5

LI NI U

Trong nhng nm gn y, mng khng dy ngy cng tr nn ph bin vi s

ra i ca hng lot nhng cng ngh khc nhau nh Wi-Fi (802.1x), WiMax

(802.16)... Cng vi l tc pht trin nhanh, mnh ca mng vin thng phc

v nhu cu s dng ca hng triu ngi mi ngy. H thng di ng th h th hai,

vi GSM v CDMA l nhng v d in hnh pht trin mnh m nhiu quc

gia. Tuy nhin, th trng vin thng cng m rng cng th hin r nhng hn ch

v dung lng v bng thng ca cc h thng thng tin di ng th h th hai. S

ra i ca h thng di ng th h th ba vi cc cng ngh tiu biu nh WCDMA

hay HSPA l mt tt yu c th p ng c nhu cu truy cp d liu, m

thanh, hnh nh vi tc cao, bng thng rng ca ngi s dng.

Mc d cc h thng thng tin di ng th h 2.5G hay 3G vn ang pht trin

khng ngng nhng cc nh khai thc vin thng ln trn th gii bt u tin

hnh trin khai th nghim mt chun di ng th h mi c rt nhiu tim nng v

c th s tr thnh chun di ng 4G trong tng lai, l LTE (Long Term

Evolution). Cc cuc th nghim v trnh din ny chng t nng lc tuyt vi

ca cng ngh LTE v kh nng thng mi ha LTE n rt gn.

Trc y, mun truy cp d liu, phi cn c 1 ng dy c nh kt ni.

Trong tng lai khng xa vi LTE, c th truy cp tt c cc dch v mi lc mi

ni trong khi vn di chuyn: xem phim cht lng cao HDTV, in thoi thy hnh,

chi game, nghe nhc trc tuyn, ti c s d liu v.v vi mt tc siu tc.

chnh l s khc bit gia mng di ng th h th 3 (3G) v mng di ng th

h th t (4G). Tuy vn cn kh mi m nhng mng di ng bng rng 4G ang

c k vng s to ra nhiu thay i khc bit so vi nhng mng di ng hin

nay. Chnh v vy, em la chn lm n tt nghip v ti Nghin cu h

thng thng tin di ng tin 4G LTE (Long Term Evolution).

n i vo tm hiu tng quan v cng ngh LTE cng nh l nhng k

thut v thnh phn c s dng trong cng ngh ny c th hiu r thm v

nhng tim nng hp dn m cng ngh ny s mang li v tnh hnh trin khai cng

ngh ny trn th gii v ti VIT NAM .

6

ti gm 6 chng :

CHNG 1: TNG QUAN H THNG THNG TIN DI NG

V GII THIU CNG NGH LTE

CHNG 2: KIN TRC MNG V GIAO THC

CHNG 3: TRUY NHP V TUYN TRONG LTE

CHNG 4: LP VT L LTE

CHNG 5: CC TH TC TRUY NHP

CHNG 6: TRIN KHAI LTE TRN TH GII V TI VIT

NAM

thc hin n tt nghip ny, em s dng nhng kin thc c trang b

trong 5 nm i hc v nhng kin thc chn lc t cc ti liu ca cc thy gio,

c gio trong v ngoi trng . Ngoi ra, n cn s dng nhng ti liu ph bin

rng ri trn Internet.

Mc d rt c gng, nhng do hn ch v thi gian cng nh nhng hiu

bit c hn ca mt sinh vin nn n khng trnh khi thiu st. n c

hon thin hn, em rt mong nhn c cc kin ng gp ca cc thy gio, c

gio cng nh cc bn sinh vin.

Sinh vin thc hin : Nguyn Tun Anh

7

MC LC

T BA.....................................................................................................1

NHIM V THIT K TT NGHIP3

LI NI U ................................................................................................. 5

MC LC7

DANH MC T VIT TT........................................................................ 11

DANH MC HNH V ................................................................................ 18

DANH MC BNG BIU ........................................................................... 21

CHNG 1 - TNG QUAN V H THNG THNG TIN DI NG &

GII THIU V CNG NGH LTE ........................................................ 22

1.1. Tng quan v h thng thng tin di ng ................................................... 22

1.1.1. H thng thng tin di ng th h th nht ( 1G) .................................... 22

1.1.2. H thng thng tin di ng th h th hai ( 2G) ...................................... 23

1.1.3. H thng thng tin di ng th h th 3 ( 3G) ......................................... 25

1.2. Gii thiu v cng ngh LTE ....................................................................... 27

CHNG 2 KIN TRC MNG V GIAO THC ............................ 30

2.1. Kin trc mng LTE .................................................................................... 30

2.1.1. Tng quan v cu hnh kin trc c bn h thng.................................... 31

2.1.2. Thit b ngi dng ( UE) ........................................................................ 32

2.1.3. E-UTRAN nodeB (eNodeB) .................................................................... 33

2.1.4. Thc th qun l tnh di ng (MME) ..................................................... 34

2.1.5. Cng phc v ( S-GW) ............................................................................. 36

2.1.6. Cng mng d liu gi( P-GW) ............................................................... 38

2.1.7. Chc nng chnh sch v tnh cc ti nguyn ( PCRF) ......................... 40

2.1.8. My ch thu bao thng tr (HSS) ........................................................ 41

2.2. Cc giao din v giao thc trong cu hnh kin trc c bn ca h thng

............................................................................................................................... 41

2.3. QoS v kin trc dch v mang chuyn ...................................................... 45

8

2.4. Giao thc trng thi v chuyn tip trng thi .......................................... 46

2.5. H tr tnh di ng lin tc .......................................................................... 47

2.6. Kin trc h thng pht qung b a im ................................................ 50

CHNG 3 - TRUY NHP V TUYN TRONG LTE ......................... 54

3.1. Cc ch truy nhp v tuyn .................................................................... 54

3.2. Bng tn truyn dn ..................................................................................... 54

3.3. Cc bng tn c h tr ............................................................................ 55

3.4. K thut a truy nhp cho ng xung OFDMA ................................... 56

3.4.1. OFDM ...................................................................................................... 56

3.4.2. Cc tham s OFDMA ............................................................................... 58

3.4.3. Truyn dn d liu hng xung ............................................................. 61

3.5. K thut a truy nhp ng ln LTE SC-FDMA ................................... 63

3.5.1. SC-FDMA ................................................................................................ 63

3.5.2. Cc tham s SC-FDMA ........................................................................... 64

3.5.3. Truyn dn d liu hng ln .................................................................. 66

3.5.4. So snh OFDMA v SC-FDMA .............................................................. 67

3.6. Tng quan v k thut a ng ten MIMO .................................................. 69

3.6.1. n u vo n u ra (SISO) .............................................................. 70

3.6.2. n u vo a u ra (SIMO) ................................................................ 70

3.6.3. a u vo n u ra (MISO) ................................................................ 70

3.6.4. a u vo a u ra (MIMO) ................................................................. 70

3.6.5. K hoch LTE a ng ten ......................................................................... 72

3.6.5.1. Ch truyn dn a ng ten ng xung LTE .......................... 73

3.6.5.2. Ch a ng ten hng ln LTE ............................................... 75

CHNG 4 - LP VT L LTE ............................................................... 76

4.1. Cc knh truyn ti v nh x ca chng ti cc knh vt l .................. 76

4.2. iu ch .......................................................................................................... 77

4.3. Truyn ti d liu ngi s dng hng ln ............................................. 78

4.4. Truyn dn d liu ngi dng hng xung ........................................... 83

9

4.5. Truyn dn tn hiu lp vt l hng ln ................................................... 87

4.5.1. Knh iu khin ng ln vt l ( PUCCH) .......................................... 88

4.5.2. Cu hnh PUCCH ..................................................................................... 89

4.5.3. Bo hiu iu khin trn PUSCH ............................................................. 89

4.6. Cu trc PRACH (Knh truy nhp ngu nhin vt l) ............................ 92

4.7. Truyn dn bo hiu lp vt l hng xung ............................................ 93

4.7.1. Knh ch th nh dng iu khin vt l (PCFICH) ................................ 93

4.7.2. Knh iu khin hng xung vt l ( PCDCH) .................................... 94

4.7.3. Knh ch th HARQ vt l ( PHICH) ....................................................... 95

4.7.4. Cc ch truyn dn hng xung ........................................................ 95

4.7.5. Knh qung b vt l ( PBCH) ................................................................. 96

4.7.6. Tn hiu ng b ....................................................................................... 97

4.8. Cc th tc lp vt l .................................................................................... 98

4.8.1. Th tc HARQ ......................................................................................... 98

4.8.2. ng trc nh thi .................................................................................. 99

4.8.3. iu khin cng sut .............................................................................. 100

4.8.4. Nhn tin .................................................................................................. 101

4.8.5. Th tc bo co phn hi knh ............................................................... 101

4.8.6. Hot ng ch bn song cng ........................................................... 102

4.8.7. Cc lp kh nng ca UE v cc c im c h tr ......................... 102

4.9. o lng lp vt l...................................................................................... 103

4.9.1. o lng eNodeB ................................................................................... 103

4.9.2. o lng UE .......................................................................................... 104

4.10. Cu hnh tham s lp vt l ..................................................................... 104

CHNG 5 CC TH TC TRUY NHP ......................................... 106

5.1. Th tc d tm .......................................................................................... 106

5.1.1. Cc bc ca th tc d tm ................................................................ 106

5.1.2. Cu trc thi gian/tn s ca tn hiu ng b ....................................... 108

5.1.3. D tm ban u v d tm ln cn ........................................................ 109

10

5.2. Truy nhp ngu nhin ................................................................................ 110

5.2.1. Bc 1 : Truyn dn phn m u truy nhp ngu nhin ...................... 111

5.2.2. Bc 2 : p ng truy nhp ngu nhin ................................................ 115

5.2.3. Bc 3: Nhn dng thit b u cui ...................................................... 116

5.2.4. Bc 4: Gii quyt tranh chp ................................................................ 117

CHNG 6 TNH HNH TRIN KHAI LTE TRN TH GII V

TI VIT NAM .......................................................................................... 118

6.1. Trin khai LTE trn th gii ..................................................................... 118

6.2. Trin khai LTE ti VIT NAM ................................................................ 122

KT LUN V HNG PHT TRIN TI .................................. 124

NHN XT CA GIO VIN HNG DN ....................................... 125

NHN XT CA GIO VIN C DUYT ........................................ 125

LI CM N .............................................................................................. 126

TI LIU THAM KHO .......................................................................... 127

11

DANH MC T VIT TT

3GPP Third Generation Partnership

Project

D n cc i tc th h th ba

AAA Authentication, Authorization

and Accounting

Xc thc, cp php v tnh cc

ACF Analog Channel Filter B lc knh tng t

ACIR Adjacent Channel Interference

Rejection

Loi b nhiu knh ln cn

ACK Acknowledgement S bo nhn

ACLR Adjacent Channel Leakage Ratio T l d knh ln cn

ACS Adjacent channel selectivity Chn lc knh ln cn

ADC Analog-to Digital Conversion Chuyn i tng t - s

ADSL Asymmetric Digital Subscriber

Line

ng dy thu bao s khng i xng

AM Acknowledged Mode Ch bo nhn

AMBR Aggregate Maximum Bit Rate Tc bt ti a cp pht

AMD Acknowledged Mode Data D liu ch bo nhn

AMR Adaptive Multi-Rate a tc thch ng

AMR-NB Adaptive Multi-Rate Narrowband Bng hp a tc thch ng

AMR-WB Adaptive Multi-Rate Wideband Bng rng a tc thch ng

ARP Allocation Retention Priority u tin duy tr cp pht

ATB Adaptive Transmission

Bandwidth

Bng thng truyn dn thch nghi

AWGN Additive White Gaussian Noise Nhiu Gauss trng thm vo

AMPS Advanced Mobile Phone Sytem H thng in thoi di ng tin tin

BB Baseband Bng gc

BCCH Broadcast Control Channel Knh iu khin pht qung b

BCH Broadcast Channel Knh pht qung b

AMPS Advanced Mobile Phone Sytem H thng in thoi di ng tin tin

BPF Band Pass Filter B lc bng tn

BPSK Binary Phase Shift Keying Kha dch pha nh phn

BS Base Station Trm gc

BSC Base Station Controller iu khin trm gc

BSR Buffer Status Report Bo co tnh trng b m

BTS Base Transceiver Station Trm thu pht gc

BW Bandwidth Di thng

CAZAC Constant Amplitude Zero

Autocorrelation Codes

M t tng quan zero bin khng i

12

CBR Constant Bit Rate Tc bt khng i

CCE Control Channel Element Phn t knh iu khin

CCCH Common Control Channel Knh iu khin chung

CDD Cyclic Delay Diversity Phn tp tr vng

CDF Cumulative Density Function Chc nng mt tch ly

CDM Code Division Multiplexing Ghp knh phn chia theo m

CDMA Code Division Multiple Access a truy nhp phn chia theo m

AIR Carrier to Interference Ratio T s sng mang trn tp m

CP Cyclic Prex Tin t vng

CPICH Common Pilot Channel Knh iu khin chung

CQI Channel Quality Information Thng tin cht lng knh

CRC Cyclic Redundancy Check Kim tra d vng

C-RNTI Radio Network Temporary Identier

Nhn dng tm thi mng v tuyn t bo

CS Circuit Switched Chuyn mch knh

CSCF Call Session Control Function Chc nng iu khin phin cuc gi

D-BCH Dynamic Broadcast Channel Knh pht qung b ng

DCCH Dedicated Control Channel Knh iu khin ring

DCI Downlink Control Information Thng tin iu khin ng xung

DFCHA Dynamic Frequency and Channel

Allocation

Cp pht knh v tn s ng

DFT Discrete Fourier Transform Bin i fourier ri rc

DL Downlink ng xung

UL uplink ng ln

DL-SCH Downlink Shared Channel Knh chia s ng xung

DPCCH Dedicated Physical Control

Channel

Knh iu khin vt l ring

DTX Discontinuous Transmission Truyn pht khng lin tc

DwPTS Downlink Pilot Time Slot Khe thi gian iu khin ng xung

E-DCH Enhanced DCH DCH c tng cng

EDGE Enhanced Data Rates for GSM

Evolution

Tc d liu tng cng cho GSM pht trin

EPC Evolved Packet Core Mng li gi pht trin

EPDG Evolved Packet Data Gateway Cng d liu gi pht trin

E-

UTRAN

Evolved Universal Terrestrial

Radio Access

Truy nhp v tuyn mt t ton cu pht trin

EDO Evolution Data Only Ch c d liu pht trin

FD Frequency Domain Min tn s

FDD Frequency Division Duplex Song cng phn chia tn s

FDM Frequency Division Multiplexing Ghp knh phn chia tn s

13

FDPS Frequency Domain Packet

Scheduling

Lp biu gi min tn s

FFT Fast Fourier Transform Bin i furier nhanh

FS Frequency Selective La chn tn s

GERAN GSM/EDGE Radio Access Network Mng truy nhp v tuyn GSM/EDGE

GGSN Gateway GPRS Support Node Nt cng h tr GPRS

GP Guard Period Khong bo v

GPRS General packet radio service Dch v v tuyn gi chung

GPS Global Positioning System H thng nh v ton cu

GRE Generic Routing Encapsulation ng gi nh tuyn chung

GSM Global System for Mobile

Communications

H thng truyn thng di ng ton cu

GTP GPRS Tunneling Protocol Giao thc ng hm GPRS

GTP-C GPRS Tunneling Protocol,

Control Plane

Mt phng iu khin, giao thc ng hm GPRS

GUTI Globally Unique Temporary

Identity

Nhn dng tm thi duy nht ton cu

GW Gateway Cng

HARQ Hybrid Automatic Repeat

reQuest

Yu cu lp li t ng h hp

HO Handover S chuyn vng

HSDPA High Speed Downlink Packet

Access

Truy nhp gi ng xung tc cao

HS-DSCH High Speed Downlink Shared

Channel

Knh chia s ng xung tc cao

HSCSD High Speed Circuit Switched

Data

S liu chuyn mch knh tc cao

HSPA High Speed Packet Access Truy nhp gi tc cao

HS-

PDSCH

High Speed Physical Downlink

Shared Channel

Knh chia s ng xung vt l tc cao

HSS Home Subscriber Server My ch thu bao thng tr

HS-SCCH High Speed Shared Control

Channel

Knh iu khin chia s tc cao

HSUPA High Speed Uplink Packet

Access

Truy nhp gi ng ln tc cao

ICI Inter-carrier Interference Nhiu lin sng mang

ICIC Inter- Interference Control iu khin nhiu lin

ID Identity Nhn dng

IFFT Inverse Fast Fourier Transform Bin i furier nhanh nghch o

IMS IP Multimedia Subsystem H thng con a phng tin IP

IMT International Mobile

Telecommunications

Truyn thng di ng quc t

14

IP Internet Protocol Giao thc Internet

ISDN Integrated Services Digital

Network

Mng s dch v tch hp

ISI Inter Symbols Interference Nhiu lin k t

LNA low noise amplifier Khuych i m nhiu thp

LO Local Oscillator B dao ng ni

LOS Line of Sight Tm nhn thng

LTE Long Term Evolution S pht trin di hn

MAC Medium Access Control iu khin truy nhp mi trng

MAP Mobile Application Part Phn ng dng di ng

MBMS Multimedia Broadcast Multicast

System

H thng pht qung b a im a phng tin

MBR Maximum Bit Rate Tc bt ti a

MCH Multicast Channel Knh a im

MCS Modulation and Coding Scheme S m ha v iu ch

MGW Media Gateway Cng phng tin

MIMO Multiple Input Multiple Output a u vo a u ra

MIP Mobile IP IP di ng

MM Mobility Management Qun l tnh di ng

MME Mobility Management Entity Phn t qun l tnh di ng

MPR Maximum Power Reduction S gim cng sut ti a

MSC Mobile Switching Center Chung tm chuyn mch di ng

NACK Negative Acknowledgement Bo nhn khng thnh cng

NAS Non-access Stratum Tng khng truy nhp

NAS Network Address Table Bng a ch mng

NB Narrowband Bng hp

NMT Nordic Mobile Telephone in thoi di ng Bc u

OFDM Orthogonal Frequency Division

Multiplexing

Ghp knh phn chia tn s trc giao

OFDMA Orthogonal Frequency Division

Multiple Access

a truy nhp phn chia tn s trc giao

O&M Operation and Maintenance Vn hnh v bo dng

PAPR Peak to Average Power Ratio T l cng sut nh ti trung bnh

PAR Peak-to-Average Ratio T l nh-trung bnh

PC Power Control iu khin cng sut

PCCC Parallel Concatenated

Convolution Coding

M xon ghp song song

PCCPCH Primary Common Control

Physical Channel

Knh vt l iu khin chung s cp

PCFICH Physical Control Format

Indicator Channel

Knh ch th dng iu khin vt l

PCH Paging Channel Knh nhn tin

15

PCI Physical Identity Nhn dng vt l

PCM Pulse Code Modulation iu ch xung m

PCRF Policy and Charging Resource

Function

Chc nng tnh cc ti nguyn v chnh sch

PCS Personal Communication

Services

Dch v truyn thng c nhn

PDCCH Physical Downlink Control

Channel

Knh iu khin ng xung vt l

PDCP Packet Data Convergence

Protocol

Giao thc hi t d liu gi

PDN Packet Data Network Mng d liu gi

PDU Payload Data Unit n v d liu ti tin

PDSCH Physical Downlink Shared

Channel

Knh chia s ng xung vt l

P-GW Packet Data Network Gateway Cng mng d liu gi

PHICH Physical HARQ Indicator

Channel

Knh ch th HARQ vt l

PHY Physical Layer Lp vt l

PLL Phase Locked Loop Vng kha pha

PLMN Public Land Mobile Network Mng di ng mt t cng cng

PMIP Proxy Mobile IP IP di ng y nhim

PN Phase Noise Ting n pha

PRACH Physical Random Access

Channel

Knh truy nhp ngu nhin vt l

PRB Physical Resource Block Khi ti nguyn vt l

PS Packet Switched Chuyn mch gi

PSD Power Spectral Density Mt ph cng sut

PSS Primary Synchronization Signal Tn hiu ng b s cp

PUCCH Physical Uplink Control Channel Knh iu khin hng ln vt l

PUSCH Physical Uplink Shared Channel Knh chia s hng ln vt l

QAM Quadrature Amplitude

Modulation

iu ch bin cu phng

QCI QoS Class Identier Nhn dng cp QoS

QoS Quality of Service Cht lng dch v

QPSK Quadrature Phase Shift Keying Kha dch pha vung gc

RACH Random Access Channel Knh truy nhp ngu nhin

RAN Radio Access Network Mng truy nhp v tuyn

RAR Random Access Response p ng truy nhp ngu nhin

RB Resource Block Khi ti nguyn

RBG Radio Bearer Group Nhm truyn ti v tuyn

RF Radio Frequency Tn s v tuyn

RI Rank Indicator Ch th bc

16

RLC Radio Link Control iu khin kt ni v tuyn

RNC Radio Network Controller iu khin mng v tuyn

RRC Radio Resource Control iu khin ti nguyn v tuyn

RRM Radio Resource Management Qun l ti nguyn v tuyn

RS Reference Signal Tn hiu chun

RSCP Received Symbol Code Power Cng sut m k hiu nhn c

RSRP Reference Symbol Received

Power

Cng sut thu c k hiu chun

RSRQ Reference Symbol Received

Quality

Cht lng thu c k hiu chun

RSSI Received Signal Strength

Indicator

Ch th cng tn hiu thu c

SAE System Architecture Evolution Pht trin kin trc h thng

SCCPCH Secondary Common Control

Physical Channel

Knh vt l iu khin chung th cp

SCM Spatial Channel Model Ch knh khng gian

SC-

FDMA

Single Carrier Frequency

Division Multiple Access

a truy nhp phn chia tn s n sng mang

SCH Synchronization Channel Knh ng b

SCTP Stream Control Transmission

Protocol

Giao thc truyn dn iu khin lung

SDU Service Data Unit n v d liu dch v

SFBC Space Frequency Block Coding M khi tn s khng gian

SFN System Frame Number S khung h thng

SGSN Serving GPRS Support Node Nt h tr dch v GPRS

S-GW Serving Gateway Cng phc v

SIB System Information Block Khi thng tin h thng

SIMO Single Input Multiple Output n u vo a u ra

SMS Short Message Service Dch v bn tin ngn

SNR Signal to Noise Ratio T l tn hiu trn nhiu

SON Self Optimized Networks Mng t ti u

SR Scheduling Request Yu cu lp lch biu

S-RACH Short Random Access Channel Knh truy nhp ngu nhin ngn

SRB Signaling Radio Bearer Phn t mang bo hiu v tuyn

SRS Sounding Reference Signals Tn hiu chun thm d

SSS Secondary Synchronization

Signal

Tn hiu ng b th cp

SU-

MIMO

Single User Multiple Input

Multiple Output

n ngi dng - a u vo a u ra

S1AP S1 Application Protocol Giao thc ng dng S1

TA Tracking Area Khu vc theo di

TBS Transport Block Size Kch thc khi truyn ti

17

TACS Total Access Communication

Sytem

H thng truyn thng truy nhp ton phn

TD Time Domain Min thi gian

TDD Time Division Duplex Song cng phn chia thi gian

TD-LTE Time Division Long Term

Evolution

Phn chia theo thi gian - LTE

TD-

SCDMA

Time Division Synchronous Code

Division Multiple Access

Phn chia theo thi gian a truy nhp phn chia theo m ng b

TPC Transmit Power Control iu khin cng sut pht

TRX Transceiver B thu pht

TTI Transmission Time Interval Khong thi gian truyn

UDP Unit Data Protocol Giao thc n v d liu

UE User Equipment Thit b u cui

UL Uplink ng ln

UL-SCH Uplink Shared Channel Knh chia s ng ln

UMTS Universal Mobile

Telecommunications System

H thng thng tin di ng ton cu

UpPTS Uplink Pilot Time Slot Khe thi gian dn hng ng ln

USIM Universal Subscriber Identity

Module

Modun nhn dng thu bao ton cu

UTRA Universal Terrestrial Radio

Access

Truy nhp v tuyn mt t ton cu

UTRAN Universal Terrestrial Radio

Access Network

Mng truy nhp v tuyn mt t ton cu

V-MIMO Virtual MIMO MIMO o

VoIP Voice over IP Thoi qua IP

WCDMA Wideband Code Division

Multiple Access

a truy nhp phn chia theo m bng rng

WLAN Wireless Local Area Network Mng ni b khng dy

X1AP X1 Application Protocol Giao thc ng dng X1

18

DANH MC HNH V

Hnh 1.1 Tin trnh pht trin ca thng tin di ng ............................................ 22

Hnh 2.1 Pht trin kin trc 3GPP hng ti kin trc phng hn ...................... 30

Hnh 2.2. Kin trc h thng cho mng ch c E-UTRAN ................................... 31

Hnh 2.3 eNodeB kt ni ti cc nt logic khc v cc chc nng chnh ............... 34

Hnh 2.4 MME kt ni ti cc nt logic khc v cc chc nng chnh .................. 36

Hnh 2.5. Cc kt ni S-GW ti cc nt logic khc v cc chc nng chnh .......... 37

Hnh 2.6 P-GW kt ni ti cc node logic khc v cc chc nng chnh ............... 39

Hnh 2.7 PCRF kt ni ti cc nt logic khc & cc chc nng chnh .................. 40

Hnh 2.8 Ngn xp giao thc mt phng iu khin trong EPS ............................ 42

Hnh 2.9 ngn xp giao thc mt phng ngi dng trong EPC ........................... 44

Hnh 2.10 Cc ngn xp giao thc mt phng iu khin v mt phng ngi dng

cho giao din X2...44

Hnh 2.11 Kin trc dch v mang truyn EPS .................................................... 46

Hnh 2.12. Trng thi ca UE v chuyn tip trng thi ....................................... 47

Hnh 2.13. Hot ng chuyn giao ..................................................................... 48

Hnh 2.14. Khu vc theo di cp nht cho UE trng thi RRC rnh ri ............. 49

Hnh 2.15. Khu vc dch v eMBMS v cc khu vc MBSFN ........................... 51

Hnh 2.16 Kin trc logic eMBMS ..................................................................... 52

Hnh 2.17 Kin trc mt phng ngi dng eMBMS cho ng b ni dung ......... 53

Hnh 3.1 Biu din tn s-thi gian ca mt tn hiu OFDM ............................... 57

Hnh 3.2 S to ra k hiu OFDM c ch s dng IFFT ...................................... 57

Hnh 3.3 S to ra chui tn hiu OFDM ............................................................ 58

Hnh 3.4 Cp pht sng mang con cho OFDM & OFDMA .................................. 58

Hnh 3.5 Cu trc khung loi 1 ........................................................................... 59

Hnh 3.6 Cu trc khung loi 2 ........................................................................... 59

19

Hnh 3.7 li ti nguyn ng xung ............................................................... 60

Hnh 3.8 Ghp knh thi gian tn s OFDMA.................................................. 61

Hnh 3.9 Pht v thu OFDMA ............................................................................ 62

Hnh 3.10 S khi DFT-S-OFDM ................................................................. 64

Hnh 3.11 Li ti nguyn ng ln ................................................................. 65

Hnh 3.12 Pht & thu hng ln LTE ................................................................. 67

Hnh 3.14 Cc ch truy nhp knh v tuyn ................................................... 69

Hnh 3.15 MIMO 22 , khng c tin m ha ..................................................... 71

Hnh 3.16 X l tn hiu cho phn tp pht v ghp knh khng gian (MIMO).73

Hnh 3.17 a ngi s dng MIMO trong hng ln .......................................... 75

Hnh 4.1 nh x ca cc knh truyn ti hng ln ti cc knh vt l ................ 77

Hnh 4.2 nh x cc knh truyn ti hng xung ti cc knh vt l .................. 77

Hnh 4.3 Cc chm im iu ch trong LTE ..................................................... 78

Hnh 4.4 Cp pht ti nguyn hng ln c iu khin bi b lp biu eNodeB 79

Hnh 4.5 Cu trc khung LTE FDD .................................................................... 79

Hnh 4.6 Tc d liu gia cc TTI theo hng ng ln ............................... 80

Hnh 4.7 Cu trc khe ng ln vi tin t vng ngn v di ............................. 80

Hnh 4.8 Chui m ha knh PUSCH ................................................................. 82

Hnh 4.9 Ghp knh ca thng tin iu khin v d liu ...................................... 82

Hnh 4.10 Cp pht ti nguyn ng xung ti eNodeB .................................... 83

Hnh 4.11 Cu trc khe ng xung cho bng thng 1,4MHz ............................ 84

Hnh 4.12 Chui m ha knh DL-SCH .............................................................. 84

Hnh 4.13 V d v chia s ti nguyn ng xung gia PDCCH & PDSCH ...... 85

Hnh 4.14 S to thnh tn hiu hng xung ..................................................... 86

Hnh 4.15 Ti nguyn PUCCH ........................................................................... 88

Hnh 4.16 Nguyn tc iu ch d liu v iu khin .......................................... 90

Hnh 4.17 Cp pht cc trng d liu & iu khin khc nhau trn PUSCH ....... 90

Hnh 4.18 Cc dng phn m u LTE RACH cho FDD ..................................... 92

20

Hnh 4.19 V tr PBCH ti cc tn s trung tm ................................................... 96

Hnh 4.20 Cc tn hiu ng b trong khung ....................................................... 97

Hnh 4.21 Vn hnh LTE HARQ vi 8 tin trnh ................................................ 98

Hnh 4.22 nh thi LTE HARQ cho mt gi tin ng xung duy nht ............. 99

Hnh 4.23 iu khin nh thi hng ln .......................................................... 99

Hnh 4.24 Cng sut hng ln LTE vi thay i tc d liu ........................ 100

Hnh 4.25 Th tc bo co thng tin trng thi knh (CSI) ................................ 101

Hnh 4.26 T cu hnh cho PCI ........................................................................ 104

Hnh 5.1 Cc tn hiu ng b s cp & th cp ...104

Hnh 5.2 S hnh thnh tn hiu ng b trong min tn s ................................ 108

Hnh 5.3 Tng quan v th tc truy nhp ngu nhin ......................................... 111

Hnh 5.4 Minh ha c bn cho truyn dn phn m u truy nhp ngu nhin .... 113

Hnh 5.5 nh thi phn m u ti eNodeB cho cc ngi s dng truy nhp ngu

nhin khc nhau..113

Hnh 5.6 S pht hin phn m u truy nhp ngu nhin trong min tn s ...... 114

Hnh 6.1 Samsung Craft - Chic in thoi 4G s dng mng LTE u tin trn th

gii..118

Hnh 6.2 Laptop X430 ..................................................................................... 122

Hnh 6.3 Ericsson phi hp vi Cc Tn s V tuyn in th nghim cng ngh

LTE ti H Ni122

Hnh 6.4 Trm gc LTE ................................................................................... 123

21

DANH MC BNG BIU

Bng 1. 1 Cc c im chnh ca cng ngh LTE..27

Bng 2.1 Cc giao thc v giao din LTE45

Bng 3.1 Cc bng tn vn hnh E-UTRAN....55

Bng 3.2 s lng cc khi ti nguyn cho bng thng LTE khc nhau.....60

Bng 3.3 Tham s cu trc khung ng xung (FDD & TDD).....61

Bng 3.4 Cc tham s cu trc khung ng ln (FDD&TDD).......65

Bng 4.1 Dng PDCCH v kch thc ca chng....94

Bng 4.2 Cc loi thit b LTE... 103

22

CHNG 1 - TNG QUAN V H THNG THNG TIN DI

NG & GII THIU V CNG NGH LTE

1.1. Tng quan v h thng thng tin di ng

1.1.1. H thng thng tin di ng th h th nht ( 1G)

Cng ngh di ng u tin l cng ngh tng t, l h thng truyn tn hiu

tng t, l mng in thoi di ng u tin ca nhn loi, c khi mo Nht

vo nm 1979. Nhng cng ngh chnh thuc th h th nht ny c th k n l:

NMT (Nordic Mobile Telephone in thoi di ng Bc u) c s dng

cc nc Bc u, Ty u v Nga.

AMPS (Advanced Mobile Phone Sytem H thng in thoi di ng tin

tin) c s dng M v c.

TACS (Total Access Communication Sytem H thng truyn thng truy

nhp ton phn) c s dng Anh.

Hnh 1.1 Tin trnh pht trin ca thng tin di ng

Hu ht cc h thng u l h thng tng t v dch v truyn ch yu l

thoi. Vi h thng ny, cuc gi c th b nghe trm bi bn th ba. Nhng im

yu ca th h 1G l dung lng thp, xc sut rt cuc gi cao, kh nng chuyn

cuc gi khng tin cy, cht lng m thanh km, khng c ch bo mtdo

vy h thng 1G khng th p ng c nhu cu s dng .

23

1.1.2. H thng thng tin di ng th h th hai ( 2G)

H thng di ng th h th 2 s dng truyn v tuyn s cho vic truyn ti.

Nhng h thng mng 2G th c dung lng ln hn nhng h thng mng th h

th nht. Mt knh tn s th ng thi c chia ra cho nhiu ngi dng (bi vic

chia theo m hoc chia theo thi gian). S sp xp c trt t cc t bo, mi khu vc

phc v th c bao bc bi mt t bo ln, nhng t bo ln v mt phn ca

nhng t bo lm tng dung lng ca h thng xa hn na.

C 4 chun chnh i vi h thng 2G: H Thng Thng Tin Di ng Ton Cu

(GSM) v nhng dn xut ca n; AMPS s (D-AMPS); a Truy Cp Phn Chia

Theo M IS-95; v Mng t bo S C Nhn (PDC). GSM t c thnh cng

nht v c s dng rng ri trong h thng 2G.

GSM

GSM c bn s dng bng tn 900MHz. S dng k thut a truy nhp theo thi

gian TDMA. nhng y cng c mt s nhng pht sinh, 2 vn quan trng l

h thng m hnh s 1800 (DCS 1800; cng c bit nh GSM 1800) v PCS

1900 (hay GSM 1900). Sau ny ch c s dng Bc M v Chil, v DCS

1800 th c tm thy mt s khu vc khc trn th gii. Nguyn do u tin v

bng tn s mi l do s thiu dung lng i vi bng tng 900 MHz. Bng tn

1800MHz c th c s dng ngha v ph bin hn i vi ngi s dng. v

th n tr nn hon ton ph bin, c bit trong nhng khu vc ng dn c. V

th ng thi c 2 bng tn di ng u c s dng, y in thoi s dng

bng tn 1800MHz khi c thnh phn khc s dng ln trn mng 900MHz.

H thng GSM 900 lm vic trong mt bng tn hp, di tn c bn t (890-

960MHz). Trong bng tn c bn c chia lm 2 phn :

+ ng ln t (890 915) MHz.

+ ng xung t (935 960)MHz.

Bng tn gm 124 sng mang c chia lm 2 bng, mi bng rng

25MHz,khong cch gia 2 sng mang k nhau l 200KHz. Mi knh s dng 2 tn

s ring bit cho 2 ng ln v xung gi l knh song cng. Khong cch gia 2

tn s l khng i bng 45MHz. Mi knh v tuyn mang 8 khe thi gian TDMA

v mi khe thi gian l mt knh vt l trao i thng tin gia MS v mng GSM.

Tc t 6.5 13 Kbps.

GSM mi ch cung cp c cc dch v thoi v nhn tin ngn, trong khi nhu cu

truy nhp internet v cc dch v t ngi s dng l rt ln nn GSM pht trin ln

2.5G.

24

Trong :

HSCSD ( High Speed Circuit Switched Data) - S liu chuyn mch knh

tc cao: Mt vn quan trng ln nht i vi GSM n gin l v tc d

liu chm. GSM c s c th ci thin tc ngi dng trc ch l 9.6Kbps. Sau

theo l thuyt tc ngi dng l 14.4Kbps, mc d n khng c thng

dng cho lm. HSCSD l cch n dng nht cho mi th c ti ln. Nhng

phng php ny chnh l s thay th mt khe thi gian, mt tram di ng c th

s dng nhiu khe thi gian cho mt kt ni d liu.Nhng b sung trong dng

thng mi, gi tr ti a thng l 4 khe thi gian. Mt khe thi gian c th s

dng tc 9.6Kbps hoc 14.4Kbps. Ton b tc chnh l s khe thi gian nhn

vi tc d liu ca mt khe thi gian. y chnh l mi tng quan khng phc

tp nng cp dung lng ca h thng, v n ch l nhng yu cu trong vic

nng cp phn mm i vi mng nhng n c nhiu tr ngi. Vn quan trng

nht trong vic s dng ti nguyn sng v tuyn mt cch khan him. Bi v n l

chuyn mch- mch, HSCSD phn b vic s dng khe thi gian mt cch lin tc

ngay c khi khng c bt c th g c truyn i.

GPRS (General Packet Radio Service) - Dch v v tuyn gi chung:

GPRS l mt h thng v tuyn thuc giai on trung gian, nhng vn l h thng

3G nu xt v mng li. 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 ang tn 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. Phn h trm gc ch cn

nng cp mt phn nh lin quan n khi iu khin gi (PCU- Packet Control

Unit) cung cp kh nng nh tuyn gi gia cc u cui di ng cc nt cng

(gateway). Mt nng cp nh v phn mm cng cn thit h tr cc h thng

m ho knh khc nhau. 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 v gateway

mi, c gi l GGSN (Gateway GPRS Support Node) v SGSN (Serving GPRS

Support Node). 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 ( Enhanced Data Rates for GSM Evolution): Tc s liu tng

cng pht trin GSM: EDGE c th pht nhiu bit gp 3 ln GPRS trong mt

chu k. y l l do chnh cho tc bit EDGE cao hn. ITU nh ngha

384kbps l gii hn tc d liu cho dch v thc hin chun IMT-2000 trong

mi trng khng l tng. 384kbps tng ng vi 48kbps trn mi khe thi gian,

gi s mt u cui c 8 khe thi gian.

25

EDGE l mt k thut truyn dn 3G c chp nhn v c th trin khai

trong ph tn hin c ca cc nh khai thc TDMA v GSM. EDGE ti s dng

bng tn sng mang v cu trc khe thi gian ca GSM, v c thit k nhm tng

tc s liu ca ngi s dng trong mng GPRS hoc HSCSD bng cch s

dng cc h thng cao cp v cng ngh tin tin khc. V vy, c s h tng v

thit b u cui hon ton ph hp vi EDGE hon ton tng thch vi GSM v

GRPS.

IS-95

H thng mng t bo IS-95A c Qualcomm cho ra mt vo nhng nm

1990 s dng k thut truy nhp v tuyn CDMA. CDMA chia s cng mt gii

tn chung. Mi khch hng c th ni ng thi v tn hiu c pht i trn cng

mt gii tn. Cc knh thu bao c tch bit bng cch s dng m ngu nhin.

Cc tn hiu ca nhiu thu bao khc nhau s c m ho bng cc m ngu nhin

khc nhau, sau c trn ln v pht i trn cng mt gii tn chung v ch c

phc hi duy nht thit b thu bao (my in thoi di ng) vi m ngu nhin

tng ng. IS 95A(2G) pht trin tip ln IS 95B(2.5G)

Mc d h thng thng tin di ng 2G c coi l nhng tin b ng k

nhng vn gp phi cc hn ch sau: Tc thp v ti nguyn hn hp. V th cn

thit phi chuyn i ln mng thng tin di ng th h tip theo ci thin dch

v truyn s liu, nng cao tc bit v ti nguyn c chia sMt khc, khi

cc h thng thng tin di ng ngy cng pht trin, khng ch s lng ngi s

dng in thoi di ng tng ln, m rng th trng m ngi s dng cn i hi

cc dch v tin tin hn khng ch l cc dch v cuc gi thoi truyn thng v

dch v s liu tc thp hin c trong mng hin ti. Nhu cu ca th trng c

th phn loi thnh cc lnh vc nh: Dch v d liu my tnh, dch v vin thng,

dch v ni dung s nh m thanh hnh nh. Nhng l do trn thc y cc t chc

nghin cu pht trin h thng thng tin di ng trn th gii tin hnh nghin cu

v p dng trong thc t chun mi cho h thng thng tin di ng: Thng tin di

ng 3G

1.1.3. H thng thng tin di ng th h th 3 ( 3G)

Vo nm 1992, ITU cng b chun IMT-2000 (International Mobil

Telecommunication -2000) cho h thng 3G vi cc u im chnh c mong i

em li bi h thng 3G l:

+ Cung cp dch v thoi cht lng cao.

+Cc dch v tin nhn (e-mail, fax, SMS, chat, ...).

+ Cc dch v a phng tin (xem phim, xem truyn hnh, nghe nhc,...).

26

+ Truy nhp Internet (duyt Web, ti ti liu, ...).

+S dng chung mt cng ngh thng nht, m bo s tng thch ton cu

gia cc h thng.

tho mn cc dch v a phng tin cng nh m bo kh nng truy cp

Internet bng thng rng, IMT-2000 ha hn cung cp bng thng 2Mbps, nhng

thc t trin khai ch ra rng vi bng thng ny vic chuyn giao rt kh, v vy

ch c nhng ngi s dng khng di ng mi c p ng bng thng kt ni

ny, cn khi i b bng thng s l 384 Kbps, khi di chuyn bng t s l

144Kbps. Cc h thng 3G in hnh l:

UMTS (W-CDMA)

UMTS (Universal Mobile Telephone System), da trn cng ngh W-CDMA, l

gii php c a chung cho cc nc ang trin khai cc h thng GSM mun

chuyn ln 3G. UMTS c h tr bi Lin Minh Chu u v c qun l bi

3GPP t chc chu trch nhim cho cc cng ngh GSM, GPRS. UMTS hot ng

bng thng 5MHz, cho php cc cuc gi c th chuyn giao mt cch hon ho

gia cc h thng UMTS v GSM c. Nhng c im ca WCDMA nh sau:

+WCDMA s dng knh truyn dn 5 MHz chuyn d liu. N cng cho

php vic truyn d liu tc 384 Kbps trong mng di ng v 2 Mbps trong h

thng tnh.

+Kt cu phn tng: H thng UMTS da trn cc dch v c phn tng,

khng ging nh mng GSM. trn cng l tng dch v, em li nhng u im

nh trin khai nhanh cc dch v, hay cc a im c tp trung ha. Tng gia l

tng iu khin, gip cho vic nng cp cc quy trnh v cho php mng li c th

c phn chia linh hot. Cui cng l tng kt ni, bt k cng ngh truyn d liu

no cng c th c s dng v d liu m thanh s c chuyn qua ATM/AAL2

hoc IP/RTP.

+Tn s: hin ti c 6 bng s dng cho UMTS/WCDMA, tp trung vo

UMTS tn s cp pht trong 2 bng ng ln (1885 MHz 2025 MHz) v ng

xung (2110 MHz 2200 MHz).

S pht trin ca WCDMA ln 3.5G l HSxPA

CDMA2000

Mt chun 3G quan trng khc l CDMA2000, chun ny l s tip ni i vi

cc h thng ang s dng cng ngh CDMA trong th h 2. CDMA2000 c

qun l bi 3GPP2, mt t chc c lp v tch ri khi 3GPP ca UMTS.

CDMA2000 c tc truyn d liu t 144Kbps n Mbps.

TD-SCDMA

Chun c t bit n hn l TD-SCDMA ang c pht trin ti Trung Quc

bi cc cng ty Datang v Siemens. Hin ti c nhiu chun cng ngh cho 2G nn

27

s c nhiu chun cng ngh 3G i theo, tuy nhin trn thc t ch c 2 tiu chun

quan trng nht c sn phm thng mi v c kh nng c trin khai rng ri

trn ton th gii l WCDMA (FDD) v CDMA 2000. WCDMA c pht trin

trn c s tng thch vi giao thc ca mng li GSM (GSM MAP), mt h thng

chim ti 65% th trng th gii. Cn CDMA 2000 nhm tung thch vi mng li

IS-41, hin chim 15% th trng.

1.2. Gii thiu v cng ngh LTE

LTE l th h th t ca chun UMTS do 3GPP pht trin. UMTS th h th ba

da trn WCDMA c trin khai trn ton th gii. m bo tnh cnh

tranh cho h thng ny trong tng lai, thng 11/2004 3GPP bt u d n nhm

xc nh bc pht trin v lu di cho cng ngh di ng UMTS vi tn gi Long

Term Evolution (LTE). 3GPP t ra yu cu cao cho LTE, bao gm gim chi ph

cho mi bit thng tin, cung cp dch v tt hn, s dng linh hot cc bng tn hin

c v bng tn mi, n gin ha kin trc mng vi cc giao tip m v gim ng

k nng lng tiu th thit b u cui.

Giao din khng gian v cc thuc tnh lin quan ca h thng LTE c

tm tt trong bng 1.1.

Bng tn 1,25 20 MHz

Song cng FDD , TDD , bn song cng FDD

Di ng

350km/h

a truy nhp ng xung OFDMA ng ln SC-FDMA

MIMO

ng xung 2 * 2 ; 4 * 2 ; 4 * 4 ng ln 1 * 2 ; 1 * 4

Tc d liu nh trong 20MHz

ng xung : 173 v 326 Mb/s tng ng vi cu hnh MIMO 2 * 2 v 4 * 4 ng ln : 86Mb/s vi cu hnh 1 * 2 anten

iu ch QPSK ; 16 QAM v 64 QAM

M ha knh M tubo

Cc cng ngh khc Lp biu chnh xc knh; lin kt thch ng ; iu khin cng sut ; ICIC v ARQ hn hp

Bng 1. 1 Cc c im chnh ca cng ngh LTE

Mc tiu ca LTE l cung cp 1 dch v d liu tc cao , tr thp , cc gi

d liu c ti u , cng ngh v tuyn h tr bng thng mt cch linh hot khi

trin khai. ng thi kin trc mng mi c thit k vi mc tiu h tr lu

28

lng chuyn mch gi cng vi tnh di ng linh hot , cht lng ca dch v ,

thi gian tr ti thiu.

Tng tc truyn d liu : Trong iu kin l tng h thng h tr tc

d liu ng xung nh ln ti 326Mb/s vi cu hnh 4*4 MIMO ( multiple

input multiple output ) trong vng 20MHZ bng thng. MIMO cho ng ln l

khng c s dng trong phin bn u tin ca chun LTE. Tc d liu nh

ng ln ti 86Mb/s trong 20MHZ bng thng. Ngoi vic ci thin tc d

liu nh h thng LTE cn cung cp hiu sut ph cao hn t 2 n 4 ln ca h

thng HSPA phin bn 6.

Di tn co gin c : Di tn v tuyn ca h thng LTE c kh nng m

rng t 1.4 MHz, 3MHz, 5 MHz, 10 MHz, 15 MHz v 20 MHz c chiu ln v

xung. iu ny dn n s linh hot s dng c hiu qu bng thng .Mc

thng sut cao hn khi hot ng bng tn cao v i vi mt s ng dng

khng cn n bng tn rng ch cn mt bng tn va th cng c p ng.

m bo hiu sut khi di chuyn : LTE ti u ha hiu sut cho thit b

u cui di chuyn t 0 n 15km/h, vn h tr vi hiu sut cao (ch gim i mt

t) khi di chuyn t 15 n 120km/h, i vi vn tc trn 120 km/h th h thng

vn duy tr c kt ni trn ton mng t bo ,chc nng h tr t 120 n

350km/h hoc thm ch l 500km/h ty thuc vo bng tn.

Gim tr trn mt phng ngi s dng v mt phng iu khin :

Gim thi gian chuyn i trng thi trn mt phng iu khin : Gim thi

gian mt thit b u cui ( UE - User Equipment) chuyn t trng thi ngh

sang ni kt vi mng, v bt u truyn thng tin trn mt knh truyn.Thi gian

ny phi nh hn 100ms.

Gim tr mt phng ngi dng: Nhc im ca cc mng t ong ()

hin nay l tr truyn cao hn nhiu so vi cc mng ng dy c nh. iu

ny nh hng ln n cc ng dng nh thoi v chi game ,v cn thi gian

thc. Giao din v tuyn ca LTE v mng li cung cp kh nng tr di

10ms cho vic truyn ti 1 gi tin t mng ti UE.

S khng cn chuyn mch knh : Tt c s da trn IP. Mt trong nhng

tnh nng ng k nht ca LTE l s chuyn dch n mng li hon ton da

trn IP vi giao din m v kin trc n gin ha. Su xa hn, phn ln cng

vic chun ha ca 3GPP nhm n s chuyn i kin trc mng li ang tn ti

sang h thng ton IP. Trong 3GPP. Chng cho php cung cp cc dch v linh

hot hn v s lin hot ng n gin vi cc mng di ng phi 3GPP v cc

mng c nh. EPC da trn cc giao thc TCP/IP ging nh phn ln cc

mng s liu c nh ngy nay- v vy cung cp cc dch v ging PC nh thoi,

video, tin nhn v cc dch v a phng tin. S chuyn dch ln kin trc ton

29

gi cng cho php ci thin s phi hp vi cc mng truyn thng khng dy v

c nh khc.VoIP s dng cho dch v thoi.

ph s ng t 5-100km : Trong vng bn knh 5km LTE cung cp ti u

v lu lng ngi dng, hiu sut ph v di ng. Phm vi ln n 30km th

c mt s gim nh cho php v lu lng ngi dng cn hiu sut ph th li

gim mt cch ng k hn nhng vn c th chp nhn c, tuy nhin yu cu

v di ng vn c p ng. dung lng hn 200 ngi/ (bng thng

5MHz).

Kin trc mng s n gin hn so vi mng 3G hin thi. Tuy nhin

mng LTE vn c th tch hp mt cch d dng vi mng 3G v 2G hin ti.

iu ny ht sc quan trng cho nh cung cp mng trin khai LTE v khng cn

thay i ton b c s h tng mng c.

OFDMA ,SC-FDMA v MIMO c s dng trong LTE :H thng ny

h tr bng thng linh hot nh cc s truy nhp OFDMA & SC-FDMA.

Ngoi ra cn c song cng phn chia tn s FDD v song cng phn chia thi

gian TDD. Bn song cng FDD c cho php h tr cho cc ngi s dng

vi chi ph thp .khng ging nh FDD, trong hot ng bn song cng FDD th

mt UE khng cn thit truyn & nhn ng thi . iu ny trnh vic phi u

t mt b song cng t tin trong UE. Truy nhp ng ln v c bn da trn

a truy nhp phn chia tn s n sng mang SC-FDMA ha hn s gia tng

vng ph sng ng ln do t s cng sut nh-trung bnh thp ( PARR) lin

quan ti OFDMA.

Gim chi ph : Yu cu t ra cho h thng LTE l gim thiu c chi ph

trong khi vn duy tr c hiu sut nhm p ng c cho tt c cc dch

v.Cc vn ng truyn,hot ng v bo dng cng lin quan n yu t

chi ph,chnh v vy khng ch giao tip m vic truyn ti n cc trm gc v

h thng qun l cng cn xc nh r, ngoi ra mt s vn cng c yu

cu nh l phc tp thp,cc thit b u cui tiu th t nng lng.

Cng tn ti vi cc chun v h thng trc: H thng LTE phi cng

tn ti v c th phi hp hot ng vi cc h thng 3GPP khc .Ngi s

dng LTE s c th thc hin cc cuc gi t thit b u cui ca mnh v thm

ch khi h khng nm trong vng ph sng ca LTE. Do , cho php chuyn

giao cc dch v xuyn sut, tri chy trong khu vc ph sng ca HSPA,

WCDMA hay GSM/GPRS/EDGE. Hn th na, LTE h tr khng ch chuyn

giao trong h thng, lin h thng m cn chuyn giao lin min gia min

chuyn mch gi v min chuyn mch knh.

30

CHNG 2 KIN TRC MNG V GIAO THC

2.1. Kin trc mng LTE

Nhiu cc mc tiu vi ng rng mt kin trc phng s cn c pht trin .

kin trc phng vi t nt tham gia s lm gim tr v ci thin hiu sut. Pht

trin theo hng ny c bt u t phin bn 7. Ni tng ng hm trc

tip cho php mt phng ngi dng ( UP) b qua SGSN.

--------mt phng iu khin

Mt phng ngi dng

Hnh 2.1 Pht trin kin trc 3GPP hng ti kin trc phng hn

Kin trc mng LTE c thit k vi mc tiu h tr lu lng chuyn mch

gi vi tnh di ng linh hot , cht lng dch v (QoS) v tr ti thiu. Mt

phng php chuyn mch gi cho php h tr tt c cc dch v bao gm c thoi

thng qua cc kt ni gi. Kt qu l trong mt kin trc phng hn , rt n gin

ch vi 2 loi nt c th l nt B pht trin ( eNB) v phn t qun l di ng /cng

( MME/GW). iu ny hon ton tri ngc vi nhiu nt mng trong kin trc

mng phn cp hin hnh ca h thng 3G. Mt thay i ln na l phn iu khin

mng v tuyn (RNC) c loi b khi ng d liu v chc nng ca n hin

nay c thnh lp eNB. Mt s ch li ca mt nt duy nht trong mng truy

nhp l gim tr v phn phi ca vic x l ti RNC vo nhiu eNB. Vic loi

b RNC ra khi mng truy nhp c th mt phn do h thng LTE khng h tr

chuyn giao mm.

31

2.1.1. Tng quan v cu hnh kin trc c bn h thng

Hnh 2.2 miu t kin trc v cc thnh phn mng trong cu hnh kin trc ni

ch c mt E-UTRAN tham gia. Hnh ny cng cho thy s phn chia kin trc

thnh bn vng chnh: thit b ngi dng (UE) ; UTRAN pht trin( E-UTRAN);

mng li gi pht trin(EPC); v cc vng dch v.

Hnh 2.2. Kin trc h thng cho mng ch c E-UTRAN

UE, E-UTRAN v EPC i din cho cc giao thc internet (IP) lp kt ni.

y l mt phn ca h thng c gi l h thng gi pht trin (EPS). Chc nng

chnh ca lp ny l cung cp kt ni da trn IP v n c ti u ha cao cho

mc tiu duy nht. Tt c cc dch v c cung cp da trn IP, tt c cc nt

chuyn mch v cc giao din c nhn thy trong kin trc 3GPP trc khng

c mt E-UTRAN v EPC. Cng ngh IP chim u th trong truyn ti, ni m

mi th c thit k hot ng v truyn ti trn IP.

Cc h thng con a phng tin IP ( IMS) l mt v d tt v my mc thit b

phc v c th c s dng trong lp kt ni dch v cung cp cc dch v da

32

trn kt ni IP c cung cp bi cc lp thp hn. V d , h tr dch v thoi

th IMS c th cung cp thoi qua IP ( VoIP) v s kt ni ti cc mng chuyn

mch-mch c PSTN v ISDN thng qua cc cng a phng tin ca n iu

khin.

S pht trin ca E-UTRAN tp chung vo mt nt, nt B pht trin ( eNode B).

Tt c cc chc nng v tuyn kt thc , tc l eNB l im kt thc cho tt c

cc giao thc v tuyn c lin quan. E-UTRAN ch n gin l mt mng li ca

cc eNodeB c kt ni ti cc eNodeB ln cn vi giao din X2.

Mt trong nhng thay i kin trc ln l trong khu vc mng li l EPC khng

c cha mt vng chuyn mch-mch, v khng c kt ni trc tip ti cc mng

chuyn mch mch truyn thng nh ISDN v PSTN l cn thit trong lp ny. Cc

chc nng ca EPC l tng ng vi vng chuyn mch gi ca mng 3GPP hin

ti. Tuy nhin nhng thay i ng k trong vic b tr cc nt chc nng v kin

trc phn ny nn c coi nh l hon tan mi.

C hai hnh 2.1 v 2.2 cho thy c mt phn t gi l SAE GW. Nh hnh 2.2 cho

thy l s kt hp ca hai cng l cng phc v (S-GW) v cng mng d liu

gi( P-GW) iu ny c nh ngha cho cc x l UP trong EPC. Gp chng li

vi nhau thnh SAE GW. Cu hnh kin trc c bn h thng v chc nng ca n

c ghi trong 3GPP TS 23.401.

2.1.2. Thit b ngi dng ( UE)

UE l thit b m ngi dng u cui s dng lin lc. Thng thng n l

nhng thit b cm tay nh in thoi thng minh hoc mt th d liu nh mi

ngi vn ang s dng hin ti trong mng 2G v 3G. Hoc n c th c nhng

vo, v d mt my tnh xch tay. UE cng c cha cc moun nhn dng thu bao

ton cu( USIM). N l mt moun ring bit vi phn cn li ca UE, thng

c gi l thit b u cui (TE). USIM l mt ng dng c t vo mt th

thng minh c th tho ri c gi l th mch tch hp ton cu ( UICC). USIM

c s dng nhn dng v xc thc ngi s dng ly kha bo mt nhm

bo v vic truyn ti trn giao din v tuyn.

Cc chc nng ca UE l nn tng cho cc ng dng truyn thng, m c tn hiu

vi mng thit lp, duy tr v loi b cc lin kt thng tin ngi dng cn. iu

ny bao gm cc chc nng qun l tnh di ng nh chuyn giao, bo co v tr ca

thit b, v cc UE phi thc hin theo hng dn ca mng. C l quan trng nht

l UE cung cp giao din ngi s dng cho ngi dng cui cc ng dng nh

VoIP c th c s dng thit lp mt cuc gi thoi.

33

2.1.3. E-UTRAN NodeB (eNodeB)

Nt duy nht trn E-UTRAN l E-UTRAN NodeB ( eNodeB). n gin t eNB

l mt trm gc v tuyn kim sot tt c cc chc nng v tuyn lin quan trong

phn c nh ca h thng. Cc trm gc nh eNB thng phn b trn ton khu

vc ph sng ca mng. Mi eNB thng c tr gn cc anten v tuyn hin ti ca

chng.

Chc nng ca eNB hot ng nh mt cu ni gia 2 lp l UE v EPC, n l

im cui ca tt c cc giao thc v tuyn v pha UE, v tip nhn d liu gia

cc kt ni v tuyn v cc kt ni IP c bn tng ng v pha EPC. Trong vai tr

ny cc EPC thc hin m ha / gii m cc d liu UP, v cng c nn / gii nn

tiu IP, trnh vic gi i lp li ging nhau hoc d liu lin tip trong tiu IP.

eNB cng chu trch nhim v nhiu cc chc nng ca mt phng iu khin

(CP). eNB chu trch nhim v qun l ti nguyn v tuyn (RRM), tc l kim sat

vic s dng giao din v tuyn , bao gm : phn b ti nguyn da trn yu cu,

u tin v lp lch trnh lu lng theo yu cu QoS, v lin tc gim st tnh hnh

s dng ti nguyn.

Ngoi ra eNodeB cn c vai tr quan trng trong qun l tnh di ng (MM).

iu khin eNB v o c phn tch mc ca tn hiu v tuyn c thc hin

bi UE. iu ny bao gm trao i tn hiu chuyn giao gia eNB khc v MME.

Khi mt UE mi kch hot theo yu cu ca eNB v kt ni vo mng, eNB cng

chu trch nhim v vic nh tuyn khi ny n s ngh cc MME m trc y

phc v cho UE, hoc la chn mt MME mi nu mt tuyn ng n cc

MME trc khng c sn hoc thng tin nh tuyn vng mt.

Hnh 2.3 cho thy cc kt ni vi eNB n xung quanh cc nt logic, v tm

tt cc chc nng chnh trong giao din ny. Trong tt c cc kt ni eNB c th l

trong mi quan h mt nhiu hoc nhiu nhiu. Cc eNB c th phc v ng

thi nhiu UE trong vng ph sng ca n nhng mi UE ch c kt ni ti mt

eNB trong cng mt thi im. Cc eNB s cn kt ni ti cc eNB ln cn vi n

trong khi chuyn giao c th cn thc hin.

C hai MME v S-GW c th c gp li, c ngha l mt tp hp cc nt c

phn cng phc v cho mt tp hp cc eNB. T mt vin cnh eNB n ny c

ngha l n c th cn phi kt ni ti nhiu MME v S-GW. Tuy nhin mi UE s

c phc v bi ch c mt MME v S-GW ti mt thi im v eNB phi duy tr

theo di cc lin kt ny.

S kt hp ny s khng bao gi thay i t mt im eNodeB duy nht, bi v

MME hoc S-GW ch c th thay i khi kt hp vi s chuyn giao lin eNodeB.

34

Hnh 2.3 eNodeB kt ni ti cc nt logic khc v cc chc nng chnh

2.1.4. Thc th qun l tnh di ng (MME)

Thc th qun l tnh di ng(MME) l thnh phn iu khin chnh trong EPC.

Thng thng MME s l mt my ch mt v tr an ton ti cc c s ca nh

iu hnh. N ch hot ng trong cc CP, v khng tham gia vo con ng ca

UP d liu.

Ngoi giao din cui vo MME trong kin trc th hin trong hnh 2.2, MME cn

c mt kt ni logic trc tip ti UE, v kt ni ny c s dng nh l knh iu

khin chnh gia UE v mng. Sau y l danh sch cc chc nng chnh ca MME

trong cu hnh kin trc c bn h thng :

Xc thc v bo mt : khi mt UE ng k vo mng ln u tin, MME s

khi to s xc thc, bng cch thc hin nhng iu sau: n tm ra danh tnh

thng tr ca UE, hoc t cc mng truy nhp trc hoc chnh bn thn UE,

yu cu t b phc v thu bao thng tr (HSS) trong mng ch ca UE cc iu

khin chng thc c cha cc mnh lnh chng thc tr li cc cp tham s, gi

cc th thch vi UE v so snh cc tr li nhn c t UE vo mt trong nhng

ci nhn t mng ch. Chc nng ny l cn thit m bo cc yu cu bo

v vi UE. Cc MME c th lp li chc nng xc thc khi cn thit hoc theo chu

k. Cc chc nng ny dng bo v cc thng tin lin lc khi vic nghe trm

v t s thay i ca bn th ba tng ng tri php. bo v s ring t ca

UE, MME cng phn b cho mi UE mt m tm thi gi l m nhn dng tm

thi duy nht ton cu(GUTI), do cn phi gi m nhn dng thng tr UE

35

m nhn dng thu bao di ng quc t ( IMIS) qua giao din v tuyn c gim

thiu. Cc GUTI c th c cp tr li, v d nh k ngn chn theo di UE.

Qun l tnh di ng: MME theo di v tr ca tt c cc UE trong khu vc

ca mnh, khi mt UE ng k vo mng ln u tin, MME s to ra mt li vo

cho UE v tn hiu vi v tr ti HSS trong mng ch ca UE. MME yu cu ti

nguyn thch hp c thit lp trong eNodeB, cng nh trong cc S-GW m n

la chn cho UE. Cc MME sau tip tc theo di v tr ca UE hoc l da trn

mc ca eNB, nu UE vn kt ni, tc l truyn thng ang hot ng hoc

mc khu vc theo di (TA). MME iu khin cc thit lp v gii phng ngun

ti nguyn da trn nhng thay i ch hot ng ca UE. MME cng tham gia

vo vic iu khin tn hiu chuyn giao ca UE trong ch hot ng gia cc

eNB, S-GW hoc MME. MME tham gia vo mi thay i ca eNB v khng c

phn t iu khin mng v tuyn ring bit nn n n hu ht cc s kin ny.

Mt UE trng thi rnh di n s bo co v tr ca n hoc l nh k, hoc l

khi n chuyn ti mt khu vc theo di. Nu du liu nhn c t bn ngoi cho

mt UE rnh di, MME s c thng bo, n s yu cu cc eNB trong TA

c lu gi cho UE ti v tr nh ca UE.

Qun l h s thu bao v dch v kt ni: vo thi im mt UE ng k

vo mng, cc MME s chu trch nhim ly h s ng k ca n t mng ch v.

Cc MME s lu tr thng tin ny trong sut thi gian phc v UE. H s ny xc

nh nhng g cc kt ni mng d liu gi c phn b ti cc mng tp tin

nh km. Cc MME s t ng thit lp mc nh phn t mang, cho php cc UE

kt ni IP c bn. iu ny bao gm tn hiu CP vi eNB v S-GW. Ti bt k thi

im no sau ny, cc MME c th cn ti c tham gia vo vic thit lp phn t

mang dnh ring cho cc dch v c hng li x l cao hn. Cc MME c th

nhn c cc yu cu thit lp mt phn t mang dnh ring, hoc t cc S-GW

nu yu cu bt ngun t khu vc dch v iu hnh, hoc trc tip t UE, nu UE

yu cu kt ni cho mt dch v m khng c bit n bi khu vc dch v iu

hnh, v do khng th c bt u t .

Hnh 2.4 cho thy cc kt ni MME n quanh cc nt logic, v tm tt cc chc

nng chnh trong giao din ny. V nguyn tc MME c th c kt ni vi bt k

MME khc trong h thng, nhng thng kt ni c gii hn trong mt nh iu

hnh mng duy nht. Cc kt ni t xa gia cc MME c th c s dng khi mt

UE i xa, trong khi i ng k vi mt MME mi sau tm kim nhn dng

thng tr mi ca UE, sau ly nhn dng thng tr ca UE, m nhn dng

thu bao di ng quc t (IMIS), t MME truy cp trc . Cc kt ni gia cc

MME vi cc MME ln cn c s dng trong chuyn giao.

36

Hnh 2.4 MME kt ni ti cc nt logic khc v cc chc nng chnh

Kt ni ti mt s HSS cng cn c h tr, cc HSS nm trong mng ch ca

ngi dng , v mt tuyn ng c th c tm thy da trn IMIS. Mi MME

c cu hnh iu khin mt tp hp cc S-GW v eNodeB. C hai S-GW v

eNodeB cng c th c kt ni ti cc MME khc. Cc MME c th phc v

mt s UE cng mt lc, trong khi mi UE s ch kt ni ti mt MME ti mt thi

im.

2.1.5. Cng phc v ( S-GW)

Trong cu hnh kin trc c bn h thng, chc nng cao cp ca S-GW l qun

l ng hm UP v chuyn mch. S-GW l mt phn ca h tng mng n c

duy tr cc phng iu hnh trung tm ca mng.

Khi giao din S5/S8 da trn GTP, S-GW s c ng hm GTP trn tt c cc

giao din UP ca n. nh x gia cc lung dch v IP v ng hm GTP c

thc hin trong P-GW, v S-GW khng cn c kt ni vi PCRF. Ton b iu

khin c lin quan ti cc ng hm GTP, n t MME hoc P-GW. Khi s dng

giao din PMIP S5/S8. S-GW s thc hin vic nh x gia cc dng dch v IP

trong cc ng hm S5/S8 v ng hm GTP trong giao din S1-U, v s kt ni

ti PCRF nhn c thng tin nh x.

S-GW c mt vai tr rt nh trong cc chc nng iu khin. N ch chu trch

nhim v ngun ti nguyn ca ring n, v n cp pht chng da trn cc yu cu

t MME, P-GW hoc PCRF, t m cc hnh ng c thit lp , sa i hoc

xa sch cc phn t mang cho UE. Nu cc lnh trn c nhn t P-GW hoc

PCRF th S-GW cng s chuyn tip cc lnh ti MME n c th iu khin

37

cc ng hm ti eNodeB. Tng t, khi MME bt u c yu cu th S-GW s

bo hiu ti mt trong hai P-GW hoc PCRF ty thuc vo S5/S8 c da trn

GTP hoc PMIP tng ng. Nu giao din S5/S8 c da trn PMIP th d liu

trong giao din s c cc lung IP trong mt ng hm GRE truyn ti mi

UE. Khi trong giao din S5/S8 da trn GTP mi phn t mang s c ng

hm ca ring mnh. Do S-GW h tr PMIP S5/S8 c trch nhim lin kt cc

phn t mang, v d : nh x cc lung IP trong giao din S5/S8 vo cc phn t

mang trong giao din S1. Chc nng ny trong S-GW c gi l chc nng lin

kt phn t mang v bo co s kin ( BBERF). Bt k ni m tn hiu phn t

mang bt u, BBERF lun nhn cc thng tin lin kt phn t mang t PCRF.

Hnh 2.5. Cc kt ni S-GW ti cc nt logic khc v cc chc nng chnh

Trong khi di chuyn gia cc eNodeB, S-GW hot ng nh nt cui di ng a

phng. MME s lnh S-GW chuyn sang ng hm t mt eNodeB khc.

MME cng c th yu cu S-GW cung cp ti nguyn ng hm cho d liu

chuyn tip khi c nhu cu cn chuyn d liu t eNodeB ngun ti eNodeB ch

trong thi im UE c chuyn giao v tuyn. Cc tnh hung di chuyn cng bao

gm s thay i t mt S-GW ti mt ci khc, v MME s iu khin s thay i

ny cho ph hp bng cch loi b cc ng hm trong S-GW c v thit lp

chng trong S-GW mi.

i vi tt c cc lun d liu thuc v mt UE trong ch kt ni th S-GW s

chuyn tip d liu gia eNodeB v P-GW. Tuy nhin khi mt UE ch nhn

ri th cc ngun ti nguyn ny trong eNodeB s c gii phng, cc ng dn

d liu c kt thc trong S-GW. Nu S-GW nhn c gi d liu t P-GW th

n s lu cc gi vo b m v yu cu MME bt u nhn tin ti UE. Tin nhn s

38

lm cho UE ti ch ti kt ni, v khi cc ng hm c ti kt ni th cc gi

tin t b m s c gi v. S-GW s theo di d liu trong cc ng hm v n

cng c th thu thp cc d liu cn thit cho vic hch ton v tnh chi ph ca

ngi dng.

Trong hnh 2.5 cho thy S-GW c kt ni ti cc nt logic khc v danh sch

cc chc nng chnh trong cc giao din ny. Tt c cc giao din c cu hnh

theo kiu mt nhiu t S-GW c thy. Mt S-GW c th ch phc v mt khu

vc a l nht nh vi mt tp gii hn cc eNodeB, v tng t c th c mt tp

gii hn ca cc MME iu khin khu vc . S-GW c th kt ni ti bt k P-

GW no trong ton b mng li, bi v P-GW s khng thay i trong khi di

chuyn, trong khi S-GW c th c nh v li trong khi UE di chuyn. Vi cc kt

ni c lin quan ti mt UE, S-GW s lun bo hiu vi ch mt MME v cc im

UP ti mt eNodeB ti mt thi im. Nu mt UE c php kt ni ti nhiu cc

PDN thng qua cc P-GW khc nhau , th S-GW cn kt ni ti cc thnh phn

ring bit. Nu giao din S5/S8 l da trn PMIP th S-GW s kt ni ti mt PCRF

cho mi P-GW ring c UE s dng.

Trn hnh cng cho thy trng hp chuyn d liu gin tip ni m d liu UP

c chuyn tip gia cc eNodeB thng qua cc S-GW. Khng c tn giao din c

th lin quan n giao din gia cc S-GW, v nh dng chnh xc ging nh trong

giao din S1-U, v c th cho rng cc S-GW lin quan chng truyn thng trc

tip vi cng mt eNodeB. y s l trng hp khi chuyn tip d liu gin tip

din ra thng qua ch mt S-GW, tc l c hai eNodeB c th c kt ni ti cng

mt S-GW.

2.1.6. Cng mng d liu g i( P-GW)

Cng mng d liu gi ( P-GW, cng thng c vit tt l PDN-GW) l tuyn

bin gia EPS v cc mng d liu gi bn ngoi. N l nt cui di ng mc cao

nht trong h thng, v n thng hot ng nh l im IP ca cc thit b cho UE.

N thc hin cc chc nng chn lu lng v lc theo yu cu bi cc dch v

c cp. Tng t nh S-GW, cc P-GW c duy tr ti cc phng iu hnh

ti mt v tr trung tm.

in hnh l P-GW cp pht cc a ch IP cho UE, v UE s dng n giao tip

vi cc my ch IP khc trong cc mng bn ngoi. ( v d nh Internet ). N cng

c th l PDN bn ngoi m UE c kt ni cp pht cc a ch l s

dng bi cc UE, cc ng hm P-GW cho tt c lu lng vo mng . a ch

IP lun c cp pht khi UE yu cu mt kt ni PDN, n s din ra t nht l khi

UE c gn vo mng, v n c th sy ra sau khi c mt kt ni PDN mi. Cc

P-GW thc hin chc nng giao thc cu hnh my ch ng (DHCP) khi cn, hoc

39

truy vn mt my ch DHCP bn ngoi, v cung cp a ch cho UE. Ngoi ra t

cu hnh ng c h tr bi cc tiu chun. Ch IPv4, ch IPv6 hoc c hai, cc

a ch c th c phn b ty theo nhu cu. UE c th bo hiu rng n mun

nhn a ch ngay trong tn hiu kt ni hoc nu n mun thc hin cu hnh a

ch sau khi lp lin kt c kt ni.

P-GW bao gm c PCEF, c ngha l n thc hin cc chc nng chn lu lng

v lc theo yu cu bi cc chnh sch c thit lp cho UE v cc dch v ni

n, n cng thu thp cc bo co thng tin chi ph lin quan.

Lu lng UP gia P-GW v cc mng bn ngoi di dng cc gi tin IP thuc

v cc dng dch v IP khc nhau. Nu giao din S5/S8 hng ti S-GW l da trn

GTP th P-GW thc hin nh x cc dng d liu IP ti cc ng hm GTP, cc P-

GW thit lp cc phn t mang c bn da trn yu cu qua PCRF hoc t S-GW,

m chuyn tip cc thng tin t MME. Nu giao din S5/S8 l da trn PMIP, P-

GW s nh x tt c cc lung dch v IP t cc mng bn ngoi thuc v mt UE

ti mt ng hm GRE duy nht, v tt c cc thng tin iu khin ch c trao

i vi PCRF. P-GW cng c chc nng gim st cc lun d liu cho mc ch

hoch ton cng nh cho ngn xen theo lut.

P-GW l im cui di ng mc cao nht trong h thng. Khi mt UE di chuyn

t mt S-GW ti mt ci khc, cc phn t mang phi c chuyn vo P-GW. P-

GW s nhn c ch dn chuyn cc lung t cc S-GW mi.

Hnh 2.6 cho thy cc kt ni P-GW n xung quanh cc nt logic, v danh

sch cc chc nng chnh trong giao din ny.

Hnh 2.6 P-GW kt ni ti cc node logic khc v cc chc nng chnh

40

Mi P-GW c th c kt ni ti mt hoc nhiu PCRF, S-GW v mng bn

ngoi. i vi mt UE lin kt vi P-GW th ch c duy nht mt S-GW, nhng c

cc kt ni ti nhiu cc mng bn ngoi v tng ng c nhiu cc PCRF c th

cn phi c h tr, nu c kt ni ti nhiu cc PDN c h tr thng qua mt

P-GW.

2.1.7. Chc nng chnh sch v tnh cc ti nguyn ( PCRF)

Chc nng chnh sch v tnh cc ti nguyn(PCRF) l phn t mng chu trch

nhim v chnh sch v iu khin tnh cc ( PCC). N to ra cc quyt nh v

cch x l cc dch v v QoS, v cung cp thng tin cho PCEF c t trong P-

GW, v nu c p dng cho c BBERF c t trong S-GW, cho vic thit

lp cc phn t mang thch hp v vic lp chnh sch. PCRF l mt my ch v

thng c t vi cc phn t CN khc ti cc trung tm iu hnh chuyn mch.

Cc thng tin PCRF cung cp cho PCEF c gi l cc quy tc PCC. PCRF s

gi cc quy tc PCC bt c khi no mt phn t mang mi c thit lp. Thit lp

phn t mang l cn thit, v d khi UE bc u c gn vo mng v phn t

mang mc nh s c thit lp, v sau khi c mt hoc nhiu cc phn t mang

dnh ring c thit lp. PCRF c kh nng cung cp cc quy tc PCC da trn

yu cu, hoc t P-GW v cng nh S-GW trong tng hp PMIP, ging nh trong

trng hp kt ni, v cng da trn yu cu t chc nng ng dng(AF) nm trong

cc dch v tn min. V d, vi IMS v AF s thc y dch v QoS thng tin ti

PCRF, t to ra mt quyt nh PCC v n s y cc quy tc PCC n P-GW,

v mang thng tin nh x ti S-GW trong trng hp S5/S8 l PMIP. Cc phn t

mang EPC sau s c thit lp da trn nhng iu .

Hnh 2.7 PCRF kt ni ti cc nt logic khc & cc chc nng chnh

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Cc kt ni gia PCRF v cc nt khc c th hin nh trong hnh 2.7, mi

PCRF c th c kt ni vi mt hoc nhiu AF, P-GW v S-GW. Ch c mt

PCRF lin kt vi mi kt ni PDN l mt UE duy nht c.

2.1.8. My ch thu bao thng tr (HSS)

My ch thu bao thng tr (HSS) l kho d liu thu bao cho tt c d liu

ngi dng thng xuyn. N cng ghi li v tr ca ngi s dng mc ca

nt iu khin mng tm tr, chng hn nh MME. N l mt my ch c s d

liu v c duy tr ti cc phng trung tm ca nh iu hnh.

HSS lu tr bn gc ca h s thu bao, trong cha cc thng tin v cc dch

v c p dng i vi ngi s dng, bao gm thng tin v cc kt ni PDN

c cho php, v liu c chuyn ti mt mng tm tr ring c hay khng. HSS

cng lu nhng nhn dng ca cc P-GW c s dng. Kha thng trc c s

dng tnh ton xc thc v c gi ti mng tm tr xc thc ngi dng v

cc kha pht sinh tip sau m ha v bo v tnh ton vn l c lu tr ti cc

trung tm xc thc(AUC), thng l mt phn ca HSS. Trong tt c cc tn hiu

lin quan ti cc chc nng ny th HSS phi tng tc vi MME. Cc HSS s cn

phi c kh nng kt ni vi mi MME trong ton b h mng li, ni m cc UE

ca n c php di chuyn. i vi mi UE, cc h s HSS s ch ti mt MME

phc v ti mt thi im, v ngay sau l bo co v mt MME mi m n phc

v cho UE, HSS s hy b v tr ca MME trc.

2.2. Cc giao din v giao thc trong cu hnh kin trc c bn ca h

thng

Hnh 2.8 cho thy cc giao thc CP lin quan ti kt ni ca UE yi mt PDN.

Cc giao din t mt MME c th hin bi hai phn, phn trn hng u l cc

giao thc hng ti E-UTRAN v UE, v phn di hin th cc giao thc hng

ti cc cng. Cc giao thc hin th trong nn trng c pht trin bi 3GPP, trong

khi cc giao thc trong nn xm c pht trin trong IETF, v i din cho cc

cng ngh mng tiu chun c s dng cho truyn ti trong EPS. 3GPP ch xc

nh nhng cch c th m cc giao thc ny c s dng.

Lp trn cng trong CP l cc lp khng truy cp (NAS), bao gm c hai giao

thc ring bit c thc hin truyn ti tn hiu trc tip gia UE m MME. Cc

giao thc lp NAS l :

Qun l tnh di ng EPS ( EMM): cc giao thc MME c trch nhim v

iu khin tnh di ng ca UE trong h thng. N bao gm cc chc nng kt ni

vo v tch ra t mng, v thc hin vic cp nht v tr. iu ny c gi l cp

nht khu vc theo di (TAU), v n din ra trong ch nhn di. Ch rng cc

42

chuyn giao trong ch kt ni c x l bi cc giao thc lp thp hn, nhng

cc lp EMM khng bao gm cc chc nng ti kch hot cc UE t ch nhn

ri.

Hnh 2.8 Ngn xp giao thc mt phng iu khin trong EPS

Qun l phin EPS ( ESM): Giao thc ny c th c s dng iu

khin vic qun l phn t mang gia UE v MME, v n c s dng b sung

cho E-UTRAN trong vic qun l phn t mang. Lu rng s khng s dng cc

th tc ESM nu tnh trng ca cc phn t mang l c sn trong mng li v

quy trnh E-UTRAN c th chy ngay lp tc.

iu khin ti nguyn v tuyn (RRC) : Giao thc ny nhm kim sot

vic s dng ngun ti nguyn v tuyn. N qun l bo hiu ca UE v cc kt

ni d liu, v n cng bao gm cc chc nng chuyn giao.

Giao thc hi t d liu g i ( PDCP) : Cc chc nng chnh ca PDCP l

nn tiu IP (UP), m ha v bo v s ton vn ( ch vi CP).

43

iu khin lin kt v tuyn (RLC) : Giao thc RLC c trch nhim phn

on v ghp ni cc PDCP-PDU truyn cho giao din v tuyn. N cng thc

hin vic sa li vi phng php yu cu truyn li t ng (ARQ).

iu khin truy nhp mi trng (MAC) : Lp MAC c trch nhim lp

k hoch d liu theo cc u tin v ghp knh d liu ti cc khi truyn ti

lp 1. Lp MAC cng cung cp vic sa li vi HARQ.

Lp vt l (PHY) : y l lp 1 ca giao din v tuyn LTE-UU n c cc

chc nng ging nh ca DS-CDMA.

Trong EPC c hai giao thc khc cho giao din S5/S8. Cc giao thc sau

c lin quan khi GTP c s dng trong S5/S8 :

Mt phng iu khin giao thc ng hm GPRS ( GTP-C) : N

qun l cc kt ni UP trong EPC. N bao gm bo hiu QoS v cc thng

s khc. Nu GTP c s dng trong giao din S5/S8 th n cn qun l

cc ng hm GTP-U. GTP-C cng thc hin cc chc nng qun l di

ng trong EPC. Nh vic khi cc ng hm GTP-U ca mt UE cn

phi c chuyn t mt nt ti mt nt khc.

Truyn ti UDP-IP : giao thc d liu n v ( UDP) v IP c s

dng nh l truyn ti IP cn bn v tiu chun. UDP c s dng thay v

giao thc iu khin truyn dn (TCP) bi v cc lp cao hn c cung

cp s truyn ti tin cy vi c ch khc phc li v truyn li. Cc gi tin

IP trong EPC c th c vn chuyn trn mt lot cc cng ngh lp 1

v lp 2.

Cc giao thc sau c s dng khi S5/S8 da trn PMIP:

IP di ng y nhim (PMIP) : PMIP l giao thc khc cho giao din

S5/S8. n gi vic qun l tnh di ng, nhng khng bao gm cc chc

nng nh qun l phn t mang. Tt c cc lu lng thuc v mt kt ni

ca UE vi mt PDN ring l c x l nh nhau.

IP : PMIP chy trc tip trn IP, v n c s dng nh l truyn ti

IP tiu chun.

Hnh 2.9 minh ha cu trc giao thc UP cho UE kt ni vi P-GW. UP c

th hin nh trong hnh 2.9 bao gm cc lp ca ngi dng IP cui, tc l cc giao

thc thnh hnh thnh nn lp 2 v c s dng vn chuyn cc gi tin IP n

ngi s dng cui. Cu trc giao thc l tng t vi CP. iu ny n nh mt

thc t l ton b h thng c thit k vn chuyn d liu gi chung, v c hai

tn hiu CP v d liu UP cui cng u l d liu gi. Ch c kch thc khc

nhau.

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Hnh 2.9 ngn xp giao thc mt phng ngi dng trong EPC

Hu ht cc giao thc c a ra c nu trn, ngoi tr hai iu sau

c la chn trong b giao thc ca giao din S5/S8:

Mt phng ngi dng giao thc ng hm GPRS ( GTP-U) : GTP-U

c s dng khi S5/S8 l da trn GTP. Dng thc ca GTP-U l ng hm

GTP-U c dng gi cc gi tin ca ngi dng IP cui v mt mang chuyn

EPS. N c s dng trong giao din S1-U v s dng trong S5/S8 nu CP s

dng GTP-C.

ng g i nh tuyn chung ( GRE) : GRE s dng giao din S5/S8 kt hp

vi PMIP. Dng thc ca GRE l mt IP trong ng hm IP vn chuyn tt c

cc d liu thuc v mt kt ni ca UE ti mt PDN c th. GRE l chy trc

tip trn IP v UDP l khng s dng.

Hnh 2.10 minh ha cu trc giao thc giao din X2, m tng t nh ca giao

din S1. Ch c giao thc ng dng CP l khc nhau.

Hnh 2.10 Cc ngn xp giao thc mt phng iu khin v mt phng ngi dng

cho giao din X2

45

Giao din X2 c s dng trong khi di chuyn gia cc eNodeB, v X2AP bao

gm cc chc nng cho s chun b chuyn giao v duy tr tan b s lin h gia

cc eNodeB ln cn. UP trong giao din X2 c s dng cho chuyn tip d liu

tm thi trong qu trnh chuyn giao, khi cc giao din v tuyn c ngt kt

ni pha ngun v cha kt ni li pha ch. Chuyn tip d liu l c thc

hin cho cc d liu hng xung, khi cc d liu hng ln c th c iu chnh

hiu qu bi UE.

Bng 2.1 tm tt cc giao thc v giao din trong cu hnh kin trc h thng c

bn.

Giao din Giao thc c t k thut LTE-Uu CP:RRC/PDCP/RLC/MAC/PHY

UP: PDCP/RLC/MAC/PHY

36.300 [6]

X2 CP: X2AP/SCTP/IP

UP: GTP-U/UDP/IP

36.423 [7]

29.274 [8]

S1-MME S1AP/SCTP/UDP/IP 36.413 [9]

S1-U GTP-U/UDP/IP 29.274 [8]

S10 GTP-C/UDP/IP 29.274 [8]

S11 GTP-C/UDP/IP 29.274 [8]

S5/S8 (GTP) GTP/UDP/IP 29.274 [8]

S5/S8 (PMIP) CP: PMIP/IP

UP: GRE/IP

29.275 [10]

SGi IP (also Diameter & Radius) 29.061 [11]

S6a Diameter/SCTP/IP 29.272 [12]

Gx Diameter/SCTP/IP 29.212 [13]

Gxc Diameter/SCTP/IP 29.212 [13]

Rx Diameter/SCTP/IP 29.214 [14]

UE-MME EMM, ESM 24.301 [15]

Bng 2.1 Cc giao thc v giao din LTE

2.3. QoS v kin trc dch v mang chuyn

Cc ng dng nh void IP , duyt WEB , thoi video v to lung video (video

treaming) c nhu cu QoS c bit. Do mt c im quan trng ca bt k

mng ton gi no l cung cp mt c ch QoS cho php phn bit cc dng gi tin

da trn nhu cu QoS. Trong EPS, dng QoS c gi l mang chuyn EPS c

thit lp gia UE v P-GW.

46

Hnh 2.11 Kin trc dch v mang truyn EPS

Mt phn t mang v tuyn vn chuyn cc gi tin ca mt mang chuyn EPS

gia mt UE v mt eNB. Mi dng IP ( v d void IP ) c kt hp vi mt mang

chuyn EPS khc nhau v cc mng c th u tin lu lng cho ph hp. Khi nhn

mt gi tin IP t internet , P-GW thc hin phn loi gi da trn cc thng s nht

nh bit v gi n mt mang chuyn EPS thch hp. Cn c vo mang chuyn

EPS , eNB nh x cc gi tin ti phn t mang v tuyn c QoS thch hp. C mt

s nh x mt mt gia mt mang chuyn EPS v mt phn t mang v tuyn.

2.4. Giao thc trng thi v chuyn tip trng thi

Trong h thng LTE , iu khin ti nguyn v tuyn (RRC) c 2 ch l ch

RRC rnh di v ch RRC kt ni c m t nh trong hnh 2.12. Mt UE

chuyn t trng thi RRC rnh di ti trng thi RRC kt ni khi mt kt ni RRC

c thit lp thnh cng. Mt UE c th chuyn t trng thi RRC kt ni ti trng

thi RRC rnh di bng cch gii phng kt ni RRC. trng thi RRC rnh di ,

UE c th nhn cc d liu pht qung b / pht a im , gim st mt knh tm

gi pht hin cc cuc gi n, thc hin cc php o ln cn, la chn / la

chn li v thu c cc thng tin v h thng. Hn na, trong trng thi RRC

rnh di, mi UE c chu k DRX ( thu khng lin tc) ring c th c cu hnh

bi cc lp pha trn cho php tit kim in nng cho UE. Ngoi ra , tnh di

ng c iu khin bi UE trong trng thi RRC rnh ri.

47

Hnh 2.12. Trng thi ca UE v chuyn tip trng thi

Trong ch RRC kt ni, vic truyn d liu n hng ti / t UE v truyn

d liu pht qung b / a im ti UE c th din ra. Ti cc lp thp hn ,UE c

th c cu hnh vi mt UE c th DRX / DTX ( truyn dn gin on ). Hn

na, cc knh iu khin gim st UE c lin kt vi knh d liu dng chung

xc nh d liu v lp biu cho n, cung cp knh thng tin phn hi v cht

lng, thc hin cc php o ln cn, bo co o c v thu nhn cc thng tin h

thng. Khc vi trng thi RRC rnh di tnh di ng c iu khin bi mng

trng thi ny.

2.5. H tr tnh di ng lin tc

Mt c im quan trng ca mt h thng khng dy di ng nh LTE l h tr

tnh di ng lin tc gia cc eNB v gia cc MME/GW. Chuyn giao nhanh

chng v lin tc (HO) l c bit quan trng vi cc dch v nhy cm vi tr nh

VoIP. Vic chuyn giao sy ra thng xuyn hn gia cc eNB hn l gia cc

mng li bi v khu vc c bao ph bi MME/GW phc v mt s lng ln cc

eNB v thng ln hn nhiu so vi cc khu vc c bao ph bi mt eNB n.

Tn hiu trn giao din X2 gia cc eNB c s dng chun b chuyn giao. S-

GW hot ng nh nt cui cho cho chuyn giao gia cc eNB.

Trong h thng LTE, mng da vo UE pht hin cc ln cn chuyn

giao v do khng c thng tin ln cn no l tn hiu t mng. i vi tm

kim v o c tn s gia cc ln cn, ch c cc tn s sng mang l cn c

ch ra. Mt v d v chuyn giao hot ng trong trng thi RRC kt ni c th

hin trong hnh 2.13, ni mt UE di chuyn t vng ph sng ca eNB ngun

(eNB1) vo vng ph sng ca eNB ch (eNB2). Vic chuyn giao trong trng

thi RRC kt ni c mng iu khin v c h tr bi cc UE. UE gi mt bo

co v o lng v tuyn ti ngun eNB1 v ch ra rng cht lng tn hiu vo

eNB2 l tt hn so vi eNB1. Khi chun b chuyn giao, ngun eNB1 s gi cc

thng tin ghp ni v hon cnh ca UE ti eNB2 ch ( HO yu cu ) vo giao din

X2. ch eNB2 c th thc hin iu khin nhp vo ph thuc vo cc thng tin

QoS mang EPS nhn. eNB ch s cu hnh ti nguyn cn thit theo thng tin

QoS nhn v d tr mt C-RNTI ( nhn dng tm thi mng v tuyn ) v ty

48

chn m u mt RACH. C-RNTI cung cp mt s nht bit UE duy nht cp

nhn din kt ni RRC. Khi eNB2 pht tn hiu ti eNB1 bo rng n sn sng

thc hin chuyn giao thng qua bn tin phn hi HO, eNB1 lnh cho UE (lnh HO

) thay i phn t mang v tuyn ti eNB2. UE nhn lnh HO vi cc thng s cn

thit v c iu khin bi cc eNB ngun thc hin cc lnh HO. UE khng

cn tr khi thc hin chuyn giao vi vic cung cp cc phn hi HARQ/ARQ ti

eNB ngun.

Hnh 2.13. Hot ng chuyn giao

Sau khi nhn lnh HO, UE thc hin ng b vi eNB ch v truy nhp ch

thng qua knh truy nhp ngu nhin ( RACH) sau mt th tc tranh chp-t do nu

mt phn m u RACH dnh ring c phn b trong cc lnh HO hoc sau mt

th tc tranh chp c bn nu khng c phn m u ginh ring no c cp

pht. Mng s tr li vi vic cp pht ti nguyn ng ln v s nh thi trc

c t vo bi UE. Khi UE truy nhp thnh cng vo ch, UE gi bn tin

xc nhn HO (C-RNTI) cng vi bo co tnh trng b m ng ln cho bit th

tc chuyn giao hon thnh vi UE. Sau khi nhn bn tin xc nhn HO, eNB

49

ch gi mt thng ip chuyn i ng dn ti MME thng bo rng UE

thay i . MME gi mt thng ip cp nht mt phng ngi dng ti S-GW. S-

GW s chuyn ng dn d liu ng xung ti eNB ch v s gi mt hoc

nhiu gi du hiu kt thc trn ng dn c ti eNB ngun v sau gii

phng mi ti nguyn mt phng ngi dng / TNL vi eNB ngun. Sau S-GW

gi mt thng bo hi p cp nht mt phng ngi dng ti MME. Sau MME

xc nhn thng bo chuyn i ng dn t eNB ch vi thng bo phn hi

chuyn i ng dn. Sau khi thng bo phn hi chuyn i ng dn c

nhn t MME, eNB ch thng bo thnh cng HO ti eNB ngun bng cch gi

thng bo gii phng ti nguyn ti eNB ngun v kch hot gii phng ti nguyn.

Nhn c thng bo gii phng ti nguyn, eNB ngun c th gii phng ti

nguyn v tuyn v ti nguyn lin quan ti mt phng iu khin c kt hp vi

hon cnh ca UE.

Trong khi chun b chuyn giao th cc ng hm mt phng ngi dng c th

c thit lp gia eNB ngun v eNB ch. Mt ng hm c thit lp

truyn d liu hng ln v mt ci khc truyn d liu hng xung cho mi

mang chuyn EPS m d liu chuyn tip c t vo. Trong khi thc hin chuyn

giao, d liu ngi dng c th c chuyn t eNB ngun ti eNB ch.

Hnh 2.14. Khu vc theo di cp nht cho UE trng thi RRC rnh ri

i vi vic qun l tnh di ng trong trng thi RRC rnh di, khi nim khu

vc theo di (TA) c a ra. Mt khu vc theo di thng bao gm nhiu eNB

50

nh c miu t trong hnh 2.14. Nhn dng khu vc theo di (TAI) cho bit

thng tin m mt eNB thuc v TA v c pht qung b nh l mt phn ca h

thng thng tin. Mt UE c th pht hin c s thay i ca khu vc theo di khi

n nhn c mt TAI khc so vi trong hin ti. Cc UE cp nht MME cng

vi thng tin TA mi ca n khi n di chuyn qua TA khc. Khi P-GW nhn d

liu ca mt UE, n lu cc gi vo b m v hi MME v v tr ca UE. Sau

MME s nhn tin ti UE trong hu ht cc TA hin ti ca n. Mt UE c th c

ng k ng thi nhiu TA. iu ny cho php tit kim nng lng cho cc UE

trong iu kin c ng cao bi v n khng cn lin tc cp nht v tr ca n vi

cc MME. Tnh nng ny cng gim thiu ti trn bin ca TA.

2.6. Kin trc h thng pht qung b a im

Trong h thng LTE, MBMS s dng hoc truyn n hoc truyn a .

Trong truyn n , MBMS ch c truyn trong phm vi mt c th v do

truyn dn MBMS t nhiu l khng c h tr. Truyn dn MBMS n c

thc hin trn DL-SCH v do s dng kin trc mng ging nh lu lng

truyn n hng. Cc MTCH v MCCH c nh x vo DL-SCH cho truyn

dn im-a im v s lp biu c thc hin bi cc eNB. Cc UE c th c

cp pht knh phn hi ng ln dnh ring ging vi ngi dng trong truyn

n hng, n cho php HARQ ACK/NACK v phn hi CQI.

Vic truyn li HARQ c thc hin bng cch s dng mt nhm ( dch v c

th ) RNTI ( nhn dng tm thi mng v tuyn ) kt hp vi truyn MTCH gc.

Tt c cc UE nhn c MBMS c th nhn c truyn li v kt hp vi bn

gc c truyn i cp HARQ. Cc UE c cp pht mt knh thng tin phn

hi dnh ring cho ng ln khi ang trong trng thi RRC kt ni. trnh

vic truyn MBMS khng cn thit trn MTCH trong mt m khng c ngi s

dng MBMS, mng c th pht hin s c mt ca ngi s dng quan tm ti dch

v MBMS bi s hi vng hoc thng qua s yu cu dch v t UE. Vic truyn

pht a gip pht trin cc dch v truyn thng a phng tin ( eMBMS) c

thc hin bng cch truyn sng ging nhau cng mt lc t nhiu mng. Trong

trng hp ny, MTCH v MCCH c nh x vo MCH cho truyn im a

im. Hnh thc truyn a ny c gi l mng n tn s pht qung b a

im (MBSFN). Truyn mt MBSFN t nhiu trong mt khu vc MBSFN c

xem nh l truyn n l ca UE. Mt khu vc MBSFN bao gm mt nhm cc

trong mt khu vc MBSFN ng b ca mt mng c phi hp truyn

MBSFN. Mt khu vc MBSFN ng b c nh ngha l mt khu vc ca mng

trong tt c cc eNB u c th c ng b v thc hin truyn MBSFN. Mt

khu vc dch v MBMS c th gm nhiu khu vc MBSFN. Mt trong mt khu

51

vc ng b MBSFN c th hnh thnh mt phn ca nhiu SFN mi khu vc c

c trng bi ni dung khc nhau v tp hp cc mng tham gia. Mt v d v

khu vc dch v MBMS gm 2 khu vc MBSFN , khu vc A v khu vc B c

m t nh hnh 2.15

Hnh 2.15. Khu vc dch v eMBMS v cc khu vc MBSFN

Khu vc MBSFNA bao gm cc t A1 ti A5 , AB1 v AB2. Khu vc

MBSFNB bao gm cc t B1 ti B5, AB1 v AB2. Cc AB1 v AB2 l mt

phn ca c 2 khu vc MBSFN A v B. B5 l mt phn ca khu vc B nhng

khng gp phn vo truyn MBSFN. Mt c gi l khu vc dnh ring

MBSFN. khu vc dnh ring MBSFN c th c php truyn ti cc dch v

khc ngun ti nguyn phn b cho cc MBSFN nhng vi kh nng hn ch. Khu

vc ng b MBSFN, khu vc MBSFN v cc dnh ring c th c cu hnh

bn tnh bi O & M.

Kin trc MBMS cho truyn dn a c m t trong hnh 2.16. phn t phi

hp pht a im a ( MCE) l mt phn t logic, c ngha l n cng c th l

mt phn ca mt b phn ca mng nh eNB. MCE thc hin cc chc nng nh

phn b ngun ti nguyn v tuyn c s dng bi tt c cc eNB trong khu vc

MBSFN cng nh xc nh cu hnh v tuyn bao gm s iu ch v m ha.

52

Cc MBMS GW cng l mt phn t logic m chc nng chnh l gi / pht qung

b cc gi MBMS vi giao thc SYNC ti mi eNB truyn dch v. MBMS GW

ch lp DPCP ca mt phng ngi dng v pht a im s dng IP cho vic

chuyn tip d liu ngi dng MBMS ti eNB.

Hnh 2.16 Kin trc logic eMBMS

Cc eNB c kt ni vi eMBMS GW thng qua mt giao din mt phng

ngi dng thun ty M1. M1 l mt giao din mt phng ngi dng thun ty, n

khng c phn ng dng mt phng iu khin c nh ngha cho giao din ny.

Hai giao din mt phng iu khin M2 v M3 c xc nh. Phn ng dng trn

giao din M2 vn chuyn d liu cu hnh v tuyn cho cc eNB c ch truyn

dn a . Phn ng dng trn giao din M3 gia MBMS GW v MCE thc hin

vic iu khin phin MBMS truyn tn hiu ln cp mang chuyn EPS trong

bao gm cc th tc nh bt u phin v dng li.

Mt yu cu quan trng i vi truyn ti cc dch v MBMS a l vic ng

b ni dung MBMS cho php hot ng MBSFN. Kin trc mt phng ngi

dng eMBMS cho ng b ni dung c th hin nh trong hnh 2.17.

53

Hnh 2.17 Kin trc mt phng ngi dng eMBMS cho ng b ni dung

Lp giao thc SYNC c nh ngha da trn lp mng vn chuyn (TNL)

h tr c ch ng b ha ni dung. Giao thc SYNC mang thng tin b sung cho

php cc eNB xc nh thi im cho truyn khung v tuyn cng nh pht hin

mt gi. Cc eNB tham gia truyn MBMS a c yu cu phi tun theo c ch

ng b ha ni dung. Cc eNB ch truyn theo dch v n th khng bt buc

phi tun theo cc yu cu thi gian nghim ngt c ch nh bi giao thc

SYNC. Trong trng hp PDCP c s dng nn tiu , n nm trong

eMBMS GW.

Cc UE thu c MTCH truyn v tham gia vo t nht mt k hoch phn hi

MBMS cn phi c t trong mt trng thi RRC kt ni. Mt khc, cc UE nhn

MTCH truyn m khng tham gia vo mt c ch phn hi MBMS c th mt

trong hai ch RRC rnh di hoc RRC kt ni. nhn c truyn n ca

MTCH, mt UE c th cn phi ch RRC kt ni. Tn hiu m kch hot UE

chuyn sang ch RRC kt ni ch dnh cho mc ch thu nhn n c mang

trn MCCH.

54

CHNG 3 - TRUY NHP V TUYN TRONG LTE

3.1. Cc ch truy nhp v tuyn

Giao din khng gian LTE h tr c hai ch l song cng phn chia theo tn

s ( FDD) v song cng phn chia theo thi gian ( TDD), mi ch c mt cu

trc khung ring. Ch bn song cng FDD cho php chia s phn cng gia

ng ln v ng xung v ng ln v ng xung khng bao gi s dng

ng thi. K thut ny c s dng trong mt s di tn v cng cho php tit

kim chi ph trong khi gim mt na kh nng truyn d liu.

Giao din khng gian LTE cng h tr pht a phng tin v cc dch