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n mn hc Thng tin V tuyn nng cao http://www.ebook.edu.vn -1-

MU

1. L do chn tia) Csl thuyt

Ngy nay cng vi spht trin khng ngng ca khoa hc kthut, ngnh in tvin thng c nhng bc pht trin vt bc. Sn phm ca n rt phong ph v adng tng bc p ng c nhu cu ngy cng cao v thng tin lin lc ca conngi trn cc lnh vc ca i sng x hi. Thng tin di ng l mt trong nhng dchvp ng c nhu cu ngy cng cao ca con ngi, n cho php con ngi lin lcvi nhau mi lc mi ni. Ngay tkhi mi ra i thng tin di ng pht trin rtnhanh cvquy m v cng ngh. Tnh n nay c hng trm triu thu bao trn thgii. Cc dch vthng tin di ng khng chgii hn cho cc khch hng giu c v ccnh doanh nghip, qun l m phcp cho mi i tng trong x hi.S tin bcakhoa hc kthut thc y nn cng nghip vin thng pht trin mnh m tmngin thoi tng t sang mng k thut shon ton. Cc loi hnh dch vngy cng

pht trin vt bc vs lng cng nhvcht lng. Mng in thoi di ng ngycng ng vai tr quan trng trn mng vin thng vtc pht trin thu bao cng nhdoanh thu trn ton mng. Trong khi vn cn cha c csvng chc khng nh tnhu vit ca cng nghWiMAX th hin ti hthng thng tin di ng CDMA vn l mt

tim nng ln vmt kinh t. Hthng di ng CDMA c nhng c im nh:- Mng CDMA c cc u im:

+ Sdng kthut tri phnn tnh bo mt cao.+ Dung lng hthng ln do cc MS (mobile station) phn bit nhau bngcc m PN (pin code).

+ Chng Fading a dng tt.+ Chuyn giao mm.+ Cht lng thoi tt hn.+ p ng c cc dch vtruyn dliu, video.+ Cn t trm thu pht gc BTS hn so vi GSM.+ iu khin cng sut.

- Nhc im:+ ng bchui PN phc tp.+ Bng thng yu cu ln.

b) Csthc tinNgy nay mng GSM vi nhng u im ni bt nh: dung lng ln, cht lng

kt ni tt, tnh bo mt cao , c mt chng vng chc trn th trng Vin


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thng th gii. Vit Nam, khi chng ta bt u c nhng my in thoi di ng sdng cng nghGSM 900 u tin vo nhng nm 1993 nh du mt bc pht trinvt bc vcng nghVin thng ca t nc. Cc thu bao di ng ti Vit Nam s

dng dch vthoi truyn thng vi tc bit l 13Kbit/s v truyn sliu vi tc 9,6kbit/s.

Cc nh khai thc GSM trn thgii ang ng trc mt sgii php c cdch v s liu truyn tc cao qua mng thng tin di ng hin c ca h v angnghin cu khoch chuyn i ln cng ngh3G. C hai hng la chn: mt lc th nng cp mng ca h ln thng CDMA (a truy nhp phn chia theo m) haynng cp ln c dch vGPRS (General Packet Radio Service Dch vv tuyn gitng hp), E - GPRS (Enhanced GPRS Dch vGPRS nng cao) v sau th su t,nng cp loi dn cng nghGSM tin ln cng nghW-CDMA (a truy nhp phnknh theo m bng rng).

Mc d cng nghGSM ang p o vslng ngi sdng nhng hthngdi ng CDMA khng ngng c hon thin v p dng rng khp cc nc trn thgii. Hin nay CDMA li tra vt tri hn bi nhng u thcng ngh, CDMA png cc mc tiu cng nghthng tin v truyn thng chnh l cung cp dch vthoi vdliu di ng dung lng cao.

Thng 9/2006, sau khi S-fone hon tt vic nng cp hthng mng, lch sphttrin cng ngh3G ti Vit Nam, ng ngha vi vic Vit Nam chnh thc c tn trn

bn 3G ton cu. Trong bc khi u ny S-fone a ra nhng ng dng mi ngdng cng nghCDMA 1x EV-DO vi tc ln n 2,4 Mbps, in hnh l xem phimv nghe nhc theo yu cu (VOD/MOD) v Mobile Internet.

Cng vi S-fone, VNPT trin khai thnghim cng nghCDMA2000 trong ccmng ni thti thnh phHCh Minh, H Ni, Qung Ninh, HT Mobile cng c don l sem li sc sng mi vi mt mng di ng 3G tin tin sdng cng nghCDMA 1x EV-DO scung cp nhiu ng dng trn nn 3G trong nm 2007.

V cc mng CDMA hin ti trn thgii bao gm:CDMA 1x EV-DO: l mt bc tin trc tip ca tiu chun v tuyn CDMA

2000 3G. CDMA2000 1x EV-DO cho php kt ni v tuyn tc cao ngang vi bngrng hu tuyn. EV-DO ang dn u vic hi tcc phng tin in tc nhn v vtuyn; cho php gi v nhn email vi file nh km ln, chi game tng tc theo thigian thc, nhn v gi hnh nh hay phim video c nt cao, ti ni dung nhc/videohoc kt ni vo cc mng ca vn phng ni hlm vic - tt cu qua in thoi ding.

CDMA2000 1x EV-DO Rev. A c mt qu trnh pht trin mnh m, cho phpcc nh khai thc mrng v pht trin mng li hin nay ca htrong tng lai lu di.


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EV-DO Rev. A kt hp nhng ci tin gip gim thi gian thit lp cuc gi, trkhichuyn pht v cho php kim sot dch vrng hn. EV- DO Rev.A cng em li sgiatng ng ktrong tc truyn dliu so vi EV-DO Rev.0- t tc kt ni ti a

3,1 Mbps v tc kt ni ngc ti a l 1.8 Mbps.CDMA2000 1xEV-DO Rev. B, mt pht trin xa hn Rev. A trn tin trnh

CDMA2000, em li kh nng a knh v cho php cc nh khai thc tng hp nhiuknh 1,25 MHz cng lc v gia tng ng ktc truyn dliu. Ln thc thi Rev. Bu tin scho php tc ti 9,3 Mbps cho kt ni ti v 5,4 Mbps cho kt ni ngc.Mt trong nhng li thchyu ca Rev. B l nh khai thc mng ton quyn kim sotvic phn chia rng bng tn iu chnh cc hthng ca htheo phtn m hcc.

HPDPA/HSUPA HSDPA (High-Speed Downlink Packet Access- Truy nhp gikt ni xung tc cao) l mt bc tin ca WCDMA, c ti u ha cho nhng ngdng dliu chuyn mch trn gi. HSDPA em li nhng bc nng cao y n tngso vi WCDMA cho ng kt ni hng xung - ha hn tc dliu ti a ln ti14.4 Mbps. n cui thng 1-2006, trn thgii c hn 50 mng HSDPA na cln khoch hoc ang trin khai v 9 mng khc thng bo giai on thnghim.

Tip bc HSDPA sl bc tin na trong pht trin cc tiu chun. Ging nhEV-DO Rev.A ci tin rt nhiu cho ng kt ni hng ln ca 1x EV-DO, HSUPA(High-Speed Uplink Packet Access Truy nhp gi kt ni hng ln tc cao) cng

mrng nhng li ch ca HSDPA cho kt ni hng ln. HSUPA st tc ti aln n 5,76 Mbps.

Vi nhng cstrn cho thy ngoi vic nghin cu xy dng hthng v thitktchc mng CDMA th cng on ti u cng c ngha ht sc quan trng. Xut

pht t nhng l do trn ti chn ti TM HIU V BI TON TI U HAMNG THNG TIN DI NG CDMA .

2. Ni dung v bcc nNi dung n gm 3 chng:

Chng 1: Gii thiu tng quan vmng in thoi di ng CDMA.Chng 2:L thuyt chung vbi ton ti u tchc mng thng tin di ngChng 3:Xy dng chng trnh thit kti u.

3. Kt lunTrc tnh hnh pht trin v ln mnh ca hthng thng tin di ng CDMA nh

hin nay th vic tm hiu v cc qui trnh thit kmng ny l thc s cn thit. Tuynhin do thi gian c hn, kin thc tch ly cha nhiu v thiu iu kin tham quanthc tnn n cha ththc hin c phn phn tch so snh nh gi gia m hnhl thuyt v m hnh thc tbi ton ti u c hon chnh.


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Chng 1: Tng quan vmng in thoi di ng CDMA


Chng 1

TNG QUAN VMNG IN THOI DI NG CDMA

1.1 Gii thiu chungThng tin tri phtlu c sdng trong nhng hthng qun i . c tnh

khc bit ca thng tin tri phl bng thng truyn cao hn ng kso vi i hi bitc thng tin, dn ti vic xut hin thut ng" tri ra ". in hnh, mt m gingunhin c sdng tri tn hiu thng tin ti di thng tn sc cp pht.

Nhng h thng a truy xut thit k cho thng tin di ng theo truyn thng trin khai kthut a truy xut phn chia theo thi gian (TDMA) v a truy xut phnchia theo tn s (FDMA). Trong FDMA, phc cp pht c chia thnh nhng khetn s, cn trong TDMA khung truyn trn min thi gian c chia ra nh k thnhnhng khe thi gian. Do vy mi user truy xut khe ca mnh trong min thi gian hocmin tn sv v thh tng ng trc giao vi nhau trong min thi gian hay tn s.Qualcomm Inc l mt trong nhng nh tin phong nghsdng a truy xut phn chiatheo m (CDMA) cho thng tin di ng cho dn thng, m thc t dn ti tiu chunIS-95 Bc M.

Hnh 1.1 Cc hthng a truy xut

CDMA l kthut a truy xut cho php nhiu user ng thi truyn thng tin clp trong cng bng tn ging nhau. Mi user c n nh mt m gingu nhin trc

giao vi m ca tt cuser khc hoc l m shu nhng thuc tnh tng quan cho gim ti a nhiu a truy xut (MAI). M ny c thm vo tn hiu thng tin, lm chotn hiu trthnh nhtn hiu nhiu i vi tt ccc user khc. Chc ngi nhn mic cp cng mt m v sdng n tch tn hiu thng tin. iu ny cho php chiasphging nhau bi nhiu user m khng gy ra nhiu MAI. N cng bo m bn tinring, t duy nht user dkin mi c khnng " gii m " tn hiu. M ny cngc bit nhl m tri ph, bi v n tri rng di thng ca tn hiu d liu gc votrong mt di thng rng hn nhiu trc khi truyn i. Bi vy l thut nga truy xuttri ph(SSMA) cng c sdng thay th thut ngCDMA.


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1.2 Qu trnh pht trin v xu hng 4G

1.2.1 Qu trnh pht trin

Hnh 1.2 Schuyn tcng ngh2G sang 3G

ng dng ca cng nghCDMA c gii thiu trong nhng hthng tong trongu nhng nm 1990 vi spht trin v thng mi ho ca tiu chun IS-95. Kt,cng nghny c trin khai rng ri trn cthgii, t n con s180 triu thu baocui nhng nm 2003. Bi v tnh thng mi ha ca n, cng nghCDMA pht trin

tIS-95 thnh CDMA2000 v cng vi n l smrng vdung lng thoi, tc dliu v nhng thnh tmng.IS-95 v phin bn PCS ca n J-STD-008 xut hin vo khong 1994 nhl nhng

tiu chun TIA, a ra sgia tng dung lng ng kso vi nhng mng TDMA angtn ti. Sau mt vi nm trin khai CDMA, IS95-B c gii thiu vo nm 1998, baogm nhng mrng sau :

+ Htrcho ng dng dch vdliu gi tc trung bnh, ln ti 64kbps, sdngtp hp nhng knh truyn m ha.

+ Nng cao hot ng chuyn giao mm vi cc mc ngng ng.

+ M rng th tc chuyn giao lin tn thun tin cho vic trin khai mng asng mang.

+ Nng cao truy xut h thng trong nhng vng chuyn giao vi nhng th tcchuyn giao trng thi truy xut.+ Nhng ci thin khc lin quan n cho php nh vvtr v roaming ton cu.


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Hnh 1.3 Khnng tng thch trong qu trnh pht trin cng nghCDMA

Trong sut qu trnh pht trin ca cng ngh ny, mi tiu chun hay phin bnmi c thit kduy tr khnng tng thch y vi nhng hthng trc. IS-95-A/B, m thng gi l IS95A/B, i cng vi mt vi tiu chun bo hiu da trncng nghdi ng tong 2G hay l CDMAone. Mc d n ci thin hot ng vnhiu c tnh, IS95A/B khng c trin khai rng ri nhcc nh iu hnh mongi cho cng nghCDMA thhktip da trn nhng tiu chun cdma2000.

Phin bn mu ca cdma2000 l IS2000 Release 0, lin quan n hthng 1X-

RTT. Mc d phin bn ny khng phi l mt phin bn hon ho, n c pht trin vxy dng gn vo chipset CDMA mi v c cung cp rng ri cho thtrng ton cu.Mt vi c tnh chcht ca cdma2000 c trong Release 0 :

Tng thch vi IS95 B bao gm mrng vchuyn giao trng thi lu thng vtruy xut.

Gii iu chkt hp hng ln vi gim st ngc.

iu khin lung hng ti nhanh. Tri phm Walsh c chiu di bin i.

Tc d liu 150kbps n 300kbps ty thuc vo cu hnh knh truyn vtuyn iu chQPSK chng ln v hng xung M ha knh truyn mrng vi bm ha turbo nhng tc cao. Htrty chn cho phn tptruyn dn. Tng tui thcho thit bu cui di ng vi knh nh smi nhanh hn.Skt hp ca tt csmrng ny cung cp mt dung lng thoi gp i so vi

nhng hthng CDMAone v tc dliu 153.6kbps hoc l 307.2kbps ty thuc vocu hnh v tuyn. Strin khai thng mi ca hthng cdma2000 bt u vo u nm


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2000 ti Hn Quc v sm m rng sang nhng quc gia khc. Mt vi li tranh lunrng 1xRTT khng theo y vi nhng yu cu ca IMT2000 l tc d liu384kbps cho thng thng v 2Mbps cho u cui cnh, n nn c coi l 1 hthng

2.5G.Phin bn CDMA2000 hon thin u tin l Release A, ra i nm 2000, bao gm

bng hp (1X) v bng rng (3X) tng ng vi cc kiu sng mang 1.25 Mhz v 3.75Mhz. Mt vi c tnh chnh ca Release A l :

Tng thch vi CDMAONE v Release 0. Htrbo hiu cho nhng knh chung mi vn c sdng cho truy xut v

truyn dn cm dliu ngn. Bo hiu mrng cho nhng dch vng thi.Nhng nh dng frame v tc mm do.

Sthng lng QoS. Thut ton m ha mrng.Khng lu sau Release A, Release B ca IS2000 c ra i vi mt vi sci thin

vgiao thc bo hiu nhChuyn giao mm phi hp m knh, Bo co thi gian trngCDMA, v nng cao lu lng ti truyn Idle.

Theo strin khai rng ri ca Release 0, v mc d c sci thin ng ktrongtiu chun, Release A v B khng lm thc y cc nh iu hnh nng cp mng ca h.Bi v Release 0 cung cp cho nh iu hnh dung lng thoi v bi v phng

tin trong vic yu cu dliu tc cao btr hon bi nhiu yu tkhc nhau, nhngsnng cp ng gi cho nhng phin bn mi skhng thc thanh minh.

Trong lc y, mt vi nh iu hnh mun gii thiu nhng dch vdliu tc cao i hi tc dliu hng xung cao hn nhiu so vi 150kbps c cung cp bicdma2000. Thc y bi nhu cu ny, 3GPP2 nghin cu nhng chi tit cthca cngnghtc dliu cao HDR, pht trin bi Qualcomm Inc., ci tin hn v cho ra inhl mt tiu chun mi gi l Dliu gi tc cao HRPD trong cui nm 2000. Tiuchun ny l IS856 hay l 1xEV-DO.

1xEV-DO c thit kcung cp nhng dch vHRPD c hiu qum khng

bt buc phi htrchuyn mch knh trong IS-95. Cng nghHRPD t c hiu sutph rt cao trn ng xung bng cch s dng iu ch mc cao, thch ng tc nhanh, v lp trnh trn mt knh d liu n tc cao m c ghp knh theo thigian gia nhng user ang hot ng. Tuy nhin hng ln ca HRPD th rt ging vihthng 1xRTT vtc dliu thp hn v trln hn nhiu so vi hng xung.

Mt trong nhng trngi chnh ca IS856 cho nhng nh iu hnh l n chcungcp nhng dch v d liu gi trn nn tng best-effort v khng cung cp nhng ngdng i hi QoS nghim ngt nhl thoi. Mi quan tm ny thc y 3GPP2 tip tc

a ra mt phin bn mi ca cdma2000 vi mc ch c th l thm vo mt kiu d


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liu tc cao. Mc tiu l t n hot ng ca HRPD m khng nh hng ti khunkhca stng thch vi nhng mng ang tn ti cho nhng dch vthoi v dliutc thp. Kt quc gi l hthng 1xEV-DV, ra i vi tcch l Release C ca

IS2000, nm 2002. Mt vi c tnh chnh ca Release C nhsau : Sgii thiu ca mt kiu knh dliu gi hng ti v nhng giao thc thch hp Khung ngn (1.25-5 ms) v lp trnh nhanh tn dng phn tp nhiu user. Cp pht ng v cng sut v ti nguyn m Walsh gia knh d liu gi v

knh thoi/dliu tc thp. Thip lp cuc gi nhanh v qu trnh nhn thc mrng Thng lng dliu hng ti c thso snh vi 1xEV-DO.C thcho rng Release C nh l skt hp ca nhng phin bn trc v nhng

khi nim sdng trong 1xEV-DO vi mt vi spht trin thm.

Vi mt vi nh iu hnh smt cn bng thng lng gia hng ti v hngngc v hot ng trl c thchp nhn c. Tuy nhin, vi mt vi ng dng yucu trthp hn nhgame, message tc thi, v thoi qua IP (VoIP), QoS c i hic thkhng c cung cp vi 1xEV-DO hay l Release C ca IS2000 trphi vi cithin ng ln c thc hin.

3GPP2 do bt u tip tc mrng ng ln cho IS2000 nhl mt phn caRelease D v song song l mt n lc c th gy tranh lun trn Release A caHRPD/IS856. Nhng smrng c a ra khin cho IS2000 v IS856 rt ging nhau

vmt bn cht v smang li s tng cng hot ng cho ng ln. Release D caIS2000 ra i vo thng 3 nm 2004 bi 3GPP2 v bao gm nhng c tnh sau y :

Mt knh dliu gi hng ngc mi tc cao v nhng giao thc thch hp. Thch ng lin kt vi sci thin ARQ lai tp v chn la. Khung truyn ngn hn v trthp hn cho knh dliu gi. Mt a chMAC vi nhiu tuchn iu khin tc ng ln v kim sot QoS. Htrdliu tc ln ti 1.8Mbps. Duy tr khnng tng thch vi CDMAone v nhng phin bn trc ca IS2000. Thng lng ng ln hn 600kbps.

Trong lc y, nhng yu t tng t cng c thm vo cho hng v ca1xEV-DO vi tcch l mt phn ca tiu chun IS856 Release A nhng trong mt thitkm tng thch vi IS856 gc. Kt qul thng lng, trv kim sot QoS caHRPD c gia tng cth, cung cp mt thit kcn bng hn nhiu gia hng lnv hng xung.

1.2.2 Xu hng 4G

Ngy nay cng nghmng ng mt vai tr quan trng trong khoa hc v thngmi. Khoa hc cch tn v pht trin nhng cng nghmi ph hp vi nhu cu


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ca thng mi v tha mn i hi ca khch hng. V vy mt chnng v angc bn lun hin nay l con ng pht trin t3G sang 4G v hn thna (5G).tm hiu vvn ny, trc ht chng ta cn hiu ngn gn 3G l g ? 3G l thh

thba ca mng v tuyn bao gm mt vi c im sau y : mrng roaming, nhngdch vdliu bng rng vi video v multimedia, cht lng thoi c tng cng, tcln n 2Mbps. Ni mt cch khc 3G l mt tiu chun, c sng chung vinhng c tnh, c pht trin v cch tn bi nhng nh nghin cu v pht trin.Trong nm 2005, 3G sn sng pht trin cng vi mng (WCDMA, WLAN) vvng sdng thit bdi ng (cell phone v GPS). Cu hi c t ra l 3G cha phttrin hon ton, ti sao mi ngi li bt u tho lun v4G v thm ch l 5G, c phi4G l spht trin hay l cuc cch mng ca 3G? ng Mikko A. Uusitalo, chtch v lngi ng u Nokia Reseach Center, chra rng 4G l mt mc tiu nghin cu cho

mng v tuyn tbo khu vc rng thhktip, trong c 1G, 2G, 3G v 4G vhn thna 5G l mtsni tip hin nhincho iu ?

Tnhng im ni trn, chng ta c thhiu r rng 4G thc ra l cha tn ti. Nichung, 4G l spht trin khng chl gii quyt nhng gii hn v vn ca 3G, mn cn mrng vcht lng dch v, gia tng bng thng v gim gi thnh ti nguyn.

Tm li, chng ta c thtm tt qu trnh pht trin ca mng thng tin di ng cngvi spht trin vtc mt cch ngn gn sau y. Thhthnht, 1G, l tng tvi tc ln ti 2.4kbps c gii thiu trong u nhng nm 1980 v hon thin vo

cui nhng nm 1990. Thhth2, hthng 2G, c xut vo cui nhng nm 1980v hon thnh vo cui nhng nm 1990, l tn hiu s cho thoi v tc ln n64kbps. Thhth3, hthng v tuyn 3G, c cung cp tc truyn dn t125kbpsti 2Mbps, c pht trin cui nm nhng 1990 gn nhl hon thin vo cui nhngnm 2000. Thhth4, 4G, th vn cha tn ti. Vcbn, 4G l spht trin giiquyt nhng gii hn v vn ca 3G; ngoi ra cn cung cp tc theo l thuyt lnti 1Gbps.


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Hnh 1.4 Xu hng 4G.

1.3 M hnh hthng CDMA

C rt nhiu cc phng php a truy nhp nh: FDMA : a truy nhp phn chia theo tn s, phc vcc cuc gi theo cc

knh tn skhc nhau TDMA : a truy nhp phn chia theo thi gian, phc vcc cuc gi theo

cc khe thi gian khc nhau

CDMA : a truy nhp phn chia theo m, phc vcc cuc gi theo ccchui m khc nhau

PDMA : a truy nhp phn chia theo cc tnh, phc vcc cuc gi theo sphn cc # ca sng v tuyn

SDMA : a truy nhp phn chia theo khng gian, phc vcuc gi theo ccanten nh hng bp sng hp


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Mi sra i ca mt thhmng di ng u c nhng m hnh ring, thm chtrong cng mt thhth nhng sci tin cho nhng mng di ng sdng cng ngh

CDMA u a ra nhng tiu chun mi v tt hn. Do , sxut hin nhng m hnhmng i lin vi nhng tiu chun .1.3.1 Bng tn ca hthng v quy hoch sdng Vit Nam

Mi hthng thng tin di ng c cp pht 1 hoc nhiu bng tn xc nh.


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CDMA c xy dng l thuyt tkhong 1950 v c p dng trong qun st1960, c thng mi ho tthp nin 80 v pht trin bi Qualcomm - vi chun IS-95nm 1991. c trin khai Vit Nam t7/2003.

Hthng CDMA c nhng u im cbn sau

Dung lng hthng gp 8-10 ln so vi AMPS v 4-5 ln so vi GSM (TDMA) Cht lng cuc gi c nng cao c tnh phsng c ci thin,kh nng phsng

Tng thi gian m thoi cho my u cui Di thng c cung cp tutheo yu cu sdngNng cp mng ddngHthng CDMA cung cp chc nng iu khin cng sut 2 chiu (tBS ->MS

v ngc li). C 2 cu hnh iu khin cng sut thch ng:

iu khin cng sut vng h:Trm gc BTS pht tn hiu pilot trong knh Pilot thuc knh hng xung, MS so cng Pilot thu c nh gi c suy hao ng truyn v do MS siukhin cng sut pht ca mnh mc cn thit

iu khin cng sut vng kn :Trm gc gim st cng sut tn hiu v tuyn nhn c tMS, tnh ton, pht

bn tin iu khin mc cng sut ca MS. Cn cvo cng Pilot thu c v siukhin cng sut ca trm gc, MS siu khin cng sut thch ng to ra mc cng sut

pht mt cch chnh xc.


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Ni dung ca n mn hc chi vo cp m hnh mng CDMA2000 ca thhth3 v m hnh mng thng tin di ng ALL IP ca thhth4.

1.3.2 Cu hnh tchc hthng mng thng tin di ng CDMA2000

Mng thng tin di ng cng cng sdng CDMA c thng mi ho honton vo nm 1990 v c phbin rng ri do sgia tng to ln vslng thu

bao. T tri, hthng CDMA da trn IS-95 c pht trin theo nhng tiu chunca IS-2000, v hot ng cu hnh nn mng thh3(3G), khi nhng tiu chun vnhng gii thiu v IP v truyn dn gi tc cao c thit lp. Trong nm 2000,mng sdng CDMA2000 c cu hnh ti Hn Quc. Mng ny c stng thch chomng IS-95, v c mong i pht trin ln thnh 1X-EV DO/DV trong tng lai. Nsc chp nhn nhl mt dch vng thi ca IMT-2000, v c thc sdng

nhl mt thnh tmng v tuyn trong 4G hay l mng ALL IP.Hthng CDMA 1X c cung cp bi LGE hin ti htrtruyn gi 144kbps v

mng li gi cung cp chc nng IP n gin. Bn cnh , thnh tWIN (WirelessIntelligent Network) v nhng n vbsung thm cung cp dch vc a ra timng li. Thm vo , vic qun l mng c cu hnh cho vic vn hnh v qun ltnh trng ca hu ht cc thnh phn mng.

Mng thng tin di ng c chia ra lm 3 phn : PCN(Packet Core Network),RAN(Radio Acess Network), CCN(Circuit Core Network) v dch vdliu gi. Mngli chuyn mch knh CCN bao gm MSC cho tng i hthng, HLR cho dch vthu

bao di ng, AuC cho vic m ho nhn thc, SMSC/VMS/FMS cho dch v trn tinnhn ngn, thoi, fax v th, IWF cho dch vdliu chuyn mch knh, v cn na.


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Hnh 1.5 Mng CDMA2000 1x

Mng truy nhp v tuyn (RAN) c cu hnh vi BTS cho kt ni cuc gi v

tuyn ca nhng thu bao di ng v BSC iu khin BTS. Mng li chuyn mch gi(PCN) c cu hnh vi PDSN, bmodem cho truy nhp mng gi, AAA cho vic nhnthc v tnh cc ca mng gi, HA cho chc nng IP di ng, v router cho truy nhpmng internet ngoi.

1.3.2a Mng li chuyn mch knh CCN (Circuit Core Network)CCN l mng cung cp dch vthoi ang tn ti v giao tip vi cc mng nh

PSTN, PLMN v ISDN. Thm vo , n c cu hnh cung cp nhng dch vbsung v dch vmng cho thu bao di ng.


15/58



Hnh 1.6 Mng li chuyn mch knhMSC

MSC (Mobile Switching Center), l trung tm ca mng thng tin di ng, cung cpchc nng interworking gia nhng mng nhmng thng tin di ng, PSTN v ISDN,hoc l gia nhng nh cung cp dch v mng khc nh l mng thng tin di ng,PLMN, mng internet v PSDN.

Thm vo , MSC trao i thng tin vi HLR (Home Location Register) v VLR(Visitor Location Register) nhm lu trthng tin ca thu bao thc hin chc nng

tng i, v giao tip vi BSC truyn v nhn tn hiu v dliu thoi vi MS.MSC l mt h thng tch hp v ng dng hiu qu, da trn nhng tiu chun

thng tin di ng quc t. MSC ddng mrng v iu chnh hthng, thng qua cutrc mcung cp tnh mm do v tnh module ddng mrng hthng theo sphttrin ca cng ngh, v c cu hnh bng cch xt n PSTN, ISDN, dch vgi, cngnhl dch vmng thng minh.VLR

VLR (Visitor Location Register) lu trv qun l thng tin tm thi tt ccc MSang c mt trong vng qun l ca n. V khi mt thu bao di ng thc hin cuc gi,

VLR chuyn thng tin lin quan ca thu bao n MSC tutheo yu cu ca MSC.Dliu lin quan VLR lun lun c duy tr ging vi HLR.HLR

HLR (Home Location Register) l hthng qun l dliu lu trv qun l thngs v thng tin nh v ca tt c MS c ng k trong khu vc ring ca n. HLRnhng thng tin quan trng nhdung lng truy xut ca MS, dch vcbn, dch vbsung, v thc hin chc nng nh tuyn ca thu bao u cui. Thm vo , HLR cungcp dch vca mng thng minh v tuyn thhsau bng cch cung cp nhng thnh


16/58



phn mng ca WIN vi dliu lin quan ca thu bao vo thi gian ca dch vthngminh.

AuC

AuC (Authentication Center) l mt hthng m thc hin qu trnh nhn thc cathu bao, v n lin kt vi mng thng tin di ng qua HLR.SMSC

SMSC (Short Message Service Center) l mt h thng thc hin dch v bn tinngn, v n lin kt vi mng thng tin di ng qua MSC v HLR.VMS

VMS (Voice Mailing System) l mt hthng thc hin dch vhp ththoi, v nlin kt bi MSC, PRI v NO.7.IWF

IWF (Interworking Function) l mt h thng cung cp d liu chuyn mch knhbng cch lin kt vi MSC.WIN/PPS

SCP (Service Control Point) iu khin dch vWIN v cung cp thng tin c yucu tSSP (MSC) bng cch qun l thng tin trn nhng thu bao dch vWIN. Hin tiSCP cha ra ti Vit Nam dch vPPS. Mt khc, SSP (Switching Service Point) caMSC nhn ra nhng cuc gi dch vthng minh cung cp SCP thng tin trn dch vc yu cu bi mt thu bao, v thc hin nh tuyn theo bn tin SCP.

IP (Intelligent Peripheral) thc hin mt dch vbsung ca mng thng minh bngcch sdng thoi hay l vn bn cho nhng thu bao ngi dng ca mng thng minh.1.3.2.b Mng li chuyn mch gi

PCN (Packet Core Network) l mt thnh phn mng cung cp dch v gi bngcch lin kt vi PSPDN v mng internet. V nhng tiu chun truy xut lin mng theonhng tiu chun ca IETF hin ang sdng ti nhng mng hin hnh.

Hnh 1.7 Mng li chuyn mch gi


17/58



PDSN (&FA)PDSN (Packet Data Serving Network) hay l FA (Foreign Agent) cung cp chc

nng modem gi cho giao tip vi mng internet, v cung cp chuyn mch cho nhng

cuc gi dliu gi v thng tin lin quan tnh cc gi.AAA

AAA (Authentication, Authorization, Accounting) cung cp chc nng ca vicnhn thc, scho php, v tnh cc cho vic truy xut mng cuc gi gi.HA

HA (Home Agent) l mt thnh phn mng cung cp thu bao gi vi chc nng IPdi ng, v n cng l mt thnh tmng thm vo bo m tnh lu ng ca nhngthu bao m u c mi FA (Foreign Agent).Router, DHCP, DNS, FW

Hthng cp trn, l mt thnh phn cu hnh nn mng dliu, cung cpkt ni lin hthng v mt ng dn trong vic hthng truyn dliu gi, cng nhl kt ni n Internet. Thm vo , n ngn nga mng bn ngoi bng cch ngn nga(FW : Fire Wall), v chuyn tn min thnh a chIP (DNS : Domain Name Server), vn nh a chIP (DHCP). Bn cnh , nhng thnh phn cho cu hnh mng khc cthc thm vo.1.3.2.c Mng truy nhp v tuyn

RAN (Radio Acess Network) c cu hnh vi nhng thnh tmng cung cp

tn hiu v nhng cuc gi v tuyn, vn l nhng yu tca dch vmng thng tin ding, v n cng cung cp PCN (Packet Core Network).

Hnh 1.8 Mng truy nhp v tuyn


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BSCBSC (Base Station Controller) giao tip vi nhiu BTS, thc hin chc nng xl

chuyn giao lin cell, iu khin cuc gi, iu khin vic bo dng v vn hnh BTS.

BSC giao tip vi MSC bng bo hiu s7.BTS

Mt vng nh hng bi nng lng ca BTS (Base Station Transceiver System)

c gi l mt cell. BTS l mt h thng m thng tin v tuyn vi MS trong cell cung cp nhng thu bao nhng dch vthng tin di ng.

lm c nhvy, BTS thc hin m ho v gii m knh truyn v tuyn thupht tn hiu vi MS. Thm vo , cung cp nhng cuc gi v tuyn cht lng tthn nhiu tin ch hn, n thc hin chc nng iu khin tc tn hiu thu pht, olng cht lng up-link, tnh a dng khng gian, qun l ti nguyn v tuyn v bo

dng chnh n.PCF

PCF (Packet Control Function) tn ti trong BSC ni, v n l mt thnh phn thmvo ca mng 1x RTT. PCF cung cp tn hiu v tuyn v d liu gi bng ng dnPCN.

1.3.3 M hnh mng 4GThc thin nay cha c ni no trin khai hthng thng tin di ng thhtht

(4G) cho nn mt m hnh c thcho 4G vn cha c xy dng. Hnh 1.9 biu din

mt cu trc trong cc kt ni lin mch nhau trong m hnh chung ca hthng 4G.

Hnh 1.9 Cu trc kt ni ca 4G.


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Ni chung, cu trc ca 4G bao gm 3 vng kt ni cbn sau: PANs (nh lBluetooth), WLANs ( tiu chun IEEE 802.11), v kt ni ca cc mng tbo. Di mhnh ny, 4G scung cp mt phm vi rng ln ca nhng thit bdi ng htrroaming

ton cu. Mi thit bsc khnng kt ni thng tin Internet m c thc iu chnhcho mng ang sdng thit b ti cng thi im.

Trong hthng di ng 4G, mi in thoi sc mt a chIP home thng trc,i cng vi mt a chcare-of cho bit c vtr tht s. Khi mt my vi tnh bt ku cn lin lc vi my di ng, u tin n gi mt gi n a chhome ca my.Mt server danh mc chuyn tip gi tin ny n a chcare-of thng qua knh, nhtrong IP di ng thng thng. Tuy nhin, server danh mc ny cng gi mt bn tin nmy vi tnh thng tin cho n bit a chcare-of chnh xc, trong tng lai gi c thc gi trc tip. Bi v rt nhiu a chv nhiu lp mng con, cho nn IPv6 c i

hi cho tnh linh ng ny. Mc tiu ca 4G l thay thsgia tng nhanh chng canhng mng li di ng bng chmt tiu chun mng li khp ton cu, da trn IPv6cho vic iu khin, video, d liu gi, v thoi. iu ny s cung cp nhng dch vvideo, thoi v dliu ng nht n my di dng, hon ton da vo IPv6. Mc ch lcung cp nhng dch va truyn thng khng dy n user khi truy xut vo mt cutrc ton IP thng qua nhng cng ngh truy xut khng ng nht. IPv6 c v nhcht keo dnh cho vic cung cp tnh kt ni v tnh di ng ton cu gia cc mng. Huht nhng cng ty v tuyn u ang chi IPv6, bi v chng c khnng gii thiu

c nhng dch vmi.Nhbiu din trong hnh 1.10 di, ta c th thy nhiu cng nghc sdng

trong cu trc mng 4G. Hin nay c 3 con ng i ln 4G. Thnht, l pht trin ththng 3G sn c, khi 3G pht trin n mt mc no th nht thit phi c nhngyu cu vgia tng tc cng nhdung lng v chnh l cs4G ra i. Conng thhai l tmng LAN v tuyn, v hin nay Wifi v Wimax ang c trinkhai rng khp cho cc thit bu cui nhPC, laptop, v PDA. Cui cng con ngth3 l nhng tiu chun IEEE 802.16e v 802.20 vn n gin hn 3G vi hiu suttng ng. Cng vi spht trin vcng ngh, nhng dch vtrong cu trc 4G cng

ht sc a dng.Tm li, c thnh ngha mt cch vn tt vhthng 4G strin khai trong tng

li nhsau : n l mt hthng tch hp ca cc hthng, mng tch hp ca cc mnghon ton da trn IP; t c nhshi tca mng v tuyn v hu tuyn v mt vishi tkhc, m c khnng cung cp tc ln ti 100Mbps hay thm ch l 1Gbps,tng ng vi mi trng trong nh hay bn ngoi; vi QoS end-to-end v tnh bo mtcao, cung cp bt cdch vno ti bt c thi im m ngi dng yu cu, d liuthng sut, gi cphi chng, tnh cc mt ln v hon ton ring t.


20/58

Chng 2: L thuyt chung vbi ton ti u tchc mng thng tin di ng


Chng II

L THUYT CHUNG VBI TON TI U TCHC MNG

THNG TIN DI NG

2.1. Tng quan vti u v qui trnh

2.1.1.

Tng quan vti u

Ti u RF- l qu trnh cn thit khi thit kmt mng khng dy, a ra mtmc thc hin xc nh trc v duy tr mc ny khi hthng hon thin .

Ti u RF t c 3 iu sau: Thc hin ci thin cuc gi

iu khin chuyn giao Qun l khnng dung lng hiu qu

2.1.2. Cc bc thc hin ti u

C 3 bc trong hot ng ti u:+ Trc khi a vo khai thc: vic ti u mt mng trc khi a vo khai thc

tp trung vo cc yu tsau:- Thc hin mt hthng hay kim tra nhm datafill v lm mt cuc thnghim

cui cng (cluster datafill audit and shakedown)- Vng phsng RF v iu khin chuyn giao- a ra danh sch cc ln cn (neighbor lists) ban u- Gim ti thiu cc cuc gi brt- Tng khnng truy nhp- Xc nh vic thit lp ca stm kim- Tng tc hon thnh chuyn giao cng+ Sau khi a vo hot ng: vic ti u tp trung vo cc vn sau:-Vng phsng RF v iu khin chuyn giao

-

Gim cuc gi brt-

Tng vic hon thnh truy nhp-Gim st sgia tng dung lng v lu lng+ Trong sut qu trnh pht trin v hon thin: vic ti u tp trung vo cc

vn sau:-

Thc hin hp nht cc site mi vo mng hin ti-

Vng phsng RF v iu khin chuyn giao-Gim st sgia tng dung lng v lu lng-Gim ti thiu cc cuc gi brt


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-Ti a vic truy nhp thnh cng-Ti a ha chuyn giao cng thnh cng

2.1.3. Thtc ti u

Cc tiu chun ban u l tp hp cc iu kin phi p ng trc khi thc hinvic ti u:

- Tt ccc BTS phi c lp t v c xc nh kch cph hp- Phtn hiu thu cn phn bit rch ri vi can nhiu gim n -110dBm cho h

thng 800MHz (-111dBm cho cc hthng 1900MHz)- Tt ccc sector cn sn sng hot ng, c khnng thit lp cc cuc gi, v

thc hin chuyn giao- Ton bnhn vin u sn sng thay i cc tham s, thc hin ghi li SBS

(SBS logging) cho php hay khng cho php OCNS, v tng hay gim cc sector.- Sn sng thc hin nng cp csdliu site trong cng cdon.- Tt cphng tin kim tra, cc cng c, cc bn v.v phi sn sng thc

hin: kim tra thit bcn c lp t v kim tra.- Qui hoch offset PN cn c thit lp v c a vo datafill- Danh sch ln cn ban u c khi to v a vo datafill.- a ra cc tiu chun c nh ngha.Trc khi a vo khai thc ( qua bc thnht- ONCS bv hiu ha):- Thc hin kim tra datafill v lm mt cuc th nghim cui cng (cluster

datafill audit and shakedown)- Thc hin vn hnh nhm sdng 2 pht cuc gi Markov (2min.Markov calls)- Ti u SRCH_WIN_A v cc ca sgii iu chBTS- Ti u SRCH_WIN_N/R- Thc hin phn tch vng phsng RF- Thc hin phn tch cuc gi brt v vic truy nhp khng thc hin c- Thc hin iu chnh danh sch cc ln cn- To ra iu chnh biu li truyn trn mt site

- To ra nhng thay i cn thit tm hiu mng trong sut qu trnh phn tch.- Thc hin li cc bc trn cho ti khi t c kt qumong mun.Trc khi a vo khai thc ( qua bc thhai- cho php ONCS ):- Thc hin kim tra nhm sdng 2 pht cuc gi Markov (2min.Markov calls)- Thc hin li cc biu phn tch vng phsng RF- Thc hin phn tch cc cuc gi brt- Thc hin phn tch vic truy nhp khng thc hin c- Xc nh ssector trung bnh trn mt user- Thc hin phn tch chi tit cc vng c bit hay vng cho trong mng


22/58



- To ra nhng thay i cn thit tm hiu mng trong sut qu trnh phn tch.- Thc hin li cc bc trn cho ti khi t c kt qumong mun.Sau khi a vo khai thc:

- Sdng cc php o hot ng MTX (OMs - Operational Measurements) v ghili dliu thc hin BTS ( Performance Data) c lp cc vng vn .

- Cho php ghi li SBS v iu kin ca RTD, sp xp vic iu chnh danh schln cn v dliu quan trng.

- Sdng vic ghi li SBS khng iu kin v chun on BTS- Nu cc chi tit v my di ng u kh nghi, phi thc hin ti u y

logmask cho cc my di ng ny- Sdng vic tin hnh kim tra nhmt phng thc cui cng xc nh mt

vng c vn

- Sdng vic tin hnh kim tra hon thnh hp nht cc site mi.Tiu chun a ra c th:- t c mc tiu tc cc cuc gi khng brt- t c mc tiu tc truy nhp thnh cng- Hon thnh phsng RF trn mt vng a l theo l thuyt- Hon thnh mc tiu gi trdung lng

2.2.

Gim st knh

2.2.1. Lin kt hng xung

C nhiu nguyn nhn v sao my di ng b rt cuc gi. Trn lin kt hngxung, my di ng gim st mi khung knh lu lng nhn c trong khi ang trongtrng thi knh lu lng. Vi mi khung knh lu lng, my di ng skim tra khungch thcht lng knh (CRC). Nu khung ch thcht lng knh ca mt knh hng,hay nu my di ng khng thbit tc d liu ca khung, khi my di ng chorng khung nhn c l khung hng. Ngc li th khung nhn c l mt khungtt.

trng thi knh lu lng, my di ng gim st thng xuyn tt ccc khung

knh lu lng nhn c. Nu my di ng nhn 12 khung hng lin tip (chng hn2mN khng i c nh ngha trong IS-95A), khi n phi tt hot ng ca bpht

ca n.Tuy nhin, nu ngay sau 12 khung hng lin tip nhn c, my di ng nhn 2

khung tt lin tip (chng hn 3mN khng i c nh ngha trong IS-95A), khi my

di ng c thmli bpht ca n. Nu khng my di ng slm mt knh lu lngv mt cuc gi brt.


23/58



Thm vo , my di ng gimt bnh thi gim (fade timer) cho knh lulng hng xung. Bnh thi c bt u hot ng khi my di ng mbphtca n trong khi ang trng thi phkhi u ca trng thi knh lu lng; bnh

thi gim thit lp 5 giy (chng hn 5mT khng i c nh ngha trong IS-95A ) vsau m li. Bnh thi ny sthit lp li 5 giy mi khi my di ng nhn 2 khung

tt lin tip ( 3mN khng i c nh ngha trong IS-95A ). Nu bnh thi kt thc,

khi my di ng phi tt bpht ca n v cng bmt mt knh lu lng hngxung.

Hn na, khi my di ng truyn bn tin yu cu mt phc p (ACK), n i 0,4

giy (chng hn 1mT khng i c nh ngha trong IS-95A ). Nu n khng nhn c

mt phc p trong khong thi gian , my di ng struyn li bn tin v i 0,4 giy

na. My di ng c 3 ln cgng thtruyn li bn tin yu cu mt phc p ( chnghn 1mN khng i c nh ngha trong IS-95A ). Nu my di ng khng nhn c

mt phc p 0,4 giy sau ln truyn th3, my di ng cng bmt phc p khngthc hin c.

2.2.2. Lin kt hng ln

Gim st knh tng tcng xut hin trn lin kt hng ln. Tuy nhin, chunIS-95 khng nh r tiu chun no sdng trnh by suy hao ca knh lu lng haymt skhng thc hin c phc p.

2.3. Cc tham siu khin cng sut

Trong tiu chun IS-95 nh r th tc iu khin cng sut trn lin kt hngxung. My di ng bo co n trm gc iu kin ca lin kt hng xung. C hai chbo co: nh kv gii hn. Trong chbo co nh k, my di ng bo co likhung thng k ti nhng thi gian n u n; trong chbo co gii hn, my ding chbo co khi li khung tm thy ti gii hn c xc nh trc.

C 5 tham siu khin cng sut lin kt hng xung c gi n my di ng

trong cc bn tin overhead: PWR_THRESH_ENABLE- chthchbo co gii hn; PWR_REP_THRESH-gii hn bo co iu khin cng sut; PWR_PERIOD_ENABLE-chthchbo co nh k; PWR_REP_FRAMES-m khung bo co iu khin cng sut; PWR_REP_DELAY-trbo co cng sut.

My di ng sdng bm TOT_FRAMES v BAD_FRAMES ca n theodi tng skhung v skhung hng nhn c. Mi khi my di ng nhn mt khung,


24/58



n tng bm TOT_FRAMES ln mt. Mi khi my di ng nhn mt khung hng, ntng bm BAD_FRAMES ln mt.

Nu PWR_THRESH_ENABLE = 1, khi vic bo co ngng c cho php.

Khi gp iu kin BAD_FRAMES = PWR_REP_THRESH, my di ng bo co khungli thng k bi vic gi PMRM n trm gc . Sau khi gi PMRM, my di ng khing li BAD_FRAMES v TOT_FRAMES v0 v skhng tng BAD_FRAMES vTOT_FRAMES trong mt chu k(PWR_REP_DELAY x 4) khung.

Nu PWR_PERIOD_ENABLE = 1, khi vic bo co nh kc cho php.

Khi gp iu kin TOT_FRAMES = ( WR_REP_FRAME/2)2 5P , my di ng bo co li

khung thng k bng vic gi PMRM n trm gc. Sau khi gi PMRM, my di ngkhi ng li TOT_FRAMES (v BAD_FRAMES ) v 0 v s khng tng

TOT_FRAMES v BAD_FRAMES trong mt chu k(PWR_REP_DELAY x 4) khung.PMRM c bo co trong hai trng sau:+ ERRORS_DETECTED -s khung li c tm thy. My di ng thit lp

trng ny cn bng vi bm BAD_FRAMES ca n.+ PWR_MEAS_FRAMES skhung knh lu lng hng xung trong chu k

o. My di ng thit lp trng ny cn bng vi bm TOT_FRAMES ca n.Trm gc sdng hai trng ny tnh ton li thng k. My di ng c thto

bo co cc PMRM thng xuyn hn. iu ny c thc hin bng cch iu chnhcc tham siu khin cng sut va c m t. V d, chai chbo co c th

c cho php cng mt lc, hoc PWR_REP_THRESH v PWR_REP_FRAMES c thbgim. Vic cn bng cc yu tny l c nhiu bn tin overhead xut hin trn lin kthng xung do nhiu PMRM.

2.4. Kch thc ca stm kim

My di ng s dng 3 ca s tm kim sau theo di tn hiu hoa tiu nhnc:

SRCH_WIN_A- kch thc ca stm kim cho cc tp hot ng v ng c(active v candidate sets),

SRCH_WIN_N- kch thc ca stm kim cho tp ln cn (neighbor set), SRCH_WIN_R- kch thc ca stm kim cho tp cn li (remaining set).

2.4.1. Ca stm kim SRCH_WIN_A

SRCH_WIN_A l ca stm kim m my di ng sdng theo di hot ngv tp ng c( candidate set) cc hoa tiu. Kch thc ca ca sny cn thit lp theomi trng truyn sng quyt nh trc. Ca sphi ln thu c tt ccc ang c thsdng c ca tn hiu ttrm gc, ng thi ca scng cn nhcc i ha vic thc hin ca btm kim.


25/58



Hnh 2- 1 SRCH_WIN_A c sdng thu c hai ng A v B

Hnh 2.1 m ttnh hnh a ng. Ca stm kim tp trung xung quanh tn hiuc thsdng ti sm nht. ng trc tip (ng A) i 1 km n my di ng, trongkhi a ng thc t(ng B) i 4km trc khi n my di ng. Do mt chip tngng vi khong cch truyn l 244,14m , ng truyn trc tip truyn mt khong cchl:

10004,2

244,14 /

mchip

m chip=

V a ng truyn mt khong cch l:4000

16,4244,14 /

mchip

m chip=

V vy, chnh lch vkhong cch truyn gia hai ng l16,4chip - 4,2chip=12,3chip

Hnh 3.1 cng cho thy ca stm kim (SRCH_WIN_A) ti my di ng. Ch ng trc tip (ng A) n sm nht v v thti trung tm ca stm kim, trong khia ng (ng B) n sau 12,3chip. ca stm kim thu c ng thi hai ng

ny, ca sphi rng t nht ( 2 12,3

) chip, hay 24,6 chip. Thng thng mt thit kRFphi thit lp SRCH_WIN_A theo hiu bit ca ngi thc hin viu kin a ngtrong vng mt cell. Nu c nhiu ta nh hay i ni ln gia im pht v thuhot ng nhmt vt phn xtn hiu, khi kch thc ca stm kim cn phi thitlp cho ph hp.

Do kch thc ca sln gii hn hot ng ca btm kim, nn ngi thit kkhng nn thit lp kch thc ca squ ln. in hnh, thnh phn a ng di hntruyn mt khong cch ln hn v do bsuy gim nng hn. Lc n n my di ng,


26/58



a ng c th c mnh tn hiu qu nh c th s dng. V th, mtSRCH_WIN_A nhhn c thc sdng gii hn sa ng c chp nhn.

Hnh 2- 2 SRCH_WIN_A v mt vng chuyn giao mm ln hn

Hnh 2.2 m tmt trng thi m SRCH_WIN_A c thc sdng thu nhvng m my di ng c thkim sot chuyn giao mm. Trong sut chuyn giao mmgia hai cell, my di ng theo di hai hoa tiu khc nhau thai trm gc trong vng castm kim. Ch rng sau khi my di ng nh dng mt hoa tiu bit, my di ngtrPN offset tpha hoa tiu nhn c do chc tr hon truyn l ngc li (left).

Trong v dthhin trong hnh 3.2, chuyn giao mm xut hin gia cc im a v

b. Ti im a, my di ng cch trm gc 1 l 3km v cch trm gc 2 l 7km. Trong iukin ca chip,

Ti im a, my di ng cch3000

12,3244,14 /

mchip

m chip= ttrm gc 1

700028,7

244,14 /

mchip

m chip= ttrm gc 2

chnh lch qung ng= 28,7chip-12,3chip= 16,4chip

Ti im b, my di ng cch7000

28,7

244,14 /

mchip

m chip

= ttrm gc 1

300012,3

244,14 /

mchip

m chip= ttrm gc 2

chnh lch qung ng=28,7 chip-12,3chip= 16,4chipHnh 3.2 cng thhin ca s tm kim ti im a v b. Ti im a, hoa tiu t

trm gc 2 trhn hoa tiu ttrm gc 1 l 16,4 chip.Nu mt thit kRF mong mun ngn cn (contain) vng chuyn giao mm n

gia hai im c v d (trn hnh 3.3), trc ht phi lp li vic phn tch tng tnhvy. By giti im c, my di ng cch trm gc 1 l 4km v cch trm gc 2 l 6km.


27/58



Ti im d, my di ng cch trm gc 1 l 6km v cch trm gc 2 l 4km. Trong iukin ca chip,

Ti im c, my di ng cch4000

16,4

244,14 /

mchip

m chip

= ttrm gc 1

600024,6

244,14 /

mchip

m chip= ttrm gc 2

chnh lch qung ng=24,6 chip -16,4chip= 8,2 chip

Ti im d, my di ng cch6000

24,6244,14 /

mchip

m chip= ttrm gc 1

400016,4

244,14 /

mchip

m chip= ttrm gc 2

chnh lch qung ng=24,6 chip -16,4chip= 8,2 chip

Hnh 2- 3 SRCH_WIN_A v vng chuyn giao mm nhhn

Nu ngi thit kRF mong mun thu vng chuyn giao mm thnh mt vngnhhn gia im c v d, ngi thit kcn thit lp SRCH_WIN_A t nht bng hai ln

chnh lch qung ng cc i (chng hn rng t nht ( 2 8.2 )chip, hay 16,4chip).Bng cch ny, khi my di ng truyn ttrm gc 1 n trm gc 2, n c thm bo

xa im d, hoa tiu ttrm gc 1 ri ra ngoi ca stm kim.

2.4.2.

SRCH_WIN_N v SRCH_WIN_R

SRCH_WIN_N l ca stm kim my di ng sdng theo di tp hoa tiuln cn. Kch thc ca sny c trng ln hn SRCH_WIN_A. Ca scn phi lnkhng ch thu c tt ccc a ng c thsdng ca tn hiu t trm gc, mcn thu c a ng c khnng ca tn hiu tcc trm gc ln cn. Phng php

phn tch c tho lun trong phn trc c th c s dng xc nh


28/58



SRCH_WIN_N. Trong trng hp ny, cn a vo tnh ton a ng v chnh lchqung ng gia trm gc home v cc trm gc ln cn.

Ta c thnhn c mt gii hn cao hn cho SRCH_WIN_N. Kch thc cc i

ca ca stm kim ny c gii hn bi khong cch gia hai trm gc gn nhau.

Hnh 2- 4 Mt gii hn cao hn cho SRCH_WIN_N

Hnh 2.4 minh ha my di ng c t bn phi kbn trm gc 1, v v vy trtruyn ttrm gc 1 n my di ng khng ng k. Khong cch gia trm gc 1(v my di ng) v trm gc 2 l 5km. Khong cch tnh bng chip l:

500020,5

244,14 /

mchip

m chip

=

Ca stm kim cho thy rng hoa tiu ttrm gc 2 n sau 20,5 chip. V vy, mt my di ng (ti vtr no trong vng cell) tm kim hoa tiu ca cc trm gc lncn c khnng, SRCH_WIN_N cn thit lp theo khong cch vt l gia trm gc hinti v cc trm gc ln cn ca n. Kch thc thc sc thcn ln ny, y l mtgii hn cao hn cho SRCH_WIN_N.

SRCH_WIN_R l ca stm kim my di ng sdng theo di tp cn li cahoa tiu. Mt c trng yu cu cho kch thc ca s ny l n t nht ln bngSRCH_WIN_N.

2.5. mnh hoa tiu

mnh hoa tiu, hay 0/cE I , l mt bin php pht hin cc vng c xut hin

vn . My di ng yu cu 0/cE I bm st hay gi nguyn tnh trng trn h

thng. Mt my di ng c thkhng bt u c trong mt vng vi 0/cE I qu thp.

0/cE I c cho bi phng trnh (2.26):

0 0 0 0 0 0

0 0

( ) ( , )c

h n m t

E a P L d

I I I I I I N

=

+ + + + +


29/58



Nhta c ththy t(2.26), 0/cE I thp l do ERP hoa tiu thp ( 0 0 0( )a P thp),

suy hao ng truyn qu thp ( 0 0 0( , )L d thp ), v/ hoc can nhiu lin kt hng

xung cao, nh m ttrong mu sca (2.26).

Tng ERP hoa tiu l mt gii php c thkhi 0/cE I thp. Trong trng hp suyhao ng truyn qu mc cho php, thm vo mt trm gc l mt gii php khc.

2.6. FER

FER l mt bin php khc pht hin vng li. V FER c thc coi nhcht lng thoi kho st, hthng phi c ti u v vy phi c mt mc FER tithiu v c thchp nhn c trn clin kt hng ln v hng xung. Kho st FER

trong iu kin chp nhn c ca 0/bE N lin kt. Trn lin kt hng xung, 0/bE N

c cho bi (2.34):

0 0 0 0 0

0 0 '

( ) ( , ) W

Rb

h n m t

E T L d G

N I I I I I N

=

+ + + + +

V trn lin kt hng ln 0/bE N c cho bi (2.38):

0 0 0 0 0

0

' '( , ) ( ) W

' ' 'b

m t n

E T L d G

N I I I N R

=

+ + +

Mt vng vi FER cao schth 0/bE N gim xung di mc ngng no .

By gi ta kho st mt s nguyn nhn thng thng xut hin lm cho FER cao

trong mi quan hvi (2.34) v (2.38)2.7. Vng phsng lin kt hng xung

Mt nguyn nhn thng thng lm FER lin kt hng xung cao l vng phsng lin kt hng xung thp. Trong trng hp ny, mt vng c m tbi FERlin kt hng xung cao v cc cuc gi brt. Vng phlin kt hng xung thp lm

cho 0/bE N trn lin kt hng xung thp. Bng nh ngha, vng ph lin kt hng

xung thp do suy hao ng truyn lin kt hng xung qu mc ( 0 0 0( , )L d trong

(2.34) thp); vng ph lin kt hng xung thp cng c thdo ERP knh lu lng

thp ( 0 0( )T trong (2.34) thp).

Du hiu ca vng phsng lin kt hng xung thp l do FER hng xungcao v cng sut my di ng nhn c thp. Nu suy hao ng truyn qu mc l

nguyn nhn, 0/cE I o thp c thcng l mt biu hin khc. V my di ng nht

qun vic nhn FER cao, cng c thl hot ng c tng trong truyn PMRM.Mt gii php c thsdng khi vng phlin kt hng xung thp l tng ERP

knh lu lng cc i v vy trm gc chp nhn phn phi cng sut cao hn trn knhlu lng. Tuy nhin, gii php ny nh hng n dung lng . Khi tng ERP knh lu


30/58



lng, th cng tng scan nhiu lin kt hng xung n my di ng trong cng cell,cng nhn cc my di ng trong cc cell ln cn. V vy ERP knh lu lng tng

phi cn bng vi vic m bo can nhiu c thchp nhn c a ti cc my di ng

khc. Gii php khc c thsdng gii quyt khi vng phlin kt hng xung thp lthm vo mt trm gc.

2.8. Can nhiu lin kt hng xung

Nguyn nhn khc lm cho FER lin kt hng xung cao l can nhiu lin kt

hng xung cao. Can nhiu lin kt hng xung lm cho 0/bE N nhn c trn lin

kt hng xung thp. Trong trng hp ny 0/bE N thp do shng can nhiu trong

mu sca (2.34) thp.Thhin ca can nhiu lin kt hng xung cao lFER hng xung caov cng

sut nhn c tmy di ng cao.C bn loi ngun can nhiu lin kt hng xung, nhsau:Ngun can nhiu thnhtl cng sut can nhiu do vic truyn knh lu lng

ca trm gc. Can nhiu ny tng ng vi shng 'mI trong mu sca (2.34). S

hng ny l tng ca tt ccng sut (can nhiu) do cng sut knh lu lng phn phin cc my di ng trong cng cell. Mt gii php gim dng can nhiu ny l giihn sknh lu lng thc t( trang b) trong cell.

Ngun can nhiu th2do vic truyn overhead hng xung ca cc trm gc

khc. Can nhiu ny tng ng vi shng 0I trong mu sca (2.34); dng can nhiuny i khi c bit n nhl mt loi nhiu hoa tiu (pilot pollution) (do thc tcng

sut hoa tiu in hnh cao nht trong scc overhead knh lu lng). Shng 0I l

tng ca tt ccng sut overhead tcc trm gc ln cn; do , vic gim cng sutoverhead ca cc trm gc ln cn l mt cch gim dng can nhiu ny.

Ngun can nhiu th 3 l cng sut can nhiu do vic truyn knh lu lng

hng xung ca cc trm gc khc. Can nhiu ny tng ng vi s hngt

I trong

mu s ca (2.34). Shng ny l tng ca tt c cng sut (can nhiu ) do cng sut

knh lu lng c phn phi bi cc trm gc khc n cc my di ng khc trongcc cell khc nhau. Mt gii php gim can nhiu ny l kho st snh hng antenca cc trm gc ln cn. Bng cch nh hng li anten ca cc trm gc ln cn, mtngi c thgim can nhiu lin kt hng xung trong cell ch. Dnhin, thay i cuhnh anten cn c thc hin m khng lm nh hng vng phsng ca cc cell lncn.

Ngun can nhiu th4 l can nhiu ca nhng ngun khng phi CDMA. Can

nhiu ny tng ng vi shngn

I trong mu s ca (2.34). S hng ny m t can

nhiu tcc my pht khng phi CDMA nhi lm nhiu m (jammer). i lm nhiu


31/58



m thng hot ng (ch ng hay khng ch ng ) bt hp php trong bng tnCDMA, v vic khcan nhiu ny yu cu nhn din vtr can nhiu. iu ny thngc thc hin bng cch o v (serveying) cng sut nhiu v tam gic c

(triangulating) vtr.2.9. Vng phsng lin kt hng ln

Mt nguyn nhn thng thng lm FER lin kt hng ln cao l vng phsnglin kt hng xung ngho nn. Mt vng ph sng lin kt hng xung ngho nnc m t bi FER lin kt hng ln cao v cc cuc gi b rt. Vng ph lin kt

hng xung ngho nn lm cho 0/bE N nhn c trn lin kt hng xung thp. Qua

nh ngha, vng phlin kt hng xung ngho nn l do suy hao ng truyn lin kt

hng xung qu mc ( 0 0 0'( , )L d trong (2.38) thp).

Vng phlin kt hng xung ngho nn c m tbiFER lin kt hng lncao v cng sut truyn cao. iu ny l do iu khin cng sut lin kt hng ln, mydi ng thkt thc (close) lin kt hng ln bng cch tng cng sut truyn ca n.

Nhng khng th tng cng sut truyn my di ng ln cc i chng li suy haong truyn qu mc, do my di ng c mt cng sut truyn cc i c gii hn

bi b khuch i ca n. Gii php s dng gii quyt cho vng ph lin kt hngxung ngho nn l thm vo mt trm gc.

2.10.Can nhiu lin kt hng ln

Mt nguyn nhn khc ca FER lin kt hng ln cao l can nhiu lin kthng ln cao. Can nhiu lin kt hng ln cao nguyn nhn l do 0/bE N nhn c

trn lin kt hng ln thp; 0/bE N thp in hnh l do shng can nhiu trong mu s

ca (2.38) cao.Thhin ca can nhiu lin kt hng xung cao lFER hng xung caov cng

sut nhn c tmy di ng cao. V cng sut trm gc nhn c l php o ca tngcng sut trong bng tn thu, cng sut trm gc nhn c cao vi FER thu c cao lthhin ca nhiu can nhiu lin kt hng ln.

C 4 ngun can nhiu lin kt hng ln nhsau:Ngun can nhiu thnhtl cng sut can nhiu do vic truyn knh lu lng

ca cc my di ng trong cng mt cell. Can nhiu ny tng ng vi s hng

'm

I trong mu sca (2.38). Shng ny l tng ca tt ccng sut (can nhiu) do cng

sut knh lu lng ca cc my di ng trong cng cell. Mt cch gim 'm

I l gim

vt ph sng (footprint) ca cell ch (qua nghing xung ca anten hay thay ianten); bng cch gim vt phsng ca vng phsng ca cell ch, c thgim smy

di ng c phc vbi cell chv v thgim 'm

I .


32/58



Ngun can nhiu thhai l cng sut can nhiu do vic truyn knh lu lngca cc my di ng trong cc cell khc nhau. Can nhiu ny tng ng vi shng

't

I trong mu sca (2.38). Mt gii php gim dng can nhiu ny l thay i snh

hng/ nghing xung ca anten trm gc ch. Bng vic iu khin vt ph sngvng phsng thu ca trm gc ch, c thgii hn scng sut can nhiu nhn c tcc my di ng khc (ca cc cell khc). Dnhin, vic thay i anten phi c thchin m khng tc ng gy bt li n vng phsng cca trm gc ch.

Ngun can nhiu th3 l can nhiu ca nhng ngun khng phi CDMA. Cannhiu ny tng ng vi shng '

nI trong mu sca (2.38). Shng ny m tcan

nhiu tcc my pht khng phi CDMA nhi lm nhiu m (jammer). i lm nhium thng hot ng (ch ng hay khng ch ng ) bt hp php trong bng tn

CDMA, v vic khcan nhiu ny yu cu nhn din vtr can nhiu. iu ny thngc thc hin bng cch o v (serveying) cng sut nhiu v tam gic c(triangulating) vtr.

2.11. Nguyn nhn v gii php cuc gi brt v struy nhp khng thc hin c

2.11.1.

Cc c im ca cuc gi thnh cngCuc gi thnh cng l cuc gi c thit lp mt cch ph hp, vn cn trong

vng dch v, hon thnh mt chuyn giao v thc hin gii ta cuc gi bnh thng.Cc thhin trong dliu di ng

-

Cng sut nhn c > -100dBm- Cng sut truyn -12dB ln thnht tt nht)

Cc thhin trong cc bn ghi SBS-

Cng sut nhn c >-100dBm- Cng sut truyn -12dB ln thnht tt nht)


33/58



Hnh 2- 5 Du hiu ca mt cuc gi thnh cng

2.11.2. Cc cuc gi brt- Nguyn nhn v gii php

M t Cc biu hin Gii php hp l

Chuyn giao chm My di ng yu cu chuyn

giao n hoa tiu mi (c trongNL), b la chn thy PSMM,bt u gi EHOD nhngkhng n my di ng v PNmi b can nhiu (cn li mthoa tiu ng c). My di ngs ng b n hoa tiu n

p ng. 0/cE I xu, xa hng

xung cao

Gim n mc ti thiu thi

gian tm kim bng cch tiu cc SRCH_WIN( nht l Akhng di 28 chip), iuchnh danh sch ln cn vgim sng HO bng cchiu khin RF. Nu hoa tiumi tng mnh t ngt,xem xt n cch xp xpanten khc

Vng phsng Bthu my di ng thu gn haydi -100dBm. Bpht my ding pht trn +18dBm. Chai

ng thu v pht 0/cE I xu,

xa xu (bad erasures). B lachn iu khin cng sut tpim cao (high selector powercontrol setppoints)

Nu cn vng phsng yv khng mt cellsite no ara c th thuyt phc phsng n khi cn c mtcellsite mi.


34/58



Chng phPN( PN aliasing)

My di ng thy v yu cuchuyn giao n mt PN trongdanh sch ln cn nhng cuc

gi tip tc gim st v b giihn vi tt ccc biu hin cacan nhiu lin kt hng xung

(bthu tt, 0/cE I xu, xa cao)

Xem xt csdliu hoa tiudanh sch cc ln cn thhinPN tht stham kho n mt

PN s dng li v khng cPN no my di ng hngn. PN phn hi c yucu

My di ng khnggi bn tin honthnh chuyn giao

My di ng gi Ack cho bntin iu khin chuyn giao mrng nhng khng bm st viHOC. B la chn ht thi hni HOC

My di ng yu cu n nh

Hoa tiu khngtrong danh sch lncn

Cng sut my di ng thu ttnhng 0/cE I v xa xu.

Nguyn nhn thng thng lbn tin khng thc hin ctrn lin kt hng xung. Saukhi rt, my di ng ng bvi mt hoa tiu khng nmtrong danh sch ln cn cp

nht cui cng. PSMM khngthxy ra (mc d c thcly trn btm kim cn li)

u tin thy rng nu hoatiu l nguyn nhn rt thc d nh cung cp dchv cho vng . Nu khng ,iu khin vng phsng (nghing xung v.v). Nukhng th chuyn vng , khi yu cu thay i danh sch

ln cn.

Can nhiu khngc nhn dng


Nguyn nhn thng thng lbn tin khng thc hin ctrn lin kt hng xung. Sau

khi rt, my di ng ng bvi mt hoa tiu m khng nmtrong danh sch ln cn cpnht cui cng nhng khng giPSMM.

C thl vn danh sch lncn nh m t trnnhng can nhiu di itheo thi gian my di ngng bv vy kh c thni

l g. Vn hnh vng chmc th thhin can nhiu PN.Dthy vi OCNS tt.

Hoa tiu nm ngoivngSRCH_WIN_N


Nguyn nhn thng thng l

bn tin khng thc hin c

u tin thy rng nu hoatiu l nguyn nhn rt thc d nh cung cp dchv cho vng Nu khng ,


35/58



trn lin kt hng xung. Saukhi rt, my di ng ng bvi mt hoa tiu m khng nm

trong danh sch ln cn cpnht cui cng nhng khng giPSMM.

iu khin vng phsng (nghing xung v.v). Nu nkhng thchuyn vng khi

cn SRCH_WIN_N trn ccside trong vng

Bng 2- 1 Bng thng k mt snguyn nhn v gii php khi cuc gi brt

2.11.3. Struy nhp khng thc hin c-Nguyn nhn v gii php

M t Cc biu hin Cc gii php hp l

Vic la chn hoatiu hng- Rt knhtm gi

Thc hin mt hay nhiu lnthm d, khng c ACK hay CAti my di ng, khi trli

ng bngay. 0/cE I thp. Nhiu

li CRC knh tm gi.

iu khin RF gim sc nhiu hoa tiu m khngc bchchnh.

Vic la chn hoatiu hng- blbntin phn knh

My di ng nhn knh P (knhtm gi) v ngng d tm nhngkhng thy CA. Bla chn ghili c bn tin NOIS cung cp tinguyn, v.v


Vic la chn hoatiu hng- Khngchim c knhlu lng hngxung

My di ng nhn c knh chnh nhng ng btrong vng 1giy. B la chn iu khincng sut setpoint khi bla chnn nh ti gi trbt u. My ding khng cho php bpht can.

iu khin RF gim sc nhiu hoa tiu m khngc b ch chnh. Tng PTX(cng sut pht) bt u1dB.

Vic la chn hoatiu hng- PN txa(remote PN)

phn cui mt cuc gi, my ding quyt nh ng bvi mtPN txa (remote PN) khi cc PNcc b lun sn sng. S khiu tip theo bloi do danh schln cn ca PN txa khng cha

bt cPN cc bno.

Nghing PN t xa xungnu c th (downtilt remotePN if possible)


36/58



Vic la chn hoatiu hng- trc khi

phc v

Lin kt hng xung kt thctrc khi chuyn giao u tinhon thnh (trc bn tin hon

thnh kt ni dch v). Thngthng thy nhiu EHOD v cckt ni dch v t b chn lanhng khng n ti my di ng


Bng 2- 2 Bng thng k mt snguyn nhn v gii php ca struy nhp khng thc

hin c


37/58



2.12.

MS thc hin cuc gi

TRM DING (MS) TRM GC BSC/DMS-

MTXPht hin cuc gi

c thit lpGi bn tin thit lp

Gi bn tin vithng tin ny nDMS-MTX

Gi thtc ACKca trm gcNgng thm d

ACCESS

PAGING

Thit lp knh lulng

Bt u gi lulng null

(Lu lng null hngxung c n nhngMS khng bit trnknh no; v vy, MSkhng thbt u giigii m n )

FWTRAFFIC

Phnphi tinguyn

LPP

LPP

Gi bn tin phnknh

PAGING

Bt u truyn dliuknh lu lng hngln null

Gi bn tin yu cudch vcho la chndch v1

Chim c knhlu lng hngln

Gi thtc ACKca BS

RVTRAFFIC

FWTRAFFIC

Phn phi tinguyn cho la chndch v1

RVTRAFFIC

Thit lp knh lulng

Nhn khung c gi tr

5mN =2 lin tip

Bt u gi knh lulng hng ln u

tin


38/58



Hnh 2- 6 Lu thit lp cuc gi tMS

TRM DING

TRM GC

Phn phi ti nguyncho la chn dch v1

Gi bn tin kt ni dchv

La chna chung phn

hi vo tngmthanh

La chna chung phn

hi ra tngmthanh

Honthnh

cucgi

FWTRAFFIC

RVTRAFFIC

RVTRAFFIC

FWTRAFFIC

FWTRAFFIC

LPP

(User m thoi) (User m thoi)

Bt u qui trnh lulng u tin phhp vi sla chndch v1Gi bn tin honthnh kt ni dch vLa chnGi bn tin thit lp

ti theo

La chnGi bn tin cnh bo vi

thng tin (m bo phnhi)

La chnGi bn tin cnh bo vi

thng tin (ngng mbo)

Bn tin gi n li DMSchthMS sn sng

BSC/DMS-MTX


39/58



2.13.

MS thc hin cuc gi bgii hn

TRM DI NG

TRM GC

Gi bn tin p ngtm gi (nhn tin)

Gi bn tin tm gi(nhn tin) chung

Nhn bn tinthit lp(SETUP) tPSTN

SdngHLR/VLRxc nhvtr v

trng thica MS chGi tin nhn

yu cu ncc trm gcthch hp

Gi thtc ACKca trm gc

Gi bn tin n

DMS-MTX botrm gc p ng

PAGING

Ngng thm d

ACCESS

PAGING

Thit lp knh lulng

Bt u gi lulng null

FWTRAFFIC

Thit lp knh lulng

Nhn khung c gitr 5mN =2 lin tip

Bt u gi knh lulng hng ln utin

Gi bn tin phnknh

PAGING

Chim c knh

lu lng hngln

Gi thtc ACKca BS

RVTRAFFIC

Bt u truyn dliu knh lu lng

hng ln null

FWTRAFFIC

Gi bn tin yu cudch vcho la chndch v1Phn phi ti

nguyn cho la chndch v1

Gi bn tin p ngdch vcho php lachn dch v1

RVTRAFFIC

FWTRAFFIC

RVTRAFFIC

LPP

Phn phiti nguyn

LPP

LPP

BSC/DMS-MTX

(Lu lng nullhng xung c nnhng MS khngbit trn knh no; vvy, MS khng thbt u gii m n )


40/58



Hnh 2- 7 Lu MS thc hin thit lp cuc gi bgii hn

TRM GC BSC/DMS-MTX

Gi bn tin kt nidch v

RVTRAFFIC

Bt u qui trnh lulng u tin phhp vi sla chndch v1Gi bn tin honthnh kt ni dch v

FWTRAFFIC

Gi bn tin cnh bovi thng tin (rungchung )

RVTRAFFIC

Bt u rung chungCc user trli cuc

giNgng rung chungGi lnh kt ni

(Connect Order)

FW

TRAFFIC

Bn tin gi n DMS-MTX chthMS sn sn

Cuc gitip tc

LPPRVTRAFFIC

(User m thoi)(User m thoi) (User m thoi)

Gi bn tin p ngdch vcho php lachn dch v1

TRM DI NG


41/58



2.14.

MS thc hin cuc gi Markov

TRM DI

NG MS

TRM GC

Pht hin cuc gi c thit lpGi bn tin thit lpnh r la

chn dch vMakov

Gi thtc ACK ca trm gcNgng thm d

ACCESS

PAGING

(Lu lng null hng xung cn nhng MS khng bit trnknh no; v vy, MS khng thbt u gii gii m n )

FWTRAFFIC

Gi bn tin phn knh

PAGING

RVTRAFFIC

FWTRAFFIC

RVTRAFFIC

Thit lp knh lu lng

Bt u gi lu lng null

Thit lp knh lu lng

Nhn khung c gi tr 5mN =2 lin

tipBt u gi knh lu lng hng

ln u tinChim c knh lu lng

hng ln

Bt u truyn dliu knh lulng hng ln null

Gi thtc ACK ca trm gc

FWTRAFFIC

Gi bn tin kt ni dch vchnh cu hnh dch vv lachn dch v0 801F (btc 2 ca Markov)

Gi thtc ACK ca MS

FWTRAFFIC

RVTRAFFIC

Gi bn tin hon thnh kt ni

dch vVo trng thi phca cuc mthoi

Kt ni v thit lp la chn dchvMakov ti thi gian hot ng nh r trong bn tin kt nidch v

Kt ni v thit lp la chn dchvMakov theo thi gian hotng nh r trong bn tin ktni dch v

RVTRAFFIC


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Hnh 2- 8 Lu MS thc hin cuc gi Markov

2.15.Cc php o hot ng ca CDMA

2.15.1.

Cc php o hot ng thit lp cuc giC 3 ln khc nhau khi mt cuc gi c thkhng thc hin c:1) Trc khi ti nguyn c phn phi2)

Khi my di ng chuyn tip tknh tm gi hay truy nhp sang knh lu lng3) Sau khi my di ng hot ng trn knh lu lng

Khng thc hin c thit lp cuc gi trc khi ti nguyn c phnphi, c phn loi nhsau:

- Cc cuc gi bchn: thit lp cuc gi bngt do cc nguyn nhn nhmt my

di ng khng c nhn thc, mt my di ng bt u gii ta hay ra khi mtside mt t (or a land side release)- Khng thc hin c cuc gi do thiu ti nguyn vt l:

Khng c cc trung kT-1Khng c cc thnh phn bla chn SBSKhng c cc thnh phn knh lu lng BTS

- Khng thc hin c thit lp cuc gi do li ht thi hn (timeouts) v li phnmm

Cc bn tin sau c lp li khong 20giy mt ln cho ti khi cuc gi cuc gibngt:

Gi thtc ACK ca MS

Gi bn tin iu khin lachn dch vvi la chn dchv0 801F (btc 2 caMarkov) v cc trng nhdng 0 0010 tng ng vichthiu khin tc thayi, bm bn sao, khngxa bm

FWTRAFFIC

Gi bn tin iu khin lachn dch vvi la chn dchv0 801F v cc trng nh dng 0 0010 tng ngvi chthsa li bm sa li FER bm

RVTRAFFIC

FW

TRAFFIC

RVTRAFFIC

Gi bn tin iu khin la chn

dch vvi la chn dch v0 801F v cc trng nhdng tng ng vi p ng FERbm

TRM DI NG MS

TRM GC


43/58



Cc thanh ghi u cui CM:TMTX07 trln cc thanh ghi CM siu khin nhn tin (page) li. iu ny

to ra mt sCAU OM dtha.

CDMAPRS1- CDMA p ng nhn tin 1 (MTXSYS1): ch th rng p ngnhn tin c nhn p li yu cu thit lp nhn tin (page request). CDMAPRS2- CDMA p ng nhn tin 2 (MTXSYS2): ch th rng mt png nhn tin nhn p li ln thnhn tin ln thhai sau khi CAU ht thihn trn ln thnhn tin thnht.Cc nhm CAU OM :Php o skin CAU cuc gi c phn thnh 1 trong 3 nhm sau: CAU sector thc hin cuc gi (CAUCPSCT): theo di skin da trn sector

u tin ngoi trcc skin chuyn giao cng. Cc skin chuyn giao cng c theo

di da trn sector ch (target sector) CAU h thng x l cuc gi (CAUCPSYS): theo di cc s kin trn mt

phn CAU cs(a per-CAU basis). CAU qun l ti nguyn (CAURM : cng theo di cc skin trn mt phn

CAU cs(a per-CAU basis).Cc php o thit lp cuc gi- Cc bghi khi u CAU

CAUOATTS- CAU php thkhi u (CAUCPSCT) CAUOBLKS-CAU khi u nghn (CAUCPSCT)

CAUOSUCC- CAU khi u thnh cng (CAUCPSCT) CAUORDR- CAU cung cp thm khi u (CAUCPSCT) CAUORLS- CAU khi u gii phng (cuc gi) (CAUCPSCT)

Cc php o thit lp cuc gi- Cc bghi u cui CAU CAUPGRES- CAU p ng nhn tin (CAUCPSCT) CAUPGRRS- CAU p ng xl nhn tin li (CAUCPSCT) SLTPGRES- p ng chia rnh chnhn tin (CAUCPSCT) SLTPGRRS- p ng chia rnh chxl nhn tin li (CAUCPSCT) CAUTBLKS- CAU nghn u cui (CAUCPSCT)

CAUTSUCC- CAU u cui thnh cng (CAUCPSCT) CAUTRLS- CAU u cui c gii ta (CAUCPSCT)

Sau MTX07, cc php o CAUPGRES v SLTPGRRS c kha trong cc thanhghi CM

Cc php o thit lp cuc gi- Cc thanh ghi CAU chuyn giao cng

CAUHATTS- CAU ln thchuyn giao cng (CAUCPSCT) CAUHBLKS-CAU nghn chuyn giao cng (CAUCPSCT) CAUHSUCC- CAU chuyn giao cng thnh cng (CAUCPSCT)

CAUHRLS-CAU gii ta chuyn giao cng (CAUCPSCT)


44/58



CAUHRLFL-CAU khng thc hin c chuyn giao cng lin kt vtuyn (CAUCPSCT)Cc php o thit lp cuc gi- Cc thanh ghi CAU trng hp li

RMNORREQ- qun l gii php cho skin khng c ti nguyn cho yu cu(CAURM)

RMSRMNAK- RM qun l gii php dch vtchi Ack (CAURM)

RMSRMTO-RM SRM ht thi hn (CAURM) CAUERSFL- CAU trng hp li v tuyn khng thc hin thit lp c(CAUCPSCT)

CAUNOTCE-CAU khng c thnh phn knh lu lng (CAUCPSCT) CAUNOWCD-CAU khng c m Walsh (CAUCPSCT)

CAUFWCAP-CAU dung lng hng xung (CAUCPSCT)

CAURECAP- CAU dung lng hng ln (CAUCPSCT) CAUEDLOT- CAU trng hp li, b rt do suy hao knh lu lng(CAUCPSCT)

RMUNSO- qun l gii php khng htrla chn dch v(CAURM) CAUESWFL-CAU trng hp li, li phn mm (CAUCPSCT) CAUERLFL- CAU trng hp li, khng thc hin c lin kt v tuyn(CAUCPSCT)

Hin ti khng c cchng tin cy o CAURECAP v vy OM ny mt kh

nng hot ng ti BTSCc cng thc cho cc cuc gi khng thit lp cSdng cc cng thc ny tnh ton hthng mrng thit lp cuc gi Khng thc hin c khi u thit lp cuc gi

[ (CAUOBLKS)/ (CAUOATTS)] 100 (3.1)

Khng thc hin c thit lp u cui

[ (CAUTBLKS)/ (CAUPGRES)] 100 (3.2)

Hay

[ (CAUTBLKS)/ (CDMAPRS1+CDMAPRS2)] 100 (3.3)

Khng thc hin c thit lp chuyn giao cng

[ (CAUHBLKS)/ (CAUHATTS)] 100 (3.4)

Cng thc ny c sdng xc nh phn trm khng thc hin c docc cuc gi bchn

Cc cuc gi bchn: cc cuc gi bchn = (# ca cc cuc gi bchn/cccuc gi th) 100 (3.5)

# ca cc cuc gi b chn = CAUORLS+ CAUTRLS

+ CAUHRLS+ CAUORODR+ RMUNSO (3.6)


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Tng cc cuc gi th = CAUOATTS + CAUHATTS

+ CAUPGRES (3.7)

Cng thc ny c sdng xc nh phn trm cc cuc gi khng thc

hin c do khng c ti nguyn vt l Cc cuc gi khng thc hin c do thiu ti nguyn vt l

% do thiu ti nguyn vt l= (# ca ti nguyn vt l nghn/ cc cucgi th) 100 (3.8)

# ca ti nguyn vt l nghn = RMNORREQ + CAUERSFL

(3.9)

Tng cc cuc gi th a ra trong cng thc (3.7)Cng thc ny c sdng xc nh phn trm cc cuc gi khng thc

hin c do thiu yu tknh lu lng Cuc gi khng thc hin c do thiu yu tknh lu lng

% do thiu cc TCE = ( CAUNOTCE/tng cc cuc gi th)

100 (3.10)


hin c do thiu m Walsh Cuc gi khng thc hin c do thiu m Walsh

% do thiu m Walsh = ( CAUNOWCD/ tng cc cuc gi th)

100 (3.11)

Tng cc cuc gi th a ra trong cng thc (3.7)

Cng thc ny c sdng xc nh phn trm cc cuc gi khng thc

hin c do thiu dung lng hng xung Cuc gi khng thc hin c do thiu dung lng hng xung

% do thiu dung lng hng xung = ( CAUFWCAP/ tng cc

cuc gi th) 100 (3.12)


hin c do li ht thi hn (timeout) v phn mm Cuc gi khng thit lp c do li ht thi hn v phn mm

%do ht thi hn v li phn mm=(sli ht thi hn v phn mm/tng cc cuc gi th) 100 (3.13)

Sli ht thi hn v phn mm= RMSRMTO + RMSRMNAK

+ CAUESWFL (3.14)

Tng cc cuc gi th a ra trong cng thc (3.7)


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Cng thc ny c sdng xc nh phn trm ca truy nhp RF khng

thc hin c. Ch thchuyn giao khng a vo tnh ton trong cng thc sau Cuc gi thit lp khng thc hin truy nhp RF c (khng bao gm chuyn giao)

% Cuc gi thit lp khng thc hin truy nhp RF c =( CAUERLFL/ tng cc cuc gi th) 100 (3.15)

Tng cc cuc gi th= CAUOATTS + CAUPGRES (3.16)

Chuyn giao cng khng thc hin truy nhp RF c% Chuyn giao cng khng thc hin truy nhp RF c =

[ (CAUHRLFL)/(CAUHATTS)] 100 (3.17)

2.15.2. Php o khi thc hin cuc gi brt

Cho cc nguyn nhn hp l, thc hin cc cuc gi brt OM v cc cng thcc tham kho khi trong trung tm vng phsng hay khng trong trung tm vng phsng

Cc php o CAU-

CAUDROPR- CAU cuc gi RF brt (CAUCPSCT)- CAUDROPN- CAU cuc gi mng brt (CAUCPSCT)

Cng thc phn trm CAU cuc gi brt% cc cuc gi brt = ( scc cuc gi brt/ scc cuc gi thitlp) 100 (3.18)

Scc cuc gi brt = CAUDROPR (3.19)CAUDROPN c thc thm vo scuc gi brt nhng hu ht ccskin xy ra ca OM l cc trng hp li v khng nn xy ra.

S cc cuc gi thit lp = CAUOSUCC + CAUTSUCC +

CAUHSUCC (3.20)

2.15.3. Php o khi thc hin chuyn giao cng

Tt c cc php o CM ny u b kha cho chuyn giao ngc li ngun hay

sector ban u ctrong v ngoi hthng. Cc php o CM ( nhm OMMTXHO2)

- CHOSRCAT- CM ngun thchuyn giao cng- CHOSRCSU- CM ngun thnh cng chuyn giao cng- CHOBLKS- CM nghn chuyn giao cng-

CHOSRCFL-CM ngun chuyn giao cng khng thc hin c- CHOSRRLS-CM ngun gii phng chuyn giao cng-

CHONSRCR- CM khng c ngun p ng chuyn giao cng Cc php o CAU (nhm CAUCPSCT)


47/58



- CAUHATTS- CAU thchuyn giao cng- CAUHBLKS- CAU nghn chuyn giao cng- CAUHSUCC-CAU thnh cng chuyn giao cng

-

CAUHRLS- CAU gii ta chuyn giao cng- CAUHRLFL-CAU khng thc hin c chuyn giao cng lin kt v tuyn

Cng thc sau c sdng tnh ton thc hin chuyn giao cng

Cng thc CM thc hin chuyn giao cng% ca cc chuyn giao cng thnh cng = ( scc chuyn giao thnhcng /scc chuyn giao cng th) 100 (3.21)

Scc chuyn giao thnh cng = CHOSRCSU (3.22)

S cc chuyn giao cng th = CHOSRCSU -

(

CHOBLKS+

CHONSRCR+

CHOSRRLS) (3.23)


48/58

Chng 3: Xy dng chng trnh thit kti u


Chng III

XY DNG CHNG TRNH THIT KTI U

3.1. Ti u mng.3.1.1. Quy trnh chung.

Quy trnh chung bao gm ba phn chnh: Qun l cht lng dch v, ti u mngv vn hnh.

Hnh 3.1: Qui trnh ti u

+ Set up:- Chn hthng ti u.- Chn mc phn tch- Vch ra phng php v khoch- Cc hthng bao gm: mng li, truy xut v truyn ti

+ Thc thi dliu:- Phthuc vo hthng cthm qu trnh thc thi l khc nhau.

+ Phn tch:- Xl trung tm.

-

Phn tch.

Select Systemfor Optimization.

Select analysisitems.

Define methodsand plans.

Systemsinclude:oo CCOORREEoo AACCCCEESSSSoo TTRRAANNSSMMIISSSSIIOONN

1. Setup 2. Perform the Data

Post-Processing

Analyzing

3. Analyze

Improving Network Quality Service & Customer satisfactory

Depends onspecific system,Performance isdifferent:oo CCOORREEoo AACCCCEESSSSoo TTRRAANNSSMMIISSSSIIOONN

Activities

Action plan

4. Optimize

Evaluation

Conclusion

Recommend

Case study


49/58



+ Ti u:-

Cc hot ng-

Khoch hot ng- c lng

-

Kt lun.- ngh.- Rt ra bi hc

3.1.2.

Ti u mng truy xutTi u mng truy xut l qu trnh ti u mng CDMA t ti ngng trn ca

qu trnh thc thi v duy tr hthng ny mc n nhm bo phsng mc chp nhn c: gim thiu cc khu vc sng yu,

mrng vng phsngNng cao ti a cht lng dch v: nng cao hiu sut cuc gi, tng mc hi

lng ca khch hng.

Cc i ha nng sut mng: cn bng ti ca cc sector, BTS, BSCTng dung lng

3.1.3.

Mc tiu+ Mc tiu:

- Xc nh KPI.- Bsung hand-of- Bsung Q-factor-

Bsung cht lng hiu sut RF: iu chnh Rx,Tx, kt hp Ec/Io.- Bsung dung lng RF- Gim thiu scuc gi rt.

-

Tng shon thnh truy xut- Tng thng lng dliu- Tng cht lng cuc gi- Gim sthan phin ca khch hng

+ Nhim vchnh:


50/58



Hnh 3.2 Nhim vti u3.2. Mc tiu (KPI 2007)

Items 07 Target

Call Success Rate(%)

(In down town area)

98% in main 12 TPs97% in other TPs excluding 12 TPs(Z1 : 15TP, Z2 : 10TP, Z3 : 9TP)

Improvement

SystemPerformance FieldqualityCustomer complaints

0.04 case/day/1,000 subs(nominal subs)

OptimizedNetworkDesign

Repeaterrelocation

Traffic balancebetween sectors afterrelocation (after optimiz.)Q-factor (theothers/max sector)

Q-Factor : over 1.0

Items 07 Target

Call Success Rate(%)(In down town area)

98% in main 12 TPs97% in other TPs excluding 12 TPs(Z1 : 15TP, Z2 : 10TP, Z3 : 9TP)

ImprovementSystemPerformance

Fieldquality

Customer complaints0.04 case/day/1,000 subs(nominal subs)

OptimizedNetworkDesign

Repeaterrelocation

Traffic balance betweensectors after relocation(after optimiz.)Q-factor (theothers/max sector)

Q-Factor : over 1.0

Bng 3.1 KPI 2007

Collecting basic data

Analyzing the drive testdata

Performing the drive test

Performing optimization

Improvement of Statistics(Call Setup Rate,

Call Drop Rate )

Improvement of Coverage

Transfer operational

Know-how

Case study and

conclusion

Stability of System

Improvementof Call Quality

Balancing Between

Coverage & Capacity

OperationalCa abilit

Traffic Balancing

Access Network Evaluation: field measurement & call quality evaluation


51/58



3.3. Tin trnh

Hnh 3.3 Tin trnh thc hin ti u

1. Chun bcho ti u l bc thnht trong tin trnh. Bc ny chun bchothng tin BTS, MAP, ltrnh

2. Bc thhai l quyt nh ti u cc thng snhtlsetup cuc gi, tlrtcuc gi,

3. y l mt bc quan trng vi mc tiu l thu thp d liu o c nhchcnng nh v

4. Khi dliu c thu gom qua vng phsng ca RF, dliu i n cc cng cphn tch nhn bit cc vn tim tng vvic phsng ca RF hoc nhiu v phntch cc cch gii quyt vn

5. Mt khi l do ca cc vn v gii php c a ra, bc ktip l gii quytvn . Mc tiu l nng cao cht lng dch v.

6. Bc ny nh gi kt quti u sau khi hon thnh ti u.7. Bc ny quyt nh mc tiu c hon thnh hay khng8. Nu cc mc tiu t c th tin trnh ti u kt thc.

START (Preparation)

StatisticsNetwork

Optimization Targets Decision

Optimization Execution

Optimization Evaluation

Performance

YES

NO


52/58



3.4. Tin hnh3.4.1.

Ln khoch Chn i tng phn tch:

+ Chn loi dch vv quyt nh phn tch:

-

nh gi cht lng chung ca dch v: thoi, d liu v cc dch vcng thm.

- Kim tra cc iu kin: Ec/Io, cng sut Rx/Tx, -

Kim tra hot ng hthng-

Thtruy xut mng: dung lng mng, bao phdch v..+ Thit lp khoch v phng php:

- Lch trnh: ngy, thng, qu, nm- Dch v: thoi, dliu v cc dch vcng thm- Chuyn n cho ngi qun l

3.4.2 Thc thi dliu

Quy trnh:-

Chn ltrnh-

Thit lp cc cng ckim tra- o v thu thp dliu

3.4.3 Phn tchQuy trnh:

- Kim tra log file, import file bng cng cphn tch-

Mcc import file v kt hp chng li thnh mt nu cn- Gim st thng tin cuc gi, tin nhn, thng sDM

Phn tch:

-

Phn tch cht lng ca dch vthoi v dliu- Phn tch qu trnh thc thi ca hthng v mc bao ph.Cht lng dch vmng:

- Tlkt ni thnh cng: l tlcc cuc gi c thit lp ng kt nithnh cng trong khong thi gian setup.

(Scuc gi kt ni thnh cng/Tng scuc gi th)x100- Tlrt cuc gi: l tlcc cuc gi brt bi ngi gi hoc ngi c

gi hoc chai trong sut thi gian gi.(Scuc gi rt/Scuc gi thnh cng)x100

- T l cuc gi thnh cng: l t l cc cuc gi kt ni v kt thc thnh

cng. (Scuc gi thnh cng/Tng scuc gi th)x100- Cht lng thoi: l tlscuc gi khng c nhiu trong sut thi gian

m thoi. MOSC 3- Tltruy xut thnh cng: l tlcc cuc gi gi truy xut thnh cng n

PDSN trong khong thi gian setu(Scuc gi truy xut thnh cng/Tng scuc gi th)x100

- T l truyn thnh cng: l t lcc cuc gi download hoc upload thnhcng tp tin test trn server FTP trong khong thi gian cho php.

(Scuc gi truyn thnh cng/Scuc gi truy xut thnh cng)x100


53/58



Hnh 3.4 Qui trnh phn tch dliu

- Thng lng trung bnh: Trung bnh cc tc c tnh ton khi downloadmt file test tFTP server

(Sbit ca file load/ tng thi gian load) [Kbps]- Tltreo: tlcc cuc gi btreo(Scuc gi treo/tng scuc gi truy xut)x100

- Dch vcng thm (SMS): tlthnh cng

3.4.4 Ti u mng liMc ch:

- Tng tnh n nh ca hthng- Ti u dung lng hthng- Cn bng ti (chuyn nhng ti nguyn)- Qun l cu hnh, chn ng i ti u

Nhim vchnh:

Network Access Indicators

Connection Success Rate

Call Drop Rate

Call Setup Success Rate

Voice Quality

Access Success Rate

Transmission Success Rate

Average Throughput

VoiceService WirelessDataService

Pending Rate

Additional Service (SMS)Q_Factor

Tx, Rx Adjust; Ec/Io


54/58



Hnh 3.5 Ti u mng li

Define collecting data type

Analyzing thesystem information

Collecting system data

Optimizing, AdjustingSystem configuration

Optimal configuration

Load balancing

Transfer operationalKnow-how

Case study and conclusion

Stability of System

System Performance

System configuration

Parameters andSW management

Core Network Evaluation: system stability, performance and efficiency evaluation


55/58



Bng 3.2 Ti u mng li

1%10ResourceCongestion

Systemquality

1.7%5Origination C/Drate(%)- Voice only

96%( min : 95.8%)5Originationsuccess rate(%)

- Voice only

Systemquality

Busy Hour( HN, DN :20~21HHCMC :

19~20H)

Improvementof

Performance

CPUs Load 15%difference BelowReference level 60%meet 15% difference

below within 2 weeks

15BSC(BMP/CCP), ASP(except forASP0)

LoadBalanceCPUs Load15%difference

below

Maximization ofOperationEfficiency

07 TargetScoreItems

15 min/mon/sys5VAS

5 min/mon/sys5Out of serviceTime (minute)

CoreFaultMgmt

StableSystemOperation

07 TargetScoreItems


56/58

Kt lun


KT LUN

1. Nhng iu thc hin c ca ti

Trong khnng c thca bn thn ti a ra c qui trnh, thtc tiu, mt stham scn ti u v gi trno thch hp nht cho hthng.

2. Nhng iu cha thc hin c ca tiDo khng c iu kin tm hiu thc t, mt schvn cn hiu cha r nn

khng thhin c chnh xc ngha ca n v nhiu chbn thn cng cha dmmnh dn thhin c.

3. Hng mca titi ny l mt vn rt cn thit trong spht trin hthng thng tin di

ng CDMA. Mi vn lin quan n thit kv ti u ny lun c cc nh khaithc quan tm thc hin thng xuyn trong xy dng h thng mi hay duy tr hthng c. ti hon thin cn bsung mt svn m hin ti bn thn chathc hin c.


57/58

Phlc A


PHLC ABng dung lng Erlang B di y c thhin nhmt hm ca sknh

(trung k) v xc xu

t ngh

n. V d

: 25 knh c th

h

tr

16,1Erlang ti 1% ngh

n v

20Erlang ti 5% nghn. Cch khc, khi nhn li cng 20Erlang th c 25 knh c thphc vyu cu , nhng cn 30 knh phc v1% nghn i vi cng mt nhmuser.

Bng dung lng Erlang-B

Dung lng Erlang B

Sknh P(B)5 0.01 P(B)5 0.02 P(B)5 0.05 P(B)5 0.10

1 0.01 0.02 0.05 0.11

2 0.15 0.22 0.38 0.60

3 0.46 0.60 0.90 1.27

4 0.87 1.09 1.52 2.05

5 1.36 1.66 2.22 2.88

6 1.91 2.28 2.96 3.76

8 3.13 3.63 4.54 5.60

10 4.46 5.08 6.22 7.51

12 5.88 6.61 7.95 9.47

14 7.35 8.20 9.73 11.47

16 8.87 9.83 11.54 13.5018 10.44 11.49 13.39 15.55

20 12.03 13.18 15.25 17.61

25 16.12 17.50 19.99 22.83

30 20.34 21.93 24.80 28.11

35 24.64 26.43 29.68 33.43

40 29.01 31.00 34.60 38.79

45 33.43 35.61 39.55 44.17

50 37.90 40.26 44.53 49.56

60 46.95 49.64 54.57 60.40

70 56.11 59.13 64.67 71.29

80 65.36 68.69 74.82 82.20

90 74.68 78.31 85.01 93.15

100 84.06 87.97 95.24 104.11


58/58

Ti liu tham kho

TI LIU THAM KHO

[1] Positioning the new Nortel+ Bay Networks. Eladio Licerio (2007)

[2] Technical Introduction to CDMA. Scott Baxter (2004)[3] Bi ging: Thng tin di ng s. H Vn Cu, Phm Thanh m (2002). HcVin Cng NghBu Chnh Vin Thng.

[4] CDMA Performance Optimization. Scott Baxter (2004)

[5] Thng tin di ng thh3- TS Nguyn Phm Anh Dng, PGS.TS Nguyn Bnh(2001). Nh xut bn Bu in

[6] Thng tin di ng, Phm Huyn, 2007, i hc Bch khoa Thnh phHChminh

[7] CDMA RF System Engineering. Samuel C.Yang (1998). Artech House

[8] IMT-2000 Network Architecture. Toshio Shimoe, Takamichi Sano (2002)[9] CDMA Concept & IS-2000 Protocol. Chang Hwan Lee (2006). LG

[10] 2007 pht trin mng CDMA 3G ti Vit Nam. Thgii vi tnh[11] Cc n mn hc v n tt nghip ca hc vin Cao hc Hc vin Cng

nghBu Chnh vin thng v Hc vin Kthut Qun s.

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