Tm hiu mng th h sau

Tm hiu mng th h sau

Mc Lc

Mc Lc1Chng 1: Gii thiu tng quan mng th h sau5 1.1 Gii thiu chng5 1.2 Mng vin thng hin ti5 1.2.2 Cc c im ca mng vin thng hin ti6 1.2.3 Nhng hn ch ca mng Vin thng hin ti7 1.3 Mng vin thng th h sau7 1.3.1 nh ngha7Chng 2: Cu trc mng NGN9 2.1.Cu trc chc nng9 2.1.1 Lp truyn dn v truy nhp11 2.1.3.Lp iu khin12 2.1.4 Lp ng dng12 2.1.5.Lp qun l12 2.2.Cc thnh phn ca NGN13 2.2.1.Cu trc vt l ca NGN13 2.2.2.Cc thnh phn ca NGN13 2.3.Cc giao thc trong NGN15 2.3.1.H323 v SIP15 2.3.2. BICC, SIP-T v SIP-I18 2.3.4.MGCP, H248/MEGACO19 2.3.5.SIGTRAN20 2.3.6.API v INAP21 2.3.7.RTP v RCTP21 2.4.Cc cng ngh nn tng cho NGN21 2.4.1.IP22 2.4.2.ATM22 2.4.3.IP Over ATM23 2.4.4.MPLS23 2.4.Gii php NGN ca cc hng23 2.4.1.M hnh NGN ca Alcatel23 2.4.2.M hnh NGN ca Ericsson24Chng 3: c im v cng ngh mang NGN27 3.2.c im27 3.2.Cc cng ngh mng28 3.2.1. Cng ngh mng 3G.28 3.2.2. Cng ngh mang 4G28Chng 4: Dich v mng NGN30 4.1. Gii thiu30 4.2. Nhu cu NGN i vi nh cung cp dch v31 4.3. Dch v NGN33 4.3.1. Xu hng cc dch v trong tng lai33 4.3.2. Cc c trng ca dch v NGN33 4.4. Kin trc dch v th h sau40 4.4.1. Kin trc phn lp40 4.4.2. Mng thng minh phn tn41Chng 5: Chin lc v hng pht trin41 Lp ng dng dich v:43 Lp iu khin:43 Lp chuyn ti:44 Lp truy nhp:44

LI M U

S tin b ca nn khoa hc cng ngh thng tin gp phn lm cho i sng x hi ngy cng phong ph. Vit Nam l mt nc ang trn pht trin v hi nhp, nhng nh hng tch cc v h qu u vit do cng ngh thng tin mang li cho nn kinh t v i sng x hi khong vi chc nm gn y chng minh iu ny.H thng mng th h sau NGN(3G,4G) l mt pht trin vt bc ca ngnh cng ngh thng tin v vin thng. Hin nay n l s la chn ti u cho ngnh vin thng bi hng lot cc tin ch v dch v ni bt l s dng in thoi video, dch vInternetdi ng, xem phim, nghe nhc theo yu cu... vi nhng ngi nng ng, nht l i nhng ngi hay i cng tc xa, thng xuyn phi di chuyn.Trc ng dng v cc dch v to ln ca mng th h sau, vic nghin cu v tm hiu l mt vn kh th v v ang c s quan tm ca rt nhiu nh nghin cu l l do chng em chn ti v: Tm hiu mng th h sau )Ni dung ti gm 5 chng: Chng 1: Tng quan v mng th h sau Chng 2: Cu trc mng th h sau Chng 3: c im v cc cng ngh mng Chng 4: Dch v mng th h sau Chng 5: Chin lc v xu hng pht trinChng em xin gi li cm n chn thnh su sc ti Thy Hunh Nguyn Thnh Lun nhit tnh gip em hon thnh n ny. ng thi em xin chn thnh cm n ti ton th cc thy c gio ca Trng Cao ng Cng Thng Tp.HCM. Xin gi li cm n c bit ti cc thy c gio Khoa Cng Ngh Thng Tin, nhng ngi tn tnh ch dy cho em trong sut qu trnh hc ti trng.Do trnh v thi gian c hn nn n khng th trnh khi cc thiu st. Chng em rt mong nhn c s hng dn v ng gp kin ca cc thy c v cc bn tt n hon thin hn.Tp.HCM, ngy 12 thng 6 nm 2011Sinh vin thc hin.Nguyn Thanh phong_Trn Th Bo Trn

NHN XT CA GIO VIN

Chng 1: Gii thiu tng quan mng th h sau1.1 Gii thiu chng Cm t mng th h sau (Next Generation Network- NGN) bt u c nhc ti t nm 1998. NGN l bc tip theo trong lnh vc truyn thng truyn thng trn th gii c h tr bi 3 mng li: mng thoi PSTN, mng khng dy v mng s liu (Internet). NGN hi t c 3 mng trn vo mt kt cu thng nht hnh thnh mt mng chung, thng minh, hiu qu cho php truy xut ton cu, tch hp nhiu cng ngh mi, ng dng mi v m ng cho cc c hi kinh doanh pht trin. Chng 1 gii thiu v Mng th h sau (NGN), trnh by s lc v mng vin thng hin ti, c im v hn ch. Sau , m t kin trc mng NGN bao gm lp truyn dn v truy cp, lp truyn thng, lp iu khin, lp ng dng v lp qun l.1.2 Mng vin thng hin ti 1.2.1 Khi nim v mng vin thng hin ti- Mng vin thng l phng tin truyn thng tin t u pht ti u thu. Mng c nhim v cung cp cc dch v cho khch hng. Mng vin thng bao gm cc thnh phn chnh: thit b chuyn mch, thit b truyn dn, mi trng truyn v thit b u cui. - Thit b chuyn mch gm tng i ni ht v tng i qu giang. Cc thu bao c ni vo tng i ni ht v tng i ni ht ni vo tng i qugiang. Nh cc thit b chuyn mch m ng truyn c dng chung v mng c th c s dng mt cch kinh t.- Thit b truyn dn dng ni thit b u cui vi tng i, hay gia cc tng i thc hin vic truyn cc tn hiu in. Thit b truyn dn chia lm 2 loi: thit b truyn dn pha thu bao v thit b truyn dn cp quang. Thit b truyn dn pha thu bao dng mi trng thng l cp kim loi. Tuy nhin c mt s trng hp mi trng truyn l cp quang hoc v tuyn.- Mi trng truyn bao gm truyn hu tuyn v v tuyn. Thit b u cui cho mng thoi truyn thng gm my in thoi, my Fax, my tnh, tng i PABX.Nh vy, mng vin thng cng c th c nh ngha nh sau: Mng vinthng l mt h thng gm cc nt chuyn mch c ni vi nhau bng cc ng truyn dn. Nt c phn thnh nhiu cp v kt hp vi cc ng truyn dn to thnh cc cp mng khc nhau.

1.2.2 Cc c im ca mng vin thng hin ti- Mng Telex: dng gi cc bc in di dng k t c m ho bng 5 bit (m Baudot). Tc truyn rt thp (t 75 n 300 bit/s). -Mng in thoi cng cng, cn gi l POTS (Plain Old Telephone Service): y thng tin ting ni c s ho v chuyn mch h thng chuyn mch in thoi cng cng PSTN. -Mng truyn s liu: gm cc mng chuyn mch gi trao i s liu gia cc my tnh da trn giao thc ca X.25 v h thng truyn s liu chuyn mch knh da trn cc giao thc X.21 Cc tn hiu truyn hnh c th truyn theo 3 cch: truyn bng sng v tuyn, truyn qua h thng mng truyn hnh cp CATV (Community AntennaTelevision) bng cp ng trc hoc truyn qua h thng v tinh, hay cn gi l truyn hnh trc tip DBS (Direct Broadcast System).Trong phm vi c quan, s liu gia cc my tnh c trao i thng qua mng cc b LAN (Local Area Network) m ni ting nht l mng Ethernet,Token Bus v Token Ring. Mi mng c thit k cho cc dch v ring bit v khng th s dng cho cc mc ch khc. Ta khng th truyn ting ni qua mng chuyn mch gi X.25 v tr qua mng ny qu ln.Xt v gc dch v: gm mng in thoi c nh, mng in thoi di ng v mng truyn s liu. Xt v gc k thut: gm mng chuyn mch, mng truyn dn, mng truy nhp, mng bo hiu v mng ng b.1.2.3 Nhng hn ch ca mng Vin thng hin tiNh phn tch trn, hin nay c nhiu loi mng khc nhau cng song song tn ti. Mi mng li yu cu phng php thit k, sn xut, vn hnh, bo dng khc nhau. Nh vy, h thng mng vin thng hin ti c nhiu nhc im m quan trng nht l:Ch truyn c cc dch v c lp tng ng vi tng mng. Thiu mm do: s ra i ca cc cng ngh mi nh hng mnh m ti tc truyn tn hiu. Ngoi ra, s xut hin nhiu dch v truyn thng trong tng lai, mi loi dch v s c tc truyn khc nhau. Ta d dng nhn thy mng hin ti s rt kh thch nghi vi nhng i hi ny.Km hiu qu trong vic bo dng, vn hnh cng nh s dng ti nguyn. Ti nguyn sn c trong mt mng khng th chia s cho cc mng khc cng s dng. Mt khc, mng vin thng hin nay c thit k nhm mc ch khai thc dch v thoi l ch yu. Kin trc tng i c quyn lm cho cc nh khai thc gn nh ph thuc hon ton vo cc nh cung cp tng i. iu ny khng nhng lm gim sc cnh tranh cho cc nh khai thc, c bit l nhng nh khai thc nh, m cn tn nhiu thi gian v tin bc khi mun nng cp v ng dng cc phn mm mi. Cc tng i chuyn mch knh khai thc ht nng lc v tr nn lc hu i vi nhu cu ca khch hng. ng trc tnh hnh pht trin ca mng vin thng hin nay, cc nh khai thc nhn thy rng s hi t gia mng PSTN v mng PSDN l chc chn xy ra. Cn c mt c s h tng duy nht cung cp cho mi dch v (tng t-s, bng hp-bng rng, c bn- a phng tin, ) vic qun l tp trung, gim chi ph bo dng v vn hnh, ng thi h tr cc dch v ca mng hin nay.1.3 Mng vin thng th h sau1.3.1 nh nghaMng vin thng th h sau c nhiu tn gi khc nhau, chng hn nh: Mng a dch v (cung cp nhiu loi dch v khc nhau). Mng hi t (h tr cho c lu lng thoi v d liu, cu trc mng hi t). Mng phn phi (phn phi tnh thng minh cho mi phn t trong mng). Mng nhiu lp (mng c phn ra nhiu lp mng c chc nng c lp nhng h tr nhau thay v mt khi thng nht nh trong mng TDM).Cho ti hin nay, mc d cc t chc vin thng quc t v cc nh cung cp thit b vin thng trn th gii u rt quan tm v nghin cu v chin lc pht trin NGN nhng vn cha c mt nh ngha c th v chnh xc no chomng NGN. Do , nh ngha mng NGN nu trn y khng th bao hm ht mi chi tit v mng th h sau, nhng n c th tng i l khi nim chung nht khi cp n NGN.Nh vy, c th xem mng thng tin th h sau l s tch hp mng thoi PSTN (ch yu da trn k thut TDM) vi mng chuyn mch gi (da trnk thut IP/ATM). N c th truyn ti tt c cc dch v vn c ca PSTN ng thi cng c th nhp mt lng d liu rt ln vo mng IP, nh c th gim nh gnh nng ca PSTN. Tuy nhin, NGN khng ch n thun l s hi t gia thoi v d liu m cn l s hi t gia truyn dn quang v cng ngh gi, gia mng c nh v di ng.

Chng 2: Cu trc mng NGN

2.1.Cu trc chc nngNhn chung NGN vn l mt xu hng mi m do vy cha c mt khuyn ngh chnh thc no c cng b r rng lm tiu chun v cu trc NGN, song da vo m hnh m mt s t chc v cc hng xy dng ta c th tm hiu cu trc NGN chc nng nh sau:1. Lp kt ni (truy nhp v truyn dn/ phn li)1. Lp trung gian hay lp truyn thng (Media)1. Lp iu khin1. Lp qun lTrong cc lp trn, lp iu khin hin nay rt phc tp vi nhiu loi giao thc, kh nng tng thch gia cc thit b ca cc hng l vn ang c cc nh khai thc quan tm. Xt t gc kinh doanh v cung cp dch v th m hnh cu trc NGN c thm lp ng dng dch v. Trong mi trng pht trin cnh tranh th s c rt nhiu thnh phn tham gia kinh doanh trong lp ng dng dch v.

Hnh 11: Cu trc mng th h sau (gc dch v)

Hnh 12: Cu trc chc nng ca NGN

2.1.1 Lp truyn dn v truy nhp2.1.1.1 Phn truyn dn1. Ti lp vt l truyn dn quang vi cng ngh ghp knh theo bc sng DWDM s c s dng.1. Cng ngh ATM hay IP c th c s dng truyn dn trn mng li m bo QoS.1. Cc router c s dng bin mng li khi lu lng ln v ngc li khi lu lng nh Switch router c th m nhn lun chc nng nhng router ny.1. Lp truyn dn c kh nng h tr cc mc QoS khc nhau cho cng mt dch v v cho cc dch v khc nhau. Lp ng dng s a ra cc yu cu v nng lc truyn ti v n s thc hin yu cu .2.1.1.2 Phn truy nhpVi truy nhp hu tuyn: c cp ng v xDSL ang c s dng. Tuy vy trong tng lai truyn dn quang DWDM, PON s dn chim u th, th trng ca xDSL v modem s dn thu nh li.Vi truy nhp v tuyn ta c h thng thng tin di ng GSM hoc CDMA, truy nhp v tuyn c nh, v tinh. Trong tng li cc h thng truy nhp khng dy s pht trin rt nhanh nh truy nhp hng ngoi, bluetooth, hay WLAN.Lp truy nhp cung cp cc kt ni gia thu bao u cui v mng ng trc qua cng giao tip thch hp. NGN cng cung cp hu ht cc truy nhp chun cng nh khng chun ca cc thit b u cui nh: truy nhp a dch v, in thoi IP, my tnh PC, tng i ni b PBX2.1.2 Lp truyn thngGm cc thit b l cc cng phng tin nh:1. Cng truy nhp: AG kt ni gia mng li v mng truy nhp, RG kt ni mng li v mng thu bao nh.1. Cng giao tip: TG kt ni mng li vi mng PSTN/ISDN, WG kt ni mng li vi mng di ng.Lp ny chu trch nhim chuyn i cc loi mi trng (FR, PSTN, LAN, v tuyn) sang mi trng truyn dn gi c p dng trn mng li v ngc li.2.1.3.Lp iu khinLp iu khin bao gm cc h thng iu khin m thnh phn chnh l Softswitch cn gi l MGC hay Call agent, c kt ni vi cc thnh phn khc nhau nh: SGW MS FS AS kt ni cuc gi hay qun l a ch IP.Lp iu khin c nhim v kt ni cung cp cc dch v truyn thng sut t u cui n u cui vi bt k loi giao thc v bo hiu no. Cc chc nng qun l v chm sc khch hng cng c tch hp trong lp iu khin. Nh c giao din m nn c s tch bit gia dch v v truyn dn, iu ny cho php cc dch v mi c a vo nhanh chng v d dng.2.1.4 Lp ng dngLp ny gm cc nt thc thi dch v ( thc cht l cc server dch v) cung cp cc ng dng cho khch hng thng qua lp truyn ti.Lp ng dng cung cp cc dch v c bng thng khc nhau v nhiu mc . Mt s dch v s thc hin lm ch vic iu khin logic ca chng v truy nhp trc tip ti lp ng dng, cn mt s dch v khc s thc hin iu khin t lp iu khin. Lp ng dng kt ni vi lp iu khin thng qua giao din m API. Nh m cc nh cung cp dch v c th pht trin cc ng dng v trin khai nhanh chng trn dch v mng.2.1.5.Lp qun lLp qun l l mt lp c bit xuyn sut cc lp t kt ni cho n lp ng dng. Ti lp qun l ngi ta c th khai thc hoc xy dng mng gim st vin thng TMN nh mt mng ring theo di v iu phi cc thnh phn mng vin thng ang hot ng. 2.2.Cc thnh phn ca NGNNGN l mng th h k tip khng phi l mng hon ton mi do vy khi xy dng NGN ta cn ch vn kt ni NGN vi mng hin hnh v tn dng cc thit b vin thng hin c trn mng nhm t c hiu qu khai thc ti a.

2.2.1.Cu trc vt l ca NGN

Hnh 1: Cu trc vt l ca NGN

2.2.2.Cc thnh phn ca NGNTrong NGN c rt nhiu thnh phn song y ch trnh by nhng thnh phn th hin r nt s tin tin ca NGN so vi mng vin thng truyn thng c th l:1. Media Gateway (MG)1. Media Gateway Controller (MGC)1. Signalling Gateway (SG)1. Media Server (MS)1. Application Server (Feature Server) Media Gateway Media Gateway cung cp phng tin truyn ti thng tin thoi, d liu, fax v video gia mng gi IP v mng PSTN. Trong mng PSTN, d liu thoi c mang trn knh DSo. truyn d liu ny vo mng gi mu thoi cn c nn li v ng gi. c bit y ngi ta s dng mt b x l tn hiu s DSP. Media Gateway controler MGCMGC l n v chnh ca Softswitch. N a ra cc quy lut x l cuc gi, cn MG v SG s thc hin cc quy lut . N iu khin SG thit lp v kt thc cuc gi. Ngoi ra n cn giao tip vi h thng OS v BSSMGC chnh l cu ni gia cc mng c c tnh khc nhau, nh PSTN, SS7, mng IP. N chu trch nhim qun l lu lng thoi v d liu qua cc mng khc nhau. N cng c gi l Call Server do chc nng iu khin cc bn tin. Signalling Gateway SGSignalling Gateway to ra chic cu ni gia mng bo hiu SS7 vi mng IP di s iu khin ca Media Gateway Controller (MGC). Media ServerMedia Server l thnh phn la chn ca Softswitch, c s dng x l cc thng tin c bit. Mt Media Server phi h tr phn cng DSP vi hiu sut cao nht. Application Server /Feature ServerServer c tnh l mt server mc ng dng cha mt lot dch v ca doanh nghip. Chnh v vy n cn c gi l Server ng dng thng mi. V hu ht cc server ny t qun l cc dch v v truyn thng qua mng IP nn chng khng rng buc nhiu vi Softswitch v vic phn chia hay nhm cc thnh phn ng dng.Cc dch v cng thm c th trc thuc Call Agent hoc cng c th thc hin mt cch c lp. Nhng ng dng ny giao tip vi Call Agent thng qua cc giao thc nh SIP, H323 Chng thng c lp vi phn cng nhng li yu cu truy nhp c s d liu c trng.Feature Server xc nh tnh hp l v h tr cc thng s dch v thng thng cho h thng a chuyn mch.2.3.Cc giao thc trong NGN2.3.1.H323 v SIP H323Vo nm 1996 ITU-T a ra khuyn ngh H323. Chun h323 m t vic iu khin cc phin a phng tin lin quan n in thoi trong kt ni im-im gia cc im cui thng minh. N cung cp nn tng cho vic truyn thng thoi, video v d liu qua cc mng da trn IPbao gm c Internet H323 c vai tr nh mt giao thc che, n thc cht l mt chng giao thc bao gm nhiu giao thc bo hiu khc nh:1. RAS dung cho qun l ng nhp v trng thi1. H225 cho bo hiu cuc gi v gi ho cc dng media cho cc h thng truyn thng a phng tin da trn cng ngh gi.1. H245 cho iu khin truyn thng gia cc h thng in thoi trc quan v cc thit b u cui.1. Mt s tiu chun cho m ho, gii m ting ni nh G711, G7281. Mt s tiu chun cho m ho, gii m hnh nh nhu H261, H263

M hnh H323 tng quan vi m hnh OSIH323 cung cp kh nng truyn dn audio, video, thng tin iu khin. D liu bao gm hnh nh, fax, d liu my tnh v cc loi d liu khc. N c th cung cp rt nhiu loi hnh dch v v dng trong nhiu lnh vc khc nhau. Cu trc H323 c th dc s dng trong mng LAN hoc mng gi din rng, bt k mt mng gi khng tin cy (khng m bo cht lng dch v), hoc c tr cao u c th c dng cho H323. SIPVo nm 1999, IETF a ra tiu chun bo hiu ring cho mnh gi l Session Initiation Protocol (SIP). SIP l giao thc bo hiu tng ng dng cho vic khi to, thay i v kt thc cc phin media, bao gm cc cuc gi thoi Internet v hi ngh a phng tin. Cng ging nh H323 n da trn cu trc phn tn.SIP da trn tng v cu trc ca SMTP v HTTP. N hot ng theo c ch client server, cc yu cu c bn gi (client) a ra v bn b gi (server) tr li. V c bn SIP l mt giao thc hng vn bn v gn gng nh HTTP nhng khng phi l s m rng ca HTTP.

Hnh 19: V tr SIP trong chng giao thc

SIP thc hin mt s nhim v trong sut mt phin ca hai pha (gi v b gi): nh v server: xc nh h thng u cui cho truyn thng thoi Cc kh nng ca User: xc nh cc phng tin v cc tham s ca phng tin s c dng Thit lp cuc gi: rung chung, thit lp cc tham s cuc gi cho c hai pha gi v b gi Kim sot cuc gi: chuyn v kt thc cuc giTa c th so snh H323 v SIP: H323: L chun ca ITU m t mt b giao thc Ton din nhng li phc tp c trin khai nhiu hn SIP SIP: L chun ca IETF c pht trin cho in thoi IP, khng khi xng t PSTNV c bn th SIP cng ging H323 l cc giao thc khc nhau truyn cc thng tin ging nhau2.3.2. BICC, SIP-T v SIP-I BICCBICC do ITU-T pht trin t nm 1999. Mc ch ca n l xc nh mt giao thc cho truyn thng gia cc server hay MGC, c lp vi cc loi ti tin. Do vy n cho php cc nh vn hnh mng chuyn c cc dch v thoi t mng TDM sang mng gi. Vi mong mun thch ng 100% vi mng hin ti v lm vic trn bt c mi trng no khc truyn thoi vi cht lng chp nhn c.Ta c th tm tt v BICC nh sau: BICC l mt giao thc chn mui BICC CS1 xut hin 6/2000 h tr VoATM (Voice over ATM) n BICC CS2 xut hin 7/2001 h tr c VoATM v VoIP Tng thch y vi giao thc SS7/ISUP. H tr y cc dch v ISUP do vy c th s dng li mng SS7 ang tn ti D dng c mang qua IP nh s dng SIGTRAN hay circuit emulation c la chn bi 3GPP (cho h thng ng dng di ng) Thch ng tt vi cc h thng bo hiu khc nh SIP v H323 SIP-TL s m rng ca SIP h tr cc dch v thoi thng thng. C th coi nh sau: SIP-T=Tp con ca SIP+SIP m rng tng tc trong sut vi mng PSTN.C th hn th SIP-T gm c SIP thng thng trong mng IP v qu trnh ng gi ISUP chuyn thng tin bo hiu t mng TDM sang truyn trn mng gi s dng giao thc SIP.

SIP-ISIP-I l tiu chun c pht trin bi ITU-T da trn SIP ca IETF. N khng cung cp mt cch chi tit, nhng li to ra c hi tt hn lin kt hon ho gia cc gii php ca cc nh cung cp khc nhau. Mt bn nhp c a ra trong khuyn ngh Q912.5 ca ITU-T v c thng qua vo 12/3/2004.

2.3.4.MGCP, H248/MEGACO MGCPMGCP l mt giao thc dng iu khin cc Gateway thoi nh phn t iu khin cuc gi bn ngoi c gi l b iu khin Media hay Call agent. MGCP do IETF pht trin v c s dng rng ri cho cc gii php cp M hnh kt ni da trn cc im cui v cc kt ni L giao thc kiu master slaver, khc vi SIP v H323 (l giao thc peer - to peer). Phi hp hot ng tt vi SIP v H323 c s dng gia Call Agent v Media server H248/MEGACOBn cnh MGCP do IETF pht trin th ITU-T cng pht trin giao thc MDCP (media device control protocol). Sau hai t chc ny tho thun v i n thng nht mt giao thc gi l MEGACO hay H248 (theo cch gi ca ITU-T). M hnh kt ni da trn cc termination v context Cc gi c nh ngha trong cc ph lc ring (cc RFC ring) Cc lp ng dng ln hn cho hi ngh a bn v cc cuc gi a phng tin Hiu qu hn v m hn cho cc tin trnh trong tng lai m khng b ph v2.3.5.SIGTRANSIGTRAN l mt nhm lm vic ca IETF nghin cu vic truyn ti bo hiu PSTN (bo hiu SS7 da trn chuyn mch gi) qua mng IP. Nhm ny thc hin cng vic: cung cp tng tc gia hai mng PSTN v mng IP, cho php truyn bo hiu PSTN trong mng IP, in hnh l VoIP. Cng vic chnh ca nhm l nghin cu truyn bo hiu gia cc Gateway (SG v MGC) nhm cung cp kh nng cho MGC nh v ti nguyn trn mng.Kin trc Sigtran gm 3 thnh phn chnh: Tng IP chun Tng vn chuyn: vi giao thc truyn ti bo hiu SCTP truyn bo hiu tin cy Tng thch ng: h tr cc hm nguyn thu xc nh yu cu bi mt giao thc ng dng bo hiu ring. Mt s giao thc thch ng c nh ngha: M2UA, M3UA, M2PA, SUA.1. M2UA: kt ni ti cc thit b c m khng cn yu cu s SP mi1. M2PA v M3UA: kt ni gia cc im bo hiu cho php IP1. SUA: cho php kt ni vi cc im bo hiu cho php IP vi cc ng dng TCAP1. IUA: truyn bo hiu thu bao ti Softswitch 2.3.6.API v INAPINAP l giao thc ng dng mng thng minh. N h tr cc dch v mng thng minh trn nn NGN. N c dng cho truyn bo hiu dch v IN gia Call server v Feature server.API l giao din chng trnh ng dng. Thng qua giao din ny nh cung cp dch v c th tng tc vi Feature server kin to nn dch v mi mt cch linh hot trn nn mng hin c m khng cn thay i thit b mng. C giao din ny gip cho qu trnh trin khai cc dch v cng n gin v nhanh chng hn.2.3.7.RTP v RCTP RTPRTP l giao thc truyn ti thi gian thc h tr vic truyn thng tin Media trong h thng H323. C th l RTP h tr thc hin trao i bn tin hai chiu t u n cui theo thi gian trn mng Unicast hay Muticast. Cc dch v truyn ti v ng m gi bao gm: nhn din ti, sp xp ng th t gi tin, chun ho thi gian tn hiu i hi thi gian thc da vo tem thi gian v cc t gim st. RTP da vo nhiu c ch khc bit v cc lp thp hn m bo truyn ng thi hn, chim gi ti nguyn, m bo tin cy v QoS. RTCPRTCP l giao thc iu khin truyn thi gian thc, lm c s iu khin ti cc thnh phn ca tp, s dng c ch phn phi ging vi gi d liu. Cc giao thc lp di phi cung cp vic phi hp gi d liu v iu khin. RTCP gim st vic gi d liu cng nh diu khin v nhn dng dch v. RTP lun s dng cng UDP chn, cn RTCP s dng cng UDP l ngay trn cng cho RTP ca n.2.4.Cc cng ngh nn tng cho NGNNgy nay do yu cu ngy cng tng v s lng v cht lng dch v thc y s pht trin nhanh chng ca th trng cng ngh in t - tin hc - vin thng. Nhng xu hng pht trin cng ngh v ang tip cn nhau, an xen ln nhau nhm cho php mng li tho mn tt hn cc nhu cu ca khch hng trong tng lai.Theo ITU c hai xu hng t chc mng chnh: Hot ng kt ni nh hng Hot ng khng kt ni Tuy vy hai phng thc pht trin ny ang dn tip cn v hi t dn n s ra i ca ca cng ngh ATM/IP. S pht trin mnh m ca cc dch v v cc cng ngh mi tc ng trc tip n s pht trin cu trc mng.2.4.1.IPIP l giao thc chuyn tip gi tin. Vic chuyn tip gi tin c thc hin theo c ch phi kt ni. IP nh ngha c cu nh s, c cu chuyn tin, c cu nh tuyn v cc chc nng iu khin mc thp (ICMP). Gi tin IP gm a ch ca bn nhn, a ch l s duy nht trong ton mng v mang y thng tin cn cho vic chuyn gi ti ch.IP l giao thc chuyn mch c tin cy v kh nng m rng cao. Tuy nhin vic iu khin lu lng rt kh thc hin do phng thc nh tuyn theo tng chng. Mt khc IP cng khng h tr cht lng dch v.2.4.2.ATMCng ngh ATM da trn c s ca phng php chuyn mch gi. Thng tin c nhm vo cc gi tin c di c nh ngn; trong v tr gi khng ph thuc vo ng h ng b v da trn nhu cu bt k ca knh cho trc. Cc chuyn mch ATM cho php hot ng vi nhiu tc v dch v khc nhau. ATM c hai c im quan trng: ATM s dng cc gi c kch thc nh v c nh gi l cc t bo ATM. Cc t bo nh vi tc truyn cao s lm cho tr truyn lan v bin ng tr gim nh i vi cc dch v thi gian thc, cng to iu kin cho vic hp knh tc cao d dng hn. ATM c kh nng nhm mt s knh o thnh mt ng o nhm gip cho cng vic nh tuyn c d dng Qu trnh chuyn giao cc t bo qua tng i ATM cng ging nh chuyn giao gi qua router. Tuy nhin ATM c th chuyn mch nhanh hn v nhn gn trn cell c kch thc c nh v nh hn IP, kch thc bng nh tuyn nh hn nhiu so vi ca IP router. Vic ny thc hin trn cc thit b phn cng chuyn dng nn dung lng tng i ATM thng ln hn dung lng IP router truyn thng.2.4.3.IP Over ATMIP over ATM l mt k thut xp chng, n xp IP ln ATM; giao thc ca hai tng hon ton c lp vi nhau, gia chng phi nh mt loi giao thc na ni thng nh NHRP, ARP. iu hin nay khng c s dng rng ri trong thc t.2.4.4.MPLSMPLS l k thut chuyn mch a giao thc nhn. Phng php ny dung hp mt cch hu hiu nng lc iu khin lu lng ca thit b chuyn mch vi tnh linh hot ca b nh tuyn. MPLS l cng ngh chuyn mch IP c nhiu trin vng. Vi tnh cht c cu nh tuyn ca mnh, MPLS c kh nng nng cao cht lng dch v ca mng IP truyn thng. Bn cnh thng lng ca mng s c ci thin mt cch r rt.

Tuy nhin tin cy l mt vn thc tin c th khin vic trin khai MPLS trn mng b chm li.2.4.Gii php NGN ca cc hng2.4.1.M hnh NGN ca AlcatelAlcatel a ra m hnh mng th h sau vi cc lp: Lp truy nhp v truyn ti Lp trung gian Lp iu khin Lp dch v mngAlcatel gii thiu cc chuyn mch a dch v, a phng tin 1000MME10 v Alcatel 1000 Softswitch cho gii php xy dng NGN. Trong h sn phm 1000MME10 l cc h thng c s xy dng mng vin thng th h mi t mng hin c. Nng lc x l ca h thng rt ln so vi cc h thng E10 trc y, ln ti 8 triu BHCA, tc chuyn mch ATM c th t ti 80Gb/s. c im ln nht ca h thng ny l lun chuyn mt s chc nng lin quan n iu khin cuc gi nh chng trnh kt ni ATM bn c nh, chng trnh x l s liu cho vic lp k hoch nh s, nh tuyn, im iu khin dch v ni hat, qun l kt ni bng thng ln my ch (Server) chy trn UNIX.H thng ny c th lm cc chc nng sau: Gateway trung k: h tr kt ni gia mng thoi dng TDM v mng chuyn mch gi. H thng ny gm Gateway cho thoi qua ATM v thoi qua IP. Gateway truy nhp: h thng ny thc hin kt ni n thu bao, tp trung cc lu lng POST, ISDN, ADSL, ATM, IP v chuyn n mng chuyn mch gi. H thng cng cung cp cc chc nng xc nhn, cho php kt ni, thng k v cc kt cui bng hp, bng rng. Tng i chuyn mch gi: c chc nng hn hp chuyn mch/ nh tuyn t ti phn li hay bin ca mng chuyn mch gi. Thit b ny chuyn ti thng tin gia Gateway trung k v Gateway truy nhp.2.4.2.M hnh NGN ca EricssonEricsson gii thiu m hnh mng th h mi c tn l ENGINE. ENGINE to ra mt mng li cung cp nhiu dch v trn mt c s h tng mng duy nht. N bao gm ton b cc sn phm mng a dch v ca Erisson v y l mt tp hp cc gii php v sn phm.Cu trc ENGINE hng ti cc ng dng, cu trc ny sa trn cc lin h Client/Server v Gateway/Server. Cc ng dng gm cc phn client trn my u cui v cc server trong mng giao tip vi nhau qua cc giao din m v hng ti mng c lp vi dch v.Cng nh cc hng khc mng ENGINE c phn thnh 3 lp, s dng cng ngh chuyn mch gi l: Lp dch v/iu khin Lp kt ni x l thng tin ngi s dng, chuyn mch v nh tuyn lu lng hay lp vn chuyn Lp truy nhpLp dch v/iu khin bao gm cc server c chc nng iu khin cc cuc gi PSTN/ISDN v s liu, cung cp cc dch v mng thng minh IN, Mutimedia thi gian thc trn c s x l AXE ca Ericsson.Lp kt ni x l cc thng tin ngi s dng, chuyn mch v nh tuyn lu lng hay cn gi l lp vn chuyn vi phn li chuyn mch chnh l ATM AXD 301 c dung lng t 10 n 160 Gb/s v kh nng m rng trong tng lai ln n 2500Gb/s. ng thi h thng chuyn mch ATM AXD 301 c th s dng nh mt giao din gia mng li v cc mng truy nhp khc: mng c nh, v tuyn c nh v mng di ng.Lp truy nhp m bo kh nng truy nhp ca thu bao t cc mng c nh, v tuyn c nh, di ng v cc mng truy nhp khc. Ericsson gii thiu sn phm ENGINE Access Ramp gm cc dng sn phm p ng yu cu ca gii php mng cn trin khai (truy nhp bng hp, a truy nhp, truy nhp ADSL, phn tch DSSL, chuyn mch ghp, chuyn mch n, tch hp ATM). i vi cu hnh truy nhp bng hp vic chuyn mch s do chuyn mch ni ht (local) thc hin. cung cp cc dch v ATM ENGINE Access Ramp s phi hp vi mng ATM cng cng.Gii php mng mi ENGINE ca Ericsson c 3 gii php ng dng: mng trung k, mng chuyn mch, mng tch hp. Mng trung k: y l bc u tin tin ti mng a dch v, chuyn mch. ATM lp ghp ti tng i Toll ca mng PSTN s cho php lu lng thoi c vn chuyn nh lu lng t trn mng ng trc. Lu lu lng thoi vn c iu khin chuyn mch trc khi a ti chuyn mch ATM. Mng chuyn mch: s dng thay th mng ng trc hon ton bng chuyn mch gi cho cc ng dng IP v ATM. Thc hin iu khin cuc gi lu lng thoi s do server lp iu khin thc hin v qu trnh chuyn mch s do chuyn mch ATM (MG thc hin - lp kt ni x l) Mng tch hp: l gii php cung cp y cc tnh nng ca mng th h sau. Vic iu khin cuc gi s c tp chung bi mt Teleephony server lp iu khin thc hin, cc h thng chuyn mch ATM s thay th cc chuyn mch ni ht v nt truy nhp cung cp cc dch v bng rng cho thu bao. y l cu trc cn ang c gi l a dch v u cui ti u cui (end to end multi service network).

Chng 3: c im v cng ngh mng NGN3.2.c imNGN c bn c im chnh :Trc ht, do p dng c cu m m: Cc khi chc nng ca tng itruyn thng chia thnh cc phn t mng c lp, cc phn t c phn theochc nng tng ng v pht trin mt cch c lp. Giao din v giao thc giacc b phn phi da trn cc tiu chun tng ng. Vic phn tch chc nnglm cho mng vin thng truyn thng dn dn i theo hng mi, nh kinhdoanh c th cn c vo nhu cu dch v t t hp cc phn t khi t chcmng li. Vic tiu chun ha giao thc gia cc phn t c th thc hin linkt gia cc mng c cu hnh khc nhau.Tip n, vic tch dch v c lp vi mng nhm thc hin mt cchlinh hot v c hiu qu vic cung cp dch v. Thu bao c th t b tr v xc nh c trng dch v ca mnh, khng quan tm n mng truyn ti dch v v loi hnh u cui. iu lm cho vic cung cp dch v v ng dng c tnh linh hot cao hn.Th ba, NGN da trn c s mng chuyn mch gi v cc giao thc thng nht. Mng thng tin hin nay, d l mng vin thng, mng my tnh hay mng truyn hnh cp, u khng th ly mt trong cc mng lm nn tng xy dng c s h tng thng tin. Nhng my nm gn y, cng vi s pht trin ca cng ngh IP, ngi ta mi nhn thy r rng l mng vin thng, mng my tnh v mng truyn hnh cp cui cng ri cng tch hp trong mt mng IP thng nht, l xu th ln m ngi ta thng gi l dung hp ba mng. Giao thc IP lm cho cc dch v ly IP lm c s u c th thc hin lin kt cc mng khc nhau; con ngi ln u tin c c giao thc thng nht m ba mng ln u c th chp nhn c, t c s vng chc v mt k thut cho h tng c s thng tin quc gia.Giao thc IP thc t tr thnh giao thc ng dng vn nng v bt u c s dng lm c s cho cc mng a dch v, mc d hin ti vn cn nhiu khuyt im v kh nng h tr lu lng thoi v cung cp cht lng dch v m bo cho s liu. Tuy nhin, chnh tc i mi nhanh chng trong th gii Internet, m n c to iu kin bi s pht trin ca cc tiu chun m s sm khc phc nhng thiu st ny.3.2.Cc cng ngh mng3.2.1. Cng ngh mng 3G3G l cng ngh truyn thng th h th 3, cho php truyn c d liu thoi v d liu ngoi thoi (ti d liu, gi email, tin nhn nhanh SMS, hnh nh,). H thng 3G yu cu mt mng truy cp radio hon ton khc so vi h thng 2 hin nay. Trong cc dch v ca 3G, cuc gi video thng c m t nh mt dch v trng tm ca s pht trin.Gi tn s cho cng ngh 3G rt t ti nhiu nc, ni cc cuc bn u gi tn s mang li hng t euro cho cc chnh ph. Do chi ph cho bn quyn cc tn s phi trang tri trong nhiu nm trc khi t ti cc thu nhp do 3G em li, nn vic xy dng mng 3G i hi mt khi lng u t khng l. Cng v vy nhiu nh cung cp dch v vin thng ri vo kh khn v ti chnh, cng khin cho vic trin khai 3G ti nhiu nc b chm tr, ngoi tr Nht Bn v Hn Quc nhng nc tm b qua cc yu cu v bn quyn tn s, m t u tin cao vic pht trin h tng cng ngh thng tin vin thng quc gia.3.2.2. Cng ngh mang 4G4G l cng ngh truyn thng khng dy th h th 4, cho php truyn ti d liu vi tc ti a trong iu kin l tng ti 1-1,5 GB/s. Nhng cng ngh nh m ni ln gn y nh WiMAX 802.16m, Wibro, UMB, 3G LTE, DVB H d p ng tc truyn ln, song ch c xem l nhng cng ngh tin 4G (pre-4G).c tnh c k vng nht ca mng 4G l cung cp kh nng kt ni ABC (Always Best Connect), mi lc, mi ni. tha mn c iu , mng 4G s l mng hn tp (bao gm nhiu cng ngh mng khc nhau), kt ni, tch hp nhau trn nn ton IP. Thit b di ng ca 4G s l a cng ngh (multi-technology), a mt (multi-mode) c th kt ni vi nhiu loi mng truy nhp khc nhau. Mun vy, thit b di ng s s dng gii php SDR (Software Defined Radio) c th t cu hnh nhiu loi raio khc nhau thng qua mt phn cng raio duy nht. Mng 4G cung cp gii php chuyn giao lin tc, khng vt ngt (seamless) gia nhiu cng ngh mng khc nhau v gia nhiu thit b di ng khc nhau. Mng 4G s l mt s hi t ca nhiu cng ngh mng hin c v ang pht trin nh 2G, 3G, WiMAX, Wi-Fi, IEEE 802.20, IEEE 802.22, pre-4G, RFID, UWB, satellite cung cp mt kt ni v tuyn ng ngha rng khp (ubiquitous), mi lc, mi ni, khng k mng thuc nh cung cp no, khng k ngi dng ang dng thit b di ng g. Ngi dng trong tng lai s thc s sng trong mt mi trng t do, c th kt ni mng bt c ni u vi tc cao, gi thnh thp, dch v cht lng cao v mang tnh c th cho tng c nhn.

Chng 4: Dich v mng NGN4.1. GII THIU S 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 i vi 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 ha nhp, lin kt v cnh tranh ca cc thnh vin mi tham gia vo th trng phi hot ng tch cc tm ra phng thc mi, nhm gi v thu ht hu ht cc khch hng c tim nng. Cc nh cung cp dch v hin nay ang c gng tm ra li i ring cho mnh to ra 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,Mng th h mi NGN l bc k tip ca th gii vin thng, c th c hiu l mng da trn cng ngh chuyn mch gi, ni m cc chuyn mch v cc phn t truyn thng (nh cc b nh tuyn, cc b chuynmch v gateway) c phn bit mt cch lun l v vt l theo kh nngiu khin thng minh dch v hoc cuc gi. Kh nng iu khin thngminh ny thng h tr cho tt c cc loi dch v trn mng truyn thngt dch v thoi c bn (Basic Voice Telephony Services) cho n cc dch v d liu, hnh nh, a phng tin, bng rng tin tin (Advanced Broadband), v cc ng dng qun l (Management Application).Nh cp cc phn trc, NGN l s tp trung ca ba loi mng chnh: mng thoi PSTN, mng di ng v mng chuyn mch gi (mng Internet). Cu trc ny phn phi tn b cc phng thc truy nhp, hu ht cc cng ngh v ng dng mi. T to ra nhiu dch v mi.C ba loi dch v ch yu trong NGN: dch v thi gian thc v thi gian khng thc, dch v ni dung, dch v qun l. Cc dch v ny gip cho cc nh khai thc c s iu khin, bo mt v tin cy tt hn ng thi gim chi ph vn hnh. Nh , cc nh cung cp dch v c th nhanh chng c ngun thu mi.Xy dng trn cc thnh phn m v c module ha, trn cc giao thc chun v cc giao din m, NGN tr thnh mt phng tin thc hin mc ch l cho php kt ni gia con ngi v my mc bt c khong cch no. Ni cch khc, NGN c kh nng cung cp cc yu cu c bit ca tt c khch hng cng ty, vn phng xa, vn phng nh, nh ring, N hp nht thoi hu tuyn v v tuyn, d liu, video, bng cch s dng chung mt lp truyn ti gi. Cc lp dch v ca NGN linh hot, chi ph hiu qu v c kh nng m rng hn i vi cc dch v trc y.4.2. NHU CU NGN I VI CC NH CUNG CP DCH VMng Internet ang x l kh tt tt c cc dch v chng ta yu cu.Gii php ca mng Internet n gin l s dng cc thit b u cui thu bao CPE (Customer Premise Equipment) tin tin nh PC, smart phone, set-top-box, Dch v c thc hin ti cc h thng u cui. Cc x nghip, cc cng ty phn mm v mt s trng i hc, trung hc s pht trin cc ng dng v ti chng t mng Internet n cc thit b CPE. Cc yu cu i vi mng truyn ti cng cng l tnh tin cy v bng thng truyn dn cao.Nh vy ti sao cc nh cung cp dch v li quan tm n dch v NGN? Ti sao h khng theo phng thc kinh doanh c? Sau y l mt s l dotiu biu: Nh cung cp c th tn ti vi phng thc c (nu h may mn), tuynhin chc chn h s khng thnh cng. Cc nh cung cp ang bt buc cnh tranh v gi m bo thu nhp. Trong lc , cc i th cnh tranh a ra cc dch v hp dn c cc khch hng bo b nht. Do nu nh cung cp dch v mun thnh cng trong thi i mi, h buc phi thm gi tr vo cc dch v truyn thng ca mnh. NGN h tr cc dch v mi tin tin nn cho php h gi c cc khch hng quan trng v m rng th trng trong nhiu khu vc Mng li hin nay khng th cung cp tt c cc yu cu ca khch hng.Mt iu khng th nghi ng l cc dch v ca mt vi khch hng ang chuyn dn ra bin mng. Nh cung cp mng cng cng khng th chng li khuynh hng ny. Tuy nhin h khng chp nhn tht bi. Kinh doanh cc dch v thng tin mi tr thnh mt ngnh cng nghip c th thu v hng t la. Cui cng c mt thc t l mt s ngi mun s dng cc dch v mi trn nn CPE, trong khi s khc li thch dch v trn nn mng. Cc dch v trn nn mng c nhiu u im. Vi mt s nh cc dch v n gin khng yu cu lm vic gia khch hng vi nhau, cc dch v trn nn CPE c th hiu qu. Tuy nhin, khi s lng khch hng lm vic vi nhau tng, cc dch v trn nn mng t ra c nhiu li th hn. V d, cc ng dng trn nn mng linh hot hn v c kh nng m rnghn so vi cc dch v trn nn CPE. Vi cc ng dng trn nn CPE, thit b CPE cn phi tinh vi, phc tp hn (v do , t tin hn) m bo cc yu cu v cc ng dng tin tin hn.Gii php trn nn mng chophp chia s ti nguyn v d dng m rng p ng cc yu cu .Th hai, dch v trn nn CPE kh khn trong vic cung cp cc dch v i vi thu bao di ng. Nu khch hng mun truy nhp vo cc dch v ca h ti nhng a im khc nhau, h cn phi mang thit b CPE theohay ti phn mm t v tr mi, lng ph thi gian v ti nguyn mng. Vi cc dch v trn nn mng, khch hng c th truy nhp vo cc dch v ca h bt k t v tr no. Cui cng, cc vn khch hng quan tm nh tnh cc, qun l cu hnh, d phng v cc dng qun l khc c x l d dng hn i vi cc dch v trn nn mng.NGN s cho php cc nh khai thc cung cp vi chi ph hiu qu ca cc dch v mi phc tp hn bng cch xy dng mt li lin h vi cc dch v truyn ti truyn thng. Thm vo , vic hp nht cc ng dng NGN lm gim chi ph bng cch loi b cc nhc im ca cc dch v ring l hin nay. NGN cn gim thi gian thng mi ha v xoay vng vn nhanh hn khi cung cp cc dch v mi. V sau cng, NGN m rng cc dch v tin tin, tng kh nng cnh tranh v m rng kh nng thm nhp th trng ca h.

4.3. DCH V NGN 4.3.1. Xu hng cc dch v trong tng lai xc nh c cc dch v trong mng th h sau cng nh chin lc u t ca cc cng ty, xu hng pht trin cc dch v trong tng lai l vn rt cn xem xt. Trc ht chng ta cn quan tm n xu hng ca dch v thoi. y l dch 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 dch v 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 mi trng cho gii php thoi qua giao thc IP v cc dch v a phng tin tng i n gin. Tuy nhin, sau SIP s thay th cho H.232 do SIP c nhiu 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 theo thi gian s chim u th. Nhiu dch v v truy nhp ng dng thng qua cc nh cung cp dch v v truy nhp ng dng s pht trin mnh. Cc dch v leased line, ATM, Frame Relay hin nay s tip tc tn ti thm mt thi gian na do cc t chc kinh doanh khng mun thay i thit b ch v thay i dch v kt ni. Dch v IP-VPN s tr thnh mt la chn hp dn. Cui cng, phng thc truy nhp mng, ra lnh, nhn thng tin, bng li ni (voice portal) s l mt chn la trong tng lai. Hin nay, k thut chuyn i t li ni sang file vn bn v ngc li ang pht trin mnh. 4.3.2. Cc c trng ca dch v NGNMc d tht kh d on ht cc ng dng trong tng lai, nhng chng ta c th ch ra cc c trng v cc kh nng quan trng ca dch v trong mi trng NGN bng cch xem xt cc xu hng cng nghip lin quan n dch v hin nay.Mt iu chc chn l chng ta ang dch chuyn t mng chuyn mch knh, trn nn TDM sang mng da trnchuyn mch gi, da trn truyn ti t bo hay khung. Tuy nhin cc thay i ny l trong mng truyn ti v y chng ta ch xem xt mc dch v.Cc nh cung cp dch v mng truyn thng cung cp cc dch v vi khuynh hng thoi bng hp, bng mt kt ni n im-im trong mi cuc gi trn mt th trng rng ln gia cc thu bao u cui, vi cc kh nng s dng cc dch v gi tr gia tng khc nhau. D sao, cc dch v ny lm thay i nhanh chng n nn kinh t th gii v thng tin cng c xem nh mt ngun ti nguyn c s.Trong khi cc dch v hin ti vn c cc nh cung cp gi li, thkhch hng li s hng n cc dch v a phng tin bng rng v cc dch v mang nhiu thng tin. Khch hng c th tng tc vi nhau thng qua mng nh cc thit b CPE tinh vi v c th chn trn phm vi rng cht lng dch v (QoS) v di tn. Trong tng lai, mng thng minh s khng ch to ra cc tuyn kt ni bng cch da trn c s d liu n gin m cn c th mang nhiu thng tin rng hn nh: qun l session a phng tin, cc kt ni a cng ngh, iu khin/qun l thng minh, bo mt cao, cc dch v ch dn trc tuyn, cc phn t gim st,S pht trin ca cc dch v truyn thng hin nay s hng ti vic cc nh cung cp dch v phi c s mm do, linh hot phc v c c th trng ln v nh. Cc quyt nh v vic cung cp dch v ca h c th gp nhiu vn phi gii quyt nh gi c, vic ng gi, tip th cng nh s tin ch ca dch v thc t khi cung cp. Khi c nhiu phng tin truyn tin, nh cung cp dch v, nh cung cp thit b v cc doanh nghip thng mi lin quan n vic cung cp dch v, lin mng v cc h thng thng mi s tr nn cng quan trng.Mc tiu chnh ca dch v NGN l cho php khch hng c th ly thng tin h 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 quan trng trong mi trng NGN: Lin lc thng tin rng khp, thi gian thc, a phng tin, m bo tin cy, thn thin trong vic lin kt cc thu bao, truy nhp tc cao v truyn ti 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 tn mng. N bao gm cc ng dng cho php truy nhp v iu khin cc dch v mng. N cng c th thc hin cc chc nng c th thay th cho nh cung cp dch v hoc mng. Ta c th xem n nh mt tc t qun l c th thc 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 hng truy xut v s dng cc dch v mng mt cch n gin hn bao gm cc giao 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 tng tc qun l xuyn sut cc dch v. Ngi ra n cn cung cp cc menu khc nhau cho nhng ngi cha c kinh nghim ngc li vi nhng ngi c kinh nghim, v cung cp mt mi trng thng nht cho cc dng thng tin.- NGN 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 d phng cc ng dng mi - Vi vic qun l thng tin thng minh, NGN gip ngi dng qun l s qu ti ca thng tin bng cch cung cp cho h kh nng tm, sp xp v lc cc bn tin hoc d liu, qun l chng cho mi phng tin. 4.3.3. Cc dch v chnh trong mng NGNRt nhiu dch v, mt s sn sng, mt s khc ch mckhi nim trong giai on u ca qu trnh trin khai NGN. Trong khi mt s dch v c th c cung cp t mt bng sn c, mt s khc c cung cp t kh nng bo hiu, qun l v iu khin ca NGN. Mc d cc dch v mi l ng lc chnh to ra NGN, nhng li nhun ca NGN trong giai on u vn do cc dch v truyn thng mang li. Do , cc dch v truyn thng c trang tri cho mng, trong khi cc dch v mi phc v cho s pht trin sau ny.Hu ht cc dch v truyn thng l cc dch v da trn c s truynhp/ truyn dn/ nh tuyn/ chuyn mch, da trn c s kh nng kt ni/ ti nguyn v iu khin phin, v cc dch v gi tr gia tng khc.NGN c kh nng cung cp phm vi rng cc loi hnh dch v, bao gm: Cc dch v ti nguyn chuyn dng nh: cung cp v qun l cc b chuyn m, cc cu ni hi ngh a phng tin a im, cc th vin nhn dng ting ni, Cc dch v lu tr v x l nh: cung cp v qun l cc n v lu tr thng tin v thng bo, file servers, terminal servers, nn tng h iu hnh (OS platforms), Cc dch v trung gian nh: mi gii, bo mt, bn quyn, Cc dch v ng dng c th nh: cc ng dng thng mi, cc ngdng thng mi in t, Cc dch v cung cp ni dung m n c th cung cp hoc mi gii ni dung thng tin nh: o to, cc dch v xc tin thng tin,.. Cc dch v interworking dng tng tc vi cc dch v khc, cc ng dng khc, cc mng khc, cc giao thc hoc cc nh dng khc nh chuyn i EDI (Electronic Data Interchange). Cc dch v qun l, bo dng v vn hnh

Sau y l mt s dch v m chng ta tin rng n s chim v trquan trng trong mi trng NGN, bao gm mt phm vi rng cc dch vt thoi thng thng n cc dch v tch hp phc tp nh Thc t o phn tn (Distributed Virtual Reality) nhm nhn mnh rng kin trc dch v th h sau s cung cp rt nhiu loi hnh dch v khc nhau. Dch v thoi (Voice Telephony)NGN vn cung cp cc dch v thoi khc nhau ang tn ti nh ch cuc gi, chuyn cuc gi, gi ba bn, cc thuc tnh AIN khc nhau, Centrex, Class, Tuy nhin cn lu l NGN khng c gng lp li cc dch v thoi truyn thng hin ang cung cp; dch v th vn m bo nhng cng ngh th thay i. Dch v d liu ( Data Service) Cho php thit lp kt ni thi gian thc gia cc u cui, cng vi cc c t gi tr gia tng nh bng thng theo yu cu, tnh tin cy v phc hi nhanh kt ni, cc kt ni chuyn mch o(SVC- Switched Virtual Connection), v qun l di tn,iu khin cuc gi, Tm li cc dch v d liu c kh nng thit lp kt ni theo bng thng v cht lng dch v QoS theo yu cu. Dch v a phng tin (Multimedia Service)Cho php nhiu ngi tham gia tng tc vi nhau qua thoi, video, d liu. Cc dch v ny cho php khch hng va ni chuyn, va hin th thng tin. Ngi ra, cc my tnh cn c th cng tc vi nhau. Dch v s dng mng ring o (VPN)Thoi qua mng ring o ci thin kh nng mng, cho php cc t chc phn tn v mt a l, m rng hn v c th phi hp cc mng ring ang tn ti vi cc phn t ca mng PSTN.D liu VPN cung cp thm kh nng bo mt v cc thuc tnh khc mng ca mng cho php khch hng chia s mng Internet nh mt mng ring o, hay ni cch khc, s dng a ch IP chia s nh mt VPN. Dch v s dng mng ring o (VPN)Thoi qua mng ring o ci thin kh nng mng, cho php cc t chc phn tn v mt a l, m rng hn v c th phihp cc mng ring ang tn ti vi cc phn t ca mng PSTN.D liu VPN cung cp thm kh nng bo mt v cc thuc tnh khc mng ca mng cho php khch hng chia s mngInternet nh mt mng ring o, hay ni cch khc, s dng ach IP chia s nh mt VPN. Tnh tn mng cng cng (PNC- Public Network Computing)Cung cp cc dch v tnh tn da trn c s mng cng cng cho thng mi v cc khch hng. V d nh cung cp mng cng cng c th cung cp kh nng 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 tn). Nh mt s la chn, cc nh cung cp dch v mng cng cng c th chung cp cc 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. Nh cung cp dch v c th tnh cc theo gi, ngy, tun, hay theo ph bn quyn i vi dch v.

Bn tin hp nht (Unified Messaging) H tr cung cp cc dch v voice mail, email, fax mail, pagesqua cc giao din chung. Thng qua cc giao din ny, ngi s dng s truy nhp (cng nh c thng bo) tt c cc loi 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, tm kim v cung cp thng tin n khch hng tng ng vi nh cung cp. V d nh khch hng c th nhn thong tin trn c s cc tiu chun c th hay trn cc c s tham chiu c nhn, Thng mi in t (E-commerce)Cho php khch hng mua hng ha, dch v c x l bng in t trn mng; c th bao gm c vic x l tin trnh, kim tra thng tin thanh tn tin, cung cp kh nng bo mt, Ngn hng ti nh v i ch ti nh nm trong danh mc cc dch v ny; bao gm c cc ng dng thng mi, v d nh qun l dy chuyn cung cp v cc ng dng qun l tri thc. Dch v thng mi in t cn c m rng sang lnh vc di ng. chnh l dch v thng mi in t di ng (m-commerce Mobile Commerce). C nhiu khi nim khc nhauv m-commerce, nhng ta c th hiu y l dch v cho php ngi s dng tham gia vo th trng thng mi in t (mua v bn) qua cc thit b di ng cm tay. Cc dch v chuyn cuc gi (Call Center Service)Mt thu bao c th chuyn mt cuc gi thng thng n trung tm phn phi cuc gi bng cch kch chut trn mt trang web. Cuc gi c th xc nh ng n mt agent thch hp, m n c th nm bt c u thm ch c nh (nh trung tm cuc gi o Vitual Call Center). Cc cuc gi thoi cng nh cc tin nhn e-mail c th c xp hng ging nhau n cc agent. Cc agent c cc truy nhp in t n cc khch hng, danh mc,ngun cung cp v thng tin yu cu, c th c truyn qua li gia khch hng v agent. Tr chi tng tc trn mng (Interactive Gaming)Cung cp cho khch hng mt phng thc gp nhau trc tuynv to ra cc tr chi tng tc (chng hn nh video games) Thc t o phn tn (Distributed Virtual Reality)Tham chiu n s thay i c to ra c tnh cht k thut ca cc s kin, con ngi, a im, kinh nghim, ca th giithc, nhng ngi tham d v cc nh cung cp kinh nghim o l phn tn v a l. Cc dch v ny l yu cu s phi hp rt phc tp ca cc ti nguyn khc nhau. Qun l ti nh (Home Manager)Vi s ra i ca c thit b mng thng minh, cc dch v ny c th gim st v iu khin cc h thng bo v ti nh, cc h thng ang hot ng, cc h thng gii tr, v cc cng c 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 xem c trn mn hnh ai ang ng trc ca nh mnh. Hoc chng hn nh chng ta c th quan st c ngi nh ca mnh trong khi ang i xa, hoc quan st c ngi trng tr ang chm sc em b nh th no khi ta ang lm vic ti c quan. Ngi cc dch v nu trn cn c rt nhiu dch v khc c th trin khai trong mi trng NGN nh: cc dch v ng dng trong y hc, chnh ph in t, nghin cu no to t xa, nhn tin a phng tin, Nh vy cc dch v th h sau l rt a 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 v n cho khch hng trong mi trng NGN.

4.4. KIN TRC DCH V TH H SAU

4.4.1. Kin trc phn lp Khi nim cu trc phn lp l khi nim trung tm ca mi trng NGN. NGN chia iu khin dch v/ session t cc phng thc truyn ti c s. iu ny cho php cc nh cung cp la chn (cho tng trng hp c th) cc phng thc truyn ti thng tin khng ph thuc vo phn mm iu khin. Nh m t trong hnh, iu khin NGN c th c phn tch thnh iu khin c tnh (feature), iu khin dch v/ phin, iu khin kt ni. S phn tch gia truy nhp, dch v v iu khin phin trong lp dch v cho php mi phin c x l c lp vi cc phin khc. Do , nhiu phin dch v c th c bt u t mt phin truy nhp. Tng t, cc phin lin lc c th c x l ring l vi phin dch v ni chung m chng l b phn (bng cch cho php cho php iu khin cuc gi v kt ni mt cch ring l). iu quan trng nht l cc s phn tch ny cho php cc dch v c pht trin c lp vi truyn dn v kt ni. Do vy, cc nh pht trin dch v c th khng cn hiu ht cc dch v h ang pht trin 4.4.2. Mng thng minh phn tn

Trong mi trng cc dch v NGN, phm vi th trng ca cc dch v c th s dng c m rng mt cch ln mnh gm cc loi hnh dch v khc nhau v mng lin kt thng minh. Mi trng x l phn tn NGN (DPE Distributed Processing Environment) s gii phng tnh thngminh t cc phn t vt l trn mng. Do vy, tnh thng minh ca mng c th c phn tn n cc v tr thch hp trong mng hoc nu c th, n CPE. V d, kh nng thng minh ca mng c th nm cc server cho mt dch v no , trn cc server nay thc hin cc chc nng c th

Chng 5: Chin lc v hng pht trin

Vit Nam cng nh nhiu nc khc trn th gii, do c im a l, kinh t, vn ho, x hi tng vng m nhu cu pht trin dch v vin thng cc vng trong ton quc l khc nhau. C s chnh lch kh ln gia nhu cu v kh nng pht trin dch v, kh nng thu hi vn u t mng vin thng gia cc vng trong c nc, c bit l mt vn kh trong vic iu ho gia cc hot ng kinh doanh v nhu cu ph cp cc dch v vin thng tin hc ti tt c cc min trong nc. C th thy r l hin nay, ngoi mng vin thng ca VNPT c phm vi tri rng cung cp dch v vin thng ti tt c 61 tnh thnh ph v c bit l hn 5000 im Bu in vn ho x ng vai tr ph cp cc dch v bu chnh, vin thng, vn ho ti cc x nng thn, min ni, vng su, vng xa; cc hot ng v d n ca cc nh kinh doanh vin thng khc nh FPT, viettel ch tp trung vo H Ni, TPHCM v mt s khu th cng nghip ln, khi cng nghip khu th ln c kh nng thu hi vn u t nhanh, c kh nng pht trin dch v mnh, li nhun cao.T xu hng pht trin mng vin thng th h sau trn th gii v thc th th trng vin thng Vit Nam hin nay vi xu hng pht trin cng ngh v cc nhu cu dch v vin thng, c th thy rng lnh vc vin thng Vit Nam trc xu th cnh tranh v hi nhp ang ng trc s la chn cng ngh v t chc mng mt cch thch hp hng ti cu trc mang th h sau NGN, l mng vin thng c h tng thng tin duy nht da trn cng ngh chuyn mch gi, trin khai cc dch v mt cch a dng v nhanh chng, p ng s hi t gia thoi v s liu, gia c nh v di ng.Mng vin thng ca VNPT c s ho hon ton c v truyn dn v chuyn chuyn mch vi cc thit b cng ngh mi hin i trn phm vi c nc, cng vi mng thu bao rng ln v nhiu ddiemr cung cp dch v bu chnh vin thng, ay l mt thun li ln trong qu trnh pht trin tin ti cu trc mng th h mi cung cp a dch v, a phng tin, cht lng cao. iu ny cng i hi s tn dung 1 cch hiu qu cc thit b u t, vi tin trnh pht trin mng th h sau l 1 qu trnh chuyn i dn trn nn tng mng vin thng c s ho hin nay. Tuy nhin mng vin thng ca VNPT vi chng loi thit b kh a dng th vic tin ti xy dng pht trin v hon thin mng NGN l mt qu trnh chuyn i phc tp i hi s la ch cng ngh ng n t chc khai thc mng hp l nhm tn dng ti a cc thit b hin c trn mng tin ti cu trc mng mc tiu NGN. Khng ging nh VNPT, cc cng ty mi bt u vo vic cung cp dch v vin thng th trng Vit Nam c li th ca ngi i sau trong vic la chn thit b. Cc cng ty khc tuy cha c mng vin thng pht trin rng, tuy nhin nu iu kin cho php, cc cng ty ny s c li th cua ngi i sau s dng ngay cc cng ngh mi NGN nh s dng cng ngh truyn dn SDH, WDM, chuyn mch softwich/Multiservice Swich xy dng mi mng NGN.Trong tng lai mng vin thng th h sau ca Vit Nam c cu trc hin i, m v n gin c linh hot v tnh sn sng cao, nng lc hot ng mnh v an ton, bo mt cao. Nhm p ng nhu cu cung cp cc dch v vin thng hin nay v cc loi dch v vin thng th h sau bao gm : cc dch v c bn cc dich v gi tr gia tng, cc dch v truyn s liu, Internet v cng ngh thng tin, a phng tin.,cu trc mng mc tiu theo xu hng pht trin mng th h sau NGN xet gc vt l bao gm hai lp: Lp chuyn ti Lp truy nhp

Xt v gc chc nng, phn lp cu trc mng th h sau s bao gm: Lp ng dng dch v Lp iu khin Lp chuyn ti Lp truy nhp Lp qun lNhm nng cao hiu qu khai thc mng hin nay, m bo hiu qu u t cng ngh mi NGN, mt vn quan trng t ra i vi cc thnh vin tham gia vo kinh doanh vin thng l vn t chc mng v kinh doanh . Vic t chc mng cn da trn s lng thu bao theo vng a l v nhu cu pht trin dch v, khng t chc theo a bn hnh chnh m t chc theo vng lu lng v cn phn chia trch nhim r rng gia: Cc nh kinh doanh dch v Cc nh kinh doanh mng( cung cp mng v dch v) Cc nh kinh doanh mng v dch v( cung cp mng v dch v)Tng qu trnh xy dng v t chc mng cn xc nh r phm vi gia cc lp, vic kt ni gia cc mng thnh vin v phn nh r trch nhim v quyn li ca cc nh cung cp dch v v cc nh cung cp mng.Lp ng dng dich v: S lng nt ng dng dch v ph thuc vo lu lng dch v, d lng v loi hnh dch v. Vic la chn v tr cc nt ng dng dch v tng ng vi cc nt mng NGN, ngha l tng ng vi v tr t cc nt iu khin v nt chuyn ti s thun tin cho vic cung cp dch v n ngi s dng mt cch thng nht v ng b.Lp iu khin:Lp iu khin c chc nng iu khin iu khin lp chuyn ti v lp truy nhp cung cp cc dich v mng NGN, gm nhiu modul nh: modul iu khin kt ni ATM, modul iu khin kt ni IP, iu khin kt ni cuc gi thoi Vic t chc theo vng lu lng s tn dng v pht trin nng lc x l cuc gi ca thit b th h mi. m bo thng sut vic cung cp cc dich v vin thng n ngi s dng, cn thng nht cc tiu chun iu khin kt ni gia cc nh cung cp dch v vi cc nh cung cp mng v gia cc nh cung cp thnh vin.

Lp chuyn ti: Chuyn mch: tin ti cu trc mang th h sau, cc chuyn mch c trang b trn mng l cc chuyenr mch cng ngh ATM/IP. Mng chuyn mch ATM/IP bao gm hai lp: lp li (core ATM/IP core swich) v lp bin( edge multidervice Swich). Truyn dn: Tin ti vo nm 2005 tt c cc tnh/thnh ph c nc c kt ni bng cp quang bng rng, v vo nm 2010 tt c cc huyn v nhiu x trong c nc c kt ni bng xa l thng tin cp quangLp truy nhp: Truy nhp v tuyn: M rng mng thng tin di ng, pht trin cc dch v mng thng tin di ng th h sau, pht trin cc dch v vin thng c bn nh: in thoi, fax cho cc vng nng thn, min ni, hi o Truy nhp hu tuyn: Tng cng nng lc cung cp dch v: Dch v thoi, s liu v thu knh ring tc cao ti 2Mb/s bao gm c VoIP, cc loi hnh dch v rng IP v ATM cho thu bao.Lp qun l:Tin ti qun l mng vin thng theo m hnh TMN vi y lp l: qun l phn t mng, qun l mng, qun l dch v, qun l kinh doanh.Khi c nhiu thnh phn tham gia vo vic khai thac mng v cung cp dch v vin thng th vai tr qun l( bao gm qun l mng v qun l dch v) l ht sc quan trng m bo vic kt ni thng sut gia cc bn tham gia nhm p ng yu cu cung cp cc dch v m bo cht lng n khch hng v cc bn cng c li v m bo tnh cht c th ca ngnh vin thng thng tin, khng ch l mt ngnh kinh doanh n gin m cn mang nghia su sc v chnh tr, x hi

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