module ha v v c tnh linh hot hp l cho vic m rng dung lng trong tng lai. H thng UTRAN c kh nng nng cp ln phin bn phn mm cao hn m ch gy ra tc ng rt nh ti hot ng thng thng ca h thng.2.3.2.1. Node-B

Node-B l mt thut ng s dng trong UMTS biu th BTS (trm thu pht gc) v s dng cng ngh WCDMA trn ng v tuyn. Cng nh trong tt c cc h thng t ong UMTS v GSM, Node B thc hin vic thu pht tn s v tuyn lin lc trc tip vi cc my di ng di chuyn t do xung quanh n.

Mt cch truyn thng, cc Node B c nhng chc nng ti thiu v thu pht v tuyn v c iu khin bi RNC (Radio Network Controller). Vic s dng cng ngh WCDMA cho php mt cell thuc mt Node B hoc cc Node B khc nhau cng c qun l bi cc RNC khc nhau chng ln nhau v vn s dng mt tn s ging nhau (trn thc t, ton b mng c th dng ch mt cp tn s).

Chc nng chnh ca Node B l thc hin x l L1 ca giao din v tuyn (m ho knh, an xen, thch ng tc , tri ph,). N cng thc hin mt phn khai thc qun l ti nguyn v tuyn nh iu khin cng sut vng trong. V phn chc nng n ging nh trm gc GSM. Lc u Node B c s dng nh l mt thut ng tm thi trong qu trnh chun ho nhng sau n khng b thay i.

Node B bao gm cc loi cu hnh: Macro Indoor, Macro Outdoor, Mini Indoor, Mini outdoor, Micro Indoor, Micro Outdoor, Pico,...

2.3.2.2. RNC (Radio Network Control)

RNC l mt thnh phn trong mng truy nhp v tuyn UTMS. RNC v c bn c nhng chc nng ging BSC trong h thng BSS GSM:

Trung gian gia trm gc (Node B trong UMTS) v h thng mng li. iu khin cuc gi v tuyn (qun l ti nguyn v tuyn, iu khin v qun l chuyn giao cuc gi )RNC c kt ni n:

Mng li, qua giao tip Iu.

Cc Node B qua giao tip Iub. Mt Node B thc hin giao tip v tuyn vi mt hoc nhiu cell.

RNC l phn t mng chu trch nhim iu khin cc ti nguyn v tuyn ca UTRAN. N giao din vi CN (thng thng vi mt MSC v mt SGSN) v kt cui giao thc iu khin ti nguyn v tuyn RRC (Radio Resource Control), giao thc ny nh ngha cc bn tin v cc th tc gia MS v UTRAN. N ng vai tr nh BSC.

Cc chc nng chnh 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

Mt s RNC ln cn qua giao tip Iur2.3.3. Mng li CN (Core Network)

Nhng chc nng chnh ca vic nghin cu mng li UMTS l:

Qun l, iu khin bo hiu thit lp cuc gi gia UE v mng li. Bo hiu gia cc nt trong mng li

nh ngha cc chc nng gia mng li v cc mng bn ngoi

Nhng vn lin quan n truy nhp gi

Giao din Iu v cc yu cu qun l v iu hnh mng

Mng li UMTS gm 2 thnh phn: chuyn mch knh v chuyn mch gi.

Thnh phn chuyn mch knh gm: MSC, VLR v cng MSC. Thnh phn chuyn mch gi gm nt h tr dch v GPRS (SGSN: Serving GPRS Support Node) v cng nt h tr GPRS (GGSN: Gateway GPRS Support Node). Mt s thnh phn ca mng nh HLR v AUC c chia s cho c hai phn. Cu trc ca mng li c th c thay i khi cc dch v mi v cc c im mi ca h thng c a ra.

Cc phn t chnh ca mng li nh sau :

HLR (Home Location Register) : Thanh ghi nh v thng tr) l mt c s d liu c t ti h thng ch nh ca ngi s dng lu tr thng tin chnh v l lch dch v ca ngi s dng, bao gm thng tin v cc dch v b sung nh trng thi chuyn hng cuc gi, s ln chuyn hng cuc gi.

MSC/VLR (Mobile Service Switching Center: Trung tm chuyn mch dch v di ng) l tng i (MSC) v c s d liu (VLR) cung cp cc dch v chuyn mch knh cho UE ti v tr hin thi ca n. Nhim v ca MSC l s dng cc giao dch chuyn mch knh. VLR lm nhim v gi bn sao v l lch ca ngi s dng cng nh v tr chnh xc hn ca UE trong h thng ang phc v. CS l phn mng c truy nhp qua MSC/VLR.

GMSC (Gateway MSC) :l chuyn mch ti im kt ni UMTS PLMN vi mng CS bn ngoi.

SGSN (Serving GPRS) : General Packet Radio Network Service Node) c chc nng ging nh MSC/VLR nhng c s dng cho cc dch v chuyn mch gi PS (Packet Switch). Vng PS l phn mng c truy nhp qua SGSN.

GGSN (Gateway GPRS Support Node) : c chc nng ging nh cc dch v in thoi, v d nh ISDN hoc PSTN.

Cc mng PS m bo cc kt ni cho nhng dch v chuyn mch gi, v d nh Internet.2.3.4. 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 m UE truy cp c vi phn c nh ca h thng v y l phn giao din m quan trng nht trong UMTS.

Giao din Iu: Giao din ny kt ni UTRAN ti mng li. Tng t nh cc giao din tng thch trong GSM nh l giao din A (i vi chuyn mch knh) v Gb (i vi chuyn mch gi). Giao din Iu 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 Node 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. Ging nh cc giao din m khc, Iub thc y hn na tnh cnh tranh gia cc nh sn xut trong lnh vc ny.2.3.5. Thit b ngi s dng UE (User Equipment)

UE l s kt hp gia thit b di ng v module nhn dng thu bao USIM (UMTS subscriber identity). Ging nh SIM trong mng GSM/GPRS, USIM l th c th gn vo my di ng v nhn dng thu bao trong mng li.

Thit b di ng (ME: Mobile Equipment) l u cui v tuyn c s dng cho thng tin v tuyn giao din Uu.

Modun nhn dng thu bao UMTS (USIM: UMTS Subscriber Identity Modulo) l mt th thng minh cha thng tin nhn dng thu bao, thc hin cc thut ton nhn thc v lu gi cc kho nhn thc cng mt s thng tin thu bao cn thit cho u cui.

2.4. Kt lun chng

H thng truy nhp v tuyn UMTS 3G da trn cng ngh truy nhp bng rng phn chia theo m WCDMA v n nay h thng ny c chun ha v s dng rng ri trn th gii. Trong kin trc h thng truy nhp v tuyn 3G (UTRAN) 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 Node-B.

Qun l ti nguyn v tuyn l bi ton quan trng khi thit k bt k h thng thng tin di ng, c bit l trong h thng t bo s dng cng ngh a truy nhp phn chia theo m CDMA. Chng ny trnh by cc chc nng c bn ca qun l ti nguyn v tuyn trong h thng WCDMA, trong iu khin cng sut v iu khin chuyn giao l cc chc nng c bit quan trng so vi cc h thng thng tin di ng trc .

CHNG 3QUN L TI NGUYN MNG UMTS

3.1. Cc chc nng trong qun l ti nguyn v tuyn3.1.1. Mc ch chung ca qun l ti nguyn v tuyn

Vic qunl ti nguyn v tuyn (RRM) trong mng di ng 3G c nhim v ci thin vic s dng ngun ti nguyn v tuyn. Cc mc ch ca cng vic qun l ti nguyn v tuyn RRM c th tm tt nh sau:

m bo QoS cho cc dch v khc nhau.

Duy tr vng ph sng c hoch nh.

Ti u dung lng h thng.

Trong cc mng 3G, vic phn b ti nguyn v nh c qu ti ca mng khng cn kh thi na do cc nhu cu khng d on trc v cc yu cu khc nhau ca cc dch v khc nhau. V th, qun l ti nguyn bao gm 2 phn: t cu hnh v t li cu hnh ti nguyn v tuyn.

Vic t cu hnh ti nguyn v tuyn c nhim v phn pht ngun ti nguyn mt cch hp l cho cc yu cu mi ang a n h thng cho mng khng b qu ti v duy tr tnh n nh. Tuy nhin, nghn c th xut hin trong mng 3G v s di chuyn ca ngi s dng.

Vic t li cu hnh c nhim v cp pht li ngun ti nguyn trong phm vi ca mng khi hin tng nghn bt u xut hin. Chc nng ny c nhim v a h thng b qu ti tr v lu lng ti mc tiu mt cch nhanh chng v c th iu khin c.

3.1.2. Cc chc nng ca qun l ti nguyn v tuyn RRM

Qun l ngun ti nguyn v tuyn c th chia thnh cc chc nng: iu khin cng sut, chuyn giao, iu khin thu nhn, iu khin ti v lp lch cho gi tin.

Hnh 3.1 ch ra cc v tr in hnh ca cc chc nng RRM trong phm vi ca mt mng WCDMA.

Hnh 3. 1 Cc v tr in hnh ca cc chc nng RRM trong mng WCDMA

iu khin cng sut

iu khin cng sut l mt cng vic quan trng trong tt c cc h thng di ng v vn tui th ca pin v cc l do an ton, nhng trong cc h thng CDMA, iu khin cng sut l cn thit bi v c im gii hn nhiu ca CDMA.

Trong cc h thng GSM, ch p dng iu khin cng sut chm (tn s xp x 2Hz). Trong IS-95, iu khin cng sut nhanh vi tn s 800Khz c h tr ng ln, nhng trn ng xung, mt vng iu khin cng sut tng i chm (xp x 50Hz) iu khin cng sut truyn. Trong WCDMA, iu khin cng sut nhanh vi tn s 1,5KHz c s dng trn c ng ln v ng xung. iu khin cng sut nhanh khp kn l mt vn quan trng ca h thng WCDMA.

iu khin chuyn giao

Chuyn giao l mt phn quan trng ca h thng thng ti di ng t bo. S di chuyn gy ra s bin i cht lng lin kt v cc mc nhiu trong cc h thng t bo, yu cu khi mt ngi s dng c th thay i trm gc phc v n. S thay i ny c gi l chuyn giao.

iu khin thu np

Nu ti giao din v tuyn c cho php tng ln mt cch lin tc, vng ph sng ca cell b gim i di gi tr hoch nh (gi l cell breathing), v QoS ca cc kt ni ang tn ti khng th m bo. Nguyn nhn ca hiu ng cell breathing l v c im gii hn nhiu ca cc h thng CDMA. V th, trc khi thu nhn mt kt ni mi, iu khin thu np cn kim tra xem vic nhn kt ni mi s khng nh hng n vng ph sng hoc QoS ca cc kt ni ang hot ng. iu khin thu np chp nhn hay t chi yu cu thit lp mt b mang truy nhp v tuyn trong mng truy nhp v tuyn. Chc nng iu khin thu np c t trong b iu khin mng v tuyn RNC, ni m lu gi thng tin v ti ca mt s cell.

Thut ton iu khin thu np tnh ton vic ti tng ln m do s thit lp thm vt mang s gy ra trong mng truy nhp v tuyn. Vic tnh ton ti c p dng cho c ng ln v ng xung. B mang yu cu c th c chp nhn ch khi iu khin thu np trong c 2 chiu chp nhn, nu khng th n b t chi bi v nhiu qu mc c th tng thm trong mng.

Ch rng vic iu khin thu np c p dng mt cch tch bit trn c ng ln v ng xung, v mi hng c th s dng cc chin lc iu khin thu np khc nhau.

iu khin ti (iu khin nghn)

Mt cng c quan trng ca chc nng qun l ngun ti nguyn v tuyn l m bo cho h thng khng b qu ti v duy tr tnh n nh. Nu h thng c quy hoch mt cch hp l, v cng vic iu khin thu np hot ng tt, cc tnh hung qu ti s b loi tr. Tuy nhin, trong mng di ng, s qu ti mt ni no l khng th trnh khi v cc ti nguyn v tuyn c n nh trc trong mng. Khi qu ti c x l bi iu khin ti, hay cn gi l iu khin nghn, hot ng iu khin ny s tr li cho h thng ti mc tiu, c vch ra trong qu trnh quy hoch mng mt cch nhanh chng v c kh nng iu khin c. Cc hot ng iu khin ti lm gim hay cn bng ti c lit k nh sau:

T chi cc lnh cng sut ti trn ng xung nhn t MS.

Gim ch tiu Eb/I0 ng ln s dng bi iu khin cng sut nhanh ng ln.

Thay i kch c ca min chuyn giao mm phc v nhiu ngi s dng hn.

Chuyn giao ti sng mang WCDMA khc (mng UMTS khc hay mng GSM).

Gim thng lng ca lu lng d liu gi (cc d liu phi thi gian thc).

Ngt cc cuc gi trn mt ng iu khin.

Hai hot ng u tin l cc hot ng nhanh c thc hin bn trong BS. Cc hot ng ny c th din ra trong mt khe thi gian, ngha l vi mt tn s 1,5KHz, cung cp mt quyn u tin cho cc dch v khc nhau. Hot ng th 3 thay i kch c ca min chuyn giao mm c mt li ch c bit i vi mng gii hn ng xung.

Cc phng php iu khin ti khc th chm hn. Chuyn giao bn trong bng tn v chuyn giao bn trong h thng c th khc phc c hin tng qu ti bng cch cn bng ti. Hot ng cui cng l ngt cc ngi s dng dch v thi gian thc (thoi hay d liu chuyn mch knh) gim ti. Hot ng ny ch c s dng ch khi ti ca ton b mng vn rt ln thm ch sau khi cc hot ng iu khin ti khc va c tc dng gim qu ti. Giao din v tuyn WCDMA v yu cu tng ca lu lng phi thi gian thc trong mng 3G em li nhiu s la chn cc hot ng kh thi iu khin tnh hung qu ti, v th nhu cu ct nhng ngi s dng dch v thi gian thc gim qu ti rt him xy ra.3.1.3. iu khin cng sut

Cc mc tiu ca iu khin cng sut c th tm tt nh sau:

Khc phc hiu ng gn-xa trn ng ln.

Ti u dung lng h thng bng vic iu khin nhiu.

Lm tng ti a tui th pin ca u cui di ng.

Mc tiu ca vic s dng iu khin cng sut l khc nhau trn ng ln v ng xung. Cc mc tiu ca iu khin cng sut c th tm tt nh sau:

Khc phc hiu ng gn-xa trn ng ln.

Ti u dung lng h thng bng vic iu khin nhiu.

Lm tng ti a tui th pin ca u cui di ng.

C 3 kiu iu khin cng sut trong cc h thng WCDMA: iu khin cng sut vng m, iu khin cng sut vng kn v iu khin cng sut vng bn ngoi.

iu khin cng sut vng m (Open-loop power control)

iu khin cng sut vng m c s dng trong h thng UMTS FDD cho vic thit lp nng lng ban u cho MS. MS s tnh suy hao ng truyn gia cc trm gc v MS bng cch o cng tn hiu nhn c bng cch s dng mch iu khin tng ch t ng (AGC). Tu theo s tnh ton suy hao ng truyn ny, MS c th quyt nh cng sut pht ng ln ca n. iu khin cng sut vng m c nh hng ln trong h thng TDD bi v ng ln v ng xung l tng h, nhng khng nh hng nhiu trong cc h thng FDD bi v cc knh ng ln v ng xung hot ng trn cc bng tn khc nhau v hin tng Fading Rayleigh trn ng ln v ng xung c lp nhau. Vy iu khin cng sut vng m ch c th b mt cch tng trng suy hao do khong cch. l l do ti sao iu khin cng sut vng m ch c s dng nh l vic thit lp nng lng ban u trong h thng FDD.iu khin cng sut vng kn (Fast power Control)

iu khin cng sut vng khp kn, c gi l iu khin cng sut nhanh trong cc h thng WCDMA, c nhim v iu khin cng sut pht ca MS (ng ln) hay l cng sut ca trm gc (ng xung) chng li Fading ca cc knh v tuyn v t c ch tiu t s tn hiu trn nhiu SIR c thit lp bi iu khin cng sut vng ngoi. Chng hn nh trn ng ln, trm gc so snh SIR nhn c t MS vi SIR mc tiu trong mi khe thi gian (0,666ms). Nu SIR nhn c ln hn mc tiu, Node-B s truyn mt lnh TPC 0 n MS thng qua knh iu khin ring ng xung. Nu SIR nhn c thp hn mc tiu, Node-B s truyn mt lnh TPC 1 n MS. Bi v tn s ca iu khin cng sut vng kn rt nhanh nn c th b c Fading nhanh v c Fading chm.

iu khin cng sut vng ngoi

iu khin cng sut vng ngoi cn thit gi cht lng truyn thng vi cc mc yu cu bng cch thit lp mc tiu cho iu khin cng sut vng kn nhanh thc hin. Mc ch ca n l cung cp cht lng yu cu. Tn s ca iu khin cng sut vng bn ngoi thng l 10-100Hz.

iu khin cng sut vng ngoi so snh cht lng nhn c vi cht lng yu cu. Thng thng, cht lng c nh ngha l t li bit mc tiu xc nh (BER) hay t s li khung (FER). Mi quan h gia SIR mc tiu v mc tiu cht lng tu thuc vo tc di ng v hin tng a ng. Nu cht lng nhn tt hn, c ngha l mc tiu SIR cao m bo QoS yu cu. 3.1.4. iu khin chuyn giao

Chuyn giao trong cng tn s

Chuyn giao mm

Chuyn giao mm ch c trong cng ngh CDMA. So vi chuyn giao cng thng thng, chuyn giao mm c mt s u im. Tuy nhin, n cng c mt s cc hn ch v s phc tp v vic tiu th ti nguyn tng ln. Trong phn ny s trnh by nguyn l ca chuyn giao mm.

Nguyn l chuyn giao mm

Chuyn giao mm khc vi qu trnh chuyn giao cng truyn thng. i vi chuyn giao cng, mt quyt nh xc nh l c thc hin chuyn giao hay khng v my di ng ch giao tip vi mt BS ti mt thi im. i vi chuyn giao mm, mt quyt nh c iu kin c to ra l c thc hin chuyn giao hay khng li tu thuc vo s thay i cng tn hiu knh hoa tiu t hai hay nhiu trm gc c lin quan, mt quyt nh cng cui cng s c to ra giao tip vi duy nht 1 BS. iu ny thng din ra sau khi tn hiu n t mt BS chc chn s mnh hn cc tn hiu n t BS khc. Trong thi k chuyn tip ca chuyn giao mm, MS giao tip ng thi vi cc BS trong tp hp tch cc (Tp hp tch cc l danh sch cc cell hin ang c kt ni vi MS).

Hnh 3.2 S so snh gia chuyn giao cng v chuyn giao mm

li lin kt chuyn giao mm

Mc ch u tin ca chuyn giao mm l em li mt s chuyn giao khng b ngt qung v lm cho h thng hot ng tt. iu ch c th t c nh 3 li ch ca c cu chuyn giao mm nh sau:

li phn tp v m: li ch phn tp nh Fading chm v s st t ngt ca cng tn hiu do cc nguyn nhn chng hn nh s di chuyn ca MS vng quanh mt gc.

li phn tp vi m: li phn tp nh Fading nhanh.

Vic chia s ti ng xung: Mt MS khi chuyn giao mm thu cng sut t nhiu Node-B, iu cho thy cng sut pht ln nht n MS trong khi chuyn giao mm X-way c nhn vi h s X, ngha l vng ph c m rng.

Ba li ch ny ca chuyn giao mm c th ci thin vng ph v dung lng mng WCDMA. Chuyn giao gia cc h thng WCDMA v GSM

Cc chun WCDMA v GSM h tr chuyn giao c hai ng gia WCDMA v GSM. S chuyn giao ny c th s dng cho mc ch ph sng v cn bng ti. Ti pha ban u khi trin khai WCDMA, chuyn giao ti h thng GSM c th s dng gim ti trong cc t bo GSM. Khi lu lng trong mng WCDMA tng, th rt cn chuyn giao cho mc ch ti trn c ng ln v ng xung. Chuyn giao gia cc h thng c khi xng ti RNC/BSC v t gc h thng thu th chuyn giao gia cc h thng tng t nh chuyn giao gia cc RNC hay chuyn giao gia cc BSC. Thut ton v vic khi xng ny khng c chun ho.

Hnh 3.3 Chuyn giao gia cc h thng GSM v WCDMA

Vic o c chuyn giao gia cc h thng khng hot ng thng xuyn nhng s c khi ng khi c nhu cu thc hin chuyn giao gia cc h thng. Vic khi xng chuyn giao l mt thut ton do RNC thc hin v c th da vo cht lng (BLER) hay cng sut pht yu cu. Khi khi xng o c, u tin UE s o cng sut tn hiu ca cc tn s GSM trong danh sch ln cn. Khi kt qu o c c gi ti RNC, n ra lnh cho MS gii m nhn dng trm gc (BSIC) ca cell GSM ng c tt nht. Khi RNC nhn c BSIC, mt lnh chuyn giao c gi ti MS.

Hnh 3.4 Th tc chuyn giao gia cc h thng

Chuyn giao gia cc tn s trong WCDMA

Hu ht cc b vn hnh UMTS u c 2 hoc 3 tn s FDD c hiu lc. Vic vn hnh c th bt u s dng mt tn s, sau tng dung lng, mt vi tn s c s dng trong cng mt site s tng dung lng ca site hoc cc lp micro v macro c s dng cc tn s khc nhau. Chuyn giao gia cc tn s sng mang WCDMA cn s dng phng php ny.

Trong chuyn giao ny, ch nn cng c s dng trong vic o c chuyn giao ging nh trong chuyn giao gia cc h thng. MS cng s dng th tc ng b WCDMA ging nh chuyn giao trong tn s nhn dng cell c tn s mc tiu. Thi gian nhn dng cell ch yu ph thuc vo s cc cell v s cc thnh phn a ng m MS c th thu c ging nh trong chuyn giao cng tn s.

Hnh 3.5 Nhu cu chuyn giao gia cc tn s sng mang WCDMA

Hnh 3.6 Th tc chuyn giao gia cc tn s3.1.5. iu khin thu np

Nu ti giao din v tuyn c cho php tng ln mt cch lin tc th vng ph sng ca cell b gim i di gi tr hoch nh (gi l cell breathing) v QoS ca cc kt ni ang tn ti khng th m bo. Nguyn nhn ca hiu ng cell breathing l v c im gii hn nhiu ca cc h thng CDMA. V th, trc khi thu nhn mt kt ni mi, iu khin thu np cn kim tra xem vic nhn kt ni mi s khng nh hng n vng ph sng hoc QoS ca cc kt ni ang hot ng hay khng. iu khin thu np chp nhn hay t chi yu cu thit lp mt truy nhp v tuyn trong mng truy nhp. Chc nng iu khin thu np c t trong b iu khin RNC, ni m lu gi thng tin v ti ca cc s cell do n qun l.

Thut ton iu khin thu np tnh ton vic ti tng ln do s thit lp thm i tng s gy ra trong mng truy nhp v tuyn. Vic tnh ton ti c p dng cho c ng ln v ng xung. u cui yu cu c th c chp nhn ch khi iu khin thu np trong c 2 chiu chp nhn, nu khng th n b t chi bi v nhiu qu mc c th tng thm trong mng. Nhn chung cc chin lc iu khin thu np c th chia thnh hai loi: chin lc iu khin thu np da vo cng sut bng rng v chin lc iu khin thu np da vo thng lng. Ngi s dng mi s khng c chp nhn nu mc nhiu tng th mi to ra cao hn gi tr mc ngng Ithreshold, c th:

+ T chi: Itotal-old + (I > Ithreshold

+ Chp nhn : Itotal-old + (I < Ithreshold

Gi tr ngng ging vi tng nhiu ng ln ln nht v c th c thit lp bi vic quy hoch mng v tuyn.

Hnh 3.7 ng cong tiTrong chin lc iu khin thu np da vo thng lng, ngi s dng mi khng c thu nhn truy nhp vo mng nu ton b ti mi gy ra cao hn gi tr ngng:

+ T chi : (total-old + (L > (threshold

+ Chp nhn : (total-old + (L < (thresholdTng t i vi chin lc iu khin thu np da vo cng sut nh sau:

+ T chi : Ptotal-old + (Ptotal > Pthreshold

+ Chp nhn : Ptotal-old + (Ptotal < PthresholdCh rng vic iu khin thu np c p dng mt cch tch bit trn c ng ln v ng xung. V mi hng c th s dng cc chin lc iu khin thu np khc nhau.3.1.6. iu khin ti (iu khin nghn)

y l mt cng c quan trng ca chc nng qun l ngun ti nguyn v tuyn m bo cho h thng khng b qu ti v duy tr tnh n nh. Nu h thng c quy hoch mt cch hp l v cng vic iu khin thu np hot ng tt, cc tnh hung qu ti gn nh s b loi tr. Tuy nhin, trong mng di ng, s qu ti mt ni no l khng th trnh khi v cc ti nguyn v tuyn c n nh trc trong mng. Khi qu ti c x l bi iu khin ti hay cn gi l iu khin nghn th hot ng iu khin ny s tr li cho h thng ti mc tiu chn c a ra trong qu trnh quy hoch mng mt cch nhanh chng v c kh nng iu khin c. Cc hot ng iu khin ti lm gim hay cn bng ti bao gm: T chi cc lnh cng sut ti trn ng xung nhn t MS.

Gim ch tiu Eb/I0 ng ln s dng bi iu khin cng sut nhanh ng ln.

Thay i kch c ca min chuyn giao mm phc v nhiu ngi s dng hn.

Chuyn giao ti sng mang WCDMA khc (mng UMTS khc hay mng GSM).

Gim thng lng ca lu lng d liu gi (cc d liu phi thi gian thc).

Ngt cc cuc gi trn mt ng iu khin.

Hai hot ng u tin l cc hot ng nhanh c thc hin bn trong BS. Cc hot ng ny c th din ra trong mt khe thi gian, ngha l vi mt tn s 1,5KHz, cung cp mt quyn u tin cho cc dch v khc nhau. Hot ng th 3 thay i kch c ca min chuyn giao mm c mt li ch c bit i vi mng gii hn ng xung.

Cc phng php iu khin ti khc th chm hn. Chuyn giao bn trong bng tn v chuyn giao bn trong h thng c th khc phc c hin tng qu ti bng cch cn bng ti. Hot ng cui cng l ngt cc ngi s dng dch v thi gian thc (nh l thoi hay d liu chuyn mch knh) gim ti. Hot ng ny ch c s dng ch khi ti ca ton b mng vn rt ln thm ch sau khi cc hot ng iu khin ti khc va c tc dng gim qu ti. Giao din v tuyn WCDMA v yu cu tng ca lu lng phi thi gian thc trong mng 3G em li nhiu s la chn cc hot ng kh thi iu khin tnh hung qu ti v v th nhu cu ct nhng ngi s dng dch v thi gian thc gim qu ti rt him xy ra.3.2. Cc th tc lp vt l

3.2.1. Th tc tm

Th tc tm s dng knh ng b gm 3 bc c bn, mc d t quan im tiu chun khng c yu cu no i vi vic thc hin cc bc no v khi no. Tiu chun ch t ra yu cu v thi gian tm cc i so vi cc iu kin kin tra. Cc bc in hnh vi tm ban u nh sau:

UE tm m ng b s cp 256 chip ging nhau cho tt c cc . V m ng b s cp nh nhau cho tt c cc khe, gi tr nh tng quan nhn c s tng ng vi bin gii khe.

Trn c s tm c m ng b s cp, UE tm nh tng quan ln nht t SCH th cp. C tt c 64 kh nng t SCH th cp. UE cn kim tra 15 v tr, cha th c bin gii chung khi cha pht hin c t m ca SCH th cp.

Khi tm c SCH th cp, UE bit c ng b khung. Khi ny UE tm m ngu nhin s cp thuc mt nhm nht nh. Mi nhm gm 8 m ngu nhin s cp. UE ch cn kim tra mt v tr ca cc m ny v im khi u bit.

Khi thit lp cc thng s ca mng cn lu n cc thuc tnh ca s ng b t c hiu qu hot ng ti u. i vi tim ban u, iu ny s hu nh khng c nh hng, nhng iu ny c th cho php ti u qu trnh tm ch chuyn giao. V mt nguyn l v c rt nhiu nhm m, nn khi quy hoch thc t, trong nhiu trng hp ta c th thc hin danh sch cc ln cn i vi mt thuc mt nhm m khc. Nh vy UE c th tm ch v hon ton b bc 3 bng cch ch khng nh pht hin, ch khng cn so snh cc m ngu nhin khc nhau cho bc ny.Cc bin php tip theo ci thin hiu nng tm gm kh nng cung cp thng tin lin quan n nh thi tng i gia cc . Ni chung loi thng tin ny c UE o cho mc ch chuyn giao v n c th c s dng ci thin c bit hiu nng ca bc 2. Nu thng tin nh thi tng i cng chnh xc th cng cn kim tra t v tr hn i vi m SCH th cp v xc sut pht hin ng cng tt hn.3.2.2. o lng trong mng UMTS

Trong sut qu trnh hat ng, UE lun o lng mi trng v gi bo co v mng c nhng iu khin kp thi tng ng vi cht lng mng. Trong bi ny ti gii thiu s v cc gi tr o lng chnh l h thng s dng iu khin qu trnh hat ng ca n.

Hnh 3.8 o lng trong mng UMTSo lng cng sut, c thc hin b cc UE gi v cho RNC thng qua knh CPICH, gm cc thng s chnh sau:

Ec/No: l t s gia mt cng sut ca tn hiu CPICH trn mt cng sut ca tan bng tn. Thng s ny c s dng cho vic chn cell v cc th tc chuyn giao.

RSCP: l tn mc cng sut ca m tn hiu nhn c da trn cc bit ca knh CPICH, ch rng y l cng sut ca mt chip ch khng phi cng sut ca bit d liu. Ngai vic phc v cho chn cell chuyn giao, thng s ny cn c s dng cho vic tnh ton suy hao ng truyn cng nh iu khin cng sut trong mng.

RSSI: y l t hiu cng sut ca cc mng GSM. Thng s ny c o kim phc v qu trnh cuyn giao 3G-2G.

SIR: T s tn hiu trn nhiu c o li Node B v UE l tch gia hn s tri ph SF v t s gia cng sut m tn hiu nhn c (RSCP) trn cng sut m tn hiu nhiu (ISCP). Thng s ny c s dng ch yu trong qu trnh iu khin cng sut.

PathLoss: l chnh lch gia cng sut pht v cng sut thu ca tn hiu CPICH, phn nh cht lng ng truyn v c s dng khi to mc cng sut cho PRACH v qu trnh handover gia hai tn s.Ngoi ra cn cc thng s nh BER, RTT, tr c node B o t ch yu trn giao din Iub nh gi cht lung ca ng truyn ny thc hin cc qu trnh iu khin v phn b ti nguyn cho dch v 3.2.3. Thit lp cuc gi

UE tm c cell thit lp kt ni khi va mi c turn on., ta s tip cn n th tc thit lp cuc gi ca UE vo mng. Khi chn c cell kt ni, UE bt u gii m cc tn hiu CCPCH ly cc thng tin v cell. kt ni vi Node B, UE bt u gi knh RACH cha cc thng tin d preamble gm mt chui tn hiu 16-chips c lp li 256 ln vi mc cng sut c nh gi ban u t tn hiu CPICH. Nu kt thc khong thi gian timer, UE khng nhn c tn hiu ACK t Node B, UE s tng mc cng sut pht ln v gi li tn hiu RACH cho n khi nhn c phn hi t node B qua knh AICH hoc n ngng gii hn. Sau khi nhn c tn hiu AICH, UE tht s bc vo qu trnh thit lp cuc gi nh hnh 3.9:

Hnh 3.9 Thit lp cuc giQu trnh thitlp cuc gi c din ra qua 4 giai an.

u tin l qu trnh kt ni RRC gia UE v RNC (trong qu trnh ny c qu trnh chun b k ni radio ca Node B). Sau khi qu trnh RRC thnh cng, RNC gi tn hiu n mng core yu cu thc hin qu trnh kt ni SCCP gia RNC v CN cho cuc gi.

Sau khi ng kt ni gia UE v CN c thit lp, qu trnh chng thc v trao i cc thng tin bo mt c thc hin gia UE v CN (Security). Sau khi han tt th tc bo mt, mng core s gi thng tin yu cu ti nguyn cho cuc gi xung RNC. RNC v Node B s thc hin th tc S.R.L.C chun b cc ti nguyn theo yu cu. Nu ti nguyn hin c p ng c vi yu cu, cuc gi s c thit lp bng vic RNC gi xc nhn kt ni n UE v xc nhn ti nguyn n CN.

y l qu trnh rt quan trng bi n nh hng n thng s cht lung hng u ca mng di ng: kh nng truy nhp mng. Thng s cht lung lin quan ti qu trnh ny l CSSR (call set up success ratio) l mt trong thng s u tin xem xt n khi nh gi v cht lng ca mt mng thng tin di ng. Thng cc nh mng lun yu cu thng s ny phi t trn 95%, tuy nhin ty cc mng khc nhau m con s ngng ny c th cao hn. L mt ngi k thut, chng ta cn nm r qu trnh ny phn tch v nh gi thng s CSSR ca mng ng thi c th xc nh c nguyn nhn gy ra cht lng mng km lin quan n thng s ny.

3.2.4. Thit lp kt ni

Ta bit v th tc thit lp cuc gi v thng s cht lng quan trong ca mng l CSSR. bi ny ta s tip tc vi mt thng s cht lng khc cng quan trng khng km, l t l rt cuc gi DCR (Drop Call Rate). Nu nh mt cuc gi han thnh v kt hc th s khng c hin tng rt mng, tuy nhin nu cuc gi cha han thnh m khng tip tc c na, y chnh l con s phn nh t l rt cuc gi mng di ng. T l ny c nh ngha l s cuc gi b rt (kt thc khng bnh thng) trn tng s cuc gi kt ni thnh cng. Nh vy r rng ta cn phi nm c th tc gii phng kt ni khi cuc gi han tt xc nh c cuc gi no l bnh thng cuc gi no b rt mng. Hnh 3.10 cho ta ci nhn tng qut v th tc kt thc cuc gi bnh thng cng nh bt bnh thng.

Hnh 3.10 Thit lp kt niNh ta thy, khi mt cuc gi kt thc bnh thng, RNC s nhn c thng ip yu cu gii phng kt ni t mng core. Sau gi thng ip kt thc cho mobile. Sau khi mobile xc nhn, th tc gii phng ti nguyn radio mi tht s bt u bng vic Node B nhn yu cu t RNC v thc hin th tc gii phng kt ni.Trong trng hp mobile b rt mng, Node B s khng pht hin c tn hiu ng b ca mobile. Node B s gi thng ip cnh bo n RNC v s c k ni radio hng. RNC s gi yu cu gii phng kt ni n mng core.

Nh vy r rng ta thy chc nng ca RNC trong hai trng hp l khc nhau. iu kin bnh thng, RNC ch yu cu gii phng kt ni, ngc li RNC s yu cu gii phng kt ni khi c li xy ra.

Da vo vai tr ca RNC v cc thng ip ca n ta c th xc nh c cuc gi no b rt v c c t l rt cuc gi qua cc s liu thng k. ng trn phng din ca mt k s vn hnh v ti u mng, da vo thng s ny cng nh cc thng tin v cuc gi b rt, ta c th nh gi s c xy ra khu vc no. T xc nh c nguyn nhn v a ra cc gii php khc phc cng nh ti u mng.3.3. Kt lun chng

Qun l ti nguyn v tuyn l bi ton quan trng khi thit k bt k h thng thng tin di ng, c bit l trong h thng t bo s dng cng ngh a truy nhp phn chia theo m CDMA. Chng ny trnh by cc chc nng c bn ca qun l ti nguyn v tuyn trong h thng WCDMA v nhng im khc bit trong thut ton qun l ti nguyn v tuyn so vi cc h thng khc. Trong , iu khin cng sut v iu khin chuyn giao c nhng im khc bit quan trng so vi cc h thng thng tin di ng trc .

i vi iu khin cng sut, r rng cc thut ton iu khin cng sut cng phc tp hn tinh vi hn khc phc hiu ng gn-xa. Trong 3 loi iu khin cng sut, iu khin cng sut vng m cn thit trong sut qu trnh thit lp kt ni, iu khin cng sut vng kn (iu khin cng sut nhanh) gip khc phc hiu ng phadinh nhanh trn knh giao din v tuyn. Trong WCDMA, iu khin cng sut nhanh c thc hin trn c ng ln v ng xung ti tn s 1.5KHz trong khi h thng IS-95 ch thc hin iu khin cng sut nhanh trn ng ln ti tn s 800Hz, cn GSM ch tn ti iu khin cng sut chm. Phng thc th 3 ca iu khin cng sut l iu khin cng sut vng ngoi gip thit lp cc gi tr mc tiu ca iu khin cng sut nhanh. Cc vn c th cng nh li ch ca iu khin cng sut cng c phn tch trong chng ny.

Mt c trng khc bit nht ca WCDMA so vi cc h thng khc l thut ton iu khin chuyn giao. Chuyn giao din ra khi ngi s dng my di ng di chuyn t cell ny n cell khc trong mng thng tin di ng t bo. Nhng chuyn giao cng c th c s dng cn bng ti trong mng thng tin, v chuyn giao mm c th tng cng dung lng v vng ph ca mng. Chuyn giao cng vn tn ti trong h thng WCDMA, l chuyn giao m kt ni c b ct trc khi kt ni mi c thit lp. Chuyn giao cng c s dng thay i tn s ca h thng khi trong h thng s dng a sng mang; hoc l trong trng hp khng h tr phn tp macro; hoc trng hp chuyn i gia hai ch FDD v TDD.

Chuyn giao gia cc h thng cn thit cho s tng thch gia UMTS v cc kin trc h thng khc (chng hn nh GSM). c trng ca loi ny l cn o c trc khi thc hin s dng ch khe thi gian do thc t vic o c din ra ti cc tn s khc nhau. T gc k thut, kiu chuyn giao ny thuc chuyn giao cng.

Chng ny cng tho lun kh chi tit v chuyn giao mm v mm hn xut hin khi my di ng trong vng ph sng chng ln ca 2 cell. Trng hp chuyn giao mm hn cc cell thuc cng mt trm gc, hai tn hiu ng thi c kt hp Nt B s dng b x l RAKE. Trong sut qu trnh chuyn giao mm, hai tn hiu thu t cc trm gc khc nhau c nh tuyn n RNC c so snh ht khung ny n khung khc. li chuyn giao mm l li c cung cp bi s kt hp nhiu tn hiu (c gi l li phn tp macro). Khi d tr chuyn giao mm thch hp c s dng li chuyn giao mm s tng cng ng k hiu nng ca h thng .

Cc th tc ca lp vt l nh : th tc tm gi, th tc RACH, th tc tm , th tc o chuyn giao ti u ha mng da trn cc ch s KPI nh : t l thit lp cuc gi, t l rt cuc gi, thi gian tr quay s trung bnh Nm vng cc th tc lp vt l th mi tm thy nhng vn cn tn ng trong mng v tm ra gii php x l hiu qu nht.CHNG 4TI U HA MNG UMTS

4.1. Khi qut v l thuyt ti u ha

4.1.1. Mc ch ti u ha

Mc ch quan trng nht khi xy dng h thng l t c dung lng cao nht. Hay ni cch khc chng ta mun mt s lng ln thu bao c th s dng trong h thng trong khi duy tr mt cp phc v v cp cuc gi c th chp nhn c. Mc ch ny phn nh trn s quy hoch mt cch ti u. l mt trong nhng bc c bn a ra khi mt h thng UMTS c c a vo hot ng.

Chi ph cho dung lng bng thng bng cch ny hay cch khc trn quan im tit kim chi ph. V vy quy hoch c xy dn thnh cng khi s lng thu bao tng ln th lu lng vn m bo.

Gi s bao ph quanh mt thnh ph. bc u ta phi xy dng trm gc cng mc bao ph ph hp cho kch thc h thng xc nh v c th tho mn nhu cu bao ph.

H thng mng UMTS ngy nay yu cu tit kim tn ti u v cho mc ch dung lng cao. Thc t, sau khi quy hoch mng thng khng th ti u so vi d kin. Nguyn nhn l do khi quy hoch cc nh khai thc mng khng th d bo chnh xc s thu bao trong khu vc trin khai mng, s thu bao s dng trn mt kiu lu lng, d bo s dng lu lng s liu v d phng tng lai. Chnh v vy sau khi mng sau khi quy hoch a vo s dng th vn ti u mng l v cng quan trng.

4.1.2. Nhng iu cn bit trong vic ti u ho h thng

Ti u mng l mt qu trnh ci thin ton b cht lng mng khi th nghim bi cc thu bao di ng v m bo rng cc ngun ti nguyn mng c s dng mt cch hiu qu. Qu trnh ti u bao gm:

o c hiu nng (cc ch tiu k thut)

Phn tch cc kt qu o c

iu chnh mng

Giai on u ca qu trnh ti u mng l nh ngha cc tiu ch hiu nng chnh bao gm cc cc kt qu o h thng qun l mng v s liu o ngoi hin trng hay bt k thng tin khc c th s dng xc nh cht lng dch v.

Tip theo, vic phn tch cc kt qu o c nhm mc ch phn tch cht lng mng cung cp cho nh khai thc mt bc tranh tng quan v cht lng v hiu qu s dng. Phn tch cht lng v bo co bao gm vic lp k hoch v cc trng hp o ti hin trng v o bng h thng qun l mng. Sau khi c t cc ch tiu cht lng dch v v phn tch s liu th c th lp ra bo co iu tra. i vi h thng thng tin di ng th h 2, th cht lng bao gm: thng k cc cuc gi b rt, phn tch nguyn nhn b rt, thng k chuyn giao v kt qu o cc ln gi thnh cng. Cc h thng thng tin di ng th h 3 c cc dch v rt a dng nn cn phi a ra cc nh ngha mi v cht lng dch v.

Vi s tr gip ca h thng qun l v vn hnh bo dng mng (OSS) c th phn tch thng k hiu sut mng trong mt khong thi gian s dng, hin ti v d bo cho tng lai. Ngoi ra, c th phn tch hiu sut thng qua cc thut ton qun l ti nguyn v tuyn RRM v cc thng s ca chng KPI in hnh nh: tng cng sut pht trm gc, tng ph chuyn giao mm; tc ngt cuc gi; tr d liu gi... Sau tin hnh so snh KPI vi cc gi tr mc tiu s ch ra cc vn tn ti ca mng c th tin hnh iu chnh mng.

Vic iu chnh mng bao gm: cp nht cc thng s RRM (v d cc thng s chuyn giao; cc cng sut knh chung; s liu gi); thay i hng anten trm gc, c th iu chnh hng anten trm gc bng b iu khin t xa trong mt s trng hp (nh khi vng chng ln vi cell ln cn qu ln, nhiu cell cao v dung lng h thng thp).

4.1.3. o kim cc ch s KPI trong mng UMTS

Cc nh khai thc mng nh ra cc ch s KPI cht lng dch v mng cng nh cc gi tr ngng cho tng loi ch s ny. Cc ch s KPI thng c xem xt thay i b sung hng nm ty vo mc tiu kinh doanh. Qun l nng lc mng v cc cng vic ti u ha ti nguyn mng s gp phn m bo yu cu cht lng dch v c t ra.

nhng khu vc c cht lng dch v khng m bo (nhng ni c ch s KPI khng p ng c ngng cho php), cc cng vic ti u ha s c tin hnh. Nng lc ca khu vc mng c phn tch bng cc phng php hin c tm hiu r nguyn nhn ca vn v t a ra cc gii php thch hp.

lm c vic ny, ngi ta phi da vo cc thng tin thu thp c t khiu ni ca khch hng, kt qu o cht lng trn cc xe lu ng v s liu thng k v hot ng ca mng. Thng thng, phn tch s liu thng k v khiu ni khch hng cho php nh khai thc pht hin vn v vic o kim cht lng dng xe lu ng s xc nhn vn cng nh gii php. Tuy vy, nu ch o kim dng xe lu ng th s khng gip cho nh khai thc c c mt ci nhn thu o v dch v cung cp. Vic o kim ny ch l mt ch th v cht lng dch v cho ngun lu lng c tnh lu ng cao. Mt lng ln lu lng pht sinh trong mng li t cc ngun khng lu ng.

Trong nhiu mng di ng chu u, trung bnh ch c mt ln chuyn vng trong mi cuc gi. iu ny cng c ngha rng kt qu thng k s l phng php tt nht xc nh cc hn ch v QoS trong mng. Tuy nhin, xc nh xu hng pht trin ca vn v QoS, cng nh xc nh nguyn nhn v hng gii quyt, ngi ta cng vn phi da trn kinh nghim ca cc chuyn gia. Cc ch s KPI c nh hng n QoS v do cn c gim st mt cch cht ch s c trnh by trong phn sau.

Vic thu thp cc s liu nng lc c thc hin bi cc phn t mng hoc cc thit b o kim t ti mt s im trong mng. S liu nng lc ny c th l mt b m cc s kin giao thc. Sau mi khong thi gian nht nh hoc gn vi thi gian thc, s liu v nng lc c truyn ti h thng qun l nng lc v gim st ti nguyn mc cao hn. Mt v d in hnh cho gii php dng ny l phn mm WatchMark1 ca Vallent Corporation. Phn mm ny nhn s liu v nng lc t RNC, MSC v GSN. Phn t mng nh RNC ghi gi tr ca b m ca n vo mt bo co XML c sau 15 pht. File bo co ny c gi qua giao din tng thch vi tiu chun CORBA ca TMF ti WatchMark1 hay h thng qun l mng cp cao khc. Cc s liu khc nh lu lng v m hnh cc c gi bi cc ngun khc v nh vy ta s c c mt gii php tng th cho qun l dch v v kinh doanh.

Vic o cc ch s KPI c thc hin bi nhiu phn t trong cc phn khc nhau ca mng nh c trnh by trong cc phn tip theo.4.1.3.1. Cm nhn ca khch hng v tham s o kim nng lc KPI theo 3GPP

Yu t chnh quyt nh thnh cng ca dch v (di ng cng nh bt k dch v no khc) l mc hi lng ca khch hng i vi dch v. Do vy, nh vn hnh mng cn phi o kim/nh gi c cht lng dch v theo cm nhn ca khch hng (QoE). Nh vy, mt cu hi cn c t ra l Liu cc php o nng lc ca 3GPP c nh gi ng cht lng dch v theo cm nhn ca khch hng?. Nh vy, cu hi cn c t ra l khi s dng dch v, khch hng cm nhn c iu g?. Khi khch hng s dng in thoi di ng, h ch cn bt my, thc hin cuc gi thoi, thc hin kt ni s liu v 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 mng

Thu bao khng th thit lp cuc gi

Cuc gi ang thc hin b rt trc khi ch gi hoc b gi h my

Tc ti s liu km, nh hng n dch v s liu

Cht lng thng tin truyn km, nh hng n cc cuc gi m thoi

Trong khi khch hng khng bao gi quan tm n cc vn xy ra trong mng, nh vn hnh mng cn phi tm c nguyn nhn gy ra s c v nh gi c mc nh hng ca s c n cht lng dch v.Quy trnh qun l cht lng mng:

Hnh 4.1 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 ch s nh gi hiu sut mng c lin quan.

4.1.3.2. Phn truy nhp v tuyn UMTSPhn quan trng nht trong mng di ng v giao din v tuyn v do vy, phn UTRAN c iu khin bi RNC l im l tng thu thp s liu, qua cho mt ci nhn tng th v cht lng giao din v tuyn. Do vy, s cn mt th h thit b o kim mi cho php bt gi nhiu terabyte s liu t giao din UTRAN, thc hin cc chc nng lc d liu phc tp v thc hin vic lin h gia cc loi s liu khc nhau, lu s liu v nng lc chnh trong c s d liu, v hin th, xut ra v nhp cc kt qu o vi cc thit b v th tc chun.

4.1.3.3. Phn liCc nh vn hnh mng di ng ang tng bc chuyn dn sang mng 3/4G. Trong kin trc mi ny, mng li s chuyn t mng chuyn mch knh TDM v chuyn mch gi ATM sang mng li s dng IP. Vi chun 4G, vic h tr IP s vi ti tn thit b u cui.

Trong qu trnh chuyn i, s tn ti song song phn chuyn mch knh TDM, chuyn mch gi ATM, v chuyn mch gi IP. Tuy nhin, cht lng dch v ca cc cng ngh truyn mch truyn thng l TDM cho thoi v ATM cho s liu vn c m bo v phng thc qun l gim st cht lng ht sc r rng. V vy, phn tip theo s ch xem xt n cht lng dch v cho mng li IP.

Cc tham s nng lc chnh KPI cho mng li IP

Cc tnh nng qun l, o kim cht lng dch v trong mng li IP ny cng tng t nh cho bt k mng IP no khc. Lit k cc tham s nh gi nng lc mng cn phi theo di trong mng li.

Bng 4.1 Tham s nh gi nng lc mng IP cho cc loi dch v khc nhauYu cuTham s nh gi nng lc

Truyn s liuTi thiu tr v mt gi tin

o c QoSJitter

T l mt gi tin

Tr

VoIPTi thiu tr, mt gi tin, jitterJitter

T l mt gi tin

Tr

MOS

Tha thun dch vo c tr, mt gi tin, jitter

Chiu iJitter

T l mt gi tin

Tr

Chiu i

chnh xc cao

Sn sng dch vo kim kt niKim tra kt ni n cc thit b IP

Truyn videoTi thiu tr, t l mt gi tinJitter

T l mt gi tin

Tr

4.1.3.4. Phn mng ngoi

Phn mng ngoi ca mng di ng c th l mng TDM, mng VoIP, hay mng truyn s liu. Ty vo loi mng ngoi m ngi ta s cn phi nh gi nng lc ca chng theo cc phng php khc nhau. Vic nh gi nng lc ny cng tng t nh i vi cc thnh phn mng ni trn.

4.2. Cc tham s o kim nng lc KPI mng li

Hnh 4.2 Phn loi cc lp KPI4.2.1. Vng ph

Kh nng ph sng Coverage ( Probability Coverage Probability ):Ch s ny c thng k trong clutter, c trong nh v ngoi tri, nh k : 15 pht, 30 pht, 1 gi., 1ngy. Phng thc o lng tnh ton c bn da trn DT (driving test) hoc CQT (cascaded quadruplet trisection)

Ch s ny th hin kh nng vng ph phn nh, sc mnh ca vng ph sng RFT cht lng thuc tn hiu RF

F=RSCP >= R

Ec/Io >=S

Vi :

RSCP: ln ca tn hiu chip nhn c (Received Pilot Signal Chip Power)Ec/Io :Dung lng tn hiu iu khin nhn c

R & S : Ngng ca RSCP

R&S khc nhau cho nhng loi dch v khc nhau.

Khi 2 thng s ny tha mn iu kin th F=1 , khng th F=0.

Kh nng ph sng c nh ngha nh l: Phn trm ca mu c F=1 Trn tt c cc mu c o lng4.2.2. Cht lng dch v

4.2.2.1. T l kt ni bo hiu RRC thnh cng -RRC Connection Setup Success Ratio (Service Related)

Ch s ny c thng k trong cell, c trong nh v ngoi tri, nh k : 15 pht, 30 pht, 1 gi, 1ngy. Phng thc o lng tnh ton c bn da trn gi tr m ca OMC. Ch s ny th hin kh nng truy cp ca dch v ca cell v RNCT l thit lp kt ni RRC thnh cng = S ln TL kt ni thnh cng / s ln yu cu TL kt ni ( %)RRC Connection Setup Succes Ratio(Service Related)RRC Connection Setup Complete Times(Service Related/RRC Connection Setup Request Time (Service Related)100%S lung tn hiu:

Hnh 4.3 S tn hiu bo hiu RRCCc ch s m rng: T l thit lp kt ni thnh cng bo hiu RRC i vi dch v thoi ca thit b gi (Mobile Origination Conversation Service RRC Connection Setup Success Ratio)

T l thit lp kt ni thnh cng bo hiu RRC i vi dch v lung ca thit b gi (Mobile Origination Streaming Service RRC Connection Setup Success Ratio)

T l thit lp kt ni thnh cng bo hiu RRC i vi dch v tng tc ca thit b gi (Mobile Origination Interactive Service RRC Connection Setup Success Ratio)

T l thit lp kt ni thnh cng bo hiu RRC i vi dch v c bn ca thit b gi (Mobile Origination Background Service RRC Connection Setup Success Ratio)

T l thit lp kt ni thnh cng bo hiu RRC i vi dch v thoi ca thit b b gi (Mobile Termination Conversation Service RRC Connection Setup Success Ratio)

T l thit lp kt ni thnh cng bo hiu RRC i vi dch v lung ca thit b b gi (Mobile Termination Streaming Service RRC Connection Setup Success Ratio)

T l thit lp kt ni thnh cng bo hiu RRC i vi dch v tng tc ca thit b b gi (Mobile Termination Interactive Service RRC Connection Setup Success Ratio)

T l thit lp kt ni thnh cng bo hiu RRC i vi dch v c bn ca thit b b gi (Mobile Termination Background Service RRC Connection Setup Success Ratio)

4.2.2.2. T l thit lp thnh cng knh mng v tuyn RAB

Ch s ny c thng k trong cell, c trong nh v ngoi tri, nh k : 15 pht, 30 pht, 1 gi., 1ngy. Phng thc o lng tnh ton c bn da trn gi tr m ca OMC. Ch s ny th hin kh nng thit lp knh mang v tuyn RAB l bc sau khi kt ni dch v nu thit lp thnh cng th kt ni n user plane th s kt ni thnh cng

T l thit lp thnh cng knh mang v tuyn RAB = (s ln thit lp thnh cng knh mang v tuyn RAB CS + s ln thit lp thnh cng knh mang v tuyn RAB PS ) / (s ln yu cu thit lp knh mang v tuyn RAB CS + s ln yu cu thit lp knh mang v tuyn RAB PS ) (%)

RAB Assignment Success Ratio=(CS RAB Assignment Success Times+PS RAB Assignment Success Times)/(CS RAB Assignment Request Times+PS RAB Assignment Request Times)100%S lung tn hiu:

Hnh 4.4 S tn hiu knh mang v tuyn RABCc ch s m rng: T l thit lp thnh cng knh mang v tuyn RAB CS (CS RAB Assignment Success Ratio)

T l thit lp thnh cng knh mang v tuyn RAB PS (PS RAB Assignment Success Ratio) T l thit lp thnh cng knh mang v tuyn RAB AMR (AMR RAB Assignment Success Ratio) T l thit lp thnh cng knh mang v tuyn RAB CS C 64/64 (CS C 64/64 RAB Assignment Success Ratio) T l thit lp thnh cng knh mang v tuyn RAB PS Interactive 64/64 (PS Interactive 64/64 RAB Assignment Success Ratio) T l thit lp thnh cng knh mang v tuyn RAB PS I 64/128 (PS I 64/128 RAB Assignment Success Ratio) T l thit lp thnh cng knh mang v tuyn RAB PS I 64/64 (PS I 64/384 RAB Assignment Success Ratio)4.2.2.3. T l thit lp cuc gi thnh cng - Call Setup Success Ratio

Ch s ny c thng k trong cell, c trong nh v ngoi tri, nh k: 15 pht, 30 pht, 1 gi, 1ngy. Phng thc o lng tnh ton c bn da trn gi tr m ca OMC. Ch s ny th hin kh nng truy nhp dch v ca cell v RNC

T l thit lp cuc gi thnh cng = T l thit lp kt ni bo hiu RRC thnh cng (lin quan ti dich v ) * T l thit lp knh mang v tuyn RAB thnh cng (%)

Call Setup Success RatioRRC Connection Setup Success Ratio (Service Related)RAB Assignment Success Ratio100%

S lung tn hiu:

Hnh 4.5 S tn hiu kt ni cuc gi

Cc ch s m rng :

T l thit lp cuc gi AMR thnh cng (AMR Call Setup Success Ratio)

T l thit lp cuc gi CS C 64/64 thnh cng (CS C 64/64 Call Setup Success Ratio)

T l thit lp cuc gi PS I 64/64 thnh cng (PS I 64/64 Call Setup Success Ratio)

T l thit lp cuc gi PS I 64/128 thnh cng ( PS I 64/128 Call Setup Success Ratio) T l thit lp cuc gi PS I 64/384 thnh cng ( PS I 64/384 Call Setup Success Ratio)

T l thit lp cuc gi PS I 64/64 thnh cng (PS S 64/64 Call Setup Success Ratio)

4.2.2.4. T l rt cuc gi - Call Drop Ratio

Ch s ny c thng k trong cell, c trong nh v ngoi tri, nh k : 15 pht, 30 pht, 1 gi., 1ngy. Phng thc o lng tnh ton c bn da trn gi tr m ca OMC. Ch s ny th hin kh nng duy tr dch v ca mng, y l mt trong nhng ch s quan trng nht khch hng cn c bit.

T l rt cuc gi = (s ln gii phng knh mang v tuyn RAB CS kch hot bo hiu RNC + s ln gii phng CS Iu kch hot bo hiu RNC + s ln gii phng knh mang v tuyn RAB PS kch hot bo hiu RNC +s ln gii phng PS Iu kch hot bo hiu RNC )/(s ln thit lp thnh cng knh mang v tuyn RAB CS + s ln thit lp thnh cng knh mang v tuyn RAB PS ) (%)

Call Drop RatioRNC Triggered CS RAB Release TimesRNC Triggered CS Iu Release TimesRNC Triggered PS RAB Release Times+RNC Triggered PS Iu Release Times/(CS RAB Assignment Success Times + PS RAB Assignment Success Times100%

S lung tn hiu :

Hnh 4.6 S yu cu gii phng knh RAB t RNC n CN

Cc ch s m rng:

T l rt cuc gi CS (CS Call Drop Ratio)

T l rt cuc gi PS (PS Call Drop Ratio)

T l rt cuc gi AMR (AMR Call Drop Ratio)

T l rt cuc gi CS C 64/64 (CS C 64/64 Call Drop Ratio)

T l rt cuc gi PS C 64/64 (PS I 64/64 Call Drop Ratio)

T l rt cuc gi PS I 64/128 (PS I 64/128 Call Drop Ratio)

T l rt cuc gi PS I 64/384 (PS I 64/384 Call Drop Ratio)4.2.3. Di chuyn

4.2.3.1. T l chuyn giao mm thnh cng ca RNC ( bao gm c chuyn giao mm hn) - RNC Soft Handover Success Ratio (Including Softer Handover)

Ch s ny c thng k trong cell, c trong nh v ngoi tri, nh k : 15 pht, 30 pht, 1 gi., 1ngy. Phng thc o lng tnh ton c bn da trn gi tr m ca OMC. Ch s ny th hin kh nng linh hot khi chuyn giao mm trong vng iu khin ca RNC

T l chuyn giao mm thnh cng =(s ln yu cu S.HO - s ln S.HO b li )/ s ln yu cu S.HO (%)Soft Handover Success RatioSoft Handover Requirement TimesSoft Handover Failure Times/Soft Handover Requirement Times100%S lung tn hiu :

Hnh 4.7 S tn hiu yu cu chuyn giaoCc ch s m rng:

Li cu hnh khng tng thch gy nn t l H.O b li (configuration unsupported failure caused handover failure ratio)

Li knh vt l gy nn t l H.O b li (physical channel failure caused handover failure ratio)

Cu hnh li khng tng thch ng b gy nn t l H.O b li (incompatible simultaneous reconfiguration caused handover failure ratio)

Li giao thc gy nn t l H.O b li (protocol error caused handover failure ratio)

Cp nht Cell gy nn t l H.O b li (cell update occurred caused handover failure ratio)

Cu hnh khng hp l gy nn t l H.O b li (invalid configuration caused handover failure ratio)

Khng c tn hiu p li gy nn t l H.O b li (No reply caused handover failure ratio)

4.2.3.2. T l chuyn giao cng thnh cng gia cc tn s - Inter Frequency Hard Handover Success Ratio Success Ratio

Ch s ny c thng k trong cell, c trong nh v ngoi tri, nh k : 15 pht, 30 pht, 1 gi., 1ngy. Phng thc o lng tnh ton c bn da trn gi tr m ca OMC. Ch s ny th hin kh nng linh hot khi chuyn giao cng trong vng iu khin ca RNC. T l chuyn giao cng thnh cng gia cc tn s = ( S ln yu cu chuyn giao cng gia cc tn s - S ln chuyn giao cng gia cc tn s b li )/ S ln yu cu chuyn giao cng gia cc tn s (%)Inter-Frequency Hard Handover Success RatioInter-Frequency Hard Handover Requirement Times Inter-Frequency Hard Handover Failure Times/ Inter-Frequency Hard Handover Requirement Times100%

Chuyn giao cng gia cc tn s gm: chuyn giao cng trong RNC, chuyn giao cng gia cc RNC.S lung tn hiu:

Hnh 4.8 S chuyn giao gia cc h thng trong RNC

Hnh 4.9 S chuyn giao gia cc h thng ca cc RNC

Cc ch s m rng:

Li cu hnh khng tng thch gy t l chuyn giao cng li gia cc tn s trong Node B (configuration unsupported caused intra-NodeB inter-frequency hard handover failure ratio)

Cu hnh li khng tng gy t l chuyn giao cng li gia cc tn s trong RNC (configuration unsupported caused intra-RNC inter-frequency hard handover failure ratio)

Li cu hnh khng tng thch gy t l chuyn giao cng li gia cc tn s nhng RNC khc nhau (configuration unsupported caused inter-RNC inter-frequency hard handover failure ratio)

Li knh vt l gy t l chuyn giao cng li gia cc tn s trong Node B (physical channel failure caused intra-NodeB inter-frequency hard handover failure ratio)

Li knh vt l gy t l chuyn giao cng li gia cc tn s trong RNC (physical channel failure caused intra-RNC inter-frequency hard handover failure ratio) Li knh vt l gy t l chuyn giao cng li gia cc tn s nhng RNC khc nhau (physical channel failure caused inter-RNC inter-frequency hard handover failure ratio)

4.