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TS. Nguyn Phm Anh Dng 1
BI GING VIETTEL
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TS. Nguyn Phm Anh Dng 2
LI NI U
Ngy ny thng tin di ng l ngnh cng nghip vin thng pht trin
nhanh nht vi con s thu bao t n 3,6 t tnh n cui nm 2008. Khingun t dch v thoi t tin cho mt s t ngi i xe, n nay vi s ng
dng ngy cng rng ri cc thit b thng tin di ng th h ba, thng tin di
ng c th cung cp nhiu hnh loi dch v i hi tc s liu cao cho
ngi s dng k c cc chc nng camera, MP3 v PDA. Vi cc dch v i
hi tc cao ngy cc tr nn ph bin ny, nhu cu 3G cng nh pht trin n
ln 4G ngy cng tr nn cp thit.
ITU a ra n tiu chun ho h thng thng tin di ng th h ba
vi tn gi IMT-2000 t c cc mc tiu chnh sau y:
Tc truy nhp cao mbo cc dch v bng rng nh truy nhpinternet nhanh hoc cc ng dng a phng tin, do yu cu ngy cng
tng v cc dch v ny.
Linh hot m bo cc dch v mi nh nh s c nhn ton cu vin thoi v tinh. Cc tnh nng ny s cho php m rng ng k tm
ph ca cc h thng thng tin di ng.
Tng thch vi cc h thng thng tin di ng hin c m bo spht trin lin tc ca thng tin di ng .
Nhiu tiu chun cho h thng thng tin di ng th h ba IMT-2000 c xut, trong hai h thng WCDMA UMTS v cdma-2000 c
ITU chp thun v c a vo hot ng. Cc h thng ny u s dng
cng ngh CDMA iu ny cho php thc hin tiu chun ton th gii cho giao
din v tuyn ca h thng thng tin ng th h ba.
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TS. Nguyn Phm Anh Dng 3
HSDPA (High Speech Downlink Packet Access: truy nhp gi ng
xung tc cao) l mt m rng ca cc h thng 3G WCDMA UMTS c
th cung cp tc ln n 10 Mbps trn ng xung. HSDPA l mt chun
tng cng ca 3GPP-3G nhm tng dung lng ng xung bng cch thay
th iu ch QPSK trong 3G UMTS bng 16QAM trong HSDPA. HSDPA hotng trn c s kt hp ghp knh theo thi gian (TDM) vi ghp knh theo m
v s dng thch ng ngtruyn. N cng a ra mt knh iu khin ring
m bo tc truyn dn s liu. Cc k thut tng t cng c p dng
cho ng ln trong chun HSUPA (High Speech Uplink Packet Access). Hai
cng ngh truy nhp HSDPA v HSUPA c gi chung l HSPA (High Speed
Packet Data). lm cho cng ngh 3GPP UTRA/UTRAN mang tnh cnh
tranh hn na (ch yu l cnh tranh vi cc cng ngh mi ca 3GPP2 v
WiMAX), 3GPP quyt nh pht trin E-UTRA v E-UTRAN (E: Elvolved k
hiu cho pht trin) cn c gi l siu 3G (Super-3G) hay LTE (Long Term
Evolution) m thc cht l giai on u 4G. Cng vic pht trin s tin hnh
trong 10 nm v sau nh l s pht trin di hn (LTE: Long Term
Evolution) ca cng ngh truy nhp v tuyn 3GPP. Trong giai on ny tc
s liu t c 30-100Mbps vi bng thng 20MHz. Tip sau LTE, IMT-Adv
(IMT tin tin) s c pht trin, y s l thi k pht trin ca 4G vi tc
t 100 n 1000 Mbps v bng thng 100MHz.Hnh L.1 cho thy vin cnh ca
thng tin di ng 4G v kh nng p ng tc chuyn ng v v tc
truyn s liu.
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TS. Nguyn Phm Anh Dng 4
B3G: Broad Band 3G: 3G bng rng
WLAN: Wirless Local Area Network: Mng ni vng khng dy
BWA: Broad Band Wirless Access: truy nhp khng dy bng rng
Hnh L.1. Vin cnh thng tin di ng 4G theo kh nng h tr tc chuyn
ng v tc truyn s liu
Hin nay tai Vit Nam bng tn I dnh cho WCDMA c chia l bn
khe v c cp pht cho bn nh khai thc: Viettel, VMS, GPC, EVN+HT.
Trong cc nm ti 3GWCDMA UMTS s ctrin khai trn bngtn ny.
Bi ging Gii thiu cng ngh 3G WCDMA UMTS nhm cung cp
cc khi nim c bn v cng ngh 3G WCDMA UMTS cho cc cn b TngCng ty Vin Thng Qun i (Viettel).
Bi ging bao gm bn chng. Chng u trnh by khi qut chung v
s pht trin ca cc h thng thng tin di ngln 4G, kin trc chung camt
mng 3G; cc kin trc R3, R4, R5 v R6 ca mng thng tin di ng 3G
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TS. Nguyn Phm Anh Dng 5
WCDMA UMTS. Chng haitrnh bya truy nhp CDMA v cc k thut
lin quan cp dng cho WCDMA. Chng ba gii thiu giao din v tuyn
c WCDMA. Chng bn gii thiu cng ngh a truy nhp tc cao HSPA
Cc chng ca ti liu ny u c kt cu theo modul hc vin d
hchc. Mi chng u c phn gii thiu chung, ni dungv tng kt.
H ng ngy12 thng 6nm 2009
Tc gi
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TS. Nguyn Phm Anh Dng 6
MC LC
Chng 1 TNG QUAN MNG 3G WCDMA UMTS...................................10
1.1. GII THIU CHUNG...........................................................................10
1.2. L TRNH PHT TRIN THNG TIN DI NG LN 4G...............11
1.3. KIN TRC CHUNG CA MT H THNG THNG TIN DI NG
3G ................................................................................................................ 13
1.4. CHUYN MCH KNH (CS), CHUYN MCH GI (PS), DCH V
CHUYN MCH KNH V DCH V CHUYN MCH GI. ..............15
1.5. CC LOI LU LNG V DCH V C 3GWCDMA UMTS
H TR.......................................................................................................20
1.6. KIN TRC 3G WCDMA UMTS R3 ..................................................23
1.7. KIN TRC 3G WCDMA UMTS R4 ..................................................37
1.8. KIN TRC 3G WCDMA UMTS R5 v R6 ........................................ 39
1.9. CHIN LC DCH CHUYN T GSM SANG UMTS ....................42
1.10. CU HNH A L CA H THNG THNG TIN DI NG 3G 46
1.11. TNG KT .........................................................................................52
Chng 2CNG NGH A TRUY NHP CA WCDMA ..........................53
2.1. GII THIU CHUNG...........................................................................53
2.2. TRI PH V A TRUY NHP PHN CHIA THEO M................54
2.3. IU KHIN CNG SUT.................................................................60
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2.4. CHUYN GIAO TRONG H THNG CDMA....................................61
2.5. MY THU PHN TP A NG HAY MY THU RAKE...........64
2.6. CC M TRI PH S DNG TRONG WCDMA ...........................67
2.7. TRI PH V IU CH NG LN ........................................... 69
2.8. TRI PH V IU CH NG XUNG.....................................73
2.9. TNG KT ...........................................................................................77
Chng 3GIAO DIN V TUYN CA WCDMA UMTS .......................... 79
3.1. GII THIU CHUNG...........................................................................79
3.2. M U...............................................................................................80
3.3. KIN TRC NGN XP GIAO THC CA GIAO DIN V TUYN
WCDMA/FDD.............................................................................................82
3.4. CC THNG S LP VT L V QUY HOCH TN S.............84
3.5. CC KNH CA WCDMA .................................................................91
3.6. CU TRC KNH VT L RING................................................. 105
3.7. S TNG QUT MY PHT V MY THU WCDMA.......... 107
3.8. PHN TP PHT .............................................................................. 108
3.9. IU KHIN CNG SUT TRONG WCDMA ................................ 111
3.10. CC KIU CHUYN GIAO V CC SKIN BO CO TRONG
WCDMA.................................................................................................... 116
3.11. CC THNG S MY THU V PHT V TUYN CA UE .....119
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3.12. AMR CODEC CHO W-CDMA......................................................... 120
3.13. TNG KT ....................................................................................... 121
Chng 4TRUY NHP GI TC CAO (HSPA) .................................. 123
4.1. GII THIU CHUNG......................................................................... 123
4.2. TNG QUAN TRUY NHP GI TC CAO (HSPA) ................124
4.3. KIN TRC NGN XP GIAO THC GIAO DIN V TUYN
HSPA CHO S LIU NGI S DNG ................................................ 126
4.4. TRUY NHP GI TC CAO NG XUNG (HSDPA) .......128
4.5. TRUY NHP GI TC CAO NG LN (HSUPA).............. 145
4.6. CHUYN GIAO TRONG HSDPA ..................................................... 156
4.7. TNG KT ......................................................................................... 160
Thut ng v vit tt....................................................................................... 161
Ti liu tham
kho..100
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TS. Nguyn Phm Anh Dng 9
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TS. Nguyn Phm Anh Dng 10
Chng 1
TNG QUAN MNG 3G WCDMA UMTS
1.1. GII THIU CHUNG
1.1.1. Mc ch chng
Hiu l trnh pht trin thng tin di ngln 4G Hiu c kin trc tng qut ca mt mng thng tin di ng 3G. Hiu cc kin trc mng 3G WCDMA UMTS: R3, R4 v R5 v chin
lc chuyn dch GSM ln 3G UMTS
1.1.2. Cc ch c trnh by trong chng
L trnh pht trin cc cng ngh thng tin di ng ln 4G Kin trc chung ca mt mng thng tin di ng 3G Cc khi nim v cc dch v chuyn mch knh v cc dch v chuyn
mch gi
Cc loi lulng v cc loi dch v m 3G WCDMA UMTS c th htr
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TS. Nguyn Phm Anh Dng 11
Kin trc 3G WCDMA UMTS qua cc pht hnh khc nhau: R3, R4, R5v R6
Chin lc chuyn dch GSM ln 3G UMTS
1.1.3. Hng dn
Hc k cc t liu ctrnh by trong chng
Tham kho thm cc ti liu tham kho cui ti liu
1.2. L TRNH PHT TRIN THNG TIN DI NG LN 4G
L trnh pht trin cc cng ngh thng tin di ng ln 4G ccho trn
hnh 1.1 v l trnh nghin cu pht trin trong 3GPP c cho trn hnh 1.2..
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TS. Nguyn Phm Anh Dng 12
AMPS: Advanced Mobile Phone System
TACS: Total Access Communication System
GSM: Global System for Mobile Telecommucations
WCDMA: Wideband Code Division Multiple Access
EVDO: Evolution Data Only
IMT: International Mobile Telecommnications
IEEE: Institute of Electrical and Electtronics Engineers
WiFi: Wireless Fidelitity
WiMAX: Worldwide Interoperability for Microwave Access
LTE: Long Term Evolution
UMB: Untra Mobile Broadband
Hnh 1.1. L trnh pht trin cc cng ngh thng tin di ng ln 4G
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Hnh 1.2. Lch trnh nghin cu pht trin trong 3GPP
Hnh 1.3. cho thy l trnh tng tc truyn s liu trong cc pht hnh ca3GPP
Hnh 1.3. L trnh tng tc truyn s liu trong cc pht hnh ca 3GPP
1.3. KIN TRC CHUNG CA MT H THNG THNG TINDI NG
3G
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TS. Nguyn Phm Anh Dng 14
Mng thng tin di ng (TTD) 3G lc u s l mng kt hp gia cc
vng chuyn mch gi (PS) v chuyn mch knh (CS) truyn s liu gi v
ting. Cc trung tm chuyn mch gi s l cc chuyn mch s dng cng ngh
ATM. Trn ng pht trin n mng ton IP, chuyn mch knh s dn c
thay th bng chuyn mch gi. Cc dch v k c s liu ln thi gian thc (nhting v video) cui cng s c truyn trn cng mt mi trng IP bng cc
chuyn mch gi. Hnh 1.4di y cho thy th d v mt kin trc tng qut
ca TTD 3G kt hp c CS v PS trong mng li.
RAN: Radio Access Network: mng truy nhp v tuyn
BTS: Base Transceiver Station: trm thupht gc
BSC: Base Station Controller: b iu khin trm gc
RNC: Rado Network Controller: b iu khin trm gc
CS: Circuit Switch: chuyn mch knh
PS: Packet Switch: chuyn mch gi
SMS: Short Message Servive: dch v nhn tin
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TS. Nguyn Phm Anh Dng 15
Server: my ch
PSTN: Public Switched Telephone Network: mng in thoi chuyn mch
cng cng
PLMN: Public Land Mobile Network: mang di ng cng cng mt t
Hnh 1.4. Kin trc tng qut ca mt mng di ng kt hp c CS v PS
Cc min chuyn mch knh (CS) v chuyn mch gi (PS) c th hin
bng mt nhm cc n v chc nng lgic: trong thc hin thc t cc min
chc nng ny c t vo cc thit b v cc nt vt l. Chng hn c th
thc hin chc nng chuyn mch knh CS (MSC/GMSC) v chc nng
chuyn mch gi (SGSN/GGSN) trong mt nt duy nht c mt h thng
tch hp cho php chuyn mch v truyn dn cc kiu phng tin khc nhau:
t lu lng tingn lu lng s liu dung lng ln.
3G UMTS (Universal Mobile Telecommunications System: H thng
thng tin di ng ton cu) c th s dng hai kiu RAN. Kiu th nht s dngcng ngh a truy nhp WCDMA (Wide Band Code Devision Multiple Acces:
a truy nhp phn chia theo m bng rng) c gi l UTRAN (UMTS
Terrestrial Radio Network: mng truy nhp v tuyn mt t ca UMTS). Kiu
th hai s dng cng ngh a truy nhp TDMA c gi l GERAN (GSM
EDGE Radio Access Network: mng truy nhp v tuyn da trn cng ngh
EDGE ca GSM). Ti liu ch xt cp n cng ngh duy nht trong
UMTS cgi l 3G WCDMA UMTS
1.4. CHUYN MCH KNH (CS), CHUYN MCH GI (PS), DCH V
CHUYN MCH KNH V DCH V CHUYN MCH GI.
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TS. Nguyn Phm Anh Dng 16
3G cung cp cc dch v chuyn mch knh nh ting, video v cc dch
v chuyn mch gi ch yu truy nhp internet.
Chuyn mch knh (CS: Circuit Switch)l s chuyn mch trong
thit b chuyn mch thc hin cc cuc truyn tin bng cch thit lp kt ni
chimmtti nguyn mng nht nh trong ton b cuc truyn tin. Kt ni ny
l tm thi, lin tc v dnh ring. Tm thi v n ch cduy tr trong thi
gian cuc gi. Lin tc v n ccung cp lin tc mt ti nguyn nht nh
(bng thng hay dung lng v cng sut) trong sut thi gian cuc gi. Dnh
ring v kt ni ny v ti nguyn ch dnh ring cho cuc gi ny. Thit b
chuyn mch s dng cho CS trong cc tng i ca TTD 2G thc hin
chuyn mch knh trntrn c s ghp knh theo thi gian trong mi knh
c tc 64 kbps v v th ph hp cho vic truyn cc ng dng lm vic ti
tc c nh 64 kbps (chng hn ting c m ho PCM).
Chuyn mch gi (PS: Packet Switch)l s chuyn mch thc hin
phn chia s liu ca mt kt ni thnh cc gi c di nht nh v chuyn
mch cc gi ny theo thng tin v ni nhn c gn vi tng gi v PS ti
nguyn mng ch b chim dng khi c gi cn truyn. Chuyn mch gi cho
php nhm tt c cc s liu ca nhiu kt ni khc nhauph thuc vo ni
dung, kiu hay cu trcs liu thnh cc gi c kch thc ph hp v truyn
chng trn mt knh chia s. Vic nhm cc s liu cn truyn c thc hin
bngghp knh thng k vi n nh ti nguyn ng.Cc cng ngh s dng
cho chuyn mch gi c th l Frame Relay, ATM hoc IP.
Hnh 1.5. cho thy cu trc ca CS v PS.
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TS. Nguyn Phm Anh Dng 17
Hnh 1.5. Chuyn mch knh (CS) v chuyn mch gi (PS).
Dch v chuyn mch knh (CS Service)l dch v trong mi u cui
c cp pht mt knh ring v n ton quyn sdng ti nguyn ca knh
ny trong thi gian cuc gi tuy nhin phi tr tin cho ton b thi gian ny d
c truyn tin hay khng. Dchv chuyn mch knh c th cthc hin trnchuyn mch knh (CS) hoc chuyn mch gi (PS). Thng thng dch v ny
c p dng cho cc dch v thi gian thc (thoi).
Dch v chuyn mch gi (PS Service)l dch v trong nhiu u cui
cng chia s mt knh v mi u cui ch chim dng ti nguyn ca knh ny
khi c thng tin cn truyn v n ch phi tr tin theo lng tin ctruyn
trn knh. Dchv chuyn mch gi ch c th cthc hin trn chuyn mchgi (PS). Dch v ny rt rt ph hp cho cc dch v phi thi gian thc (truyn
s liu), tuy nhin nh s pht trin ca cng ngh dch v ny cng c p
dng cho cc dch v thi gian thc (VoIP).
Chuyn mch gi c th thc hin trn c s ATM hoc IP.
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TS. Nguyn Phm Anh Dng 18
ATM (Asynchronous Transfer Mode: ch truyn d b)l cng ngh
thc hin phn chia thng tin cn pht thnh cc t bo 53 byte truyn dn v
chuyn mch. Mt t bo ATM gm 5 byte tiu (c cha thng tin nh
tuyn) v 48 byte ti tin (cha s liu ca ngi s dng). Thit b chuyn mch
ATM cho php chuyn mch nhanh trn c s chuyn mch phn cng thamchun theo thng tin nh tuyn tiu m khng thc hin pht hin li trong
tng t bo. Thng tin nh tuyntrong tiu gm: ng dn o (VP) v knh
o (VC). iu khin kt ni bng VC (tng ng vi knh ca ngi s dng)
v VP (l mt b cc VC) cho php khai thc v qun l c kh nng m rng
v c linh hot cao. Thng thng VP c thit lp trn c s s liu ca h
thng ti thi im xy dng mng.Vic s dng ATM trong mng li cho ta
nhiu ci li: c th qun l lu lng kt hp vi RAN, cho php thc hin cc
chc nng CS v PS trong cng mt kin trc v thc hin khai thc cng nh
iu khin cht lng lin kt.
Chuyn mch hay Router IP (Internet Protocol)cng l mt cng ngh
thc hin phn chia thng tin pht thnh cc gi cgi l ti tin (Payload).
Sau mi gi cgn mt tiu cha cc thng tin a ch cn thit cho
chuyn mch. Trong thng tin di ng do v tr ca u cui di ng thay inn cn phi c thm tiu b sung nh tuyn theo v tr hin thi ca my
di ng. Qu trnh nh tuyn ny cgi l truyn ng hm (Tunnel). C
hai c ch thc hin iu ny: MIP (Mobile IP: IP ding) v GTP (GPRS
Tunnel Protocol: giao thc ng hm GPRS).Tunnel l mt ng truyn m
ti u vo ca n gi IP c ng bao vo mt tiu mang a ch ni nhn
(trong trng hp ny l a ch hin thi ca my di ng) v ti u ra gi IP
c tho bao bng cch loi b tiu bcngoi (hnh 1.6).
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TS. Nguyn Phm Anh Dng 19
Hnh 1.6. ng bao v tho bao cho gi IP trong qu trnh truyn tunnel
Hnh 1.7 cho thy qu trnh nh tuyn tunnel (chuyn mch tunnel)trong
h thng 3G UMTS t tng i gi cng (GGSN)cho mt my di ng (UE)
khi n chuyn t vng phc v ca mt tng i gi ni ht (SGSN1) ny sang
mt vng phc v ca mt tng i gi ni ht khc (SGSN2)thng qua giao
thc GTP.
Hnh 1.7. Thit lp kt ni tunnel trong chuyn mch tunnel
V 3G WCDMA UMTS cpht trin t nhng nm 1999 khi m ATM
l cng ngh chuyn mch gi cn ng tr nn cc tiu chun cng c xy
dng trn cng ngh ny. Tuy nhin hin nay v tng lai mng vin thng s
cxy dng trn c s internet v th cc chuyn mch gi s l chuyn mch
hoc router IP.
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TS. Nguyn Phm Anh Dng 20
1.5. CC LOI LU LNG V DCH V C 3GWCDMA UMTS H
TR
V TTD 3G cho php truyn dn nhanh hn, nn truy nhp Internet v
lu lng thng tin s liu khc s pht trin nhanh. Ngoi ra TTD 3G cng
cs dng cho cc dch v ting. Ni chung TTD 3G h tr cc dch v
tryn thng a phng tin. V th mi kiu lu lng cn m bo mt mc
QoS nht nh tu theo ng dng cadch v. QoS W-CDMA c phn loi
nh sau:
Loi hi thoi (Conversational, rt): Thng tin tng tc yu cu tr nh (thoi
chng hn).
Loi lung (Streaming, rt): Thng tin mt chiu i hi dch v lung vi tr
nh (phn phi truyn hnh thi gian thc chng hn: Video Streaming)
Loi tng tc (Interactive, nrt): i hi trli trong mt thi gian nht nh v
t l li thp (trnh duyt Web, truy nhp server chng hn).
Loinn (Background, nrt): i hi cc dch v n lc nhtc thc hin trn
nn c s (e-mail, ti xung file: Video Download)
Mi trnghot ng ca 3WCDMA UMTS c chia thnh bn vng
vi cc tc bit Rbphc v nh sau:
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TS. Nguyn Phm Anh Dng 21
Vng 1: trong nh, pico, Rb2Mbps Vng 2: thnh ph, micro, Rb384 kbps Vng 2: ngoi , macro, Rb144 kbps Vng 4: Ton cu, Rb= 12,2 kbps
C th tng kt cc dchv do 3GWCDMA UMTS cung cp bng 1.1.
Bng 1.1. Phn loi cc dch v 3GWDCMA UMTS
Kiu Phn loi Dch v chi tit
Dch v
di ng
Dch v di ng Di ng u cui/di ng c nhn/di ng
dch v
Dch v thng
tin nh v
- Theo di di ng/ theo di di ng thng
minh
Dch v m
thanh
- Dch v m thanh cht lng cao (16-64
kbps)
- Dch v truyn thanh AM (32-64 kbps)
- Dch v truyn thanh FM(64-384 kbps)
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Kiu Phn loi Dch v chi tit
Dch v
vinthng
Dch v s liu - Dch v s liu tc trung bnh (64-144
kbps)
- Dch v s liu tc tng i cao (144
kbps- 2Mbps)
- Dch v s liu tc cao (2Mbps)
Dch v a
phng tin
- Dch v Video (384 kbps)
- Dch v hnh chuyn ng (384kbps- 2
Mbps)
- Dch v hnh chuyn ng thi gian thc
(2 Mbps)
Dch v Internet
n gin
Dch v truy nhp Web (384 kbps-2Mbps)
Dch v Internet
thi gian thc
Dch v Internet (384 kbps-2Mbps)Dch v
Internet
Dch v internet
a phng tin
Dch v Website a phng tin thi gian
thc (2Mbps)
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TS. Nguyn Phm Anh Dng 23
3G WCDMA UMTS cxy dng theo ba pht hnh chnh c gi l
R3, R4, R5. Trong mng li R3 v R4 bao gm hai min: min CS (Circuit
Switch: chuyn mch knh) v min PS (Packet Switch: chuyn mch gi). Vic
kt hp ny ph hp cho giai on u khi PS cha p ng ttcc dch v thi
gian thc nh thoi v hnh nh. Khi ny min CS s m nhim cc dch vthoicn s liu c truyn trn min PS. R4 pht trin hn R3 ch min CS
chuyn sang chuyn mch mm v th ton b mng truyn ti gia cc nt
chuyn mch u trn IP. Di y ta xt ba kin trc 3G WCDMA
UMTS ni trn.
1.6. KIN TRC3G WCDMA UMTS R3
WCDMA UMTS R3 h tr c kt ni chuyn mch knh ln chuyn
mch gi: n 384 Mbps trong min CS v 2Mbps trong min PS. Cc kt ni
tc cao ny m bo cung cp mt tp cc dich v mi cho ngi s dng di
ng ging nh trong cc mng in thoi c nh v Internet. Cc dch v nygm: in thoi c hnh (Hi ngh video), m thanh cht lng cao (CD) v tc
truyn cao ti u cui. Mt tnh nng khc cng c a ra cng vi GPRS
l "lun lun kt ni" n Internet. UMTS cng cung cp thng tin v tr tt hn
v v th h tr tt hn cc dch v da trn v tr.
Mt mng UMTS bao gm ba phn: thit b di ng(UE: User
Equipment), mng truy nhp vtuyn mt t UMTS (UTRAN: UMTSTerrestrial Radio Network), mng li (CN: Core Network) (xem hnh 1.8). UE
bao gm ba thit b: thit b u cui (TE), thit b di ng (ME) v module
nhn dng thu bao UMTS (USIM: UMTS Subscriber Identity Module).
UTRAN gm cc h thng mng v tuyn (RNS: Radio Network System) v
mi RNS bao gmRNC (Radio Network Controller: b iu khin mng v
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tuyn)v cc nt B ni vi n.Mng li CN bao gm min chuyn mch knh,
chuyn mch gi v HE (Home Environment: Mi trng nh). HE bao gm cc
c s d liu: AuC (Authentication Center: Trung tm nhn thc), HLR (Home
Location Register: B ghi nh v thng tr) v EIR (Equipment Identity
Register: B ghi nhn dng thit b).
Hnh 1.8. Kin trc 3G WCDMA UMTS R3
1.6.1. Thit b ngi s dng (UE)
UE (User Equipment: thit b ngi s dng) l u cui mng UMTS
ca ngi s dng. C th ni y l phn h thng c nhiu thit b nht v s
pht trin ca n s nh hng ln ln cc ng dng v cc dch v kh dng.
Gi thnh gim nhanh chng s to iu kin cho ngi s dng mua thit b
ca UMTS. iu ny t c nh tiu chun ha giao din v tuyn v ci t
mi tr tu ti cc card thng minh.
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1.6.1.1. Cc u cui (TE)
V my u cui by gi khng ch n thun dnh cho in thoi m cn
cung cp cc dch v s liu mi, nn tn ca n c chuyn thnh u cui.
Cc nh sn xut chnh a ra rt nhiu u cui da trn cc khi nim mi,
nhng trong thc t ch mt s t l c a vo sn xut. Mc dcc u cui
d kin khc nhau v kch thc v thit k, tt c chng u c mn hnh ln
v t phm hn so vi 2G. L do chnh l tng cng s dng u cui cho
nhiu dch v s liu hn v v th u cui tr thnh t hp camy thoi di
ng, modem v my tnh bn tay.
u cui h tr hai giao din. Giao dinUu nh ngha lin kt v tuyn
(giao din WCDMA). N m nhim ton b kt ni vt l vi mng UMTS.
Giao din th hai l giao din Cu gia UMTS IC card (UICC) v u cui. Giao
din ny tun theo tiu chun cho cc card thng minh.
Mc d cc nh sn xut u cui crt nhiu tng v thit b, h phi
tun theo mt tp ti thiu cc nh ngha tiu chun cc ngi s dng bngcc u cui khc nhau c th truy nhp n mt s cc chc nng c stheo
cng mt cch.
Cc tiu chun ny gm:
Bn phm (cc phm vt l hay cc phm o trn mn hnh)
ng k mt khu mi Thay i m PIN Gii chn PIN/PIN2(PUK) Trnh by IMEI
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iu khin cuc gi
Cc phn cn li cagiao din s dnh ring cho nh thit k v ngi s
dng s chn cho mnh u cui da trn hai tiu chun (nu xu th 2G cn ko
di) l thit k v giao din. Giao din l kt hp ca kch c v thng tin do
mn hnh cung cp (mn hnh nt chm), cc phm v menu.
1.6.1.2. UICC
UMTS IC card l mt card thng minh. iu m ta quan tm n n l
dung lng nh v tc b x l do n cung cp. ng dng USIM chy trn
UICC.
1.6.1.3. USIM
Trong h thng GSM, SIM card lu gi thng tin c nhn (ng k thu
bao) ci cng trn card. iu ny thay i trong UMTS, Modul nhn dng
thu bao UMTS c ci nh mt ng dng trn UICC. iu ny cho php lu
nhiu ng dng hn v nhiu ch k (kha) in thn cng vi USIM cho ccmc ch khc (cc m truy nhp giao dch ngn hng an ninh). Ngoi ra c th
c nhiu USIM trn cng mt UICC h tr truy nhp n nhiu mng.
USIM cha cc hm v s liu cn nhn dng v nhn thc thu bao
trong mng UMTS.N c th lu c bn sao h s ca thu bao.
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Ngi s dng phi tmnh nhn thc i vi USIM bng cch nhp m
PIN. iu ny m bo rng ch ngi s dng ch thc mi c truy nhp
mng UMTS. Mng s ch cung cp cc dch v chongi no s dng u cui
da trn nhn dng USIM c ng k.
1.6.2. Mng truy nhpv tuyn UMTS
UTRAN (UMTS Terrestrial Radio Access Network: Mng truy nhp v
tuyn mt t UMTS) l lin kt gia ngi s dng v CN. N gm cc phn
t m bo cc cuc truyn thngUMTS trn v tuyn v iu khin chng.
UTRAN c nh ngha giahai giao din. Giao din Iu gia UTRAN
v CN, gm hai phn: IuPS cho min chuyn mch gi v IuCS cho min
chuyn mch knh; giao din Uu gia UTRAN v thit b ngi s dng. Gia
hai giao din ny l hai nt, RNC v nt B.
1.6.2.1. RNC
RNC (Radio Network Controller) chu trch nhimcho mt hay nhiu
trm gc v iu khin cc ti nguyn ca chng. y cngchnh l im truy
nhp dch v m UTRAN cung cp cho CN. N c ni n CN bng hai kt
ni, mt cho min chuyn mch gi (n GPRS) v mt n min chuyn mch
knh (MSC).
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Mt nhim v quan trng na ca RNC l bo v s b mt v ton vn.
Sau th tcnhn thc v tha thun kha, cc kho bo mt v ton vn c
t vo RNC. Sau cc kha ny c s dngbi cc hm an ninh f8 v f9.
RNC c nhiu chc nng logic ty thuc vo vic n phc v nt no.
Ngi s dng c kt ni vo mt RNC phc v (SRNC: Serving RNC). Khi
ngi s dng chuyn vng n mt RNC khc nhng vn kt ni vi RNC c,
mt RNC tri (DRNC: Drift RNC) s cung cp ti nguyn v tuyn cho ngi
s dng, nhng RNC phc v vn qun l kt ni ca ngi s dng n CN .
Vai tr logic ca SRNC v DRNC c m t trn hnh 1.9. Khi UE trong
chuyn giao mm gia cc RNC, tn ti nhiu kt ni qua Iub v c t nht mt
kt ni qua Iur. Ch mt trong s cc RNC ny (SRNC) l m bo giao din Iukt ni vi mng li cn cc RNC khc (DRNC) ch lm nhim v nh tuyn
thng tin gia cc Iub v Iur.
Chcnng cui cng ca RNC l RNC iu khin (CRNC: Control
RNC). Mi nt B c mt RNC iu khin chu trch nhim cho cc ti nguyn
v tuyn ca n.
Hnh 1.9. Vai tr logic ca SRNC v DRNC
1.6.2.2. Nt B
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Trong UMTS trm gc c gi l nt B v nhim v ca n l thc hin
kt ni v tuyn vt l gia u cui vi n. N nhn tn hiu trn giao din Iub
t RNC v chuyn n vo tn hiu v tuyn trn giao dinUu. N cng thc
hin mt s thao tc qun l ti nguyn v tuyn c s nh "iu khin cng
sut vng trong". Tnh nng ny phng nga vn gn xa; ngha l nu tt
c cc u cui u pht cng mt cng sut, th cc u cui gn nt B nht s
che lp tn hiu t ccu cui xa. Nt Bkim tracng sut thu t cc u
cui khc nhau v thng bo cho chng gim cng sut hoc tng cng sut sao
cho nt B lun thuc cng sut nh nhau t tt c cc u cui.
1.6.3. Mng li
Mng li (CN) c chia thnh ba phn, min PS, min CS v HE. Min
PS m bo cc dch v s liu cho ngi s dng bng cc kt ni n Internet
v cc mng s liu khc v min CSmbo cc dch v in thoi n cc
mng khc bng cc kt ni TDM. Cc nt B trong CN c kt ni vi nhau
bng ng trc ca nh khai thc, thng s dng cc cng ngh mng tc
cao nhATM v IP. Mng ng trc trong min CS s dng TDM cn trong
min PS s dng IP.
1.6.3.1. SGSN
SGSN (SGSN: Serving GPRS Support Node: nt h tr GPRS phc v)
l nt chnh ca min chuyn mch gi. N ni n UTRAN thng qua giao
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din IuPS v n GGSN thng quan giao din Gn. SGSN chu trchnhim cho
tt c kt ni PS ca tt c cc thu bao. N lu hai kiu d liu thu bao: thng
tin ng k thu bao v thng tin v tr thu bao.
S liu thu bao lu trong SGSN gm:
IMSI (International Mobile Subsscriber Identity: s nhn dng thu bao ding quc t)
Cc nhn dng tm thigi (P-TMSI: Packet- Temporary Mobile SubscriberIdentity: s nhn dng thu bao di ng tm thi gi)
Cc a ch PDP (Packet Data Protocol: Giao thc s liu gi)
S liu v tr lu trn SGSN:
Vng nh tuyn thu bao (RA: Routing Area) SVLR Cc a ch GGSN ca tng GGSN c kt ni tch cc
1.6.3.2. GGSN
GGSN (Gateway GPRS Support Node: Nt h tr GPRS cng) l mt
SGSN kt ni vi cc mng s liu khc. Tt c cc cuc truyn thng s liu t
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thu bao n cc mng ngoi u qua GGSN.Cng nhSGSN, n lu c hai
kiu s liu: thng tin thu bao v thng tin v tr.
S liu thu bao lu trong GGSN:
IMSI Cc a ch PDP
S liu v tr lu trong GGSN:
a ch SGSN hin thu bao ang ni n
GGSN ni n Internet thng qua giao din Gi v n BGthng qua Gp.
1.6.3.3. BG
BG (Border Gatway: Cng bin gii) l mt cng gia min PS ca
PLMN vi cc mng khc. Chc nng cant ny ging nh tng la ca
Internet: m bo mng an ninh chng li cc tn cng bn ngoi.
1.6.3.4. VLR
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MSC thc hin cc kt ni CS gia u cui v mng. N thc hin cc
chc nng bo hiu v chuyn mch cho cc thu bao trong vng qun l ca
mnh. Chc nng ca MSC trong UMTS ging chc nng MSC trong GSM,
nhng n c nhiu kh nnghn. Cc kt ni CS c thc hin trn giao din
CS gia UTRAN v MSC. Cc MSC c ni n cc mng ngoi qua GMSC.
1.6.3.6. GMSC
GMSC c th l mt trong s cc MSC. GMSC chu trch nhim thc
hin cc chc nng nh tuyn n vng c MS. Khi mng ngoi tm cch kt
ni n PLMN camt nh khai thc, GMSC nhn yu cu thit lp kt ni v
hi HLR v MSC hin thi qun l MS.
1.6.3.7. Mi trng nh
Mi trng nh (HE: Home Environment) lu cc h s thu bao ca
hng khai thc. N cng cung cp cho cc mng phc v (SN: Serving Network)
cc thng tin v thu bao v v cc cn thit nhn thc ngi s dng v
tnh cc cho cc dch v cung cp. Tt c cc dch v c cung cp v cc
dch v b cm u c lit k y.
B ghi nh v thng tr (HLR)
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HLR l mt c s d liu c nhim v qun l cc thu bao di ng. Mt
mng di ng c thcha nhiu HLR ty thuc vo s lng thu bao, dung
lng ca tng HLR v t chc bn trong mng.
C s d liu ny cha IMSI (International Mobile Subsscriber Identity:
s nhn dng thu bao di ngquc t), t nht mt MSISDN (Mobile Station
ISDN: s thu bao c trong danh b in thoi) v t nht mt a ch PDP
(Packet Data Protocol: Giao thc s liu gi). C IMSI v MSISDN c th s
dng lm kho truy nhp n cc thng tin c lu khc. nh tuyn v
tnh cc cc cuc gi, HLR cn lu gi thng tin v SGSN v VLR no hin
ang chu trch nhim thu bao. Cc dch v khc nh chuyn hng cuc gi,
tc s liu v th thoi cng c trong danh sch cng vi cc hn ch dch v
nh cc hn ch chuyn mng.
HLR v AuC l hai nt mng logic, nhng thng c thc hin trong
cng mt nt vt l. HLR lu gi mi thng tin v ngi s dng v ng k
thu bao. Nh: thng tin tnh cc, cc dch v no c cung cp v cc dch
v no b t chi v thng tin chuyn hng cuc gi. Nhng thng tin quan
trngnht l hin VLR v SGSN no ang ph trch ngi s dng.
Trung tm nhn thc (AuC)
AUC (Authentication Center) lu gi ton b s liu cn thit nhn
thc, mt m ha v bo v s ton vn thng tin cho ngi s dng. N lin kt
vi HLR v c thc hin cng vi HLR trong cng mt nt vt l. Tuy nhin
cn m bo rng AuC ch cung cp thng tin v cc vect nhn thc (AV:
Authetication Vector) cho HLR.
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AuC lu gi kha b mt chia s K cho tng thu bao cng vi tt c cc
hm to kha t f0 n f5. N to ra cc AV, c trong thi gian thc khi
SGSN/VLR yu cu hay khi ti x l thp, lncc AV d tr.
B ghi nhn dngthit b (EIR)
EIR (Equipment Identity Register) chu trch nhim lu cc s nhn dng
thit b di ngquc t (IMEI: International Mobile Equipment Identity). y l
s nhn dng duy nht cho thitb u cui. C s d liu ny c chia thnh
ba danh mc: danh mc trng, xm v en. Danh mc trng cha cc s IMEI
c php truy nhp mng. Danh mc xm cha IMEI ca cc u cui ang b
theo di cn danh mc en cha cc s IMEI ca cc u cui b cm truy nhp
mng.Khi mt u cui c thng bo l b mt cp, IMEI ca n s b t vo
danh mc en v th n b cm truy nhp mng. Danh mc ny cng c th c
s dng cm cc seri my c bit khng c truy nhp mng khi chng
khng hot ng theo tiu chun.
1.6.4. Cc mng ngoi
Cc mng ngoi khng phi l b phn ca h thng UMTS, nhng chng
cn thit m bo truyn thng gia cc nh khai thc. Cc mng ngoi c
th l cc mng in thoi nh: PLMN (Public Land Mobile Network: mng ding mt t cng cng), PSTN (Public Switched Telephone Network: Mng
in thoi chuyn mch cng cng), ISDN hay cc mng s liu nhInternet.
Min PS kt ni n cc mng s liu cn min CS ni n cc mng in thoi.
1.6.5. Cc giao din
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Vai tr cc cc nt khc nhau camng ch c nh ngha thng qua
cc giao din khc nhau. Cc giao din ny c nh nghacht ch cc nh
sn xutc th kt ni cc phn cng khc nhau ca h.
Giao din Cu. Giao din Cu l giao din chun cho cc card thng minh.Trong UE y l ni kt ni gia USIM v UE
Giao din Uu. Giao din Uu l giao din v tuyn ca WCDMA trongUMTS. y l giao din m qua UE truy nhp vo phn c nh ca
mng. Giao din ny nm gia nt B v u cui.
Giao din Iu. Giao din Iu kt ni UTRAN v CN. N gm hai phn,IuPS cho min chuyn mchgi, IuCS cho min chuyn mch knh. CN
c th kt ni n nhiu UTRAN cho c giao dinIuCS v IuPS. Nhng
mt UTRAN ch c th kt ni n mt im truy nhp CN.
Giao din Iur. y l giao din RNC-RNC. Ban u c thit k mbo chuyn giao mm gia cc RNC, nhng trong qu trnh pht trin
nhiu tnh nng mi c b sung. Giao din ny m bo bn tnh nng
ni bt sau:
1. Di ng gia cc RNC2. Lu thng knh ring3. Lu thng knh chung4. Qun l ti nguyn ton cc
Giao din Iub. Giao din Iub ni nt B v RNC. Khc vi GSM y lgiao din m.
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1.7. KIN TRC 3G WCDMA UMTS R4
Hnh 1.10 cho thy kin trc c s ca 3G UMTS R4. S khc nhau c bn
gia R3 v R4 l ch khi ny mng li l mng phn b v chuyn mch mm.
Thay cho vic c cc MSC chuyn mch knh truyn thng nh kin trc
trc, kin trc chuyn mch phn b v chuyn mch mmc a vo.
V cn bn, MSC c chia thnh MSC server v cng cc phng tin
(MGW: Media Gateway). MSC cha tt c cc phn mm iu khin cuc gi,
qun l di ng c mt MSC tiu chun. Tuy nhin n khng cha ma trn
chuyn mch. Ma trn chuyn mch nm trong MGW c MSC Server iu
khin v c th t xa MSC Server.
Hnh 1.10. Kin trc mng phn b ca pht hnh 3GPP R4
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Bo hiu iu khin cc cuc gi chuyn mch knh c thc hin gia
RNC v MSC Server. ng truyn cho cc cuc gi chuyn mchknh c
thc hin gia RNC v MGW. Thng thng MGW nhn cc cuc gi t RNC
v nhtuyn cc cuc gi ny n ni nhn trn cc ng trc gi. Trong
nhiu trng hp ng trc gi s dng Giao thc truyn ti thi gian thc(RTP: Real Time Transport Protocol)trn Giao thc Internet (IP). T hnh 1.10
ta thy lu lng s liu gi t RNC i qua SGSN v t SGSN n GGSN trn
mng ng trc IP. C s liu v ting u c th s dng truyn ti IP bn
trong mng li. y l mng truyn ti hon ton IP.
Ti ni mmt cuc gi cn chuynn mt mng khc, PSTN chng hn,
s c mt cng cc phng tin khc (MGW) c iu khin bi MSC Servercng (GMSC server). MGW ny s chuyn ting thoi c ng gi thnh
PCM tiu chun a n PSTN. Nh vy chuyn i m ch cn thc hin ti
im ny. th d, ta gi thit rng nu ting giao din v tuyn c truyn
ti tc 12,2 kbps, th tc ny ch phi chuyn vo 64 kbps MGW giao
tip vi PSTN. Truyn ti kiu ny cho php tit kim ng k rng bng tn
nht l khi cc MGW cch xa nhau.
Giao thc iu khin giaMSC Server hoc GMSC Server viMGW l
giao thc ITU H.248. Giao thc ny c ITU v IETF cng tc pht trin. N
c tn l iu khin cng cc phng tin (MEGACO: Media Gateway Control).
Giao thc iu khin cuc gi gia MSC Server v GMSC Server c th l mt
giao thc iu khin cuc gi bt k. 3GPP ngh s dng (khng bt buc)
giao thciu khin cuc gi c lp vt mang (BICC: Bearer Independent
Call Control)c xy dng trn c s khuyn ngh Q.1902 ca ITU.
Trong nhiu trng hp MSC Server h tr c cc chc nng ca GMSC
Server. Ngoi ra MGW c kh nng giao din vi c RAN v PSTN. Khi ny
cuc gi nhoc t PSTN c th chuyn ni ht, nh vy c th tit kim ng
k u t.
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lm th d ta xt trng hp khi mt RNC c t tithnh ph A v
c iu khin bi mt MSC t ti thnh ph B. Gi s thu bao thnh ph A
thc hin cuc gi ni ht. Nu khng c cu trc phn b, cuc gi cn chuyn
t thnh phA n thnh phB (ni c MSC) u ni vi thu bao PSTN ti
chnh thnh ph A. Vi cu trc phn b, cuc gi c th c iu khin tiMSC Server thnh ph B nhng ng truyn cc phng tin thc t c th
vn thnh ph A, nh vy gim ng k yu cu truyn dn v gi thnh khai
thc mng.
T hnh 1.10 ta cng thy rng HLR cng c th c gi l Server thu
bao ti nh (HSS: Home Subscriber Server). HSS v HLR c chc nng tng
ng, ngoitr giao din vi HSS l giao din trn c s truyn ti gi (IPchng hn) trong khi HLR s dng giao din trn c s bo hiu s 7. Ngoi ra
cn c cc giao din (khng c trn hnh v) gia SGSN vi HLR/HSS v gia
GGSN vi HLR/HSS.
Rt nhiu giao thc c s dng bn trong mng li l cc giao thc trn
c s gi s dng hoc IP hoc ATM. Tuy nhin mng phi giao din vi cc
mng truyn thng qua vic s dng cc cng cc phng tin. Ngoi ra mng
cng phi giao din vi cc mng SS7 tiu chun. Giao din ny c thc hin
thng qua cng SS7 (SS7 GW). y l cng m mt pha n h tr truyn ti
bn tin SS7 trn ng truyn tiSS7 tiu chun, pha kia n truyn ti cc
bn tin ng dng SS7 trn mng gi(IP chng hn). Cc thc th nh MSC
Server, GMSC Server v HSS lin lc vi cng SS7 bng cch s dng cc giao
thc truyn ti c thit k c bit mang cc bn tin SS7 mng IP. B
giao thc ny c gi l Sigtran.
1.8. KIN TRC 3G WCDMA UMTS R5 v R6
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Bc pht trin tip theo ca UMTSl a ra kin trc mng a phng
tin IP (hnh 1.11). Bc pht trin ny th hin s thay i ton b m hnh
cuc gi. y cting v s liu c x l ging nhau trn ton b ng
truyn t u cui ca ngi s dng n ni nhn cui cng. C th coi kin
trc ny l s hi t ton din ca ting v s liu.
Hnh 1.11. Kin trc mng 3GPP R5 v R6
im mi ca R5 v R6 l n a ra mt min mi c gi l phn h a
phng tin IP (IMS: IP Multimedia Subsystem). y l mt min mng IP
c thit k h tr cc dch v a phng tin thi gian thc IP.T hnh
1.11 ta thy ting v s liu khng cn cc giao din cchbit; ch c mt giao
din Iu duy nht mang tt c phng tin. Trong mng li giao din ny kt cui
ti SGSN v khng c MGW ring.
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Phn h a phng tin IP (IMS) cha cc phn t sau: Chc nng iu
khin trng thi kt ni (CSCF: Connection State Control Function), Chc nng
ti nguyn a phng tin(MRF: Multimedia Resource Function), chc nng
iu khin cng cc phng tin (MGCF: Media Gateway ControlFunction),
Cng bo hiu truyn ti (T-SGW: Transport Signalling Gateway) v Cng bohiu chuyn mng (R-SGW: Roaming Signalling Gateway).
Mt nt quan trng ca kin trc ton IP l thit b ca ngi s dng c
tng cng rt nhiu. Nhiu phn mm c ci t UE. Trong thc t, UE h
tr giao thc khi u phin (SIP: Session Initiation Protocol). UE tr thnh
mt tc nhn ca ngi s dng SIP. Nh vy, UE c kh nng iu khin cc
dch v ln hn trc rt nhiu.
CSCF qun l vic thit lp , duy tr v gii phng cc phin a phng
tin n v t ngi s dng. N bao gm cc chc nng nh: phin dch v
nh tuyn. CSCF hot ng nh mt i dinServer /h tch vin.
SGSN v GGSN l cc phin bn tng cng ca cc ntc s dng
GPRS v UMTS R3 v R4. im khc nhau duy nht l ch cc nt ny
khng ch h tr dch v s liu gi m c dch v chuyn mch knh (ting
chng hn). V th cn h tr cc kh nng cht lng dch v (QoS) hoc b n
trong SGSN v GGSN hoc t nht cc Router kt ni trc tip vi chng.
Chc nng ti nguyn a phng tin (MRF) l chc nng lp cu hi nghi
c s dng h tr cc tnh nng nh t chc cuc gi nhiu pha v dch v
hi ngh .
Cng bo hiu truyn ti (T-SGW)l mt cng bo hiu SS7 m bo
tng tc SS7 vi cc mng tiu chun ngoi nh PSTN. T-SGW h tr cc
giao thc Sigtran. Cng bo hiu chuyn mng (R-SGW)l mt nt m bo
tng tc bo hiu vi cc mng di ng hin c s dng SS7 tiu chun. Trong
nhiu trng hp T-SGW v R-SGW cng tn ti trn cng mt nn tng.
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MGW thc hin tng tc vi cc mng ngoi mc ng truyn a
phng tin. MGW kin trc mngca UMTS R5 c chc nng ging nh
R4. MGW c iu khin bi Chc nng cng iu khin cc phng tin
(MGCF). Giao thc iu khin gia cc thc th ny l ITU-T H.248.
MGCF cng lin lc vi CSCF. Giao thc c chn cho giao din ny l
SIP.
Tuy nhin c th nhiu nh khai thc vn s dng n kt hp vi cc min
chuyn mch knh trong R3 v R4. iu ny cho php chuyn i dn dn t
cc phin bn R3 v R4 sang R5. Mt s cc cuc gi thoi c th vn s dng
min CS mt s cc dch v khc chng hn video c th cthc hin qua R5
IMS. Cu hnh lai ghp c th hin trn hnh 1.12.
Hnh 1.12. Chuyn i dn t R4 sang R5
1.9. CHIN LC DCH CHUYN T GSM SANG UMTS
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Trong phn ny ta s xt chin lc dch chuyn t GSM sang UMTS ca
hng Alcatel. Alcatel d kin pht trin RAN t GSM ln 3G UMTS theo ba
pht hnh: 3GR1, 3GR2 v 3GR3. Vi mi pht hnh, cc sn phm mi v cc
tnh nng mi c a ra.
1.9.1. 3GR1 : Kin trc mng UMTS chng ln
Pht hnh 3GP1 da trn pht hnh ca 3GPP vo thng 3 v cc c t
k thut vo thng 6 nm 2000. Pht hnh u ca 3GR1 ch h tr UTRA-FDD
v s c trin khai chng ln ln GSM. Chin lc dch chuyn t GSM sang
UMTS pht hnh 3GR1 c chia thnh ba giai on c k hiu l R1.1,
R1.2 v R1.3 (R: Release: pht hnh). Trong cc pht hnh ny cc phn cng
v cc tnh nng mi c a ra. Cc nt B c gi l MBS (Multistandard
Base Station: trm gc a tiu chun). Tuy nhin MBS V1 ch nthun l nt
B, ch MBS V2 mi thc s a tiu chun v cha cc chc nng ca c nt B
v BTS trong cng mt hp my. Tng t RNC V2 v OMC-R V2 c a ra phc v cho c UMTS v GSM.
Hnh 1.13 cho thy kin trc ng tn ti GSM v UMTS c pht trin
trong giai on trin khai UMTS ban u (3GR1.1).
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Hnh 1.13. Kin trc ng tn ti GSM v UMTS (pht hnh 3GR1.1)
1.9.2. 3GR2 : Tch hp cc mng UMTS v GSM
Trong giai on trin khai UMTS th hai s tch hp u tin gia hai
mng s c thc hin bng cch a ra cc thit b a tiu chun nh: Nt B
kt hp BTS (MBS V2) v RNC kt hp BSC (RNC V2). Cc chc nng khai
thc v bo dng mng v tuyn cng c th c thc hin chung bi cng
mt OMC-R (V2). Hnh 1.14 m t kin trc mng RANtch hp ca giai on
hai.
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Hnh 1.14. Kin trc mng RAN tch hp pht hnh 3GR2 (R2.1).
1.9.3. 3GR3 : Kin trc RAN thng nht
Trong kin trc RAN ca pht hnh ny cxy dng trn c s pht
hnh R5 vo thng 9 nm 2000 ca 3GPP.Trong pht hnh ny RAN chung cho
c h thng UMTS v GSM. C UTRA-FDD v UTRA-TDD u c h tr.
Giao thc truyn ti c thng nht cho GSM, E-GPRS v UMTS, ngoi ra cth ATM kt hp IP. GERAN (GSM/EDGE RAN) cng s c h tr bi pht
hnh ny ca mng. Kin trc RAN ca 3GR1.3 c th hin trn hnh 1.15.
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Hnh 1.15. Kin trc RAN thng nht ca 3GR3.1
1.10. CU HNH A L CA H THNG THNG TIN DI NG 3G
Do tnh cht di ng ca thu bao di ng nn mng di ng phi c t chc
theo mt cu trc a l nht nh mng c th theo di c v tr ca thu
bao.
1.10.1. Phn chia theo vng mng
Trong mt quc gia c th c nhiu vng mng vin thng, vic gi vo
mt vng mng no phi c thc hin thng qua tng i cng. Cc vng
mng di ng3Gc i din bng tng i cng GMSChoc GGSN. Tt c
cc cuc gi n mt mng di ng t mt mng khc u c nh tuyn n
GMSC hoc GGSN. Tng i ny lm vic nh mt tng i trung k vo cho
mng3G. y l ni thc hin chc nng hi nhtuyn cuc gi kt cui
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trm di ng. GMSC/GGSN cho php h thng nh tuyn cc cuc gi vo t
mng ngoin ni nhn cui cng: cc trm di ng b gi.
1.10.2. Phn chia theo vng phc v MSC/VLRv SGSN
Mt mng thng tin di ng c phn chia thnh nhiu vng nh hn,
mi vng nh ny c phc v bi mt MSC/VLR (hnh 1.16a). hay SGSN
(1.16b) Ta gi y l vng phc v ca MSC/VLRhay SGSN.
Hnh 1.16. Phn chia mng thnh cc vng phc v ca MSC/VLRv SGSN
nh tuyn mt cuc gi n mt thu bao di ng, ng truyn qua
mng s c ni n MSC ang phc v thu bao di ng cn gi. mi vng
phc v MSC/VLR thng tin v thu bao c ghi li tm thi VLR. Thng
tin ny bao gm hai loi:
Thng tin v ng k v cc dch v ca thu bao. Thng tin v v tr ca thu bao (thu bao ang vng nh vhoc
vng nh tuyn no).
1.10.3. Phn chia theo vng nh vv vng nh tuyn
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Mi vng phc v MSC/VLR c chia thnh mt s vng nh v: LA
(Location Area) (hnh 1.17a). Mi vng phc v ca SGSN c chia thnh cc
vng nh tuyn (RA: Routing Area) (1.17b).
Hnh 1.17. Phn chia vng phc v ca MSC/VLRv SGSN thnh cc vng
nh v (LA: Location Area)v nh tuyn (RA: Routing Area)
Vng nh v (hay vng nh tuynl mt phn ca vng phc v
MSC/VLR (hay SGSN) m mt trm di ng c th chuyn ng t do v
khng cn cp nht thng tin v v tr cho MSC/VLR(hay SGSN) qun l v tr
ny. C th ni vng nh v (hay vng nh tuyn)l v tr c th nht ca trm
di ng m mng cn bit nh tuyn cho mt cuc gi n n. vng nh
v ny thng bo tm s c pht qung b tm thu bao di ng b gi.Hthng c th nhn dng vng nh v bng cch s dng nhn dng vng nh v
(LAI: Location Area Identity) hay nhn dng vng nh tuyn (RAI Routing
Area Identity). Vng nh v (hay vng nh tuyn) c th bao gm mt s v
thuc mthay nhiu RNC, nhng ch thuc mt MSC(hay mt SGSN).
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1.10.4. Phn chia theo
Vng nh v hay vng nh tuyncchia thnh mt s (hnh 1.18).
Hnh 1.18. Phn chia LA v RA
l mt vng ph v tuyn c mng nhn dng bng nhn dng ton cu
(CGI: Cell Global Identity). Trm di ng nhn dng bng m nhn dng trmgc (BSIC: Base Station Identity Code).Vng ph ca cc thng c m
phng bng hnh lc gic tin cho vic tnh ton thit k.
1.10.5. Mu
Mu c hai kiu: v hng ngang (omnidirectional) v phn on
(sectorized). Cc mu ny c cho trn hnh 1.19.
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Hnh 1.19. Cc kiu mu
v hng ngang (hnh 1.19a) nhn c t pht x camt anten cbp sng trn trong mt ngang (mt phng song song vi mt t) v bp sng
c hng chc xung mt t trong mt ng (mt phng vung gc vi mt
t). phn on (hnh 1.19b) l nhn c t pht x ca ba anten vi hng
pht x cc i lch nhau 1200. Cc anten ny c bp sng dng na s 8 trong
mt ngang v trong mt ng bp sng ca chng chc xung mt t. Trong
mt s trng hp phn on c th c to ra t pht x ca nhiu hn ba
anten. Trong thc t mu c th rt a dng ty vo a hnh cn ph sng.
Tuy nhin cc mu nh trn hnh 1.19thng c s dng thit k cho s
ph sng chun.
1.10.6. Tng kt phn chia vng a l trong cc h thng thng tin di ng 3G
Trong cc kin trc mng bao gm c min chuyn mch knh v min
chuyn mch gi, vng phcmng khng ch c phn chia thnh cc vng
nh v (LA) m cn c phn chia thnh cc vng nh tuyn (RA: Routing
Area). Cc vng nh v (LA:Location Area) l khi nim qun l di ng ca
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min CS k tha t mng GSM. Cc vng nh tuyn (RA: Routing Area) l cc
thc th ca min PS. Mng li PS s dng RA tm gi. Nhn dng thu bao
P-TMSI (Packet- Temporary Mobile Subsscriber Identity: nhn dng thu bao di
ng gi tm thi) l duy nht trong mt RA.
Trong mng truy nhp v tuyn, RA li c chia tip thnh cc vng
ng k UTRAN (URA: UTRAN Registration Area). Tm gi khi xng
UTRAN s dng URA khi knh bo hiu u cui c thit lp. URA
khng th nhn thy c bn ngoi UTRAN.
Quan h gia cc vng c phn cp nh cho hnh 1.20( khng c
th hin). LA thuc 3G MSC v RA thuc 3G SGSN. URA thuc RNC. Theo
di v tr theo URA v trong UTRAN c thc hinkhi c ktni RRC
(Radio Resource Control: iu khin ti nguyn v tuyn) cho knh bo hiu
u cui.Nu khng c kt ni RRC, 3G SGSN thc hin tm gi v cp nht
thng tin v trc thc hin theo RA.
Hnh 1.20. Cc khi nimphn chia vng a l trong3G WCDMA UMTS.
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1.11. TNG KT
Chng ny trc ht xt tng quan qu trnh pht trin thng tin di ng
ln 4G. Nu cng ngh a truy nhp cho 3G l CDMA th cng ngh a truy
nhp cho 4G l OFDMA. Sau kin trc mng 3G c xt. Mng li 3G bao
gmhai vng chuyn mch: (1) vng chuyn mch cc dch v CS v (2) vng
chuyn mch cc dch v PS. Cc pht hnh nh du cc mc quan trng pht
trin mng 3G WCDMA UMTS cxt: R3, R4, R5 v R6. R3 bao gm hai
min chuyn mch knh v chuyn mch gi trong kt ni gia cc nt
chuyn mch gi l TDM (ghp knh theo thi gian). R4 l s pht trin ca R3
trong min chuyn mch knh chuyn thnh chuyn mch mm v kt ni
gia cc nt mng bng IP. R5 v R6 h tr cc dch v a phng tin IP hon
ton da trn chuyn mch gi. p ng c nhim v ny ngoi min
chuyn mch gi, mng cb sung thm phn h a phng tin IP (IMS).
Ct li ca IMS l CSCF thc hin khi u kt ni a phng tin IP da trn
giao thc khi u phin (SIP Session Initiation Protocol). Ngoi ra IMS vn
cn cha chuyn mch mm h tr dch v chuyn mch knh (MGCF).
Hin nay mng 3GWCDMA UMTS ang giai don chuyn dn t R4 sang R5
(hnh 1.12). Cui chng trnh by cu trc a l ca mt mng thng tin di
ng 3G c cha c vng chuyn mchknh v vng chuyn mch gi.
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Chng 2
CNG NGH A TRUY NHP CA WCDMA
2.1. GII THIU CHUNG
2.1.1. Mc ch chng
Hiu tng quan tri ph v phng php a truy nhp ca WCDMA Hiu iu khin cng sut, chuyn giao mm v my thu phn tp a
ng (RAKE)
Hiu cc dng m tri ph v cc s iu ch ca WCDMA
2.1.2. Cc ch c trnh by trong chng
Nguyn l tri ph v a truy nhp phn chia theo m iu khin cng sut Chuyn giao My thu phn tp a ng (my thu RAKE) Cc dng m tri ph v cc s iu cht cs dng cho WCDMA
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2.1.3. Hng dn
Hc k cc t liu ctrnh by trong chng Tham kho thm cc ti liu tham kho cui ti liu ging dy ca kha
hc
2.2. TRI PH V A TRUY NHP PHN CHIA THEO M
2.2.1. Cc h thng thng tin tri ph
Trong cc h thng thng tin thng thng rng bng tn l vn
quan tm chnh v cc h thng ny c thit k s dng cng t rng
bng tn cng tt. Trong cc h thng iu ch bin song bin, rng bngtn cn thit pht mt ngun tn hiu tng t gp hai ln rng bng tn
ca ngun ny. Trong cc h thng iu tn rng bng tn ny c th bng
vi ln rng bng tn ngun ph thuc vo ch s iu ch. i vi mt tn
hiu s, rng bng tn cn thit c cng gi tr vi tc bit ca ngun.
rng bng tn chnh xc cn thit trong trng hp ny ph thuc v kiu iu
ch (BPSK, QPSK v.v...).
Trong cc h thng thng tin tri ph (vit tt l SS: Spread Spectrum)
rng bng tn ca tn hiu c m rng, thng thng hng trm ln trc khi
c pht. Khi ch c mt ngi s dng trong bng tn SS, s dng bng tn
nh vy khng c hiu qu. Tuy nhin mi trng nhiu ngi s dng, cc
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ngi s dng ny c th dng chung mt bng tn SS (tri ph) v h thng tr
nn s dng bng tn c hiu sut m vn duy tr c cc u im catri ph.
Mt h thng thng tin s c coi l SS nu:
* Tn hiu c pht chim rng bng tn ln hn rng bng tn ti thiu
cn thit pht thng tin.
* Tri ph c thc hin bng mt m c lp vi s liu.
C ba kiu h thng SS c bn: chui trc tip (DSSS: Direct-Sequence
Spreading Spectrum), nhy tn (FHSS: Frequency-Hopping Spreading
Spectrum) v nhy thi gian (THSS: Time-Hopping Spreading Spectrum). Cng
c th nhn c cc h thng lai ghp t cc h thng ni trn. WCDMA s
dng DSSS. DSSSt c tri ph bng cch nhn lung s cn truyn vi
mt m tri ph c tc chip (Rc=1/Tc, Tc l thi gian mt chip) cao hn nhiu
tc bit (Rb=1/Tb, Tbl thi gian mt bit) ca lung s cn pht.Hnh 2.1
minh ha qu trnh tri ph trong Tb=15Tchay Rc=15Rb. Hnh 2.1a cho thy
s n gin cab tri ph DSSS trong lung s cn truyn xc tc Rb
cnhn vi mt m tri ph c tc Rc c lung u ra y c tc Rcln hn nhiu so vi tc Rbcalung vo. Cc hnh 2.1b v 2.1b biu th qu
trnh tri ph trong min thi gian v min tn s.
Ti pha thu lung y c thc hin gii tri ph khi phc li lung x
bng cch nhn lung ny vi m tri ph c ging nh pha pht: x=yc
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x, y v c k hiu tng qut cho tn hiu vo, ra v m tri ph; x(t), y(t) v c(t)
k hiu cho cc tn hiu vo, ra v m tri ph trong min thi gian; X(f), Y(f)
v C(f) k hiu cho cc tn hiu vo, ra v m tri ph trong min tn s; Tbl
thi gian mt bit ca lung s cn pht, Rb=1/Tbl tc bit ca lung s cn
truyn; Tcl thi gian mt chip ca m tri ph, Rc=1/Tcl tc chip ca m
tri ph. Rc=15Rbv Tb=15Tc.
Hnh 2.1. Tri ph chui trc tip (DSSS)
2.2.2. p dng DSSS cho CDMA
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Trong cng ngh a truy nhp phn chia theo m da trn CDMA, mt
tp m trc giao cs dng v mi ngi s dng c gn mt m tri ph
ring. Cc m tri ph ny phi m bo iu kin trc giao sau y:
1. Tch hai m ging nhau bng 1: cici=12. Tch hai m khc nhau s l mt m mi trong tp m: cicj=ck3. C s bit 1 bng s bit -1 trong mt m
1
10
N
k
k
CN
, trong N l s
chip v Ckl gi tr chip k trong mt m
Bng 2.1. cho thy th d s dng b m gm tm m trc giao: c0, c1, ,
c7. Bng 2.2 v 2.3 cho thy th d khi nhn hai m ging nhau trong bng 1
c 1 v nhn hai m khc nhau trong bng 2.1 ta c mt m mi..
Bng 2.1. Th d b tm m trc giao
c0 +1 +1 +1 +1 +1 +1 +1 +1
c1 +1 +1 +1 +1 -1 -1 -1 -1
c2 +1 +1 -1 -1 +1 +1 -1 -1
c3 +1 +1 -1 -1 -1 -1 +1 +1
c4 +1 -1 +1 -1 +1 -1 +1 -1
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c5 +1 -1 +1 -1 -1 +1 -1 +1
c6 +1 -1 -1 +1 +1 -1 -1 +1
c7 +1 -1 -1 +1 -1 +1 +1 -1
Bng 2.2. Th d nhn hai m ging nhau trong bng 1 c mt
c1 +1 +1 +1 +1 -1 -1 -1 -1
c1 +1 +1 +1 +1 -1 -1 -1 -1
c1c1 +1 +1 +1 +1 +1 +1 +1 +1
Bng 2.3. Th d nhn hai m khc nhau trong bng 1 c mt m mi trong
tp 8 m
c1 +1 +1 +1 +1 -1 -1 -1 -1
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c3 +1 +1 -1 -1 -1 -1 +1 +1
= c2 +1 +1 -1 -1 +1 +1 -1 -1
Nu ta xt mt h thng gm K ngi s dng c xy dng trn c s
CDMA, th sau tri ph cc ngi s dng ny s pht vo khng gian tp cc
tn hiu y nh sau:
1 1
K K
i i ii iy y c x (2.1)
Ta xt qu trnh x l tn hiu ny ti mt my thu k. Nhim v ca my thu ny
l phi ly ra xkv loi b cc tn hiu khc (cc tn hiu ny c gi l nhiu
ng knh v trong h thng CDMA chng c pht trn cng mt tn s vi
xk). Nhn (2.1) vi xkv p dng quy tc trc giao ni trn ta c:
1
K
k k i i
ii k
x x c x
% (2.2)
Thnh phn th nht trong (2.2) chnh l tn hiu hu ch cn thnh phn th hai
l nhiu ca cc ngi s dng cn l nhiu ca cc ngi s dng khc c
gi l MAI (Multiple Access Interferrence: nhiu a ngi s dng). loi b
thnh phn th hai my thu s dng b lc tng quan trngmin thi gian kt
hp vi b lc tn s trong min tn s. Hnh 2.2 xt qu trnh gii tri ph v
lc ra tn hiu hu ch ti my thu k trong mt h thng CDMA c K ngi s
dng vi gi thit cng sut pht t K my pht nh nhau ti u vo my thu k.
Hnh 2.2a cho thy s gii tri ph DSSS. Hnh 2.2b cho thy ph ca tn
hiu tng c pht i t K my pht sau tri ph, hnh 2.2c cho thy ph ca
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tn hiu ny sau gii tri ph ti my thu k v hnh 2.2d cho thy ph ca tn
hiu sau b lc thng thp vi bng thng bng Rb.
Hnh 2.2. Qu trnh gii tri ph v lc tn hiu ca ngi s dng k t K tn
hiu.
T hnh 2.2 ta thy t s tn hiu trn nhiu (SIR: Signal to Interference
Ratio) l t s gia din tch hnh ch nht c t m trn hnh 2.2.b v tng
din tch cc hnh ch nht trng trn hnh 2.2.c: SIR=S1/S2. T s ny t l vi
t s Rc/Rb. v th t s Rc/Rb c gi l li x l (TA: Processing Gain).
2.3. IU KHIN CNG SUT
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Trong trng hp mt my pht gy nhiu n gn my thu k (n gn
nt B chng hn), cng sut camy pht ny tng cao dn n MAI tng cao,
t s tn hiu trn nhiu gim mnh v my thu k khng th tch ra c tn hiu
ca mnh. Hin tng ny cgi l hin tng gn v xa. trnhhin tng
ny h thng phi iu khin cng sut sao cho cng sut thu ti nt B ca tt ccc UE u bng nhau (l tng).iu khin cng sut trong WCDMA c
chia thnh:
iu khin cng sut vng h iu khin cng sut vng kn
iu khin cng sut vng h cthc hin t ng ti UE khi n thc
hin th tc xin truy nhp Nt B (da trn cng sut m n thu c t knh hoa
tiu pht i t B), khi ny UE chac kt ni vi nt ny. Cn iu khin cng
sutvng kn c thc hin khi UE kt ni vi nt B. iukhin cng sut
vng h li c chia thnh:
iu khin cng sut vng trong c thc hin ti nt B. iu khincngsut vng trong cthc hin nhanh vi 1500 ln trong mt giy da trn
so snh SIR thu vi SIR ch
iu khin cng sut vng ngoi cthc hin ti RNC thit lp SIRch cho nt B. iu khin cng sut ny da trn so snh t l li khi
(BLER) thu cvi t l ch.
2.4. CHUYN GIAO TRONG H THNG CDMA
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Thng thng chuyn giao (HO: Handover) chiu l qu trnh trong
knh lu lng ca mt UE cchuyn sang mt knh khc m bo
cht lng truyn dn. Tuy nhin trong CDMA khi nim ny ch thch hp cho
chuyn giao cng cn i vi chuyn giao mm khi nim ny phc tp hn, ta
s xt c th trong phn di y.
C th chia HO thnh cc kiu HO sau:
HO ni h thngxy ra bn trong mt h thng WCDMA. C th chia nhHO ny thnh
o HO ni h thnggia cc thuc cng mt tn s sng mang WCDMAo HO gia cc tn s (IF-HO)gia cc hot ng trn cc tn s
WCDMA khc nhau
HO gia cc h thng (IS-HO) gia cc thuc hai cng ngh truy nhp vtuyn (RAT) khc nhau hay cc ch truy nhp v tuyn (RAM) khc
nhau. Trng hp thng xuyn xy ra nht i vi kiu th nht l HO
gia cc h thng WCDMA v GSM/EDGE. Tuy nhin cng c th l IS-
HO gia WCDMA v h thngcc h thng CDMA khc (cdma2000 1x
chng hn). Th d v HO gia cc RAM l HO gia cc ch UTRA
FDD v UTRA TDD.
C th c cc th tc HO sau:
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TS. Nguyn Phm Anh Dng 64
Tp ln cn/ tp cgim st(c hai t c s dng nh nhau). Tp nybao gm tt c cc c gim st/o lin tc bi UE v hin thi khng c
trong tp tch cc
Tp c pht hin. Tp ny bao gm cc cUE pht hin nhngkhng thuctp tch cc ln tp ln cn.
SHO l mt tnh nng chung ca h thng WCDMA trong cc ln
cn hat ng trn cng mt tn s. Trong ch kt ni, UE lin tc o cc
phc v v cc ln cn (do RNC ch dn) trn tn s sng mang hin thi. UE
so snh cc kt qu o vi cc ngng HO do RNC cung cp v gi bo co ktqu o n RNC khi thc hin cc tiu chun bo co. V th SHO l kiu
chuyn giao c nh gi bi u cui di ng (MEHO: Mobile Estimated
HO). Tuy nhin gii thut quyt nh SHO c t trong RNC. Da trn cc
bo co kt qu o nhn c t UE (hoc nh k hoc c khi ng bi
mt s cc s kin nht nh), RNC lnh cho UE b sung hay loi b mt s
khi tp tch cc ca mnh (ASU: Active Set Apdate: cp nht tp tch cc).
2.5. MY THU PHN TP A NG HAY MY THU RAKE
Phainh a ng trn knh v tuyn dn n tn thi v chn lc tn s
lm hng tn hiu thu. nh gi hin tng tn thi trn ng truyn vtuyn, ngi ta pht i mt xung hp (xung kim) v o p ng xung ny ti
pha thu. p ng ny l bc tranh th hin s ph thuc cng sut ca cc
ng truyn khc nhau n my thu vo thi gian tr ca cc ng truyn
ny. p ng ny c gi l l lch tr cng sut. Hnh 2.4a cho thy truyn
sng a ng v hnh 2.4b cho thy th d v l lch tr cng sut.
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Hnh 2.4. Truyn sng a ng v l lch tr cng sut
Chui tn hiu gingu nhin c pht i CDMA c thuc tnh l cc
phin bn dch thi ca n ti pha thu hu nh khng tng quan. Nh vy mt
tn hiu c truyn t my pht n my thu theo nhiu ng khc nhau (thi
gian tr khc nhau) c th c phn gii vo cc tn hiu phainh khc nhau
bng cch ly tng quan tn hiu thu chanhiu phin bn dch thi ca chui
gi ngu nhin. My thu s dng nguyn l ny c gi l my thu phn tp a
ng hay my thu RAKE (hnh 2.5).
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TS. Nguyn Phm Anh Dng 66
Hnh 2.5. My thu RAKE
Trong my thu RAKE nhn c cc phin bn dch thi ca
chui ngu nhin, tn hiu thu phi i qua ng tr trc khi c ly tng
quan v c kt hp. ng tr bao gm nhiu mt tr c thi gian tr bng
thi gian mt chip Tc. My thu dch nh thi bn sao m tri ph tng chip cho
tng k hiu thng tin gii tri ph k hiu trong vng mt k hiu v to nn
l lch tr cng sut (xem hnh 2.5a). Vi tham kho l lch tr cng sut (bc
tranh th hin cng sut v tr ca cc ng truyn) c to ra, my thu chn
cc ng truyn c cng sut vt ngng kt hp RAKE trn c s s
lng b tng quan, b c tnh knh v b b tr thay i pha(c gi l
cc ngn my thu RAKE). Trong trng hp p dng thu phn tp khng gian hay phn tp gia cc on , l lch tr cng sut c to ra cho mi nhnh v
cc ngtruyn c chnt l lch tr cng sut sut tng hp ca tt c cc
nhnh. Trong thc t, v cc tn hiu tri ph gm nhiu ca cc ngi s dng
khc v cc tn hiu a ng ca knh ngi s dng, nn gi tr ngng c
lp d trn mc cng sut tp m nn v cc ng truyn c SIR h iu dng
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TS. Nguyn Phm Anh Dng 67
(c cng sut thu vt ngng) c chn.V MS chuyn ng (hoc mi
trng truyn sng thay i khi MS c nh), nn v tr ng truyn (thi gian
tr) c kt hp RAKE cng s thng xuyn thay i, my phi nh k cp
nht l lch tr ngtruyn v cp nht cc ng truyn c kt hp RAKE
trn c s l lch mi (qu trnh ny c gi l tm kim ng truyn v nlin quan n tm kim ng truyn kt hp RAKE).
2.6. CC M TRI PH S DNG TRONG WCDMA
Khi nim tri ph c p dng cho cc knh vt l, khi nim ny bao
gm hai thao tc. u tin l thao tc nh knh, trong mi k hiu s liu
dc chuyn thnh mt s chip nh vy tng rng ph tn hiu. S chip trn
mt k hiu (hay t s gia tc chip v tc khiu) c gi l h s tri
ph (SF: Spectrum Factor), hay ni mt cch khc SF=Rs/Rctrong Rsl tc
k hiu cn Rcl tc chip. H s tri ph l mt gi tr kh bin, ngoi tr
i vi knh chia s ng xung vt l tc cao (HS-PDSCH ) trong HSDPAc SF=16. Thao tc th hai l thao tc ngu nhin ha tng tnh trc giao
trong mt m ngu nhin ha c trn vi tn hiu tri ph. M ngu
nhin ho c xy dng trn c s m Gold.
Trong qu trnh nh knh, cc k hiu s liu c nhn vi mt m
OVSF (Orthogonal Variable Spread Factor: m trc giao h s kh bin) ng
b v thi gian vi bin ca k hiu. Trong 3GPP, OVSF (hnh 2.6) c sdng cho cc tc k hiu khc nhau v c k hiu l Cch,SF,ktrong SF l
h s tri ph ca m v k l s th t m (0kSF-1). Cc m nh knh c cc
tnh cht trc giao v c s dng phn bit cc thng tin c pht i cng
t mt ngun: (1) cc kt ni khc nhau trn ng xung trong cng mt trn
ng xung v gim nhiuni , (2) cc knh s liu vt l ng ln t mt
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TS. Nguyn Phm Anh Dng 68
UE. Trn ng xung cc m OVSF trong m b hn ch v th cn c
qun l bi RNC, tuy nhin iu ny khng xy ra i vi ng ln.
Cn lu khi chn m nh knh chng khng tng quan vi nhau. Chng
hn khi chn m Cch,8,4=+1-1+1-1+1-1+1-1, khng c s dng m
Cch,16,8=+1-1+1-1+1-1+1-1+1-1+1-1+1-1+1-1; v hai m ny hon ton ging
nhau (tch ca chng bng 1) v chng s gy nhiu cho nhau.
Cc m OVSF ch hiu qu khi cc knh c ng b hon ho ti mc
k hiu. Mt tng quan cho do truyn sng a ng c b tr bi thao tc
ngu nhin ha b sung. Vi thao tc ngu nhin ha, phn thc (I) v phn o
(Q) ca tn hiu tri ph c nhn b sung vi m ngu nhin ha phc. M
ngu nhin ha phc c s dng phn bit cc ngun pht: (1) cc khc
nhau i vi ng xung v (2) cc UE khc nhau i vi ng ln. Cc m
ny c cc tnh cht tng quan tt (trung bnh ha nhiu) v lun cs dng
trn vi cc m triph nhng khng lm nh hng rng ph tn hiu
v bng thng truyn dn.
Hnh 2.6. Cy m nh knh
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ng truyn gia nt B v UE trong WCDMA cha nhiu knh. C th
chia cc knh ny thnh hai loi: (1) knh ring truyn lu lng v (2) knh
chung mang cc thng tin iu khin v bo hiu. ng truyn t UE n nt
B c gi l ngln, cn ng ngc li t nt B n UE cgi l
ngxung. Trc ht ta xt tri ph cho cc knh ng ln.
2.7. TRI PH V IU CH NG LN
2.7.1. Tri ph v iu ch cc knh ring ng ln
Nguyn l tri ph cho DPDCH (Dedicated Physical Data Channel: knh
s liu vt l ring,knh truyn lu lng ca ngi s dng) v DPCCH
(Dedicated Physical Control Channel: knh iu khin vt l ring; knh i cng
vi DPDCH mang thng tin iu khin lp vt l)c minh ha trn hnh
2.7.
Mt DPCCH v cc i su DPDCH song song gi tr thc c th c
tri ph v pht ng thi. DPCCH lun c tri ph bng m Cc=Cch,256,0,
trong k=0. Nu ch mt knh DPDCH c pht trn ng ln, th DPDCH1
c tri ph vi m Cd,1=Cch,SF,k, trong k=SF/4 l s m OVSF v k=SF/4.
Ngha l nu h s tri ph SF=128 th k=32. Nu nhiu DPDCH c pht, th
tt c DPDCH u c h s tri ph l 4 (tc bit knh l 960kbps) vDPDCHnc tri ph bi m Cd,n=Cch,4,k, trong k=1 nu n{1,2}, k=3 nu
n{3,4} v k=2 nu n{5,6}. b tr s khc nhau gia cc h s tri ph
ca s liu, tn hiu tri ph c nh trng s bng cc h s khuych i k
hiu l ccho DPCCH v dcho DPDCH. Cc h s khuych i ny ctnh
ton bi SRNC v c gi n UE trong giai on thit lp ng truyn v
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tuyn hay t li cu hnh. Cc h s khuych i nm trong di t 0 n 1 v t
nht mt trong s cc gi tr ca cv dlun lun bng 1. Lung chip ca cc
nhnh I v Q sau c cng phc vi nhau v c ngu nhin ha bi mt
m ngu nhin ha phc c k hiu l Sdpch,ntrn hnh 2.7. M ngu nhin ha
ny c ng b vi khung v tuyn, ngha l chip th nht tng ng vi ukhung v tuyn.
Hnh 2.7. Tri ph v iu ch DPDCH v DPCCH ng ln
Cc nghin cu cho thy mi s pht khng lin tc trn ng ln c th
gy nhiu m thanh cho thit b m thanh t gn my u cui di ng. Th d
in hnh l trng hp nhiu tn s khung (217 Hz=1/4,615ms) gy ra do cc
u cui GSM. trnh hiu ng ny, knh DPCCH v cc knh DPDCH
khng cghp theo thi gian m c ghp theo m I/Q (iu ch QPSK hai
knh) vi ngu nhin ho phc. Minh ha trn hnh 2.8 cho thy s iu ch
ny cho php truyn dn lin tc ngay c trong cc chu k im lng khi ch c
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TS. Nguyn Phm Anh Dng 71
thng tin iu khin lp 1 duy tr hot ng ng truyn (DPCCH) l c
pht.
Hnh 2.8. Truyn dn knh iu khin vt l ringng ln v knh s liu vt
l ring ng ln khi c/ khng c (DTX) s liu ca ngi s dng
Nh minh ha trn hnh 2.9, cc m ngu nhin ha phc c to ra
bng cch quay pha gia cc chip trong mt chu k k hiu trong gii hn 900.
Bng cchny hiu sut ca b khuch i (lin quan n t s cng sut nh
trn cng sut trung bnh) trong UE hu nh khng i khng ph th thuc vo
t s gia DPDCH v DPCCH.
Hnh 2.9. Chm tn hiu i vi ghp m I/Q s dung ngu nhin ha phc,
biu din cho t s cng sut gia DPDCH v DPCCH.
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DPCCH v cc DPDCH c th c ngu nhin ha bng cc m ngu
nhin di hoc ngn. C 224m ngu nhin ha di ng ln v 224 m ngu
nhin ngn ng ln. V c th s dng c hng triu m nn khng cn quy
hochm ng ln. S m ngu nhin cho DPCH (0,., 16777215), cng vi
SF thp nht c php ca m nh knh (4, 8, 16, 32, 128 v 256) cho phn s
liu c n nh bi cc lp cao hn, chng hn khi thit lp ktni RRC hoc
khi iu khinchuyn giao.
2.7.2. Tri ph v iu ch knh chung ng ln PRACH
Phn ny s trnh by n nh m cho tin t v phn bn tin ca PRACH
l mt dng knh chung ng ln.
Tri ph v ngu nhin ha phn bn tin PRACH c minh ha trn
hnh 2.10.
Hnh 2.10. Tri ph v iu chphn bn tin PRACH
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TS. Nguyn Phm Anh Dng 73
Phn iu khin ca bn tin PRACH c tri ph bng m nh knh
Cc=Cch,256,m, trong m=16.s+15 v s (0s15) l ch k tin t v phn s liu
c tri ph bng m nh knh Cd=Cch,SF,m, trong SF (c gi tr t 32 n
256) l h s tri ph s dng cho phn s liu v m=SF.s/16.
Phn bn tin PRACH lun lun c tri ph bng m ngu nhin ha
di. di ca m ngu nhin ha c s dng cho phn bn tin l 10ms. C
tt c l 8192 m ngu nhin ha.
2.8. TRI PH V IU CH NG XUNG
2.8.1. S tri phv iu ch ng xung
Khi nim tri ph v ngu nhin ha ng xung c minh ha trn
hnh 2.11. Ngoi tr cc SCH (knh ng b s xt trong chng 3), mi cp haibit knh trc ht c bin i t ni tip vo song song tng ng mt k
hiu iu ch, sau c t ln cc nhnh I v Q. Sau cc nhnh I v Q
c tri ph n tc 3,84Mcps bng cng mi m dnh knh Cch,SF,m. Cc
chui chip gi tr thc trn cc nhnh Iv Q sau c ngu nhin ha bng
m ngu nhin ha phc nhn dng ngun pht nt B, m ny ck hiu
l Sdl,ntrn hnh 2.11. M ngu nhin ha ny c ng b vi m ngu nhin
ha s dng cho P-CCPCH (knh vt l iu khin chung s cp s xt trongcng 3), trong chp phc u tin ca khung P-CCPCH c nhn vi chip
s 0 ca m ngu nhin ha ny.
Sau tri ph, mi knh vt l ng xung (tr cc SCH) c nh trng
s bng cc h s trng s ring k hiu l Ginh trn hnh 2.11. P-SCH v S-
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SCH gi tr phc c nh trng s ring bng cc h s trng s Gpv Gs. Tt
c cc knh ng xung c kt hp vi nhau bng cng phc. Chui nhn
c sau tri ph v ngu nhin ha c iu ch QPSK.
Hnh 2.11. S tri ph v iu ch cho tt c cc knh vt l ng xung
2.8.2. Cc m tri ph ng xung
Trn ng xung, cng cc m nh knh nh trn ng ln (m
OVSF) c s dng. Thng thng mi ch c mt cy m v mi cy m
c t di mt m ngu nhin ha dng chung cho nhiu ngi s dng.
Theo quy inh, cc m nh knh dng cho P-CPICH(knh hoa tiu chung s
cp s xt trong chng 3)v P-CCPCH l Cch,256,0v Cch,256,1. B qun l ti
nguyn trong RNC n nh cc m nh knh cho tt c cc knh khc vi gii
hn SF=512 trong trng hp s dngchuyn giao phn tp.
M OVSF c th thay i theo tng khung trn knh PDSCH (knh chia
s ng xung vt l s xt trong chng 3). Quy tc thay i nh sau, m (cc
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m) OVSF c s dng cho kt ni pha dih s tri ph nh nhtl m t
nhnh cy, m nhnh cy m c ch ra bi h s tri ph thp nht ny. Nu
DSCH c sp xp ln nhiu PDSCH song song, th quy tc tng t c p
dng, nhng tt cc nhnh m c s dng bi cc m ny tng ng vi h s
tri ph nh nht u c th s dng cho n nh h s tri ph cao hn.
2.8.3. Cc m ngu nhin ha ng xung
Trn ng xung ch c cc m ngu nhin ha di l c s dng. C
c thy 218-1=262143 m ngu nhin c nh s t 0 n 262142. Cc chui
m ngu nhin c k hiu l Sdl,nc cu trc bng cc on ca chui
Gold. tng tc qu trnh tm , ch 8192 m trong s 262143 c s dng
trong thc t v c ct ngn ly on u 38400 chip ph hp vi chu k
khung 10 ms. Nh minh ha trn hnh 2.12, ch c cc m vi n=0,1,, 8191
c s dng. Cc m ny c chia thnh 512 tp. Mi tp gm 16 m
(i=015) vi mt m s cp v 15 m th cp. 8 tp (i=07) vi 8x16 m hpthnh mt nhm to nn 64 nhm (j=063).
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Hnh 2.12. Cc m ngu nhin ha s cp v th cp
V thng thng mi c nhn dng bng mt m ngu nhin ho s
cp, nn qu trnh tm kim cng l qu trnh tm kim m ny. Qu trnh tm
kim c th c thc hin theo ba bc sau:
Tm P-SCH (knh ng b s cp) thit lp ng b khe v ng b khiu
Tm S-SCH (knh ng b th cp) thit lp ng b khung v nhm m Tm m ngu nhin ha nhn dng
2.8.4. Ghp knh a m ng xung
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tng dung lng knh ng xung ta c th s dng s ghp knh
a m nh cho hnh 2.13.
S/P: bin i ni tip thnh song song
Hnh 2.13. Truyn dn a m cho ng xung
2.9. TNG KT
Cc h thng CDMA c xy dng trn c s tri ph chui trc tip
(DSSS). Vic s dng tri ph cng vi cc m trc giao cho php nhiu u
cui di ng c th dng chung mt tn s. Khi ny tnh trc giao ca cc m v
tri ph cho php mt my thu u cui c th d dng tch ra c tn hiu ca
mnh. Do s dng chung mt tn s nn c th p dng chuyn giao mm cho
CDMA. Trong chuyn giao mm mt my di ng c th kt ni n nhiu trmgc trn cng mt tn s nhng vi m tri ph khc nhau. u im ca chuyn
giao mm l khng lm mt cuc gi trong qu trnh chuyn giao mc d n lm
gim phn no dng lng v tng thm tnh phc tp h thng. Nhng cng
v s dng chung mt tn s nn c th xy ra hin tng gn xa, trong my
di ng gn trm gc s gy nhiu cho cc ngi s dng khc. khc phc
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nhc im ny phi p dng iu khin cng sut nhanh cho CDMA trong
my di ng gn trm gc s c iu chnh pht cng sut thp hn my di
ng xa trm gc. iu khin cng sut nhanh trong WCDMA c thc hin
1500 ln trong mt giy.Mt c im na ca CDMA l cc m ngu nhin
ha mang tnh trc giao kh cao nn cc ng truyn n my thu c trkhc nhau thi gian chip hoc ln hn thi gian ny u c lp vi nhau v v
th c th s dng phn tp a ng (hay my thu RAKE) trong CDMA.
Nguyn tc ca my thu RAKE l chn mt s ng (mt s ngn) c cng
sut thu ln hn ngng, ng chnh pha cc ng ny ri cng cng sut thu
ca chng vi nhau. WCDMA s dng hai tng tri ph: (1) tri ph bng m
nh knh, (2) tri ph bng m nhn dng ngun pht. M nh knh c xy
dng trn c s m h s tri ph trc giao kh bin (OVSF), trong h s tri
ph SF=Rs/Rcvi Rsl tc k hiu v Rc l tc chip. M ngu nhin ha
ccu trc t m Gold. WCDMA s dng iu ch QPSK cho ng xung
v BPSK cho ng ln. gim t s cng sut nh trn cng sut trung bnh
ca tn hiu iu ch, ngu nhin ha phc cs dng.
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Chng 3
GIAO DIN V TUYN CA WCDMA UMTS
3.1. GII THIU CHUNG
3.1.1. Mc ch chng
Hiu tng quan v WCDMA/FDD
Hiu kin trcWCDMA v cc knh ca n Hiu c cc k thut phn tp pht trong WCDMA
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3.1.2. Cc ch c trnh by trong chng
Kin trc giao din v tuyn ca 3G WCDMA/FDD Cc thng s lp vt l v quy hoch tn sca WCDMA/FDD Cc kiu knh ca WCDMA/FDD S tng qut ca mt thit b thu pht WCDMA Cc s phn tp pht cs dng cho WCDMA Cc s iu ch v chuyn giao trong WCDMA Cc thng s quan trng my thu v my pht v tuyn ca UE M ha ting AMR
3.1.3. Hng dn
Hc k cc t liu ctrnh by trong chng Tham kho thm cc ti liu tham kho cui ti liu ging dy ca kha
hc
3.2. M U
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WCDMA UMTS l mt trong cc tiu chun ca IMT-2000 nhm pht
trin ca GSM cung cp cc kh nng cho th h ba. WCDMA UMTS s
dng mng a truy nhp v tuyn trn c s W-CDMA v mng li c pht
trin t GSM/GPRS. W-CDMA c th c hai gii php cho giao din v tuyn:
ghp song cng phn chia theo tn s (FDD: Frequency Division Duplex) vghp song cng phn chia theo thi gian (TDD: Time Division Duplex). C hai
giao din ny u s dng tri ph chui trc tip (DS-CDMA). Gii php th
nht s c trin khai rng ri cn gii php th hai ch yu s c trin khai
cho cc nh (Micro v Pico). Hin nay mi ch c WCDMA/FDD c trin
khai v th trong kha hc ny ta s ch xt WCDMA/FDD
Gii php FDD s dng hai bng tn 5 MHz vi haisng mang phn cchnhau 190 MHz: ng ln c bng tn nm trong di ph t 1920 MHz n
1980 MHz, ng xung c bng tn nm trong di ph t 2110 MHz n 2170
Mhz. Mc d 5 MHz l rng bng danh nh, ta cng c th chn rng
bng t 4,4 MHz n 5 MHzvi nc tng l 200 KHz. Vic chn rng bng
ng n cho php ta trnh c nhiu giaothoa nht l khi khi 5 MHz tip
theo thuc nh khai thc khc.
Gii php TDD s dng cc tn s nm trong di 1900 n 1920 MHz v
t 2010 MHz n 2025 MHz; y ng ln v ng xung s dng chung
mt bng tn.
Giao din v tuyn ca W-CDMA/FDD ( n gin ta s b qua k hiu
FDD nu khng xt n TDD)hon ton khc vi GSM v GPRS, W-CDMA
s dung phng thc tri ph chui trc tip vi tc chip l 3,84 Mcps.
Trong WCDMA mng truy nhp v tuyn c gi l UTRAN (UMTS
Terrestrial Radio Access Network). Cc phn t ca UTRAN rt khc vi cc
phn t mng truy nhp v tuyn ca GSM. V th kh nng s dng li cc
BTS v BSC ca GSM l rt hn ch. Mt s nh sn xut cng c k hoch
nng cp cc GSM BTScho WCDMA. i vi cc nh sn sut ny c th ch
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tho ra mt s b thu pht GSM t BTS v thay vo cc b thu pht mi cho
WCDMA. Mt s rt t nh sn sut cn lp k hoch xa hn. H ch to cc
BSC ng thi cho c GSM v WCDMA. Tuy nhin a phn cc nh sn sut
phi thay th GSM BSCbng RNC mi cho WCDMA.
W-CDMA s dng rt nhiu kin trc ca mng GSM, GPRShin c cho
mng ca mnh. Cc phn t nh MSC, HLR, SGSN, GGSN c th c nng
cp t mng hin c h tr ng thi WCDMA v GSM.
Giao din v tuyn ca WCDMA/FDD c xy dng trn ba kiu knh:
knh logic, knh truyn ti v knh vt l. Knh logic c hnh thnh trn c
s ng gi cc thng tin t lp cao trc khi sp xp vo knh truyn ti.
Nhiu knh truyn ti c ghp chng vo knh vt l. Knh vt l c xy
dng trn cng ngh a truy nhp CDMA kt hp vi FDMA/FDD. Mi knh
vt l c c trng bi mt cp tn s v mt m tri ph. Ngoi ra knh vt
l ng ln cn c c trng bi gc pha. Trong phn di y ta trc ht
ta xt kin trc giao thc ca giao din v tuyn sau ta s xt giao din v
tuyn ca WCDMA/FDD, sau s xt cc knh ny.
3.3. KIN TRC NGN XP GIAO THC CA GIAO DIN V TUYN
WCDMA/FDD
Kin trc giao din v tuyn ca WCDMA c cho trn hnh 3.1.
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UP: Mt phng ngi s dng
CP: Mt phng iu khin
Hnh 3.1. Kintrc giao thc v tuyn cho UTRA FDD.
Ngn xp giao thc ca giao din v tuyn bao gm 3 lp giao thc:
Lp vt l (L1).c t cc vn lin quan n giao din v tuyn nh iuch v m ha, tri ph v.v..
Lp lin kt ni s liu (L2).Lp khun s liu vo cc khi s liu v mbo truyn dn tin cy gia cc nt ln cn hay cc thc th ng cp
Lp mng (L3).c t nh a ch v nh tuyn
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Mi khi th hin mt trng hp ca giao thc tng ng. ng khng
lin nt th hin cc giao din iu khin, qua giao thc RRC iu khin v
lp cu hnh cc lp di.
Lp 2 c chia thnh cc lp con: MAC (Medium Access Control: iu
khin truy nhp mi trng) v RLC (Radio link Control: iu khin lin kt),
PDCP (Packet Data Convergence Protocol: Giao thc hi t s liu gi) v
BMC (Broadcast/Multicast Control: iu khin qung b/a phng ).
Lp 3 v RLC cchia thnh hai mt phng: mt phng iu khin (C-
Plane) v mt phng ngi s dng (U-Plane). PDCP v BMC ch c mt
phng U.
Trong mt phng C lp 3bao gm RRC (Radio Resource Control: iu
khin ti nguyn v tuyn)kt cui ti RAN v cc lpconcao hn: MM
(Mobility Management) v CC (Connection Management), GMM (GPRS
Mobility Management), SM (Session Management) kt cui ti mng li (CN).
Lp vt l l lp thp nht giao din v tuyn. Lp vt l c s dng
truyn dn giao din v tuyn. Mi knh vt l lp ny c xc nhbng mt t hp tn s, m ngu nhin ho (m nh knh) v pha (ch cho
ng ln). Cc knh c s dng vt l truynthng tin cacc lp cao
trn giao din v tuyn, tuy nhin cng c mt s knh vt l ch c dnh cho
hot ng ca lp vt l.
truyn thng tin giao din v tuyn, cc lp cao phi chuyn cc
thng tin ny qua lp MAC n lp vt l bng cch s dng cc knh logic.MAC sp xp cc knh ny ln cc knhtruyn ti trc khi a n lp vt l
lp ny sp xp chng ln ccknh vt l.
3.4. CC THNG S LP VT L V QUY HOCH TN S
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3.4.1. Cc thng s lp vt l
Cc thng s lp vt l ca WCDMA ccho trong bng 3.1.
Bng 3.1. Cc thng slp vt l W-CDMA
W-CDMA
S a truy nhp DS-CDMA bng rng
rng bng tn (MHz) 5/10/15/20
Mnh ph 200 kHz
Tc chip (Mcps) (1,28)/3,84/7,68/11,52/15,36
di khung 10 ms
ng bgia cc nt B Db/ng b
M ha sa li M turbo, m xon
iu chDL/UL QPSK/BPSK
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Tri phDL/UL QPSK/OCQPSK (HPSK)
Bm ha thoi CS-ACELP/(AMR)
Tchc tiu chun 3GPP/ETSI/ARIB
DL: Downlink: ng xung; UL: Uplink: ng ln
OCQPSK (HPSK): Orthogonal Complex Quadrature Phase Shift Keying
(Hybrid PSK) = kha chuyn pha vung gc trc giao
CS-ACELP: Conjugate Structure-Algebraic Code Excited Linear Prediction
= D bo tuyn tnh kch thch theo m lis cu trc phc hp
3GPP: Third Generation Parnership Project: n ca cc i tc th h ba
ETSI: European Telecommunications Standards Institute: Vin tiu chun
vin thng Chu u
ARIB: Association of Radio Industries and Business: Lin hip cng nghip
v kinh doanh v tuyn
3.4.2. Quy hoch tn s
Cc bng tn s dng cho WCDMA FDDtrn ton cu c cho trn
hnh 3.2a. WCDMA s dng phn b tn s quy nh cho IMT-2000
(International Mobile Telecommunications-2000) (hnh 3.2b) nh sau. chu
u v hu ht cc nc chu bng tn IMT-2000 l 260 MHz (1920-1980
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MHz cng vi 2110-2170 MHz) c th s dng cho WCDMA/FDD. Bng tn
s dng cho TDD chu u thay i, bng tn c cp theo giy php c th
l 25 MHz cho s dng TDD 1900-1920 (TDD1) v 2020-2025 MHz (TDD2).
Bng tn cho cc ng dng TDD khng cn xin php (SPA= Self Provided
Application: ng dng t cp) c th l 2010-2020 MHz. Cc h thng FDDsdng cc bng tn khc nhau cho ng ln v ng xung vi phn cch l
khong cch song cng, cn cc h thng TDD s dng cng tn s cho c
ng ln v ng xung.
UMTS quy nh khai thc song cng phn chia theo tn s l ch tiu
chun cho thng tin thoiv s liu. Hot ng ng thi v lin tc ca cc
mch in pht v thu l cc thay i ng knht so vi hat ng ca GSM.
Hnh 3.2. Phn b tn s cho WCDMA/FDD. a) Cc bng c th dng cho
WCDMA FDD ton cu; b) Bng tn IMT-2000.
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Bng tn cho hat ng FDD cho cc bng I, II v III c cho trn hnh
3.3. Bng I (B1) l n nh bng chnh Chu u. Quy nh dnh hai cp pht
60MHz vi khong cch song cng chun 190MHz, tuy nhin quy nh cng
cho php song cng kh bin, trong khong cch pht thu nm trong khong
130 n 250MHz. H thng song cng kh bin t ra cc yu cu b sung ivi thit k my pht thu v cc b t tn s my pht v my thu phi hot ng
c lp vi nhau. Bng II (B2) ti s dng bng hin c ca h thng thng tin
di ng c nhn v d nh s dng M m bo ng tnti UMTS v
GSM. Khong cch song cng ch bng 80MHz i vi bng II v th t ra cc
yu cu kh khn hn i vi phn cng ca my thu pht.
Hnh 3.3 Cp pht bng tn WCDMA/FDD
Hnh 3.4 cho thy cp pht bng thng theo u thu ti Vng Quc
Anh. Ph tn c chia cho nm nh khai thc nh sau:
Cp php A(Hutchison) nhn cp pht bng kp 14,6 MHz(tng ng35MHz vi bng bo v nh hn)
Cp php B Vodafon) nhn cp pht bng kp 14,8MHz (tng ng35MHz vi bng bo v nh hn)
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Cp php C (BT3G) nhn cp pht bng kp 10MHz (25MHz) v bngn 5MHz ti 1910 MHz
Cp php D (One2One) nhn cp pht bng kp 10MHz (25MHz) vbngdn 5MHz ti 1900MHz
Cp php E(Orange) nhn cp pht bng kp (25MHz) v bng n 5MHzti 1905MHz.
Hnh 3.4. Th d cp pht bng tn cho nm nh khai thc ti Vng Quc Anh
Cp pht tn s ca c khc vi cp pht tn s Anh ch, cc
10MHz bng kp c cp pht cho su nh khai thc (610MHz), tt c bnknh TDD1 c cp pht (1900 n 1920 MHz) cng vi mt trong s cc
knh TDD2 (hnh 3.5).
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Hnh 3.5. Cppht tn s cho su nh khai thc ti c
Ti Vit Nam bng tn 3G c cp pht tn s theo tm khe tn s nh
cho trong bng 3.2, trong hai hoc nhiu nh khai thc c th cng tham gia
xin cp pht chung mt khe.
Bng 3.2. Cp pht tn s 3G ti Vit Nam
FDD TDDKhe tn s
BSTx* BSRx** BSTx/BSRx
A 2110-2125 MHz 1920-1935 MHz 1915-1920 MHz
B 2125-2140 MHz 1935-1950 MHz 1910-1915 MHz
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C 2140-2155 MHz 1950-1965 MHz 1905-1910 MHz
D 2155-2170 MHz 1965-1980 MHz 1900-1905 MHz
* BSTx: my pht trm gc
** BSRx: my thu trm gc
L do cp pht cc knh 5MHz khc nhau ti cc nc khc nhau l ch
cc nh khai thc phi quy hoch m v phi trnh vic s dng cc m gy ranhiu knh ln cn trong cng mt nc hoc cc nh khai thc khc trong nc
lin k. V th cn phi nghin cu quan h gia cc t hp m tri ph v hot
ng ca cc knh ln cn.
3.5. CC KNH CA WCDMA
Cc knh ca WCDMA c chia thnh cc loi knh sauy:
Knh vt l (PhCH).Knh mang s liu trn giao din v tuyn. Mi PhCHc mt tri ph m nh knh duy nht phn bit vi knh khc. Mt
ngi s dng tch cc c th s dng cc PhCH ring, chung hoc c hai.
Knh ring l knh PhCH dnh ring cho mt UE cn knh chung c chia
s gia ccUE trong mt .
Knh truyn ti (TrCH). Knh do lp vt l cung cp cho lp 2 truyn sliu. Cc knh TrCH c sp xp ln cc PhCH
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Knh Logic (LoCH). Knh c lp con MAC ca lp 2 cung cp cho lpcaohn. Knh LoCH c xc nh bi kiu thng tin m n truyn.
3.5.1. Cc knh logic, LoCH
Ni chung cc knh logic (LoCH: Logical Channel) c chia thnh hai
nhm: cc knh iu khin (CCH: Control Channel) truyn thng tin iu
khin v cc knh lu lng (TCH: Traffic Channel) truyn thng tin ca
ngi s dng. Cc knh logic v ng dng ca chng c tng kttrong bng
3.2.
Bng 3.2. Danh sch cc knh logic
Nhm knh Knh logic ng dng
BCCH (Broadcast Control
Channel: Knh iu khin
qung b)
Knh ng xung pht qung
b thng tin h thngCCH
(Control
Channel:
Knh iu
khin)PCCH (Paging Control
Channel: Knh iu khin
tm gi)
Knh ng xung pht qung
b thng tin tm gi
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CCCH (Common Control
Channel: Knh iu khin
chung)
Knh hai chiu pht thng tin
iu khin gia mng v cc UE.
c s dng khi khng c kt
ni RRC hoc khi truy nhp mt
mi
DCCH (Dedicated Control
Channel: Knh iu khin
ring).
Knh hai chiu im n im
pht thng tin iu khin ring
gia UE v mng. c thit lp
bi thit