mang 4g viettel

8/3/2019 mang 4g viettel

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LI M U

Trc s pht trin v cng mnh m ca cc dch v s liu, trc xu hng tchhp v IP ho t ra cc yu cu mi i vi cng nghip Vin Thng di ng. Mngthng tin di ng th h ba ra i khc phc c cc nhc im ca cc mng thngtin di ng th h trc . Tuy nhin, mng di ng ny cng c mt s nhc im nh:Tc truyn d liu ln nht l 2Mbps, vn cha p ng c yu cu ngy cng caoca ngi dng, kh nng p ng cc dch v thi gian thc nh hi ngh truyn hnh lcha cao, rt kh trong vic download cc file d liu ln,cha p ng c cc yucu nh: kh nng tch hp vi cc mng khc (V d: WLAN, WiMAX,) cha tt, tnhm ca mng cha cao, khi a mt dch v mi vo mng s gp rt nhiu vn do tc

mng thp, ti nguyn bng tn t,Trong bi cnh ngi ta chuyn hng sang nghin cu h thng thng tin di

ng mi c tn gi l 4G. S ra i ca h thng ny m ra kh nng tch hp tt c ccdch v, cung cp bng thng rng, dung lng ln, truyn dn d liu tc cao, cung cpcho ngi s dng nhng hnh nh video mu cht lng cao, cc tr chi ho 3D linhhot, cc dich v m thanh s. Vic pht trin cng ngh giao thc u cui dung lngln, cc dich v gi d liu tc cao, cng ngh da trn nn tng phn mm cng cngmang n cc chng trnh ng dng download, cng ngh truy nhp v tuyn a mode, vcng ngh m ho media cht lng cao trn nn cc mng di ng.

Hin nay th trng di ng Vit Nam c nh gi l tng trng ng th 2 trnth gii sau Trung Quc, s thu bao khng ngng tng, nhu cu v vic s dng cc dchv v cc dch v a phng tin ngy cng cao v cng i hi cao hn trong tng lai.Do vic nghin cu mt cng ngh mi p ng cc nhu cu th trng trong tnglai l rt cn thit.

Hin nay Viettel a vo s dng GPRS p ng nhu cu s dng cc dch vd liu ngy cng cao ca cc thu bao. Cc dch v ch yu ca GPRS nh: WAP, truynhp Internet c hai phng thc l truy nhp gin tip v truy nhp trc tip, dch v nhntin a phng tin, video, xem cc on phim ti v, xem video trc tuyn. Ngoi ra cn cdch v thng mi in t di ng, dch v ngn hng, qung co trn in thoi di ng

do gi cc cn cao nn cc loi bao c thu nhp trung bnh v cao. Da trn nhu cu thtrng Vit Nam, hin ti chng ta thy rng nhu cu chnh trong thng tin di ng vn ldch v thoi truyn thng, dch v d liu cng bt u tng trng, theo d on tng sthu bao c nhu cu dch v d liu chim khong 50% vo nm 2010. Vi i sng thunhp ngy cng cao ca ngi dn, nhu cu cc dch v cht lng tt ngy cng ln, thmng di ng Viettel ngy cng phi nng cp p ng c cc nhu cu ny. Mt khc,xu hng chung trn th gii l hi t tt c cc mng vin thng li vi nhau. Do , yu


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cu pht trin mng thng tin di ng ln th h 4G c tc cao, s dng all IP c khnng tch hp vi cc mng khc l yu cu tt yu ca mng di ng Viettel.

ti Nghin cu ng dng cng ngh 4G cho mng di ng di ng ViettelMobile c a ra khng ch nhm mc ch tm hiu, nghin cu cc dch v m n png m cn c gng a vo p dng Vit Nam c th l trn mng di ng caViettel.Vi mc ch ti nghin cu ca chng ti dc chia lm 4 chng:

Chng 1: Xu hng pht trin cng ngh v dch v ca cc mng di ngChng 2: M hnh cu trc mng 4GChng 3: Dch v v cht lng dch v trong mng 4GChng 4: L trnh tin ln mng thng tin di ng 4G cho Viettel Mobile

Vi vic trin khai ti Nghin cu ng dng cng ngh 4G cho mng di ng ding Viettel Mobile , Viettel m ra mt c hi mi, ng lc mi cho s pht trincng ngh mng cng nh thng mi in t trong thi i kinh t s hin nay, khng chcho cng ty m cn mong mun s ng gp mt phn vo s pht trin trong lnh vcvin thng cng ngh thng tin ca nc nh. cng l mong mun ln nht ca nhngngi thc hin ti ny.

CHNG 1

XU HNG PHT TRIN CNG NGH V DCH V CA CC MNG

DI NG


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1.1. GII THIU H THNG THNG TIN DI NG 4GVic nghin cu chuyn hng sang cc h thng thng tin di ng th h 4 (4G)

gii quyt cc vn tn ti trong h thng di ng th h 3 (3G). l vic cung cp ccloi hnh dch v ngy cng a dng hn, t tn hiu thoi cht lng cao sang tn hiuvideo phn gii cao, cc knh v tuyn c tc d liu cao. Khi nim 4G c s

dng rng ri khng ch c cc h thng in thoi t bo m cn bao gm cc kiu hthng vin thng truy nhp v tuyn bng thng rng. Mt trong s cc thut ng dng m t 4G l MAGIC: Mobile multimedia (a phng tin di ng), Anytime anywhere(Bt c khi no, bt c ni u), Global mobility support (H tr di ng ton cu),Integrated wireless solution (Gii php v tuyn tch hp) v Customized personal service(Dch v theo yu cu c nhn). Nh l mt li ha cho tng lai, h thng 4G l h thngtruy nhp v tuyn t bo bng thng rng, v ang l mi quan tm ln ca lnh vcthng tin di ng. 4G khng ch h tr cho cc dch v thng tin di ng th h tip theom cn h tr cho c cc mng v tuyn c nh.

Chng ta xem xt trn c s ci nhn tng quan v cc c trng ca 4G, cch tchc v tch hp h thng di ng. c trng ca 4G c th c ng li bng t tch hp.Cc h thng 4G l mt s tch hp gn kt khng tch ri ca cc thnh phn thit b ucui, mng li v cc ng dng nhm tho mn i hi khng ngng v ngy cng caoca ngi s dng.

1.2. LCH S V XU HNG PHT TRINLch s ra i v s pht trin ca dch v di ng t th h u tin 1G ti th h

4G tri qua nhiu giai on khc nhau. Bng 1.1 cho thy tm lc qu trnh tin trin cacng ngh thng tin di ng thoi.

Qu trnh bt u vi cc thit k u tin c bit n nh l 1G trong nhng nm70 ca th k trc! Cc h thng ra i sm nht c thc hin da trn cng ngh tngt v cu trc t bo c bn ca thng tin di ng. Nhiu vn c tnh nguyn tc c bn c gii quyt trong nhng h thng ny. V c nhiu cc h thng khng tng thch c a ra cung cp dch v trong nhng nm 80.

Cc h thng th h th 2 (2G) c xy dng trong nhng nm 80 vn c sdng ch yu cho thoi nhng c thc hin trn c s cng ngh s, bao gm cc k

thut x l tn hiu s. Cc h thng 2G ny cung cp cc dch v thng tin d liu chuynmch knh tc thp. Tnh cnh tranh li mt ln na dn ti vic thit k v thc hincc h thng b phn ho thnh cc chun khc nhau khng tng thch nh: GSM (hthng di ng ton cu) ch yu chu u, TDMA (a truy nhp phn chia theo thi gian)IS-54/IS-136 M, PDC (h thng di ng t bo s c nhn) Nht v CDMA (a truynhp phn chia theo m) IS95, mt h thng khc ti M. Cc h thng ny hot ng rngkhp trn lnh th quc gia hoc quc t v hin nay chng vn chim vai tr l cc hthng ch o, mc d tc d liu ca cc thu bao trong h thng b gii hn nhiu.


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Bc chuyn tip gia 2G v 3G l 2.5G. Th h 2,5G c pht trin t 2G vidch v d liu v cc phng thc chuyn mch gi, v n cng ch trng ti cc dch v3G cho cc mng 2G. V c bn n l s pht trin ca cng ngh 2G tng dung lngtrn cc knh tn s v tuyn ca 2G v bc u a cc dch v d liu dung lng caohn vo, c th nng ti 384 Kbps. Mt kha cnh rt quan trng ca 2.5G l cc knh d

liu c ti u ho cho d liu gi truy nhp vo Internet t cc thit b di ng nh inthoi, PDA hoc my tnh xch tay. Trn cng mt mng li vi 2G, th h 2.5G ainternet vo th gii thng tin di ng c nhn. y thc s l mt khi nim mang tnhcch mng cho h thng vin thng lai ghp hybrid.

Trong thp k 90, cc nh nghin cu nh ngha ra h thng di ng th h ktip, th h th 3, loi tr c nhng s khng tng thch ca cc h thng trc yv thc s tr thnh h thng ton cu. H thng 3G c cc knh thoi cht lng cao cngnh cc kh nng v d liu bng rng, c th t ti 2Mbps.

Cc h thng 3G ha hn cung cp nhng dch v vin thng tc cao hn, bao

gm thoi, fax v internet bt c thi gian no, bt c ni u vi s chuyn vngroaming ton cu khng gin on. Chun 3G ton cu ca ITU m ng cho cc ngdng v dch v sng to (v d loi hnh gii tr a phng tin, cc dch v da trn v tr,). Mng 3G u tin c thit lp ti Nht bn nm 2001. Cc mng 2.5G, nh l GPRS(dch v v tuyn gi chung) sn sng Chu u. Cng ngh 3G h tr bng thng 144Kbps vi tc di chuyn ln (trn xe hi), 384 Kbps (trong mt khu vc), v 2 Mbps (ivi trng hp trong nh).


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Hnh 1.1 Cc th h di ng

Bng 1.1 Bng so snh tham s cng ngh c bn

Tuy nhin i hi ca vin thng a phng tin truy nhp tc cao i vi x hingy nay, ph thuc rt ln vo cng ngh thng tin s. Theo cc con s lch s ca cuc

cch mng v cng ngh din ra trong 1 thp k th thi im hin ti chnh l thi imthch hp nghin cu h thng thng tin di ng 4G.Hin nay tc download ch d liu ang b gii hn 9.6 Kbps, thp hn

khong 6 ln so vi 1 ng kt ni c nh ISDN (Mng s tch hp dch v). Gn y,vi cc thit b cm tay 504i tc download d liu c tng ln 3 ln t 28.8 Kbps.Tuy nhin trong thc t s dng tc d liu thng thp hn, c bit l nhng khuvc ng c, hoc l khi mng b nghn. Tc d liu di ng th h 3 l ti a 384Kbps download, in hnh l xp x 200 kbps, v upload t 64 kbps t nm 2001. Thngtin di ng th h 4 s c tc truyn d liu cao hn, d kin c th t ti 20 Mbps.

3G c cc nh sn xut xut u tin m khng phi l t cc nh khai thc.

Nm 1996 n c trin khai nh NTT (Hng in thoi v in bo Nht bn) cngEricsson, nm 1997 Hip hi cng nghip Vin thng TIA M chn CDMA nh l 1cng ngh cho 3G, nm 1998 CDMA bng rng (W-CDMA) v CDMA2000 c thngqua cho H thng thng tin di ng chung UMTS. Trong W-CDMA v CDMA2000 l 2 xut chnh ca 3G. Tuy nhin 3G vn tn ti mt s vn khim khuyt nhng imsau:

Rt kh cho vic tng bng thng lin tc v tc d liu cao p ng c yu


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cu ca cc dch v a phng tin, cng vi s tn ti song song ca cc dch vkhc nhau cn c bng thng v QoS khc nhau.

Gii hn ph v phn b ph Kh roamingqua cc mi trng dch v khc nhau cc bng

tn khc nhau. Thiu c ch vn chuyn lin tct u cui n u cui lin kt m

rng mt mng di ng nh vi mt mng c nh nh khc. Trong cc lnh vcthng tin di ng, dch v di ng 4G l s pht trin ca cc dch v thng tin di ng 3G.Cc dch v di ng 4G c cho n bi kh nng cung cp bng thng rng, dung lngln, truyn dn d liu tc cao, cung cp cho ngi s dng nhng hnh nh video mucht lng cao, cc tr chi ho 3D linh hot, cc dich v m thanh s. Vic pht trincng ngh giao thc u cui dung lng ln, cc dich v gi d liu tc cao, cng nghda trn nn tng phn mm cng cng mang n cc chng trnh ng dng download,cng ngh truy nhp v tuyn a mode, v cng ngh m ho media cht lng cao trn

nn cc mng di ng.Vi s xut hin ca mng 4G, n s gii quyt c:

1. 1. H tr cc dch v tng tc a phng tin: truyn hnh hi ngh, Internet khngdy,2. 2. Bng thng rng hn, tc bit ln hn3. 3. Tinh di ng ton cu v tnh di chuyn dch v

4. 4. Gi thnh h5. 5. Tng kh dng ca h thng thng tin di ng

Cc nh nghin cu v nh cung cp pht trin cc mi quan tm vo mng v tuyn 4G h tr a roaming cc mng di ng v v tuyn ton cu, v d t mt mng di ng tbo sang mt mng cng ngh v tinh cng nh sang ti mng LAN khng dy bng rng.

Vi c trng ny, ngi dng s c th truy nhp vo cc dch v khc nhau, tngvng ph, thun tin cho cc thit b n l, mt ho n cho vic gim ti a tng cngcc chi ph v rt nhiu truy nhp khng dy ng tin cy khc, thm ch ngay c khi c sh hng hay li ca 1 hay nhiu mng ng thi. Cc mng 4G cng c c trng lin h

IP cho truy nhp Internet di ng khng ngt qung v tc bit c th t 50 Mbps haycao hn.

Do vic trin khai 4G trn thc t ch c th thc hin c t sau nm 2006 hoc thmch cn lu hn na nn cc nh pht trin hy vng c thi gian gii quyt nhiuvn lin quan ti cc mng hn hp, c th l:

Truy nhp

Chuyn giao


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nh v ng thi

nh ngun ti nguyn mng ng thi cung cp cho ngi s dng mi

H tr multicasting

H tr cht lng dch v QoS

Xc thc v bo mt v tuyn Li mng v backup

Tnh cc Cu trc mng s ng vai tr quan trng trong vic p ng c tt cnhng i hi trn. H tr QoS trong mng 4G l mt th thch chnh v tc bit,c trng knh, gn bng thng, mc li v h tr chuyn giao gia cc mng vtuyn hn hp. H tr QoS c th thc hin i vi gi, chuyn dch tc v, knh,ngi dng v cc cp mng.

Mc QoS gi ng dng cho jitter, thng lng, v t l li. Cc ngun ti nguynmng nh khong m v giao thc truy nhp l nhng nh hng c kh nng.

Mc QoS chuyn giao tc v m t c 2 yu t: thi gian cn thit hon thnhtransaction v t l mt gi. Cc chuyn giao chc chn c th rt nhy v thi gian,trong khi mt s chuyn giao khc th khng c php mt gi.

Mc QoS knh bao gm block cuc gi mi cng nh cc cuc gi ang thc hin.N ph thuc ngay vo kh nng ca mng thit lp v duy tr knh thng tin t thitb u cui n thit b u cui. nh tuyn cuc gi v qun l nh v l 2 thuctnh quan trng ca mc knh.

Mc QoS ngi s dng ph thuc vo tnh di ng v loi ng dng ca ngidng. V tr mi c th h tr nhu cu QoS cc tiu, thm ch vi cc ng dng thchnghi.

Trong mt gii php v tuyn hon thin, thng tin t im cui n im cui gia haingi s dng cng c kh nng lin quan ti nhiu mng v tuyn. V QoS s thay i quacc mng khc nhau, nn QoS cho nhng thu bao ny c kh nng l mc ti thiu mnhng mng ny h tr.* Xu hng v cng ngh

C ba xu hng c th tip cn. Th nht l hng tp trung quanh 3G, trong atruy cp phn chia theo m (CDMA) s c y dn ti im ti cc nh sn xut thitb u cui s t b. Khi t ti thi im , cn c cng ngh khc p ng c ihi tng ln v dung lng v tc d liu.

Xu hng th hai l xu hng v mng LAN v tuyn. S pht trin rng khp ca

WiFi c bt u t nm 2005 cho cc PC, my tnh xch tay, v PDA. Trong cc doanhnghip, tn hiu thoi c truyn i bi cng ngh Voice qua mng LAN v tuyn(VoWLAN). Tuy nhin cha ai thy r c cng ngh thnh cng tip theo l cng nghno. t ti s thng nht v cng ngh 200 Mbps (v cao hn na) vn cn l mtchng ng lu di v c qu nhiu gii php cn xut.

Xu hng th 3 l IEEE 802.16e v 802.20 thc hin n gin hn 3G. S phttrin ca mng li hng ti th h NGN bng rng s h tr cho vic p dng cc cng


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ngh mng truy nhp mi thng qua cc gateway truy nhp tiu chun, da trn cc chunETSI-TISPAN, ITU-T,3GPP, hip hi tiu chun vinthng Trung Quc (CCSA) v cc chun khc.Mt s cng ngh quan trng ca 4G c m t nh sau:

OFDMAGhp knh phn chia tn s trc giao OFDM khng ch to nn li ch r rng cho thc thilp vt l, m cn hp nht vic ci thin hiu nng lp 2 nh vic a ra thm mt mc t do. Nh vic s dng OFDM c th khai thc min thi gian, min khng gian, min tns v thm ch c min m ti u ho vic s dng knh v tuyn. Chc chn rng n cu th ln vi truyn dn trong mi trng a ng vi vic lm gim thiu s phc tpca b thu.

Tn hiu c chia thnh cc sng mang nh trc giao, trn mi sng mang tnhiu l bng hp (vi KHz) v v vy trnh c hiu ng a ng, to nn mt khongbo v chn vo gia mi tn hiu OFDM. OFDM cng to nn mt li v phn tp tns, ci thin hiu nng ca lp vt l. N cng tng thch vi nhng cng ngh m rngnng cao khc, nh l cc anten thng minh v MIMO.

iu ch OFDM cng c th tn dng nh l mt cng ngh a truy nhp (a truynhp phn chia tn s trc giao, OFDMA). Trong trng hp ny mi tn hiu OFDM cth truyn thng tin t/ti mt vi thu bao s dng mt b cc sng mang nh khc nhau(subcarrier, subchannel). iu ny khng ch cung cp thm linh hot cho vic cpngun ti nguyn (tng dung lng), m cn c th ti u ho cc lp cho ca vic s

dng link v tuyn. V tuyn c nh ngha bng phn mm - SDRLi ch ca v tuyn c nh ngha bng phn mm SDR mang li hiu sut x l

cao pht trin cc trm gc v thit b u cui a bng, a chun. Mc d trong tnglai cc u cui s thch ng vi giao din v tuyn sn sng cho cng ngh truy nhp vtuyn, thi im hin nay iu ny c thc hin nh c c s h tng. SDR mang linhiu li ch cho mt s c s h tng. V d tng dung lng mng ti thi im nhtnh (v d nh 1 s kin th thao), nh khai thc s cu hnh li mng ca h nh vic lpthm vo trm gc vi thit b modem. SDR khin cho vic cu hnh li ny rt d dng.

Trong bi cnh cc h thng 4G, SDR s to iu kin d dng cho mt tp hp rt

nhiu cc picocell v microcell a chun. i vi nh sn xut, vic ny c th l mt s htr ln trong vic cung cp cc thit b a chun, a bng v gim i nhng n lc phttrin v h gi thnh thng qua vic x l a knh mt cch ng thi.

MIMO Multiple Input Multiple OutputMIMO s dng ghp knh tn hiu gia rt nhiu cc anten pht (a thnh phn

khng gian) trn min thi gian hoc min tn s. iu ny rt ph hp vi OFDM, bi vc th x l cc tn hiu thi gian c lp ngay khi dng sng OFDM c thit lp chnh


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xc cho knh. c im ny ca OFDM gip cho cng on x l c n gin ho i rtnhiu. Tn hiu pht i bi m anten c n anten thu li. Vic x l cc tn hiu thu cc th mang li mt vi ci thin hiu nng: phm vi, cht lng ca tn hiu thu v hiusut ph. Trin khai hiu nng trong mng t bo vn ang cn l i tng cho nhiunghin cu v m phng (hnh 1.2). Tuy nhin, ni chung c th tha nhn rng nhng g

nhn c t vic s dng hiu qu ph lin quan trc tip ti s lng anten cc tiu trongtuyn kt ni.

Hnh 1.2: L trnh hiu nng do Alcatel th nghim

Ti u gia cc lpHin nhin c s nh hng qua li gia MIMO v lp MAC. Cc mi nh hng qua likhc c th hin trn hnh 1.3.

Hnh1.3: nh hng qua li gia cc lp v ti u lin quan


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Chuyn giao v tnh di ng

Cc cng ngh chuyn giao da trn cng ngh IP di ng cn c s xem xt c v d liuv thoi. Cc k thut IP di ng thng chm nhng c th c tng tc vi cc phng

php c in (IP di ng nhanh, phn cp). Cc phng php ny c th p dng c chod liu v cng c th cho c thoi. Trong nhng mng n tn, c th xem xt cc phngphp chuyn giao. Mt s k thut c th s dng khi t s sng mang/nhiu c gi tr m(v d VSFOFDM), nhng iu tr ngi ca nhng k thut ny chnh l dung lng.Trong OFDM, cng mt la chn c th thay th c trong CDMA, c th s dng phn tpmacro. Trong trng hp OFDM, MIMO cho php x l phn tp macro vi cc li vhiu nng. Tuy nhin, thc hin phn tp macro dn n vic x l MIMO c tp trungv truyn dn c ng b. iu ny khng phc tp nh trong CDMA, nhng nhng kthut ny ch s dng trong cc tnh hung m ph rt khan him.

1.3. CC NG DNG V DCH V TRONG 4GPhn ny s nh gi v ch ra c cc dch v v tuyn ang ni ln, cc cng ngh

tim nng cho tnh an ton chung c s dng trong tng lai gn v xa hn. N s a ramt chui cc nghin cu tip theo cho cc cng ngh v tuyn khng dy ang xut hin.S nghin cu ny tp chung chnh vo cc ng dng (cc dch v v cc thch thc) anghoch nh cho s pht trin ca mng v tuyn khng dy th h th t 4G.

Phn ny s trnh by nhiu hn v cung cp chi tit hn cc dch v thy c trongmng 4G. Trn thc t s thc y mnh m ch yu cho cc cng ngh 4G l cung cpthng tin d liu gi ha, rng bng ln, tc cao. Thm ch ngi ta mong mun rnglu lng thoi c truyn i ti cc thit b cm tay trong cc gi (tri ngc vi vicphn pht thng qua knh chuyn mch dnh ring). Chuyn mch knh lin quan ti kthut trong cc knh dnh ring c s dng pht v nhn tn hiu thoi hay d liu.S thng tin d liu gi ha lin quan ti k thut bo hiu s trong thng tin (thoi hayd liu) c chuyn thnh m nh phn v c chia ct thnh cc on ngn (segments).Cc on ny sau s c gii ng gi theo th t sp xp chnh xc v c chuyni ngc li thnh cc thng tin ban u pha thu. Trong chuyn mch gi ch c tn hiuthai c ni dung thc s c ng gi v gi ti h thng. iu ny l c th nh s tin

b trong cc k thut a truy cp v cng ngh. Tht ng tic l cc k thut truy nhp vtuyn khng dy ngy nay khng h tr vic truyn bng rng v truyn tc cao. S hnch ny chnh l s thc y cho qu trnh pht trin thng tin v tuyn khng dy. Trongth trng v tuyn khng dy ngy nay, nhng ngi s dng yu cu cc dch v gi trgia tng. Cng vi s gii thiu rm r cc dch v th h 3, nhng ngi s dng mongmun cng ngh v tuyn th h k tip s khng ch l phng tin thng tin thoi mcn s c chc nng ha ging nh Internet. Cc nh cung cp dch v v cc nh pht trinng dng ang trn con ng nhn ra cc nhu cu ca ngi s dng nhng vn l con


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ng di pha trc. Thc t, trong trin khai 3G, vic mong mun vic chc nng hac im Internet theo ng thng tin v tuyn khng dy chng ta c th khng nhnthc y c. Cc k thut a truy nhp hoch nh cho 3G s khng h tr cc tc truyn d liu v bng thng c yu cu cho cc ng dng ci tin m ngi s dngmong mun. Cc cng ngh 3G s thc s c cc chc nng mnh hn cc h thng v

tuyn khng dy ngy nay, tuy nhin khng mnh bng khi chng ta trin khai 4G.Nhng ngi s dng v tuyn khng khng dy hm nay mong i nhiu th ln

t cc mng v tuyn khng dy ngy mai. H ch i rng cc mng v tuyn khng dyth h tip theo nht l 4G s mang li g. Cc nh cung cp dch v cc pht trin ng dngang ch hn na ti s mong i ca ngi s dng quyt nh hng pht trin va ra cc loi hnh dch v. T cc nh cung cp phn chia nhng ngi s dng vtuyn ra thnh cc mng chung. Cc nghnh kinh doanh v tuyn phi hiu c cc mngny, s mong ch v cc nhu cu ca mng (segment) s i theo hng no trong cngngh v tuyn khng dy th h tip theo ln 4G. Nhng ngi s dng c phn mng

theo nhiu cch. Theo nh cch trnh by hi tho gn y ca Lucent Technologies tiSupercomm, Lucent ang xem xt phn chia cc ngi s dng thnh 5 mng nh sau:

.1-Mng Gender.

.2-Mng theo tui (Age).

.3 -Mng theo cch s dng Internet (Internet Usage).

.4-Mng theo mc thu nhp (Income Brackets).

.1-Mng nhng ngi chuyn s dng Mobile (Mobile Profesional).

.2 Mng Gender: Tm n cc ngi s dng l ph n. Nhng ngi s dng ny inhnh l nhng c nhn thu nhp trung bnh. Cc kiu ng dng ang pht trin cho mngny l cc ng dng gii tr v x hi nh dch v chat v nhn tin nhanh..3 Mng Age: c bao gm th trng gii tr cc i tng 18 tui hoc tr hn. Hkhng phi tr tin cho dch v do chnh h dng m vic tr tin l do b m hay ngic lin quan thc hin. Cc kiu ng dng ang c pht trin cho on ny l cc ngdng gii tr v x hi nh cc dch v m nhc..4 Mng Internet Usage : Bao gm in hnh l cc c nhn s dng nhiu hn so vi mctrung bnh (nhiu hn 30 pht trn mt phin) trnh duyt Internet. Nhng ngi s dngtrong mng ny c hi t cng ngh. Cc kiu ng dng ang pht trin l cc ng dngthng tin nh cc dch v tin tc c nhn v cc dng tin tc chnh (c truyn i vi mthanh, hnh nh, vn bn, hoc bt k s kt hp no th h th 3). Cc nh cung cp dch

c bit kh khn trong vic p ng nhu cu ca cc khch hng ny bi h quen vivic tnh tin kiu Internet..5 Mng ngi s dng Income Bracket: Bao gm nhng c nhn tui trung lunhng c nhn bit hiu r gi tr dch v. Cc loi ng dng ang pht trin trong mngny l cc dch v thng tin nh dch v thi gian ngn (up-to-the-minute), personalizedstock tickers. Nhng ngi s dng ny cng c nh hng tnh an ton chung; v thcc thng tin d liu v thoi c tin cy c nng cao..6 Mng Mobile Profesional: Hng ti nhng ngi s dng tin tng vo cc thit b


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v tuyn khng dy qun l cng vic kinh doanh hng ngy. Mng ny bao gm nhngngi s dng chuyn nghip. Nhng ngi s dng ny hu ht rt quan trng i vi ccnh cung cp dch v bi h thng xuyn s dng nhiu hn cc dch v m h yu cu.Cc kiu ng dng ang pht trin cho mng ny l fax di ng, th in t, nhn tinnhanh. tng s tin cy cc ng dng, cc nh cung cp cng ang pht trin thit b thu

bao c th chuyn vng vo cc mng v tuyn khng dy khc nhau trn ton th giis dng mt thit b thng tin n. Ging nh mng Income Brackets, Mobile Professionalyu cu cc phng tin thng tin d liu v thoi phi tin cy v lin tc. Tnh an tonchung s c quan tm v hiu chnh hp l trong mng ny. Ton b chc nng s cthm vo m bo tnh bo mt thng tin cho ngi s dng..7

Hnh 1.4. Cc dch v v ng dng trong 4G

- Cc trnh ng dng v cc dch chung:

Mc ch ca phn ny l nh ngha cc dch v cng nh chc nng m nh cung cp ara cho khch hng. Cc trnh ng dng c nh ngha nh cc phn mm, chng trnhhoc cc tnh nng mang li li th cho cc dch v cung cp bi nh khai thc. Nhn chungc bn loi dch v hoc trnh ng dng c pht trin v a vo s dng thng tin vtuyn th h tip theo. l dch v thng tin c nhn/khoanh vng, cc phng tin linlc, t chc, gii tr. Cc ng dng v cc dch v thng tin c nhn/ khoanh vng hng tiphc v hu ht ngi s dng cc mng cp trc y n ni n nhiu hn ccmng Inernet Usage, Income Brackets, v Mobile Professional. Cc ng dng v cc dchv thng tin ny s cung cp cho ngi s dng cc bn tin chung, cc bn tin ti chnh,hng dn v tr, thng mi di ng, v cc dch v du lch. Cc dch v ny cho php

ngi s dng xc minh cc thng tin n l lin quan ti ngi s dng d h trongvng phc v hay chuyn vng sang cc h thng khc. Cc quc gia Chu c cc ngdng theo di phng tin giao thng cng cng. T cc thng tin gim st ny ngi sdng c th xc nh thi gian xe but hay tu in dng li bn. Kiu dch v thng tinc nhn/khoanh vng ny c trin khai gii hn trong cc quc gia. Dch v ny cth l push-based hoc pull-based, ph thuc vo v tr thu bao mun thng tin pht tptrung t ng gi ti thit b v tuyn khng giy hoc nu mun thng tin pht tp trung


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trn mt im c nhu cu. Cc dch v push v pull s c tho lun chi tit sau phnny. Cc dch v v cc ng dng c mt tm quan trng i vi tt c cc mng ngi sdng c bit l mng Mobile Professional..1-Cc dch v thng tin (Communication) bao gm c dch v nhn tin ngn (SMS), th

in t, hi tho truyn hnh, fax, v cc bulletin board. Mc d mt s cc dch v csn sng trong cc h thng khng dy ngy nay, nhng cc dch v ny s tip tc cnng cao hn trong th h tng lai. Trong cc dch v ny: thoi v tin cy c ch nht trong k hoch pht trin..2-Cc dch v Organizational bao gm cc kh nng h tr s c nhn (PDA Personaldigital assistant), trao i tin t da trn c s xc nh ngi s dng, v cc trnh ngdng qun l c nhn khc (v d: lch cng tc, qun l cuc gi, s lu a ch). Cc dchv v cch trnh ng dng Organizational c lin quan ti tt c cc mng ngi s dngnhng n c hng ti phc v cho cc mng ngi s dng l Income Brackets v

Mobile Professional.

- Cc dch v gii tr (Entertainment) c a vo tm ngm ca cc nh cung cpdch v v cc nh cung cp quay tr li u t vo n khi nhn thy n c mt tim nngln. Cc dch v gii tr c th gm c on m thanh, on video, chat, trao i hnh nh,v chi game. Trong th trng v tuyn khng giy Chu 3G ang c pht trin, ccdch v gi tr ang to ra li nhun ng k. Mng m cc dch v gii tr hng ti lmng Age. Mt dch v khc ang to ra rt nhiu s si ng trong nghnh kinh doanh l thng mi di ng (M-Commerce). Thng mi di ng a ra kh nng cho thu baong k mua cc mn hng ( v d: mua gas, thc n t cc my bn hng t ng.v.v) s

dung mt thit b v tuyn khng dy. V d ng k mua mt mn hng t my bnhng t ng, mi ngi s dng s quay s in thoi hoc m truy nhp lin quan timn hng v mn hng s c phn phi ti ngi mua. Trong s phi hp ny,my bn hng t ng s c kt ni ti mng in thoi chuyn mch cng cng (PSTN)thng qua mt modem hoc mt thit b kiu gateway. Cc nh cung cp dch v v tuynkhng dy s gi thng tin ti cng ty bn hng v cng ty ny s gi thng tin ti my bnhng t ng ch th cho my bn hng phn phi mn hng. Ti khon ca ngi sdng dch v khng dy s c tnh vo cc mn hng m h ng k, ging nh mt thtn dng. Kiu dch v thng mi di ng ny hin thi ang c th nghim v cthc hin (trn c s cn nhiu hn ch) trong cc quc gia Chu u v Chu v thcs ang tin xa. Thng mi di ng c th c xem nh l mt kiu dch v Informationhoc Organzation.

- Cc dch v da trn c s xc nh v tr Push, Pull.Cc dch v Push v Pull a ra tin cy cho mng v kh nng xc nh v tr cc thubao. Trong mng 4G, iu c th nhn thy, mng c kh nng xc nh v tr chnh xcca cc thu bao c trong nh v ngoi nh. Kh nng ny c thc hin t cc chc


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nng c thm vo t cc nh cung cp dch v. Cc thng tin c nhn ngi dng cthit lp v cp nht bi cc thu bao, m bo thng tin ti mi ngi s dng ng yucu. Thng tin c nhn cha ng cc s thch ca thu bao (v d., thch/khng thch, khoch lm vic, khun kh) v s cho php cc thu bao ( v d: ngi no c php bithin ti h ang u). Nh cung cp dch v s duy tr v lu d thng tin c nhn ngi

s dng trong c s d liu. Mng phc v s s dng cc thng tin ny y cc dch vcho cc thu bao. V d: nu mt thu bao thch mt kiu thc n ring, mng s xem trongthng tin c nhn ca thu bao v s y (push) cc thng tin c lin quan ti nhiu nhhng m phc v ki mn n v tr ca thu bao. Tng t, ngi s dng c th yucu cc thng tin ging nh vy xut pht t mng (pull) nu c ta hay anh ta khng lachn c thng tin ny v thng tin ny c y ti (push) thit b khng dy. S thchthc vi cc dch v da trn c s xc nh v tr l n khng c trong cc trnh ng dngnhng c trong s b sung. cho cc dch v nh v tn ti bt k gi tr thc no,mng phi c kh nng ch ta v tr ca cc thu bao vi chnh xc cao c th trong

khong vi Feet. Cc mng khng dy hin thi khng c kh nng ny. Cc mng ngynay nhn vo cc cell ang phc v v ang thng tin vi thit b cm tay xc nh v trca thu bao. K thut ny c th chnh xc cao nht mt vi khi nh trong thnh phnhng i vi cc trnh ng dng ca 4G s chnh xc ny gn nh l khng cn thit. Cck hoch hin thi cho mng 4G bao gm s dng giao thc Internet phin bn 6 (IPv6) nh tuyn cc gi d liu ti my in thoi cm tay. IPv6 gn lin vi vic theo dinh v v iu ny s lm tng kh nng xc nh mt cch chnh xc v tr ca thu baotrong mng. Mt s c xut p dng cc kh nng ca h thng nh v ton cu(GPS) vo cc my cm tay gip cho vic xc nh v tr ca cc thu bao. Tuy nhin GPSs ch hu ch i vi phm vi nh. GPS tin vo kh nng my thu bt c tn hiu t cc

v tinh quay quanh tri t. Nu my thu khng truy cp bn ngoi ( trong nh), ccthng tin v v tr khng c cung cp. Ngoi v tr ra, mng phi c kh nng xc nhcc s liu thng k khc.

-Kt lun:Cc dch v v cc trnh ng dng cho 4G vn ang c nh ngha, n pht trin v

dch chuyn theo nhu cu ngi s dng. Cc ng dng 4G hng ti phc v cho thtrng khch hng c nhu cu ln v cht lng dch v cng nh s a dng ca dch v.Vi kh nng ca mnh, 4G thc s p ng c cc nhu cu v a dch v ca khchhng hin ti v trong tng lai. Chng ny mi ch gii thiu v a ra mt s loi hnhdch v in hnh v mt s v d v cc ng dng trong 4G theo mt kha quan imchung. Phn dch v v m hnh c th ca n s c gii thiu k hn trong chng 3.nh hng pht trin cc dch v cho 4G da trn nn tng ca 3G nhng vi tin cy vtnh an ton cao hn, m hnh di y c th l cc dch v c th cho 4G :


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Hnh 1.5. M hnh cc dch v trong mng 4G

CHNG 2

M HNH CU TRC MNG 4G

2.1. CC YU CU V CU TRC MNG MI


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Mng 4G ra i l cuc cch mng v tc truyn d liu, kh nng tng tc,giao tip gia cc mng khc nhau. N l s kt hp gia cc mng khc nhau da trn nnIP. Mc ch chnh ca mng l cho php ngi dng c th truy nhp v khai thc cc dchv trong mng vi tc cao, cht lng tt, an ton, bo mt. V vy, p ng c ccnhu cu v cc dch v , mng 4G phi p ng c cc yu cu sau:

a. Mng 4G phi p ng c yu cu tch hp c cc mng khc nh cc mngdi ng th h 2, th h 3, th h 3,5G, v WLAN, WiMAX, v cc mng khng dykhc.

Hnh 2.1: S pht trin ca cc mng khc nhau dn n 4G

Mng 4G c kh nng kt hp vi cc mng khc nhau da trn nn giao thc IP,vi tc cao, n cung cp cc dch v a dng thi gian thc, cc ng dng cht lngcao, y l yu t rt quan trng gip cho mt mng, cng ngh mi t c thnhcng. Vi s kt hp ny, ngi s dng c kh nng kt ni ti nhiu mng, c th sdng nhiu dng dch v khc nhau nh PSTN, ISDN, internet, WLAN, WiMAX,vv, mkhng cn quan tm ti dng thit b ang s dng cng nh vic h ang u.


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Hnh 2.2: S kt hp cc mng khc nhau

b. Mng c tnh mXem xt cc ng dng, dch v mng hin nay, chng ta thy rng cc h thng

mng hin nay vn ang pht trin nh l cc h thng ng. Trong mng th h hai, dchv cung cp ch l nhng dch v n gin nh tin nhn SMS, MMS, Cc mng di ngth h ba bt u cung cp mt s ng dng, dch v nhng cn rt t, cht lng cha

cao. Cc nh cung cp dch v cng ch trong phm vi l third-party trong mng. iuny c th c khc phc trong mng 4G. Cu trc m ca mng 4G cho php ci t ccthnh phn mi vi cc giao din mi gia cc cu trc khc nhau trn cc lp. y l iurt quan trng, c bit cho cc dch v ti u trong mng di ng vi lin kt khng dy vcc c tnh di ng. M hnh c xy dng ra phi c tnh m. iu ny gip cho hthng tr nn linh hot trong qu trnh pht trin. Yu cu v m rng, nng cp h thnghay thm vo cc ng dng, dch v mi lun l mt i hi i vi cc mng vin thnghin nay. Do mng phi m bo cho kh nng p ng cc nhu cu ny ngay t thiim hin ti cho n tng lai.


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Hnh 2.3: Ngi dng cc mng khc nhau c th truy nhp vo h thngc. m bo cht lng dch v cho cc ng dng a phng tin trn nn IP:

m bo cht lng dch v, cn s kt hp cht ch gia cc lp truy nhp,truyn ti v cc dch v Internet. c bit i vi cc vn v tr mng, bng thngdch vvv. Mng 4G yu cu tc truyn d liu cao, tr nh, dch v thi gianthc, cht lng cao.

d. m bo tnh an ton, bo mt thng tin

y l yu cu quan trng hng u ca h thng. H thng thng tin cng phttrin, cng c nhiu ngi dng cc mng khc nhau cung truy nhp vo h thng ththng tin b mt ca ngi dng cng khng m bo an ton. Tnh an ton ca h thngc nh gi qua kh nng bo mt trong truyn thng, tnh ng n v ring t ca ccd liu ngi s dng cng nh kh nng qun l, gim st h thng. Bo mt l yu cuchung i vi tt c cc h thng vin thng.

e. Mng m bo tnh di ng:Mt trong nhng vn quan trng ca 4G l cch truy nhp nhiu mng di

ng v khng dy khc nhau. C ba kh nng: S dng thit b a ch , vng ph a


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dch v, hoc s dng giao thc truy nhp chung.Cc thit b a ch :Thit b a ch c nhiu ch hot ng khc nhau, v d nh a truy nhp

phn chia theo m, thng tin di ng ton cu GSM, ch truy nhp v tinh, Do , khithit b nm ngoi vng ph ca mng mnh th n vn c th truy nhp c vo thng

thng qua cc mng khc. i vi loi thit b ny th vn cht lng dch v yu cuphi c x l tt. Xem hnh 2.4 - a

Vng ph a dch v:Trong kin trc ny, ngi dng truy nhp vo vng ph a dch v gm nhiu im

truy chung (UAP: Universal Access Point). Nhng UAP ny kch hot chn mng datrn nhng ci c sn, c im cht lng, v s la chn thng thng ca ngi dng.Ngi dng, thit b c th chuyn dch v khi di chuyn t UAP ny sang UAP khc. Xemhnh 2.4 - b

Giao thc truy nhp chung: Trong trng hp ny cc mng khng dy c th h trmt hoc hai giao thc truy nhp chun. Khi thit b c th chuyn mng c cng giaothc truy nhp khi khng truy nhp c vo mng ca mnh. Xem hnh 2.4 - c


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Hnh 2.4: Tnh di ng ca mng


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f) Mng phi m bo v tc :Mng mi ra i phi c tc truyn d liu cao, p ng c yu cu ca ngi

s dng. Tc truyn d liu trong mng mi c th ln n 100Mbps, v 160Mbps khis dng MIMO (Nhiu u vo - Nhiu u ra)

Hnh 2.5: Tc truyn d liu trong mng 4G

2.2. M HNH MNG 4G

2.2.1. u nhc im ca cu trc mng 3G v 3,5G a)Mng thng tin di ng th h ba WCDMAMng thng tin di ng th h ba ra i khc phc c cc nhc im ca cc

mng thng tin di ng th h trc . Vi vic cu trc mng dng giao thc IP kt hpvi cng ngh ATM, cng vi vic h tr tc ln ti 2Mbps, mng thng tin di ng thh ba WCDMA c th h tr ngi dng cc dch v nh: hi ngh truyn hnh, truy cpinternet tc cao, download cc file d liu nh,

Tuy nhin, mng di ng ny cng c mt s nhc im nh: Tc truyn dliu ln nht l 2Mbps, vn cha p ng c yu cu ngy cng cao ca ngi dng, kh

nng p ng cc dch v thi gian thc nh hi ngh truyn hnh l cha cao, rt kh trongvic download cc file d liu ln,

Mng thng tin di ng th h ba WCDMA cha p ng c cc yu cu nh:kh nng tch hp vi cc mng khc (V d: WLAN, WiMAX,) cha tt, tnh m camng cha cao, khi a mt dch v mi vo mng s gp rt nhiu vn do tc mngthp, ti nguyn bng tn t,


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b) Mng thng tin di ng th h 3,5G HSDPA v HSUPACuc cch mng ca th trng thng tin di ng a ra cc yu cu nng cp ci

tin v c dung lng h thng ln tc truyn dn d liu. Mng thng tin di ng th hba WCDMA ra i l mt bc pht trin mnh m v tc v cht lng dch v. Tuynhin, tc d liu ti a trong WCDMA ch t ti 2Mbps. tng kh nng h tr cho

cc dch v d liu chuyn mch gi, c bit l nng cao tc truyn d liu, m trcht l tc ng xung, 3GPP pht trin v chun ha trong phin bn Release 5 mtcng ngh mi, l cng ngh truy nhp gi ng xung tc cao (HSDPA) vi nhngtnh nng mi c cp trong cc phin bn R5 ca 3GPP cho h thng truy nhp vtuyn WCDMA/UTRA FDD v c xem nh l mt trong nhng cng ngh tin tincho h thng thng tin di ng 3,5G. HSDPA bao gm mt tp cc tnh nng mi kt hpcht ch vi nhau ci thin dung lng mng, v tng tc d liu nh trn 10 Mbpsi vi lu lng gi ng xung. Nhng ci tin v mt k thut cho php cc nh khaithc c th a ra nhiu dch v tc bit cao, ci thin cht lng dch v (QoS) ca cc

dch v hin c, v t chi ph thp nht. Kh nng h tr tc d liu v tnh di ng caHSDPA l cha tng c trong cc phin bn trc y ca 3GPP.Cc kha cnh k thut trong ni dung HSDPA bao gm:

Pht knh chia s

iu ch v m ha thch ng

K thut pht a m

Yu cu lp li t ng nhanh HARQ.

Mc ch ca HSDPA l h tr truy nhp gi ng xung tc cao bng cch sdng mt knh chia s ng xung tc cao (HS-DSCH) v h tr thoi c tch hptrn knh DCH v d liu tc cao trn knh HS-DSCH trn cng mt sng mang (tngt nh DSCH trong Release 99).

Li ch ca HSDPA nh trnh by trong cc phn trc cho ng xung khi huht lu thng d liu 3G c trng i u tin l ng xung. Release 6 s ni v citin, nng cp ng ln, c gi l nng cp ng ln HSUPA (HSUPA: High SpeedUplink Packet Access). HSUPA s dng tng t cc c im chnh nh HSDPA, nhngthay v p dng cho ng xung th n li p dng cho ng ln. iu ny s lm tngtc truyn ng xung.

c) Nhn xt:Cc mng thng tin di ng th h 3 WCDMA v th h 3,5G HSDPA v HSUPAra i phn no p ng c nhu cu ca ngi tin dng nh: tc truyn d liu lnti 2Mbps i vi mng WCDMA, 10Mbps ng xung i vi cng ngh 3,5G), c thtruy nhp c nhiu dch v nh: truyn hnh hi ngh, truy nhp Internet tc cao,

Tuy nhin, cc mng di ng ny cn nhiu nhc im nh: tc truyn d liucha cao, do cht lng ca cc dch v thi gian thc cha cao, tc truyn d liuvn cn thp, c bit l tnh di ng km. Khi ngi dng i vo vng ph ca loi mng


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khc v d nh mng WLAN, WiMAX, m khng nm trong vng ph sng ca mnhth mng khng th phc v ngi dng c. Ngoi ra, vic s dng IPv4 cng gy ra cchn ch nh khng a ch trin khai theo yu cu ca mng, Kh nng trin khaicc dch v mi trn cc mng ny rt kh do cc hn ch v tc truyn thng v bngtn,

Trong tng lai, ngi s dng mong mun c s dng nhiu loi hnh dch vkhc nhau vi tc truyn cao ln ti hng trm Mbps, c cht lng tt, c th thmnhp vo mng t mi ni, c kh nng s dng cc dch v mi mt cch d dng,

2.2.2. M hnh mng thng tin di ng 4G:Phm vi ca mng 4G s bao ph ton b t cc phn truyn dn v tuyn, truyn

dn trong mng li n tn cc ng dng trn thit b u cui. Vi yu cu mt kin trcphn lp cho h thng, nhm m bo tnh m v tnh thch ng cho h thng, cc thnhphn chc nng trong mng s c chun ho theo cc chc nng chung v mi chc nngchung ny s i din cho chc nng trong 1 lp. Vi yu cu ny, chng ti phn chia cutrc mng trn c s ca 4 lp chc nng, tng ng vi 4 phm vi chc nng ca ccthnh phn trong h thng mng.


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Hnh 2.6: M hnh cu trc mng 4G

Vi m hnh trn, tnh tch hp h thng c gii quyt trn lp truyn dn. Cch thng s dng mi trng truyn v tuyn c tch hp chung vo mng RAN. Vi mhnh ny, cc mng truy nhp v tuyn c tch hp vo mt mi trng chung, c nghathu bao di ng u cui khi bt c mi trng truyn v tuyn no cng m bo hotng trong mng.


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Tnh tng tc gia cc lp gip cho m hnh c tnh m trong vic pht trin cngngh cng nh dch v trong tng lai. Vic x l cc cng ngh iu ch, m ho v truynhp trn cc lp tng tc cng to ra tnh thch nghi vi cc yu cu v dch v, m boy cc yu cu v tc dch v trong tng lai.

Chc nng mng truy nhp v tuyn:-C kh nng tch hp gia cc

thit b u cui-m bo tc dch v Chc

nng ca mng li:-Kt ni cc mng khc nhau:

mng khng dy v mng c dy.-Truyn ti traffic trn cc tuyn t ni gi n ch an ton.-nh tuyn lu lng-Chuyn i dng d liu all IP

Chc nng iu khin:-Cung cp nn tng h tng kt ni mng dch v-iu khin h thng:

.1+ Bo hiu

.2+ Lu lng

.3+ Bo mt (Security)

.4+ Billing

.5+ Mobity v Roaming

Dch v:Cung cp dch v s dng cho ngi dng

2.3.CHC NNG CC PHN T TRONG M HNH

2.3.1 .Cc phn t lp truy nhp v tuynNhim v chnh ca mng truy nhp v tuyn (Radio Access Network) l to v

duy tr cc knh mang truy nhp v tuyn (RAB) thc hin thng tin gia thit b ding (UE) vi mng li (CN). Thit b ngi dng y c th l cc MS, cc thit b xch

tay, Do , mng truy nhp v tuyn phi c kh nng giao tip vi cc thit b u cui,k c khi thit b u cui l thit b di ng khng dy thuc mng khc.

- Thit b u cui:


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Thit b u cui di ng trong mng 4G phi c s pht trin trong vic chy nhiudng ng dng khc nhau. iu ny cng m bo c hi tng li nhun cho cc nh cungcp dch v bng vic cung cp thm cc dch v gi tr gia tng. Do vy, cc thit b nyphi hot ng c tnh thch nghi v linh ng cao. Hin nay, cc thit b u cui di ngang trong qu trnh chuyn dch sang dng tch hp hi t. Cc nh sn xut cng cung

cp cc h iu hnh (OS) v phn mm dch v c tnh m, c kin trc dng lp v ckh nng chy trn nhng phn mm ca cc nh cung cp th 3. Tnh phc tp ca th hthit b u cui di ng ny s phi cha ng y cc iu kin v phn cng v phnmm nh sau:-Cc dng ng dng khc nhau v di ng ( nh email, MMS ) -Thchin c nhiu phn mm ghp ng dng ( nh d on kiu g, sontho vn bn, kim tra pht m ) -Thc hin trn nhiu dng h iuhnh (nh Symbian, SmartPhone,

Linux..) -Hot ng trn nhiu mi trng ng dng ( nh J2ME, .NET) -Hot ng

trn nhiu phng thc m ho v tuyn ( nh cdma2000,GPRS, GSM, W-CDMA, WiFi .) -Hot ng trn nhiu phng thc m ho( ting ni, hnh nh). -Hot ng trn nhiu phm vi giao thc mng ( Ipv4, IPv6 )-B vi x l mng vi cc ng dng ca di ng v tnh nng chung ca PC. -C b nhln.

-im truy nhp v tuyn RAP (Radio Access Point):Chc nng chnh ca RAP l thc hin x l lp 1 ca giao din v tuyn (m ha

knh, an xen, thch ng tc , tri ph,). N cng thc hin mt phn khai thc qun l

ti nguyn v tuyn nh iu khin cng sut vng trong.im truy nhp v tuyn cng tng t nh Node B trong 3G, tuy nhin c mt s

k thut mi nhm lm tng tc ng truyn, l:+ S dng Anten thng minhAnten thng minh l mt thnh phn khng th thiu c trong mng 4G. Mt h

thng anten thng minh l s kt hp ca nhiu phn t anten vi mt kh nng x l tnhiu t ng ti u mu thu v bc x ca n da vo s hi p ca mi trng tnhhiu. H thng 3.5G dng Truy nhp gi ng xung tc cao (HSDPA High SpeedDownlink Packet Access) da trn cng ngh giao din v tuyn W-CDMA d nh cung

cp tc ln n 10 Mbps bng cch s dng hiu qu hn ph tn s 3G hin hnh. Hthng 4G s dng mt ph tn khc (c th l 40 hoc 60 GHz) v c th cung cp ln n100 Mbps cho t bo WAN v n 1 Gbps i vi truy sut khng dy ni b.

Mc ch ca h thng anten thng minh l lm tng cht lng tn hiu ca hthng v tuyn bng cch truyn tp trung cc tn hiu v tuyn trong khi tng dung lngbng cch tng vic dng li tn s. Bng sau s lit k cc c tnh v li ch ca mt hthng anten thng minh.


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c tnh Li ch

li tn hiu: Tn hiu ng vo t Vng ph tt hn: Vic tp trung nng

nhiu anten c kt hp li ti u lng gi ra trong mt t bo s lm

cng sut c sn nhm thit lp mc tng vng ph ca trm gc. Cc yu

vng ph cho. cu cng sut tiu th thp hn dn nthi gian dng pin lu hn v kch

thc handset s nh hn

S loi b nhiu: Antenna pattern c Tng dung lng:Vic iu khin cht

th c to ra do cc ngun nhiu ngknh, vic ci thin t s tn hiu

lng cc null tn hiu chnh xc vgim nhiu kt hp vi vic s dng li

trn nhiu ca tn hiu thu c. tn s s lm tng dung lng mng. Kthut thch nghi (nh l a truy cp phnchia theo khng gian) h tr vic

s dng li tn s trong cng mt t bo.

Phn tp khng gian: Thng tin c Loi b a ng: C th gim tc

tp hp t mng anten c dng ti ng tri tr ca knh, cho php truyn

thiu fading v cc tc ng ca truyn tc bit cao hn m khng cn dng

a ng khng mong mun. b cn bng.

Hiu qu cng sut: kt hp cc ng Chi ph gim: Chi ph khuych i cngvo n nhiu thit b ti u tng ch sut, cng sut tiu th gim v tin

x l c sn trn ng xung. cy cao hn.

Bng 2.1: Cc c tnh v li ch ca h thng anten thng minh

.1+ Mt trong nhng k thut thch ng lin kt s c cp n gi l iu ch v mha thch ng (AMC Adaptation and Modulation Coding).Vi k thut AMC, iu ch vt l m ha c thch ng mt cch lin tc v cht lng knh thay cho vic iu chnhcng sut. Truyn dn s dng nhiu m Walsh cng c s dng trong qu trnh thchng lin kt. S kt hp ca hai k thut thch ng lin kt trn thay th hon ton kthut h s tri ph bin thin ca truyn dn v tuyn tc cao..2+ Ghp knh phn chia tn s trc giao OFDM: Tn hiu gi i c chia thnh cc sngmang nh, trn mi sng mang tn hiu l bng hp v v vy trnh c hiu ng a


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ng, to nn mt khong bo v chn vo gia mi tn hiu OMDF. OFDM cng to nnmt li v phn tp tn s, ci thin hiu nng ca lp vt l. N cng tng thch vinhng cng ngh m rng nng cao khc, nh l cc anten thng minh v MIMO. iu nykhng ch to nn li ch r rng cho thc thi lp vt l, m cn hp nht vic ci thin hiunng lp 2 nh vic a ra thm mt mc t do.

Hnh 2.7. Nguyn l OFDM

+ MIMO:MIMO s dng ghp knh tn hiu gia rt nhiu cc anten pht v thigian hay tn s. N kt hp vi OFDM x l cc tn hiu thi gian c lp ngay khi dngsng OFDM c thit k chnh xc cho knh. S kt hp gia OFDM v MIMO gip chovic x l n gin hn, hiu qu thu pht cao.

Ngoi ra lp thm nhp dch v cn s dng thm mt s k thut khc nh k thutSDR, tng thm tnh thch nghi cho UE trong mi trng mng tch hp chung.

-B iu khin truy nhp v tuyn (RAC: Radio Access Controller):

B iu khin truy nhp v tuyn (RAC) l phn t iu khin ca lp truy nhp vtuyn. Chc nng RNC dng iu khin lu lng v qun l ti nguyn v tuyn calp thm nhp v tuyn.

i vi mt UE th RAC thc hin kt cui c ng ni Iu truyn s liu ngis dng v c bo hiu tng ng t/ti mng li. RAC cng kt cui bo hiu iu khinti nguyn v tuyn, x l s liu lp on ni s liu t/ti giao din v tuyn. Cc thaotc qun l ti nguyn v tuyn nh sp xp cc thng s vt mang thm nhp v tuyn vicc thng s knh truyn ti giao din v tuyn.

Chc nng qun l ti nguyn v tuyn: RRM (Radio Resources Management) l mttp hp cc thut ton c s dng m bo s n nh ca ng truyn v tuyn v

QoS ca kt ni v tuyn bng cch chia s v qun l ti nguyn v tuyn mt cch chiu qu.

Trong 4G, thm mt s k nng mi nh yu cu pht li t ng nhanh (HARQ:Hybrid Automatic Repeat Request), lp lch nhanh, thi gian pht truyn dn ngn (TTI:Transmission Time Interval). Hai tnh nng quan trng nht ca cng ngh WCDMA nhiu khin cng sut vng kn v h s tri ph bin thin khng cn c s dng.


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2.3.2. Lp mng liMng li phi tch hp c tt c cc mng vin thng khc nh cc mng di ng,

WLAN, WiMAX, cc mng khng dy khc, t c iu th trong mng liphi c:

-Nh s pht trin mnh m ca NGN trn ton cu, ngi ta xy dng h thng

truyn dn trong mng li s dng giao thc IPv6, c bit vic s dng IP di ng mtcch linh hot gip cho vic kt hp gia cc mng.

-Cng a phng tin (MGW: Multimedia Gateway): Trong mng li, MGW thchin cc chc nng chnh l:+ Thc hin chuyn i d liu sang gi IP v ngc li

+ Thc hin chc nng chuyn mch, nh tuyn d liu t/ti mt vng dchv ca mng tu thuc vo v tr thu bao. MGW c iu khin bi MGCF.ng truyn cho cc cuc gi c

thc hin gia RNC v MGW. Thng thng MGW nhn cc cuc gi t RNC, chuyn i

d liu theo nh dng gi IP v nh tuyn cc cuc gi ny n ni nhn trn cc ngtrc gi. Trong nhiu trng hp ng trc gi s dng Giao thc truyn ti thi gianthc(RTP: Real Time Transport Protocol) trn Giao thc Internet (IP).

ni m mt cuc gi cn chuyn n mt mng khc, PTSN chng hn, c mtcng cc phng tin khc (MGW), MGW ny s chuyn ting thoi ng gi thnh PCMtiu chun a n PTSN. Nh vy chuyn i m ch cn thc hin ti im ny.Truyn ti kiu ng gi ny cho php tit kim ng k rng bng tn, nht l khi ccMGW cch xa nhau.

-Cc router: Trong mng li th cc router thc hin chc nng chnh l nh tuyn

cuc gi, a cc gi s liu t/ti cc ni theo ng yu cu. Cc router s dng giao thcnh tuyn tin tin trong mng IP nh BGP (BGP: Border Gateway Protocol). BGP l giaothc nh tuyn mt h thng mng t tr AS (AS: Autonomous System). H thng t tr y l mt mng hoc mt nhm mng c cng qun l chung vi cng chnh sch nhtuyn chung. BGP c s dng thay i thng tin nh tuyn cho Internet v l giaothc c s dng gia cc nh cung cp dch v ISP. Khi nh tuyn trong mng, da trnbng nh tuyn router gi cho cc router lng ging cc BGP lng ging thay ithng tin nh tuyn. Vic cp nhp nh tuyn BGP ch thng bo con ng ti u gitin ti mng ch.Cng vi vic s dng Tuyn lin vng khng phn lp CIDR (ClasslessInterdomain Routing), lm tng hiu qu ca vic phn lp s dng a ch IP. Khi BGPc s gia mt nhm mng (AS) th giao thc gi l BGP ngoi, cn nu nh cungcp dch v s dng BGP thay i nh tuyn trong mt AS, th giao thc l BGPtrong.

Ngoi ra, mng li cn s dng mt k thut mi na l Chuyn mch nhn a giaothc MPLS (MPLS: Multiprotocol Label Switching). Trong mi trng nh tuyn bnhthng, cc khung truyn t ngun n ch theo tng bc tng bc mt. nh tuynnh gi mi khung tiu lp 3 v thc hin bng nh tuyn xc nh bc nhy tip


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theo hng n ch. iu ny c khuynh hng lm gim dung lng mng bi v cc yucu CPU tp trung x l mi khung. Vi s bng n s ngi s dng Internet, cng vivic yu cu thay i v lu lng truyn ti th phng php c khng p ng c.MPLS thay i kiu nh tuyn tng bc bng cch cho php cc ng dn c th trongmng da trn cht lng v bng tn cn dng cho cc ng dng. Ni cch khc, la chn

ng dn by gi c th a vo lp 2. iu ny s lm tng hiu qu s dng lu lngtrong mng.

2.3.3. Lp chc nngLp chc nng iu khin dng iu khin h thng nh iu khin h thng bo

hiu, iu khin lu lng, bo mt thng tin, ng thi cung cp c s h tng cho lpdch v cung cp cc loi hnh dch v khc nhau. Chc nng iu khin gm c:.1 -Chc nng bo hiu: Bo hiu trong mng li l loi bo hiu tp trung. Do yu cu tchhp c cc mng khc nhau, do phi c phng thc bo hiu ging nhau cho cc

mng. mng li ngi ta xy dng cc trung tm m im bo hiu STP dng iukhin bo hiu trong ton mng v lin kt vi cc trung tm m im bo hiu ca ccnh cung cp dch v khc trong nc v trn quc t. Mt c im chnh trong mng 4Gl tt c u hi t trn nn IP, do giao thc bo hiu thc hin chnh trn mng 4G lSS7oIP. iu ny c thc hin thng qua Gateway bo hiu (SGW Signallinggateway). Chc nng chnh ca SGW l kt ni cc mng bo hiu khc nhau thng quavic chuyn i gia cc lp v iu khin thc hin bo hiu trong ni mng thng quagiao thc SS7oIP..2 -Chc nng bo mt: y l mt trong nhng chc nng quan trng trong h thng tnglai, n m bo cho vic thng tin ca ngi s dng c an ton, b mt v c tnh ring

t. Chc nng ny c thc hin thng qua Gateway an ninh (SEG - Security Gateway) cung cp v chnh sch an ton (proxy server) v bc tng la (firewall). Proxy server snh ra cc chnh sch v an ninh trong ton mng. Bn cnh , Firewall s thc hin phnvng an ninh v m bo tnh bo mt cho cc vng mng. thc hin bo mt thng tin,d liu s c i qua Security Gateway trc khi vo hoc ra khi vng bo mt. Vngbo mt ny thng l mng c qun l cht ch v SEG c t bin ca mng ny.Mt nh cung cp c th c 1 hoc mt vi SEG m bo tnh an ninh cho mng ngthi phng nga trng hp b s c trn 1 SEG n l gy nh hng n hot ng camng.

.1-Chc nng v Billing: Chc nng ny cung cp cho mng kh nng v nhn thc, tnhcc i vi cc dch v s dng trong mng. N thc hin nhn cc thng tin v tnh cct lp mng li, cn c vo cc c im v thng tin.2tinh cc ca tng UE, tng dch v chn lc thng tin v tnh cc. Cc thng tin nysau c nh dng li v c gi n cc h thng tnh cc tng ng v gi n ccUE..3-Chc nng v tnh di ng trong mng (Mobility): Chc nng ny c k tha t ccmng di ng th h trc. N c th hin qua cc thnh phn c ca mng nh HLR,


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VLR, EIR, AUC, MSCS v c cu iu khin handover, handoff ca thu bao..4+ Thanh ghi nh v thng tr (HLR): l mt c s d liu c t ti h thng ch cangi s dng lu bn sao chnh v l lch dch v ca ngi s dng. L lch dch vny bao gm: thng tin v cc dch v c php, cc vng khng c php chuyn mng,v thng tin v cc dch v b sung nh: trng thi chuyn hng cuc gi Cc thng tin

lin quan n vic cung cp cc dch v vin thng c lu trong HLR khng ph thucvo v tr hin thi ca thu bao. HLR thng l mt my tnh ng ring khng c khnng chuyn mng nhng c kh nng qun l hng trm ngn thu bao..5+ B ghi nh v tm tr (VLR): chc nng ca VLR l lu gi bn sao v l lch cangi s dng khch cng nh v tr ca UE trong h thng ang phc v mc chnhxc hn HLR..6+ EIR: thc hin qun l thit b ngi s dng UE. EIR lu tt c cc d liu lin quann UE. EIR c ni n MSC v SGSN qua ng bo hiu kim tra s c phpca thit b. Mt thit b khng c php s b cm.

.7+ Trung tm nhn thc (AUC): qun l cc thng tin nhn thc v mt m ha lin quann tng c nhn lin quan n tng c nhn thu bao da trn kha b mt. Vic qun lthu bao c thc hin thng qua kha nhn dng b mt duy nht cho tng thu bao.Kha ny c lu gi vnh cu v b mt trong b nh ca UE..8+ MSCS MSC server l b phn ci tin ca mng 3G so vi cc th h trc. Khi yucu v d liu s dng tng cao, s thu bao pht trin cao buc MSC truyn thng tchthnh 2 b phn chc nng ring bit: MSC Server dng iu khin chung vic nhtuyn cuc gi v phn chuyn mch PS + CS c tp trung trong chc nng ca MGW.Vi vic tch ra 2 thnh phn chc nng ny, MSCS tng c hiu qu hot ng cah thng thng qua vic iu khin tp trung cc MGW. N cng th hin c tnh linh

ng ng thi gip phn tng dung lng h thng..1+ Chc nng qun l di ng c thc hin ring bit trn mng li v mng RAN.Nhng tin trnh v truy nhp v tuyn c thc hin trn mng RAN. Do RAN qunl tnh di ng mc cell, trong khi mng li khng cn quan tm n cu trc cell. Ccqu trnh qun l di ng bao gm:.2+ Qun l trng thi UE v v tr ca n..3+ Qun l UE khi thm nhp vo mng..4+ Cp nht cc vng nh tuyn..2+ Qun l thay i Handover v phn nh li vng phc v cho cc UE thc hinhandover.

-Chc nng IP Multimedia: y l khi chc nng tin tin so vi cc mng di ng2G. im chnh ca khi chc nng ny l thc hin cc chc nng iu khin, qun l ccphin lm vic IP trong mng 4G. Cc thnh phn trong IP Multimedia bao gm:


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Hnh 2.8. Cu trc chc nng ca khi IP Multimedia

+ HSS (Home Subcriber Server): y l c s d liu chnh ca h thng trong lu gi ton b cc thng tin v thu bao v cc d liu lin quan n dch v IP Media.Cc thng tin ny bao gm s nhn thc thu bao, cc thng tin ng k, cc tham s truynhp . N bao gm cc chc nng tng t nh ca HLR, AUC trong h thng di ngchuyn mch knh nhng i vi cc thu bao v dch v chuyn mch gi.

+CSCF (Call Session Control Function): Chc nng iu khin trng thi

phin cuc gi, qun l vic thit lp, duy tr v gii phng cc phin a phng tinn v t ngi s dng. N bao gm cc chc nng nh: phin dch v nh tuyn.

+MRCF (Multimedia Resource Control Function): Chc nng iu khin tinguyn a phng tin. Khi c yu cu v cc phin lm vic a phng tin,MRFC s iu khin thc hin trn MRFP. MRFC cng m nhn chc nng gicc thng tin v tnh cc.

.1+ MRFP (Multimedia Resource Function Process): Cung cp ti nguync yu cu vch dn bi MRFC. MRFP thc hin nhng chc nng sau:

Kt hp gia cc dng d liu media u vo (c th t nhiu nh cung cp).

L ngun cung cp cc thng bo v a phng tin.

X l cc dng d liu a phng tin nh chuyn i m m thanh ..2+ MGCF (Media Gateway Control Function): Chc nng iu khin thit lp kt ni giamng chuyn mch gi v chuyn mch knh. N x l cc bo hiu dch v n t ccthu bao chuyn mch gi v thc hin chuyn i giao thc lm vic gia 2 mng.

2.3.4. Lp dch v:C chc nng cung cp cc dch v theo yu cu ca ngi dng, c cht lng cao


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nh: Cc dch v thng tin nh v, dch v a phng tin cht lng cao, dch v iukhin t xa, Vi m hnh ny, lp dch v l lp cung cp cc ni dung v d liu chongi s dng, ng thi n tng tc vi

2.4. CNG NGH TRN IP V IP DI NG

Trong h thng thng tin di ng 4G th IP di ng (MIP: Mobile IP) l mt vn rt quan trng. Vn thch thc i vi IP di ng l phi chuyn cc ng dng IP ncc kt cui di ng. Hin nay c hai phin bn MIP l MIPv4 v MIPv6 c thit k m bo h tr di ng bn trong mng IPv4 v mng IPv6 tng ng. Trong h thngthng tin di ng 4G, trong giai on u, chng ta s dng c hai loi ny, sau s dnthay th IPv4 c mng ton IPv6. Bi v MIPv6 c nhiu u im hn hn so viMIPv4 nh:

-nh a ch: Chng ta thy rng vi di 32bit th MIPv4 khng th nh ht ach cho cc thit b u cui c, cn MIPv6 th s bit dng nh a ch l 128bit

sc nh a ch cho ton b cc thit b.-Vic nh tuyn ti u ch l mt b phn thm vo cho MIPv4 nhng n li l mt

b phn tch hp ca MIPv6.-nh tuyn ti u MIPv4 vn i hi truyn ng hm lu lng gia cc my

tnh i tc v nt di ng. Trong MIPv6 cc gi c th gi i khng theo tunnel m ch cnb sung thm mt tiu nh tuyn

Cc loi truy nhp trong mng 4GTrong giai on pht trin u ca mng 4G, th tn ti c hai giao thc IP l MIPv4 vMIPv6, do yu cu phi c s chuyn i a ch trong qu trnh truy nhp khi cn thit.

Truy nhp t MS n cc dch v c cc kh nng sau:

1) MS IPv4 truy nhp dch v IPv4 qua mng IPv4:C MS, loi dch v, v c mng s dng chung mt giao thc l IPv4.Trng hp ny thng xy ra khi chng l cc dch v v thit b u cuica 2,5G v 3G. Khi MS v dch v trong cng mng, a ch IPv4 c nhnc s dng, cn khi dch v ngoi mng th phi s dng a ch IPv4cng cng nh tuyn, do b phin dch a ch mng NAT (NAT:Network Address Translator) c s dng.2) MS IPv6 truy nhp dch v IPv6 qua mng IPv6Trong trng hp ny, c MS, loi hnh dch v v mng cng u s dng

cng giao thc IPv6. Vi a ch IPv6, chng ta khng cn h tr ca b phin dcha ch mng (NAT). Khi c dch v v ngi dng nm cng trong mt mng thchng ta c th dng a ch v tr IPv6. 3) MS IPv6 truy nhp dch v IPv6 thngqua mang IPv4 Thng xy ra trong giai on u pht trin IPv6, yu cu c tunnelca IPv6 qua IPv4. C hai trng hp xy ra: a) MS IPv6 trong mng IPv6 nhngphn mng ngoi kt ni ti dch v l IPv4. b) MS IPv6 roam ti mt mng IPv4 4)MS IPv6 truy nhp dch v IPv4 Trng hp ny t xy ra trong mng 4G. Tuynhin khi xy ra nhiu th yu cu phi c NAT. 5) MS IPv4 truy nhp dch v ca


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IPv6 Trng hp ny yu cu phi c b phin dch a ch t a ch IPv4 sang ach IPv6. iu ny s c h tr bi mt Router hoc mt node no 6) MS IPv4truy nhp dch v IPv4 thng qua mng IPv6

Giao tip gia hai mng dch v: 7) Server IPv4 giao tip vi Server IPv4 thng qua mngIPv4 8) Server IPv6 giao tip vi Server IPv6 thng qua mng IPv6 9) Server IPv6

giao tip vi Server IPv6 thng qua mng IPv4 Trng hp ny thng xy ra tronggiai on u chuyn tip ln IPv6. Yu cu phi c ng hm (Tunnel) t IPv6qua IPv4. ng hm ny c th c thit lp trc hoc c thit lp t ng.10) Server IPv6 giao tip vi Server IPv4 Trng hp ny yu cu c b phin dcha ch mng-phin dch giao thc NAT-PT. Nu Server IPv6 l mt IMS, th ngoivic chuyn i v ring bit giao thc IP, cn phi chuyn i SIP/SDP qua mtALG. 11) Server IPv4 giao tip vi Server IPv6 Trng hp ny ging trng hp 412) Server IPv4 giao tip vi Server IPv4 thng qua mng IPv6 Trng hp ny txy ra, bi khi IPv6 chim u th trong mng v IPv4 khng th khi tt c dch

v s c trin khai IPv6.

CHNG 3

DCH V V CHT LNG DCH V TRONG MNG 4G

3.1. DCH V TRONG MNG 4GS cnh tranh gay gt trong lnh vc mng thng tin cng nh mng vin thng ang

din ra trong nhng nm gn y. Khi s cnh tranh gia tng, iu c bit quan trng ivi cc cng ty l xc nh v tr thch hp mang li thun li cho bn thn mnh, v chun b cho mi trng truyn thng mi ang ni ln. Trong mi trng ny, s hanhp, lin kt v cnh tranh ca cc thnh vin mi tham gia vo th trng phi hot ngtch cc tm ra phng thc mi, nhm gi v thu ht hu ht cc khch hng c timnng. Cc nh cung cp dch v hin nay ang c gng tm ra li i ring cho mnh tora s khc bit vi cc nh cung cp khc, chng hn nh tm kim phng thc mi ng nhn v ng gi dch v, thc hin gim cc chi ph hot ng,

Trong cc chng trc chng ta nghin cu v sao phi ln 4G? V n c th png c: tc truy nhp ln ti 200Mb/s, h tr roaming ton cu, da trn mng lithun IP, tng tc mnh vi cc mng khc cng tn ti Tt c cc yu t m ramt kh nng cung cp dch v di do cho mng 4G. C ba loi dch v ch yu trong 4G:dch v thi gian thc v thi gian khng thc, dch v ni dung, dch v qun l. Cc dchv ny gip cho cc nh khai thc c s iu khin, bo mt v tin cy tt hn ng thigim chi ph vn hnh. Nh , cc nh cung cp dch v c th nhanh chng c ngun thu


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mi. Phn sau s cp ti cc yu cu v dch v trong 4G v mt s dch v c th trinkhai trc mt.

3.1.2 Cc loi dch v cung cpCng ging nh h thng thng tin di dng th h 3, cc h thng thng tin di ng th

h 4 cng s cung cp cc loi dich v chnh: di ng, vin thng v internet nhng vi tc cao hn ln n 200 Mbit/s v iu ng quan tm hn l cc dch v a phng tin.Vi kh nng cung cp cc dch v tc bit cao, cc h thng thng tin di ng th h 4cung cp cc dch v cht lng tt, m bo: in thoi thy hnh, ti d liu nhanh, ccdch v thng tin v v tr, cc dch v thng mi di ng, cc dch v phn phi ni dung,cc dch v h tr ti d liu, cc dch v iu khin t xa, cc dch s liu tc bt thp,dch v s liu bt cao Cng c th phn chia dch v thnh hai loi chnh: Dch v c sv dch v a phng tin.Cc dch v c s gm:

-Cc dch v xa (Teleservice): L mt kiu dch v vin thng cung cp cc kh nngy bao gm c chc nng thit b u cui thng tin gia hai ngi s dng theo ccgiao thc c tha thun gia cc c quan qun l bao gm: in thoi, cc cuc gikhn, dch v bn tin ngn, cc dch v nhm thoi, pht thanh thoi.v.v

-Cc dch v mang (Bearer Service): L mt loi dch v vin thng cung cp khnng truyn dn tn hiu gia hai giao din ngi s dng mng.

-Cc dch v b sung (Supplementary): gm c:

.1 + Cc dch v b sung bao gm

.2+ Cc dch v b sung cho gi.3+ Cc dch v b sung a pha

.4+ Cc dch v b sung cho mt cng ng

.5 + Cc dch v b sung tnh cc

+ Cc dch v b sung hn ch cuc gi Ccdch v a phng tin gm:

.1 -Cc dch v im ti im i xng: Truyn hnh hi ngh (cht lng cao, thp), inthoi thy hnh, in thoi, truy nhp Internet th in t, in thoi IP.2-Cc dch v im ti im khng i xng: Y t t xa c hnh nh, th ting, truy xut cs d liu nh mua hng theo catalog video, video theo yu cu (tin tc, th thao, phim),bo in t, xut bn in t, Fax.

-Cc dch im a im a phng: Cc dch v phn phi thng tin gm ctin tc, d bo thi tit, truyn hnh di ng, truyn thanh di ng, Sau

y xin a ra mt s dch v in hnh cho mng 4G.


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Mt s loi hnh dch v in hnh cho 4G

Truyn thng tc cao (High Multimedia): Vi kh nng truyn sliu tc cao, 4G cho php truy cp internet vi tc rt cao, phc v chocc ng dng theo yu cu nh: video phn gii cao, audio cht lng hoc

cc ng dng mua bn trc tuyn vi cc sn phm hu hnh nh m nhc,phn mm

Dch v thoi (Voice telephony): 4G vn cung cp cc dch v thoikhcnhau ang tn ti nh ch cuc gi, chuyn cuc gi, gi ba bn, ccthuctnh AIN khc nhau, Centrex, Class, Tuy nhin cn lu l 4Gkhng cgng lp li cc dch v thoi truyn thng hin ang cung cp; dchv thvn m bo nhng cng ngh th thay i, ch yu dng thoi trnnn IP.

Tin nhn (Messaging): Khng ging nh dch v tin nhn thngthngtrong mng 2G, 3G ch n thun l bn tin text. Tin nhn trong 4Gchophp email i km v c th c s dng trong vic thanh ton trctuyncho cc dch v gia nh nh mua v xem phim, thanh ton ha ninnc,

Dch v d liu (Data Service) cho php thit lp kt ni thi gianthcgia cc u cui, cng vi cc c t gi tr gi tng nh tnh tin cyvphc hi nhanh kt ni, cc kt ni chuyn mch o (SVC- Switched

Virtual Connection), v qun l di tn, iu khin cuc gi, Tmli ccdch v d liu c kh nng thit lp kt ni theo bng thng v chtlngdch v QoS theo yu cu.

Dch v a phng tin (Multimedia Service): cho php nhiungitham gia tng tc vi nhau qua thoi, video, d liu. Cc dch v nychophp khch hng va ni chuyn, va hin th thng tin. Ngoi ra, ccmytnh cn c th cng tc vi nhau.


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Tnh ton mng cng cng (PNC: Public Network Computing):Cungcp cc dch v tnh ton da trn c s mng cng cng cho thngmi vcc khch hng. V d nh cung cp mng cng cng c th cung cp

khnng lu tr v x l ring ( chng hn nh lm ch mt trang web,lu tr/bo v/ d phng cc file s liu hay chy mt ng dng tnh ton).Nhmt s la chn, cc nh cung cp dch v mng cng cng c thcung cpcc dch v thng mi c th (nh hoch nh ti nguyn cng ty(ERP:Enterprise Resource Planning), d bo thi gian, ha n chng thc,

)vi tt c hoc mt phn cc lu tr v x l xy ra trn mng. Nhcungcp dch v c th tnh cc theo gi, ngy, tun, hay theo ph bnquyni vi dch v.

Bn tin hp nht (Unified Messaging): H tr cung cp cc dch vvoice

mail, email, fax mail, pages qua cc giao din chung. Thng qua cc giao

din ny, ngi s dng s truy nhp (cng nh c thng bo) tt c ccloi tin nhn trn, khng ph thuc vo hnh thc truy nhp (hu tuyn hay

v tuyn, my tnh, thit b d liu v tuyn). c bit k thut chuyn i

li ni sang file vn bn v ngc li c thc hin server ng dng cn

phi c s dng dch v ny.

Mi gii thng tin (Information Brokering): Bao gm qung co,tmkim v cung cp thng tin n khch hng tng ng vi nh cungcp. V

d nh khch hng c th nhn thng tin trn c s cc tiu chun cthhay trn cc c s tham chiu c nhn,

Thng mi in t (E-Commerce/ M-Commerce): Cho phpkhchhng mua hng ha, dch v c x l bng in t trn mng; c thbao


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gm c vic x l tin trnh, kim tra thng tin thanh ton tin, cungcpkh nng bo mt, Ngn hng ti nh v i ch ti nh nm trongdanhmc cc dch v ny; bao gm c cc ng dng thng mi, v d nh

qunl dy chuyn cung cp v cc ng dng qun l tri thc.

Tr chi tng tc trn mng (Interactive gaming): Cung cp chokhchhng mt phng thc gp nhau trc tuyn v to ra cc tr chitng tc(chng hn nh video games)

Thc t o phn tn (Distributed Virtual Reality): tham chiu nsthay i c to ra c tnh cht k thut ca cc s kin, con ngi,aim, kinh nghim, ca th gii thc, nhng ngi tham d vccnh cung cp kinh nghim o l phn tn v a l. Dch v ny yucu sphi hp rt phc tp ca cc ti nguyn khc nhau.

Qun l ti gia (Home Manager): Vi s ra i ca cc thit bmngthng minh, cc dch v ny c th gim st v iu khin cc h

thng bov ti nh, cc h thng ang hot ng, cc h thng gii tr, v cccngc khc ti nh. Gi s nh chng ta ang xem ti vi v c chung ca,

khng vn g c, ta ch vic s dng iu khin ti vi t xa xemctrn mn hnh ai ang ng trc ca nh mnh. Hoc chng hn nhchngta c th quan st c ngi nh ca mnh trong khi ang i xa, hocquanst c ngi trng tr ang chm sc em b nh th no khi ta anglmvic ti c quan.

Ngoi cc dch v nu trn cn c rt nhiu dch v khc c th trin khaitrong mi trng 4G nh: cc dch v ng dng trong y hc, chnh ph in t, nghincu o to t xa, nhn tin a phng tin, Nh vy cc dch v th h sau l rt a


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dng v phong ph, vic xy dng, pht trin v trin khai chng l m v linh hot.Chnh v vy n thun tin cho cc nh cung cp dch v v ng dng trin khai dch vn cho khch hng trong mng 4G.

3.1.2.1 Cc yu cu v dch v Dch v trn mng di ng 4G cn tun theo cc c tnh

sau: Dch v truy nhp khng ng nht: cc h thng 4G s phi cung cp nhiu dng

dch v ng vi nhiu loi thit b truy nhp u cui ca khch hng, cc mngtruyn dn v cc tiu chun dch v c mong i. Cc kin trc dch v u cuis phi khai thc phng tin phn mm c c s ng hp tc.

Mng truy nhp khng ng nht: C mt lot cc k thut mng s c s dngti cng mt thi gian bao gm cc k thut dng trong cc mng c nh EDGE,HSCSD, GPRS v c cc mng peer-to-peer, Wifi, bluetoothCc kin trc 4Gphi cung cp dch v trong sut nh tru tng ha cc mode khc bit c bn

trong hot ng ca mng. Nhn dch v: Kin trc dch v phi l mt thc th thng mi cung cp cc dch

v tng cng, vi ngha t nh cung cp dch v ny n nh cung cp dch vkhc, iu ny c thc hin nh kin trc mng v kin trc dch v.

Cc kin trc dch v trong mng di ng 4G phi tun theo cc tnh cht sau:

Cc mu n nh ti nguyn v dch v m: Cc khung dch v phi c to ra,thit lp v sp xp mt cch c lp trong cc min chng ln ca cc nh cung cpdch v. Vic cung cp cc ti nguyn, kh nng v trng thi hin thi cn c mt v trao i gia cc nh cung cp dch v lin kt vi nhau, l mc ch tibn li ti nguyn ti cc dch v c kt hp hay thc hin cc chc nngthng qua nh cung cp a phng.

Mu nguyn l v tha thun kh nng m: Hin nhin tha thun kh nng cnc hiu trong mi trng c nhiu s kt hp v phc tp hn cc mng inthoi truyn thng. y l yu cu t nhin ging nh mt th trng da trn khundng n nh dch v. Thc ra l cc k thut n nh ng da trn cc phngphp kinh t nh u gi in t, i i vi cc h thng thanh ton/qung co/thanhton thi gian thc cho s dng cc ti nguyn.

Qun l trch nhim: Cc k thut qun l trch nhim da trn quan h gia ccnh cung cp dch v vi ngi s dng v gia cc nh cung cp dch v vi nhau.Cc mi quan h ang tn ti gia cc nh cung cp dch v c da trn cc hpng gia cc hng kinh doanh ln mnh. Cc gi thit c th khng ph hp trongtrng hp cc nh cung cp dch v tng bt thng. Better business bureau cungcp mt tc dch v chia thnh cc bn tham gia tin cy t cc thnh vinkhng tin cy.


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Cc nhm dch v kt hp: Mt mu c s dng cho nh hnh kt hp dch vng thng qua cc k thut hp tc c yu cu. Cc tnh cht mong mun c thbao gm kh nng khm ph cc lin kt tim nng, cc k thut cho thit lp ccmi quan h trch nhim, cho qun l cc lin h trch nhim phn tn v qun lcc cp thay i ca cc h thng trong sut. Ch l khng phi tt c cc linkt u l cc i tc tim nng. V d nh cung cp WiFi c th kt hp vi mtnh cung cp dch v thoi di ng t bo cung cp hai phn tch bit ng d liucn bng thng ln v cc lung thoi cn bng thng thp trong vic h tr cc ngdng hi tho a phng tin ca ngi s dng. Trong trng hp ny, gi s ltrong cng ln cn ca ngi s dng tn ti mt in thoi di ng v mt s loithit b vi tnh mn hnh lin, cc thit b ny hnh thnh mt lin kt cho mt ngdng h tr trong sut vi dch v audio di theo ng mng in thoi cn dch vvideo di theo ng mng WiFi.

Kh nng chu li dch v: Cc lin minh c th, nhm dch v kt hp cung cp c

hi cho kh nng chu li tin tin. Cc tnh cht mong mun trong kha cnh nybao gm khm ph li, ng k dch v v pht hin nh mode a truy nhp.

3.1.2.2 Xu hng dch v trong mng 4G xc nh c cc dch v trong mng 4G cng nh chin lc u t

ca cc cng ty, xu hng pht trin cc dch v trong tng lai l vn rt cnxem xt.

Trc ht chng ta cn quan tm n xu hng ca dch v thoi. y ldch v ph bin, lu i v thu nhiu li nhun nht t nhng ngy u cho n nay. Do, dch v thoi truyn thng s tip tc tn ti trong thi gian di. Sau , mt phn dchv truyn thng ny chuyn sang thng tin di ng v thoi qua IP.

i vi dch v truyn thng a phng tin, hin nay H.323 l mitrng cho gii php thoi qua giao thc IP v cc dch v a phng tintng i n gin. Tuy nhin, sau SIP s thay th cho H.323 do SIP cnhiu u im hn v thch hp vi cc dch v truyn thng a phng tin

phc tp.

Trong tng lai, tnh cc dch v theo ni dung v cht lng, khng theothi gian s chim u th.

Cui cng, phng thc truy nhp mng, ra lnh, nhn thng tin, bng lini (voice portal) s l mt chn la trong tng lai. Hin nay, k thutchuyn i t li ni sang file vn bn v ngc li ang pht trin mnh.


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Mc tiu chnh ca cc dch v trong 4G l cho php khch hng c th ly thng tinh mun bt k dng no, trong bt k iu kin no, ti mi ni v dung lng ty .Da trn cc khuynh hng c cp trn, sau y l mt s c tnh dch v quantrng trong mng 4G:

Lin lc thng tin rng khp, thi gian thc, a phng tin, m bo tincy, thn thin trong vic lin kt cc thu bao, truy nhp tc cao v truynti thng tin vi bt k phng tin no, vo mi lc, ti mi ni,

Nhiu thc th v cc phn t mng thng minh c phn b trn tonmng. N bao gm cc ng dng cho php truy nhp v iu khin cc dchv mng. N cng c th thc hin cc chc nng c th thay th cho nhcung cp dch v hoc mng. Ta c th xem n nh mt tc t qun l c ththc hin gim st ti nguyn mng, tp hp cc s liu,

D dng s dng. Khch hng khng b nh hng t cc qu trnh tp trung,

x l v truyn dn thng tin phc tp ca h thng. N cho php khch hngtruy xut v s dng cc dch v mng mt cch n gin hn, bao gm ccgiao din ngi dng cho php tng tc t nhin gia khch hng v mng.Khch hng c cung cp cc thng tin hng dn, cc ty chn, cc tngtc qun l xuyn sut cc dch v. Ngoi ra n cn cung cp cc menu khcnhau cho nhng ngi cha c kinh nghim ngc li vi nhng ngi ckinh nghim, v cung cp mt mi trng thng nht cho cc dng thng tin.

Cho php khch hng qun l h s cc nhn, t d phng cc dch v mng,

gim st thng tin tnh cc, c nhn ha giao din ngi dng, to ra v dphng cc ng dng mi

Qun l thng tin thng minh, gip ngi dng qun l s qu ti ca thngtin bng cch cung cp cho h kh nng tm, sp xp v lc cc bn tin hocd liu, qun l chng cho mi phng tin.

1. 3.2. CHT LNG DCH V TRONG MNG DI NG 4G2. 3.2.1 Khi nim QoS

3.2.1.1 Khi nim QoS theo ITU

nh ngha v QoS theo tiu chun E800 ca ITU: Cht lng dch v vin thngl kt qu tng hp ca cc ch tiu dch v, th hin mc hi lng ca i tng sdng dch v .

Hnh 3.1 m t mt cch tng qut cc khi nim c bn v QoS theo khuyn nghca ITU-T. Cc khi nim c trnh by trong s c th c p dng nh gi mcQoS c th t c trong thc t, hng ti mc QoS theo ch tiu hoc cc yu cu m tc tnh thit k mng. Tuy nhin tng khi nim trong s c th mang ngha th hin


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theo mc tng th hay ring l, nhng khi nim c trnh by trong s c th cha thhin ton b nhng mi lin h ca chng. Kha cnh cn quan tm khi nh gi tng thmt dch v l quan im s dng dch v. Kt qu nh gi ny th hin mc hi lngca nhng ngi s dng dch v. iu ny s c xem xt theo cc ni dung sau:

Khi nim QoS. Mi quan h gia QoS v NP

Cc ch tiu v QoS v NP

Mt iu hin nhin l mt dch v c s dng ch khi n c cung cp vngi ta mong mun nh cung cp dch v c s hiu bit c th v cht lng cacc dch v m h pht hnh. Theo quan im ca nh cung cp dch v, khi nimNP l mt chui cc tham s mng c th c xc nh, c o v c iuhnh c th t mc hi lng ca ngi s dng v cht lng dch v. Nhcung cp dch v c nhim v phi t hp cc tham s NP khc nhau thnh mt b

ch tiu c th va m bo cc nhu cu li ch kinh t ca mnh ng thi phitho mn mt cch tt nht cho nhng ngi s dng dch v.

Trong khi s dng dch v, thng thng ngi s dng ch bit n nh cung cpdch v. Mc hi lng ca ngi s dng dch v ph thuc vo cht lng dch v QoShay nhng cm nhn sau cng ca khch hng v thc hin dch v

H tr dch v (service support performance)

Khai thc dch v (service operability performance)

Nng lc phc v (serveability performance)

An ton dch v ( service security performance)


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Hnh 3.1: Khi nim QoS v mi quan h QoS vi cht lng mng

H tr dch v: l kh nng ca mt t chc cung cp dch v v tr gip trong

vic s dng dch v cung cp .Khai thc dch v: l kh nng vn hnh dch v mt cch thnh cng v d dng

ca ngi s dng, bao gm cc c tnh v thit b u cui, cc m hiu v tin bo dhiu

Mc an ton dch v: l mc bo v chng li s gim st tri php, s dnggian ln, quy ph, thao tc sai, thm ho thin nhin.


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Nng lc phc v: l kh nng dch v t c khi ngi s dng yu cu v tiptc c cung cp m khng c s suy gim qu mc trong khong thi gian s dng(trong nhng s thay i xc nh v cc iu kin khc nhau). Kh nng phc v l phnph thuc vo c tnh mng nhiu nht v tip tc c chia thnh ba khi nim:

-Nng lc truy nhp n dch v (service accessibility performance): l kh nng dchv t c trong nhng s thay i xc nh v cc iu kin khc nhau khi cyu cu bi ngi s dng

-Nng lc duy tr dch v (service retainability performance): l kh nng ca mt dchv tip tc c cung cp trong cc iu kin a ra trong khong thi gian s dng.

-Mc hon ho ca dch v (service integrity performance): l mc dch v ccung cp m khng b suy gim qu mc, mt khi t c

Nng lc tnh cc chnh l thng s nh gi v ghi cc v ho n, trong

phn xc sut v tnh cc sai, tnh cc tha v tnh cc thiu thuc v ch tiu ca QoS.Phn nh gi v chnh xc ghi cc l ch tiu ca cht lng mng.

Qua hnh v 3.1, chng ta cng thy rng nng lc phc v s c mi lin h vicc khi nim thuc phn cht lng mng nh kh nng x l lu lng, tin cy, tinguyn v phng tin cng nh cht lng truyn dn (gm c nng lc truyn lan). iuny c ngha l QoS c mi quan h cht ch vi cht lng mng. Cht lng mng l khnng ca mng cung cp cc chc nng lin quan n thng tin gia nhng ngi s dng(theo ITU-E800).

Dch v vin thng l cc hot ng trc tip hoc gin tip ca cc doanh nghip

cung cp cho khch hng kh nng truyn, a v nhn cc loi thng tin thng qua mngli vin thng cng cng. QoS c xc nh bng cc ch tiu nh tnh v ch tiu nhlng. Ch tiu nh tnh th hin s cm nhn ca khch hng, cn ch tiu nh lngc th hin bng s liu o c th.

C rt nhiu t chc a ra cc khi nim QoS nh ISO/IEC, RM-ODP, ETSI tuynhin cc khi nim ny khng hon ton ging nhau. Sau y s trnh by thm khi nimQoS theo ETSI.

3.2.1.2 Khi nim QoS theo ETSI

Theo ETSI th quan im ca ngi s dng /khch hng vmc QoS l s m t cc tham s sau: -Tng hp nhngkt qu m ngi s dng/khch hng nhn c, bao gm cnhng nguyn nhn lin quan n mng -Khng ph thucvo nhng hiu bit ca khch hng v thit k mng chi tit-Nm c cc kha cch ca dch v theo quan im cangi s dng/khch hng -Cc khi nim lin quan nmng c m t theo mt ngn ng chung, d hiu bi


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ngi s dng/khch hng v nh cung cp dch v. -C shiu bit gia ngi s dng/khch hng v nh cung cpdch v

Hnh 3.2: Mi lin h gia cc khi nim QoS theo ETSI

3.2.2 Kin trc QoSC rt nhiu kin trc QoS c a ra cho mng di ng 4G. Sau y s gii

thiu mt kin trc QoS: m bo QoS cn phi c kin trc QoS. N l mt framework m bo cht

lng t u cui n u cui v cung cp cc chc nng tch hp v qun l iu khinQoS, v giao din QoS

Cc nguyn tc ca QoS: -Tch hp (Integration): c kh nng cu hnh li, c th d on

truc v c th qun l c thng qua tt c cc lp mng-Phn tch (Separation): tch gia bo hiu v d liu truyn.-Trong sut (Transparency): tch bit gia QoS v ng dng

-Thc thi (performance): X l cc giao thc mt cch c hiu quNh vy kin trc QoS lin quan n: QoSspecification, QoS mechanism, Traffic Engineering,

QoS supporting protcol. QoS specification: -Yucu QoS mc ng dng -K hoch chnh sch QoStrong mi lp -Cu hnh v duy tr c ch QoS -Theotnh ng b, kh nng thc thi, mc dch v, chnh

sch, gi,... QoS Mechanism -Cung cp QoS: sp


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xp QoS, kim tra kt qu vo -iu khin QoS: theotrng thi, theo k hoch, chnh sch, iu khin,ng b. iu ny lin quan n qun l lu lng

-Qun l QoS: gim st QoS, duy tr QoS QoSsupporting protcol -H tr chuyn vng ca Micromobility: CIP, Hawaii, HMIP

-H tr chuyn vng ca Macro mobility: MIP v4, MIP v6 Tuy nhin cctiu chun v cht lng ca dch v 4G cng nh 3G vn cn l vn anguc cc nh chuyn mn, cc hng trn ton th gii nghin cu. Hin ticha c cc tiu chun c th no v cht lng dch v ca mng 4G.

cng l d hiu v theo kin trc QoS trn: nh gi ca ngi s dng:h mi s dng cc dch v th h mi cho nn cha c c s nh gi vcht lng. Bn cnh qu trnh pht

trin mng cng nh dch v mng vn ang pht trin mnh v thit b, v cht

lng dch v theo xu hng ngy mt tt hn v hon thin hn.

QoS ca cc ng dng: cc ng dng mi giai on u ca s pht trin nncha c nh gi mt cch chnh xc, c th v QoS

Hiu nng ca cc thit b u cui, hiu nng ca mng, v hiu nng ca ccphn t mng: cc hng sn xut thit b trn th gii cng tp trung vo vn lin quan n cht lng dch v trong cc sn phm ca mnh, l mt uth cnh tranh quan trng. Tuy nhin qu trnh vn ang pht trin.

Cc dch v v ng dng ca mng di ng 4G c phn loi theo tiu chun chungca ITU-T/-R. Tuy nhin ng trn quan im QoS chng ta c th phn loi dch v theonm mc sau:

-m bo chc chn (deterministic guarantee)

-m bo thng k (Statistical guarantee)

-Mc tiu ch ( Target objectives)

-N lc nht (best effort)

-Khng m bo (no guarantee)

-m bo chc chn: lun lun cung cp cc dch v vi QoS theo yu cu hoc tthn trong mi hon cnh.

-m bo thng k: cho php QoS c th khng c nh yu cu trong mt khongthi gian no .

Ba phng php cui khng m bo QoS, nhng chng ta phn loi c ccbin php k thut hp l t c QoS mong mun. Vi h thng target objectivesmng s c gng tho mn cc yu cu, sau cn c vo mc tiu m mng c th a ra


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bin php hp l nh quyt nh u tin scheduling. Vi h thng best effort (v dmng internet), mng s cung cp QoS nh nhau cho ton b cc thu bao. No guaranteecng tng t nh best effort.

Hnh 3.3: Kin trc dch v trong mng di ng th h sau

3.2.3 Cc tham s QoS trong mng di ng 4GPhn loi Tham s Ghi ch

tr Thi gian mt bn tin( delay) c truyn

Tnh ng lc Thi gian p ng(Timeliness) (response time)


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Jitter bin ng ca trhay thi gian phn hi

Tc d liu mc h

thng

Bng thng Tc d liu mc mg(Bandwidth) dng

Tc truyn ti Kh nng x l/s(Transaction rate

tin cy

MTTF (Mean time tofailure)

Khong thi gian hotng bnh thng gia ccs c

MTTR (Mean time torepair)

Khong thi gian t khi cs c ti lc bt u hotng bnh thng

(reliability) MTBF MTBF=MTTF+MTTR(Mean time between

failures)

Phn trm thi gian s MTTF/MTTF+MTTRdng

T l li hay mt mt T l li mng

Cm nhn ca khchhng (Perceived QoS)

- Picture detail - Videosmoothness -Video/audiosynchronisation

- phn gii nh

Tin phi tr thit lp

Per-use cost kt ni, hay truy cp li ti

Cc (Cost) ti nguyn

Per-unit cost

Tin phi tr cho mt nv d liu hay n v thigian (tc l cc kt ni

v cc per query)

S tin cn Ngn chn truy cp thng

(Confidentiality) tin


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Tnh bo mt (Security)

Tnh nguyn vn(Integrity)

m bo d liu khngthay i trong qu trnhtruyn dn

Non-repudiation of

sending or delivery

Cc ch k xc nhn

ngi gi hay ngi nhnKim chng nhn dng

S xc nhn ca ngi s dng hay nh

(Authentication) cung cp dch v ngn

chn s gian ln....

3.2.4 Thch thc v cht lng dch v trong mng di ng 4GTrong cc mng v tuyn, cht lng dch v c da trn o lng hiu qu ca

mt h thng c phn nh t cht lng truyn dn ti cc dch v ang c (v d 4G yucu tin cy t ti 99,99%). QoS trong mng 4G phi i mt vi rt nhiu kh khn.Khi xem xt QoS phi quan tm ti rt nhiu yu t trong mng 4G nh: c tnh knh tc bin thin, n nh bng tn, mc dung sai li v h tr chuyn giao gia cc mngv tuyn khc nhau, H tr QoS xut hin trong ng gi, truyn dn, nh tuyn v ticp mng. QoS c th khc nhau ti cc cp hot ng khc nhau. Cc c tnh knhtc thch ng cho cc ng dng thc t 4G c rng bng v cc yu cu truyn dnkhc nhau. Theo yu cu cung cp mt mng vng chc cho truy nhp ti cc ng dng 4Gh tr d cp pha trn, mng 4G phi oc thit k trn c hai phong din mm do

v quy m. Cc tnh cht knh tc thay i phi c xem xt trn hiu nng ngi sdng yu cu v m bo qun l mng hiu qu.

Ph l mt ti nguyn hu hn. Trong cc h thng v tuyn hin ti cp php tn sv qun l ph hiu qu l vn mu cht. Vi cc h thng 4G, n nh rng bng tnvn cn l mt s quan tm ln. S quan tm khc l ng hp tc gia cc k thut bohiu c nh hng s dng trong 4G (v d 3xRTT, W-CDMA).

So snh vi mng 2G v 2.5G hin ti, 4G c nhiu kh nng khc phc li nhchp nhn hay loi tr khi mng s c, vng ph km, rtt cuc gi. K thut 4G ha hnci thin QoS nh s dng cc k thut chun on v cc cng c bo hiu. 4G s h tr

tt hn roaming v chuyn giao gia cc mng khc nhau. 4G thm ch c th h trroaming gia cc mng c cng ngh khc nhau nh s dng k thut bo hiu LAS-CDMA. Mt gii php khc l v tuyn nh ngha bng phn mm cng c th h trroaming gia cc mng p dng cng ngh khc nhau.

Phn ln cc thch thc v QoS trong 4G u dang c nghin cu v cc giiphp ang c pht trin. Cc nh nghin cu rt tin tng 4G s to ra cht lng dchv hn hn mng 2G v 2.5G hin ti.


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3.2.5 Bo mt dch v

C nhiu thnh phn yu cu v bo mt mc cao trong mng 4G:

Khch hng/ thu bao cn phi c tnh ring t trong mng v cc dch v ccung cp, bao gm c vic tnh cc. Thm vo , h yu cu dch v phi c tnh

sn sng cao, cnh tranh lnh mnh v bo m s ring t ca h.

Cc nh vn hnh mng, cc nh cung cp dch v, cc nh cung cp truy nhp ucn phi bo mt bo v hot ng, vn hnh v kinh doanh ca h, ng thi cth gip h phc v tt khch hng cng nh cng ng.

Cc quc gia khc nhau yu cu v i hi tnh bo mt bng cch a ra cc hngdn v to ra cc b lut m bo tnh sn sng ca dch v, cnh tranh lnh mnhv tnh ring t.

S gia tng ri ro do s thay i trong ton b cc quy nh v cc mi trng k

thut cng nhn mnh s cn thit ngy cng gia tng v tnh bo mt trong mng.Cc vn cn bo mt

Cc vn ny c thc hin trong mi dng cu hnh 4G, bao gm cc dng truyndn khc nhau v x l cc nguy c sau y:

T chi dch v: Nguy c ny tn cng vo cc thnh phn mng truyn dn bngcch lin tc a dn dp d liu lm cho cc khch hng khc khng th s dngti nguyn mng.

Nghe trm: Nguy c ny nh hng n tnh ring t ca mt cuc ni chuyn bngcch chn ng dy gia ngi gi v ngi nhn.

Gi dng: Th phm s dng mt mt n to ra mt c tnh gi. V d anh ta cth thu c mt c tnh gi bng cch theo di mt m v ID ca khch hng,bng cch thao tc khi to tin nhn hay thao tc a ch vo/ra ca mng.

Truy nhp tri php: Truy nhp vo cc thc th mng phi c hn ch v phhp vi chnh sch bo mt. Nu k tn cng truy nhp tri php vo cc thc thmng th cc dng tn cng khc nh t chi dch v, nghe trm hay gi dng cng

c th xy ra. Truy nhp tri php cng l kt qu ca cc nguy c k trn. Sai thng tin: Trong trng hp ny, d liu b ph hng hay lm cho khng th s

dng c do thao tc ca hacker. Mt hu qu ca hnh ng ny l nhng khchhng hp php khng truy xut vo ti nguyn mng c. Trn nguyn tc khngth ngn cn khch hng thao tc trn d liu hay ph hy mt c s d liu trong

phm vi truy nhp cho php ca h. T chi khch hng: Mt hay nhiu khchhng trong mng c th b t chi tham gia vo mt phn hay ton b mng vi cckhch hng/ dch v/server khc. Phng php tn cng c th l tc ng lnng truyn, truy nhp d liu hay sa i d liu. Trn quan im ca nh vnhnh mng hay nh cung cp dch v, dng tn cng ny gy hu qu l mt nim


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tin, mt khch hng dn ti mt doanh thu.

Cc gii php tm thiCc bin php i ph c th chia thnhhai loi sau: phng chng v d tm.

Sau y l cc bin php tiu biu: Nhn thc Ch k s iu

khin truy nhp Mng ring o

Pht hin xm nhp Ghi nht kv kim ton

M ha Trong mi trng hp cn lu rng cc h thng vn hnh trong ccthnh phn ca mng 4G cn phi bo v cu hnh nh mt bin php i ph c bn:

Tt c cc thnh phn khng quan trng (chng hn nh cc cng TCP/UDP) phi tnh trng th ng.

Cc c tnh truy nhp t xa cho truy nhp trong v truy nhp ngoi cng phi thng. Nu cc c tnh ny c ng nhp, tt c cc hot ng cn c kimtra.

Bng iu khin server iu khin tt c cc c tnh vn hnh ca h thng cn cbo v. Tt c cc h thng vn hnh c mt vi c tnh c bit bo v bng iukhin ny.

H thng hon chnh c th ng nhp v kim tra. Cc log file cn phi c gimst thng xuyn.

Thm vo , cn phi nhn mnh rng mng t n phi c cch bo v cu hnh. V dnh nh vn hnh phi thc hin cc cng vic sau:

Thay i password l. Lm cho cc port khng dng phi khng hot ng c. Duy tr mt nht k password. S dng s nhn thc cc thc th. Bo v iu khin cu hnh.


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CHNG 4

L TRNH TIN LN MNG THNG TIN DI NG TH H TH 4 CHOVIETTEL MOBILE

4.1. C IM MNG THNGTIN DI NG VIETTELVietTel tuy l mng mi c hn mt nm nhng tnh n ngy 01/3/2006 c hn

hai triu vt qua S-fone tr thnh nh cung cp dch v ln th 3 ti Vit Nam. Viettelang y mnh pht trin thm cc vng ph sng v mua sm thm cc thit b mi. Vihn 1700 trm thu pht sng hin ti v trn 1000 trm pht sng s u t vo nm 2006mng ny s m rng vng ph sng v phc v nhu cu pht trin ca thu bao. V dchv chuyn vng quc t, d kin, n u qu II/2006 thu bao Viettel s lin lc c tihu ht cc nc s dng cng ngh GSM (hn 200 mng GSM khc trn th gii).

Th trng di ng Vit Nam hin ti c nh gi l tng trng ng th 2 trn thgii sau Trung Quc, s thu bao khng ngng tng, do nhu cu v vic s dng ccdch v ngy cng cao. Trong thi gian gn y, mng Viettel lin tc pht trin c v vngph sng v cc loi hnh dch v.

Hin nay Viettel a vo s dng GPRS p ng nhu cu s dng cc dch v dliu ngy cng cao ca cc thu bao. Cc dch v ch yu ca GPRS nh: WAP, truy nhpInternet c hai phng thc truy nhp Internet bng GPRS l truy nhp gin tip v truynhp trc tip. Dch v nhn tin a phng tin. Video, xem cc on phim ti v, xemvideo trc tuyn. Ngoi ra cn c dch v thng mi in t di ng, dch v ngn hng,qung co trn in thoi di ngdo gi cc cn cao nn cc loi hnh dch v ny cha

thu ht c nhiu thu bao ch thu ht c nhng thu bao c thu nhp cao. Da trnnhu cu th trng Vit Nam, hin ti chng ta thy rng nhu cu chnh trong thng tin ding vn l dch v thoi truyn thng, dch v d liu cng bt u tng trng, theo don tng s thu bao c nhu cu dch v d liu chim khong 50% vo nm 2010. Vii sng thu nhp ngy cng cao ca ngi dn, nhu cu cc dch v cht lng tt ngycng ln, th mng di ng Viettel ngy cng phi nng cp p ng c cc nhu cuny. Mt khc, xu hng chung trn th gii l hi t tt c cc mng vin thng li vinhau. Do , yu cu pht trin mng thng tin di ng ln th h 4G c tc cao, sdng all IP c kh nng tch hp vi cc mng khc l yu cu tt yu ca mng di ngViettel. Vi nn tng h tng c s, cng vi s pht trin ca mng di ng Viettel hinnay, chng ta thy rng mng thng tin di ng ny hon ton c th pht trin ln 4G trongtng lai. pht trin cc h thng GSM hin ti ln 4G, nh khai thc dch v cn ch ti nhng vn sau:

Pht trin dch v: Song song vi vic gim gi cc, cn pht trin cc dch v mi


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theo hng i ln thng tin di ng th h th t nh GPRS, EDGEnhm thu ht thubao v tin gn n s tng thch vi cc h thng 4G. S xut hin nhng kh khn lntrong vic ng thi gim gi cc v pht trin dch v, v gi cc gim s lm gim linhun tc thi ca doanh nghip, dn n cn tr s pht trin cc dch v mi. Nhng yl hai vn m cc nh khai thc vin thng cn phi thc hin nu mun cnh tranh hiu

qu trong bi cnh m ca ca th trng vin thng.

Quy hoch mng: Quy hoch mng hin nay ang l mt vn cn quan tm i vicc mng di ng. Khi mng li pht trin cng ln, s lng thu bao cng tng th hintng nhiu gia cc ln cn cng tng tng ng. Do vn ti u ho mng thng tindi ng trong qu trnh pht trin i ln thng tin di ng th h th ba l rt cn thit.

Xy dng c s h tng vin thng: iu kin tin quyt pht trin h thng di ngbng rng l cc mng xng sng backbone phi c dung lng ln v cng nghtng thch vi mng core network ca 3G, 4G. Ni mt cch khc, thc ht phi phttrin cc dch v c tc cc v linh hot nh ATM ng thi cng phi tng tc

cho cc kt ni vo Internet v mc ch chnh ca vic tng tc truyn d liu cho thubao l tng tc thuy cp Internet. M hnh pht trin ca cng ngh di ng t 2G ln4G:

Hnh 4.1: M hnh pht trin ln 4G t h thng GSM

4.2. TIN TRNH TRIN KHAI LN 4G T 2.5 G CA MNG VIETTEL

c th a ra c cc bc pht trin theo mi giai on, chng ta cn xem xt xuhng pht trin mng 3G trong tng lai. Phin bn 3GPP R5 hng ti vic pht trinmt mng ton IP. Cc bc chuyn i cho cc nh khai thc GSM nc ta hin nay ltrin khai mng li d liu gi GPRS (IP) ri mi n WCDMA s l phng n ph hpnht vi mt iu kin duy nht l mng li IP ca GPRS phi c s dng lm c s chomng li ca mng 3G WCDMA. tin ln 4G, c th chia thnh 5 giai on. Giai on

u kt hp GSM vi GPRS, giai on th hai thit lp mng UMTS, giai on ba chuynsang mng li c s IP, giai on l mng c s IP, v cui cng l trin khai mng 4G.Cc bc chi tit c gii thiu nh sau:

Giai on 1: Kt hp GPRS vo mng GSM

Giai on ny d kin hon thnh trong nm 2006. Thc cht vn y l ch yu


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nhm vo vic chun b mt mng li IP cho 3G trong tng lai gn vi hai nt mng chodch v d liu gi l GGSN v SGSN. GGSN c kt ni vi mng GSM ang c quaSGSN v PCU (Packet Control Unit). PCU c lp t pha BSC vi mc ch b sungchc nng iu khin gi cho BSC trong qu trnh khai thc dch v GPRS.

Cu trc mng GPRS c xy dng trn nn ca h thng GSM hin ti. H thngmng truy cp ca GSM c gi nguyn m ch cn nng cp phn mm. C th BTS,BSC phi c nng cp phn mm, MS phi c chc nng GPRS, HLR/VLR, AuC v EIRcng cn c nng cp phn mm qun l dch v d liu. Phn h mng li c bsung thm phn chuyn mch gi vi hai nt chnh: Nt h tr dch v GPRS(SGSN) vnt h tr cng GPRS(GGSN). Bng cch ny, vi nng cp khng ng k, h thng cth cung cp dch v d liu gi cho thu bao di ng rt thch hp vi cc dch v d liukhng i xng. Giai on ny ch yu nhm vo vic chun b mt mng li IP cho 3Gtrong tng lai gn vi hai nt mng cho dch v d liu gi l GGSN v SGSN.

Chc nng nh tuyn chnh c thc hin thc hin thng qua cc im h tr, bao

gm: GGSN v SGSN. Bn cnh c mt mng backbone ni cc im GGSN vSGSN vi nhau, v mt cng bin gii kt ni vi cc mng PLMN khc. Ngoi ra cnc server qun l tn min phc v cho mc ch bin dch a ch.

Hnh 4.2: Cu trc mng GSM-GPRS tng tc trn giao din v tuyn, EDGE thay th phng thc iu ch GMK ca

GSM (1bit/ symbol) bng iu ch 8-PSK, tng ng vi 3bit/symbol. Tc symbol camt knh vt l trong EDGE l 271 kbit/s, tc l 69,2 kbp/khe thi gian, gp 3 ln so vitc 22,8 kbit/s /khe thi gian nu dng GSMK.


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Bng vic s dng li cu trc ca GPRS, EDGE c th cung cp dch v truyn d liugi vi tc t 11,2 kbit/s n 69,2 kbit/s cho mt khe thi gian. Ngoi ra, EDGE cn htr phng thc s dng nhiu khe thi gian tng tc truyn gi ln 554 kbit/s.

Vic trin khai EDGE trong cc h thng GSM i hi phi nng cp h tng v tuyn,

cn phn core network s khng c nhiu thay i v cc node ca GPRS, SGSN, GGSNu t nhiu c lp vi tc truyn d liu. i vi cc giao thc truyn trong sut,EDGE s thc hn c ch tng tch kt ni (lin adaptation) thay i cc phng thcm ho v iu ch nhm cung cp cc khe thi gian c cht lng p ng cc yu cu vtc bit v BER.

Giai on hai: Trin khai mng UMTS

Trong giai on ny, bn cnh vic s dng cc BTS GSM sn c, cc trm mi trinkhai l cc Node B (Node B Universal BTS), c kt ni vi mng di ng qua cc RNC(Radio Network Controler). Cc RNC c th ni trc tip vi SGSN hoc ni vi MSC.

Lc ny MSC v SGSN c thay i cho mc ch thch ng vi mng UMTS nn gi lMSCu v SGSNu. Nhng thay i ny l cn thit tng bc xo b mng GSM th hhai, pht trin ln mng 3G. Cc Node B l cc trm thu pht gc chung (Node B UniversalBTS) tch hp u t v t cc site GSM ang tn ti (tng v m, M-Cell, InCell). Chngrt linh hot s dng li/ trin khai cc site ang tn ti.

Trong giai on ny chng ta tin hnh trin khai th nghim mng 3G ti H Ni, Nng v Thnh ph H Ch Minh. D kin t

mang 4g viettel

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