n tt nghip i hc

n tt nghip i hc Ti liu tham kho

MC LC

MC LC...........................................................................................................................1

THUT NG VIT TT..................................................................................................3

Nhng ng dng cho cc mng di ng nng cao logic....................................................3

DANH MUC HINH VE......................................................................................................9

Danh mC bng biu......................................................................................................11

LI NI U...................................................................................................................12

IPTV l dch v truyn hnh qua kt ni bng rng da trn giao thc Internet. y l mt trong cc dch v Triple-play m cc nh khai thc dch v vin thng ang gii thiu trn phm vi ton th gii. Orange/France Telecom kh thnh cng vi gi dch v Orange TV ti Php, Hn Quc m rng IPTV ra c nc, PCCW thnh cng vi dch v IPTV ti Hng Kng, Nokia Siemens Networks trin khai IPTV ti Ba Lan (4/2007), IPTV v ang pht trin vi tc rt nhanh, theo Telecom Asia (http://www.iptv-asia.net/), s thu bao IPTV ring khu vc chu - Thi Bnh Dng s gia tng 75% mi nm, t 34,9 triu thu bao vdoanh thu 7 t USD vo nm 2011. .............................................................................................12

Ti Vit Nam, IPTV tr nn kh gn gi i vi ngi s dng Internet ti Vit

Nam. Cc nh cung cp nh VNPT, FPT, SPT, VTC a IPTV, VoD... ra th trng nhng

phm vi v quy m nh. ...........................................................................................................12

Xu hng pht trin mng th h sau NGN hin nay l chuyn t Softswitch sang IMS do IMS em li kh nng cung ng dch v a phng tin cho ngi s dng u cui m khng b ph thuc vo v tr, cng ngh truy nhp mng v vo thit b u cui ca ngi s dng. IMS h tr cc loi hnh dch v khc nhau (thoi, d liu, hnh nh v kh nng tch hp ca c ba loi hnh dch v ni trn - Tripple Play m in hnh l dch v IPTV), cc cngngh mng v cc thit b u cui. c bit, trn nn tng IMS, yu t di ng v truy nhp khng dy tr nn kh thi, cng to iu kin cho IPTV pht trin thnh mt trong nhng dng dch v Quad-Play.........................................................................................................................12 trong nc c mt s nghin cu v IPTV v IMS, tuy nhin nhng nghin cu v pht trin ng dng IPTV trn IMS-NGN cha c y v h thng. nc ngoi c mt s cc hng ln nh Alcatel-Lucent, Ecrisson, Fokus ... bt u trin khai pht trin mt s m hnh th nghim IPTV trn IMS-NGN. ...........................................................................12CHNG 1. GII THIU CHUNG V CNG NGH IPTV......................................14

1.1.Tng quan v cng ngh IPTV...................................................................................14

1.1.1.nh ngha................................................................................................................14

n tt nghip i hcMc lc

SV: Nguyn Thi Sn H09VT34

IPTV l tn vit tt ting anh ca cm t Internet Protocol Television, biu din ni dung video s, bao gm v tuyn truyn hnh, c phn phi qua vic s dng giao thc Internet (IP). nh ngha IPTV ny khng ch rt n gin m cn nhn mnh rng Internet khng ch cn thit cho vic thc hin vai tr trong truyn pht tn hiu truyn hnh hoc l bt c loi ni dung video khc. V vy, IPTV cp ti cch dng IP l c ch c th s dng Internet, trnh by mng cng cng trn c s IP, hoc IPTV s dng truyn pht ni dung video qua mt mng ring trn c s IP.......................................................................................14V IPTV yu cu dng IP khng ch l mt c ch truyn pht, IP c th c s dng truyn pht cc loi ni dung khc nhau qua c mng Internet v mng ring trn c s IP.V d ni dung IPTV c th gii hn t nhc hnh ti cc cuc biu din trn truyn hnh, phim, v nhiu s kin c bit khc, nh l bng . iu ny c ngha l nh ngha ngn gn ca IPTV bao gm mt di rng c cc chng trnh ang c v chng trnh c kh nng pht trin. Ngoi cc dch v truyn hnh qung b thng thng, Video theo yu cu (Video on Demand VoD), IPTV cn h tr s tng tc gia ngi xem vi chng trnh v y cng chnh im c bit v hp dn nht ca IPTV. Khng nh truyn hnh cp truyn thng, IPTV l mt tng th chui cc dch v truyn hnh c tnh tng tc. Ngoi vic t do la chn chng trnh truyn hnh hay phim mun xem, NSD c th tham gia cc cuc hi tho t xa, chi game, mua hng qua TV hoc vit blog video (vlog), nhn tin qua TV thng qua my vitnh PC hoc my thu hnh cng vi hp phi ghp set topbox...................................................14

1.1.2.M hnh kin trc h thng cung cp dch v IPTV...............................................14

1.2.Cc phng thc truyn dn tn hiu IPTV................................................................18

1.2.1.S dng MPEG-2.....................................................................................................19

1.2.2.Giao thc truyn ti thi gian thc RTP...............................................................20

1.2.3.Giao thc iu khin truyn ti thi gian thc RTCP..........................................20

1.2.4.Giao thc lung thi gian thc - RTSP ..................................................................21

1.2.5.Giao thc qun l nhm Internet - IGMP ...............................................................21

1.3.Cc dch v c bn cung cp bi IPTV......................................................................22

CHNG 2. PHN H A PHNG TIN IMS........................................................29

2.1.Tin trnh pht trin IMS.............................................................................................29

2.1.1.3GPP phin bn 99 ..................................................................................................29

2.1.2.3GPP phin bn 4.....................................................................................................30

2.1.3.3GPP phin bn 5, 6 v 7.........................................................................................30

2.2.Kin trc phn h a phng tin IMS.......................................................................32

2.2.1.Yu cu kin trc......................................................................................................32

2.2.2.M t cc chc nng v cc thc th trong IMS.....................................................36

2.3.Cc giao thc s dng trong IMS...............................................................................40

2.3.1.Giao thc khi to phin SIP Session Initiation Protocol ...................................40

2.3.2.Giao thc m t phin SDP Session Description Protocol..................................41

2.3.3.Giao thc truyn ti thi gian thc RTP..................................................................42

2.3.4.Giao thc iu khin RTP RTCP..........................................................................43

CHNG 3. CNG NGH IPTV TRN NN IMS NGN........................................44

3.3.Kin trc IPTV trn nn non-NGN v non-IMS........................................................47

3.3.1. KIN TRC IPTV TRN NN NON-NGN ......................................................................................................473.3.2. KIN TRC IPTV NGN TRN NN NON-IMS..............................................................................................493.4.Kin trc IPTV trn nn IMS/NGN............................................................................49

3.4.1.Kin trc chc nng trn c s IMS/ NGN s dng cho cc dch v IPTV...........50

3.4.1.1. Cc thnh phn chc nng................................................................................51

3.4.1.2. Cc giao din....................................................................................................55

3.4.2.Phn h a phng tin IP li..................................................................................56

3.4.3.Cc chc nng iu khin dch v IPTV.................................................................57

3.4.4.Cc chc nng phng tin IPTV............................................................................58

3.5.M hnh giao thc IPTV trn nn IMS/NGN.............................................................59

3.6.VoD s dng NGN/IMS.............................................................................................61

3.6.1.H s ngi dng IPTV...........................................................................................61

3.6.2.D liu hot ng dch v IPTV..............................................................................62

3.6.3.Dch v v phin di ng.........................................................................................63

3.6.4.Trn tn hiu.............................................................................................................64

3.7.Thit k lc truyn tn hiu cho VOD da trn IMS - NGN..............................70

3.7.1.Khi to dch v VoD..............................................................................................71

3.7.1.1. Dch v VOD ch y.................................................................................71

3.7.1.2. Dch v VoD ch ko..................................................................................72

3.7.1.3. Phc hi danh sch .........................................................................................74

3.7.2.Phin trnh by v lung...........................................................................................75

3.7.2.1. Giao thc..........................................................................................................75

3.7.2.2. t vn .........................................................................................................75

Nhu cu thng tin ........................................................................................................76

3.7.2.3. p ng nhu cu thng tin ...............................................................................76

3.7.2.4. Kim sot Stream (iu khin lung)...............................................................79

3.7.2.5. Mt phin mu .................................................................................................79

3.8.Kt lun chng 3.......................................................................................................84

...........................................................................................................................................84

CHNG 4. TNH HNH PHT TRIN IPTV TI VIT NAM.................................85

KT LUN.......................................................................................................................92

TI LIU THAM KHO.................................................................................................93

THUT NG VIT TT

T vit ttTing AnhTing Vit

3GPPThird Generation Partnership ProjectD n hp tc th h th 3

AAAAuthentication, Authorization andAccountingNhn thc, trao quyn v thanh ton

ACSAuto-Configuration ServerMy ch t ng cu hnh

ADSLAsynchronous Digital Subscriber Lineng dy thu bao s bt i xng

AGCFAccess Gateway Control FunctionChc nng iu khin cng truy nhp

AGWAccess GatewayCng truy nhp

AKAAuthentication and Key AgreeentXc thc v Hip nh chnh

APIApplication Programming InterfaceGiao din lp trnh ng dng

ASApplication ServerServer ng dng

ATMAsynchronous Transfer ModePhng thc truyn dn khng ng b

BCBroadcastQung b

BSBilling SystemsH thng tnh cc

BGCFBorder Gateway Control FunctionChc nng iu khin cng bin

BGFBorder GatewayCng bin

B-ISDNBroadband ISDNMng ISDN bng rng

BRASBroadband Remote Access ServerServer truy nhp t xa bng rng

CAMELCustomeised Applications for Mobile networks Enhanced LogicNhng ng dng cho cc mng di ng nng cao logic

CDRCall Detail RecordBn ghi chi tit cuc gi

Charging Data RecordBn ghi d liu tnh cc

CDMACode Division Multiple Accessa truy nhp phn chia theo m

CODContent on DemandNi dung theo yu cu

CPECustomer Premises EquipmentThit b c s khch hng

CLFConnectivity session Location and reposi tory FunctionV tr phin lin kt v kho chc nng

CPCPConference Policy Control ProtocolGiao thc iu khin chnh sch hi ngh

CSCFCall Session Control FunctionChc nng iu khin phin cuc gi

n tt nghip i hc Thut ng vit tt

SV: Nguyn Thi Sn - H09VT37

CSCircuit SwitchChuyn mch knh

CSCCall Session ControllerB iu khin phin cuc gi

CSNCircuit Switch NetworkMng chuyn mch

DBMSDatabase Management SystemH thng qun l c s d liu

DSLAMDigital Subscriber Line AccesMultiplexersB ghp knh truy nhp ng dy thu bao s

DVBDigital Video BroadcastingVideo s pht qung b

DWDMDense Wavelength DivisionMultiplexingGhp knh phn chia theo bc sng cht

EDGEEnhanced Data Rates for GlobalEvolutionMng v tuyn ci tin v giao din v tuyn GSM nhm tng tc truyn s liu

ETSIEuropean TelecommunicationsStandards InstituteVin tiu chun vin thng chu u

FMCFixed Mobile ConvergenceHi t di ng-c nh

GGSNGateway GPRS Support NodeNode h tr cng GPRS/

GPRSGeneral Packet Radio ServiceDch v v tuyn gi thng thng

GSMGlobal System for MobileH thng di ng ton cu

GUIGraphic User InterfaceGiao din ho ca ngi dng

HDHigh Definition phn gii cao

HLRHome Location RegisterThanh ghi nh v thng tr

HSSHome Subscriber ServerServer thu bao nh

HTTPHyper Text Transfer ProtocolGiao thc truyn dn siu vn bn

I-BCFInter-Border Control FunctionChc nng iu khin lin kt bin

ICPInternet Cache ProtocolGiao thc m Internet

ICSIMS Common SystemH thng IMS chung

I-CSCFInterrogating CSCFCSCF truy vn

IDIdentifierNhn dng

IETFInternet Engineering Task ForceNhm lm vic lin quan n cc giao thc Internet

IFSIntergrated Feature ServerMy ch tch hp cc c tnh

IMSIP Multimedia SubsystemPhn h a phng tin IP

INIntelligent NetworkMng thng minh

IPInternet ProtocolGiao thc mng Internet

ISDNIntegrated Services Digital NetworkMng s a dch v tch hp

ISUPISDN User PartPhn ngi dng ISDN

ITU-TInternational Telecommunication Union Telecommunication StandardizationBureauTiu ban chun ha vin thng trongLin minh vin thng th gii

IWFInterWorking FunctionChc nng tng tc

LANLocal Area NetworkMng cc b

LIALocation-Info-AnswerTr li thng tin v tr

LIRLocation-Info-RequestYu cu thng tin v tr

MEDMediatorThit b trung gian

MGMedia GatewayCng phng tin

MGCMedia Gateway ControllerB iu khin cng phng tin

MGFMedia Gateway FunctionChc nng cng phng tin

MGCFMedia Gateway Control FunctionChc nng iu khin cng phng tin

MGCPMedia Gateway Control ProtocolGiao thc iu khin cng phng tin

MGWMedia GatewayCng phng tin

MMLMan Manchine LanguageNgn ng giao din ngi-my

MRCMedia Resource ControllerB iu khin ti nguyn phng tin

MRCFMedia Resource Control FunctionChc nng iu khin ti nguyn phng tin

MRFMedia Resource FunctionChc nng ti nguyn phng tin

MRFCMultimedia Resource Function ControlB iu khin ti nguyn a phng tin

MRFPMultimedia Resource Function ProcessB x l ti nguyn a phng tin

MRPMedia Resources ProcessorB x l ti nguyn phng tin

MSANMulti Service Access NetworkMng truy nhp a dch v

MSCMobile Services switching CenterTrung tm chuyn mch dch v di ng.

NACFNetwork Access Configuration FunctionChc nng cu hnh truy nhp mng

NASSNetwork Attachment SubsystemPhn h gn mng

NATNetwork Address TranslatorB bin dch a ch mng

NGNNext Generation NetworkMng th h mi

NGOSSNew Generation Operations Systems andSoftwareH thng v phn mm hot ng th h mi

OADMOptic Add/Drop MultiplexerB xen/r quang

OCGOperator Charging GatewayCng iu hnh tnh cc

OMAOpen Mobile AllianceLin minh di ng m

OSAOpen Services ArchitectureKin trc cc dch v m

PAPresencer AgentTc nhn hin th

PBXPrivate Branch ExchangeTng i nhnh c nhn

P-CSCFProxy CSCFCSCF th quyn

PDFPolicy Decision FunctionChc nng quyt nh chnh sch

PEAPresencer External AgentTc nhn hin th m rng

PEFPolicy Enforcement FunctionChc nng bt buc chnh sch

PEPPolicy Enforcement Pointim bt buc chnh sch

PESPSTN Emulation ServerServer m phng PSTN

PLMNPublic Land Mobile NetworkMng di ng mt t cng cng

PNAPresencer Network AgentTc nhn mng hin th

PoCPush to Talk

POTSPlain Old Telephone SystemH thng in thoi truyn thng

PRACKProvisional ResponseACKnowledgementTha nhn p ng tm thi

PSPacket SwitchChuyn mch gi

QoSQuality of ServiceCht lng dch v

RNCRadio Network ControllerB iu khin mng v tuyn

R-SGWReligion Signalling GatewayCng bo hiu chuyn vng

RTCPRealtime Transport Control ProtocolGiao thc iu khin truyn ti thi gian thc

RTPRealtime Transport ProtocolGiao thc truyn ti thi gian thc

S-CSCFServing CSCFCSCF phc v

SCTPStream Control Transmission ProtocolGiao thc truyn dn iu khin lung

SDHSynchronous Digital HierarchyPhn cp s ng b

SDPService Delivery PlatformNn tng phn phi dch v

SGWSignaling GatewayCng bo hiu

SHDSLSymmetric High-speed DSLDSL tc cao i xng

SIPSession Initial ProtocolGiao thc khi to phin

SIPSEESIP Servlet Excution EnvironmentMi trng thc hin servlet SIP

SLAService Level AggrementTha thun mc dch v

SLFSubscriber Locate FunctionChc nng nh v thu bao

SMSShort Messaging ServiceDch v nhn tin ngn

STMSynchronous Transport ModuleModule truyn dn ng b

TDMTime Division MultiplexGhp knh phn chia theo thi gian

TDMATime Division Multiple Accessa truy nhp phn chia theo thi gian

TGTrunk GatewayCng trung k

TISPANTelecoms & Internet converged Services& Protocols for Advanced NetworksT chc hi t vin thng v Internet v dch v v giao thc cho cc mng tin tin

T-MGFTrunk Media Gateway FunctionChc nng cng phng tin trung k

T-SGWTransport Signalling GatewayCng bo hiu truyn ti

UAUser AgentTc nhn ngi dng

UEUser EquipmentThit b ca ngi dng

UMTSUniversal Mobile TelecommunicationSystemH thng thng tin di ng ton cu

URIUniform Resource IdentifierNhn dng ti nguyn ng dng

WASWLAN Access ServerServer truy nhp WLAN

WCDMAWireless CDMACDMA khng dy

WDMWavelength Division MultiplexingGhp knh phn chia theo bc sng

WiMAXWorldwide interoperability forMicrowave AccessTng tc ton cu i vi truy nhp vi ba

WLANWireless LANMng LAN khng dy

DANH MUC HINH VE

Hnh 1.3. Cc phng thc truyn pht IPTV.............................................................................18

Hnh 1.4. Truyn pht MPEG-2 qua IP........................................................................................19

Hnh 1.5. Giao thc RTSP............................................................................................................21

Hnh 2.1. Vai tr ca IMS trong cc mng chuyn mch gi.....................................................30

Hnh 2.2. Cc la chn kt ni IMS khi mt ngi dng ang chuyn vng............................32

Hnh 2.3. Tng quan v tnh cc trong IMS..............................................................................33

Hnh 2.4. Cc thay i chuyn vng IMS/CS..............................................................................34

Hnh 2.5. Kin trc cc lp v IMS............................................................................................35

Hnh 2.6. Thit lp phin IMS c bn v nh tuyn S-CSCF....................................................38

Hnh 2.7. Cu trc HSS................................................................................................................38

Hnh 2.8. Mi quan h gia cc loi server ng dng.................................................................39

Hnh 2.9. Ngn xp giao thc.......................................................................................................41

Hnh 2.10. nh dng gi RTP....................................................................................................43

Hnh 3.1. Cc bc pht trin chnh ca IPTV............................................................................45

Hnh 3.2. Kin trc IPTV thng thng......................................................................................48

Hnh 3.3. Kin trc IPTV trn IMS/NGN n gin ca TISPAN...............................................50

Hnh 3.4. Kin trc IPTV trn nn IMS/NGN............................................................................51

Hnh 3.5. Chc nng ti nguyn phng tin IMS (tri) v chc nng phng tin NGN (phi).

55

Hnh 3.6. Cc khi chnh ca IMS...............................................................................................57

Hnh 3.7. M hnh IPTV trn nn IMS.......................................................................................59

Hnh 3.8. Cc dch v IPTV NGN...............................................................................................62

Hnh 3.9. H s ngi dng IPTV...............................................................................................63

Hnh 3.10. Bn ghi d liu hot ng dch v IPTV...................................................................64

Hnh 3.11. Cc bc khi to.......................................................................................................65

Hnh 3.12. Dch v s dng ch ko......................................................................................66

Hnh 3.13. Dch v km theo s dng ch y......................................................................67

Khi to phin c m t nh trong hnh v sau y:................................................................67

Hnh 3.14. Khi to phin...........................................................................................................67

n tt nghip i hc Danh mc hnh v

SV: Nguyn Thi Sn - H09VT39

Hnh 3.15. Sa phin....................................................................................................................68

Hnh 3.16. UE bt u kt thc phin.........................................................................................69

Hnh 3.17 SCF bt u kt thc phin........................................................................................69

Hnh 3.18 MF bt u kt thc phin..........................................................................................70

Hnh 3.19. Dch v km theo VOD ch y...........................................................................72

Hnh 3.20. Dch v VoD ch ko s dng MESSAGE.........................................................73

Hnh 3.21. Dch v VoD ch ko s dng SuBSCRIBE/NOTIFY........................................74

Hnh 3.22. Phc hi danh sch s dng HTTP/GET...................................................................75

Hnh 3.23. Bt u phin............................................................................................................80

Hnh 3.24. Thit lp v kim sot lung......................................................................................82

Hnh 3.25. UE bt u kt thc phin mu..................................................................................83

SV: Nguyn Thi Sn - H09VT319

DANH MC BNG BIU

Bng 2. Cc c im IMS..........................................................................................................30

Bng 3. Cc Giao thc IETF v s dng trong dch v VOD IMS/NGN.................................70

n tt nghip i hc Danh mc bng biu

LI NI U

Cng vi s bng n ca cc cng ngh mi v nhu cu s dng dch v vin thng ca khch hng, mng vin thng c nhng bc tin vt bc. Hin ti v trong tng lai nhu cu pht trin cc loi hnh dch v thoi, phi thoi, Internet v c bit l cc loi hnh dch v bng rng ngy mt tng v khng th tch ri i sng x hi. tha mn nhu cu mng vin thng i hi phi c cu trc hin i linh hot v nht l tha mn mi nhu cu v dch v a phng tin.

IPTV l dch v truyn hnh qua kt ni bng rng da trn giao thc Internet. y l mt trong cc dch v Triple-play m cc nh khai thc dch v vin thng ang gii thiu trn phm vi ton th gii. Orange/France Telecom kh thnh cng vi gi dch v Orange TV ti Php, Hn Quc m rng IPTV ra c nc, PCCW thnh cng vi dch v IPTV ti Hng Kng, Nokia Siemens Networks trin khai IPTV ti Ba Lan (4/2007), IPTV v ang pht trin vi tc rt nhanh, theo Telecom Asia (http://www.iptv- asia.net/), s thu bao IPTV ring khu vc chu - Thi Bnh Dng s gia tng 75% mi nm, t 34,9 triu thu bao v doanh thu 7 t USD vo nm 2011.

Ti Vit Nam, IPTV tr nn kh gn gi i vi ngi s dng Internet ti Vit Nam. Cc nh cung cp nh VNPT, FPT, SPT, VTC a IPTV, VoD... ra th trng nhng phm vi v quy m nh.

Xu hng pht trin mng th h sau NGN hin nay l chuyn t Softswitch sang IMS do IMS em li kh nng cung ng dch v a phng tin cho ngi s dng u cui m khng b ph thuc vo v tr, cng ngh truy nhp mng v vo thit b u cui ca ngi s dng. IMS h tr cc loi hnh dch v khc nhau (thoi, d liu, hnh nh v kh nng tch hp ca c ba loi hnh dch v ni trn - Tripple Play m in hnh l dch v IPTV), cc cng ngh mng v cc thit b u cui. c bit, trn nn tng IMS, yu t di ng v truy nhp khng dy tr nn kh thi, cng to iu kin cho IPTV pht trin thnh mt trong nhng dng dch v Quad-Play.

trong nc c mt s nghin cu v IPTV v IMS, tuy nhin nhng nghin cu v pht trin ng dng IPTV trn IMS-NGN cha c y v h thng. nc ngoi c mt s cc hng ln nh Alcatel-Lucent, Ecrisson, Fokus ... bt u trin khai pht trin mt s m hnh th nghim IPTV trn IMS-NGN.

Do vy, em chn ti: Cng ngh IPTV trn nn IMS/ NGN vi mc tiu nm bt c cc vn lin quan ti truyn hnh trn nn giao thc Internet IPTV v cc dch v IPTV trn nn IMS/NGN, tp trung ch yu vo kin trc IPTV theo s pht trin ca NGN / IMS, chc nng cc phn t ca IMS v cc th tc cn thit khi cung cp dch v VOD trn nn IMS/NGN, cung cp cc dch v a phng tin v hi t di ng-c nh. , ti c xy dng theo ni dung nh sau:

n tt nghip i hc Li ni u

Chng 1: Tng quan v IPTV

Chng 2: Gii thiu phn h a phng tin IP Chng 3: Cng ngh IPTV trn nn IMS/NGNChng 4: Tnh hnh pht trin dc v IPTV ti Vit Nam

Em xin chn thnh cm n cc Thy C trong khoa Vin thng 1 ca Hc vin v c bit l C gio V Th Ngoan nhit tnh hng dn, gip v to iu kin rt tt em c th hon thnh n ny.

Mc d ht sc c gng v dy cng nghin cu su tm ti liu nhng do cng ngh mi v phc tp, lng kin thc li c hn nn bn n tt nghip khng trnh khi nhng thiu st, c vn cha c cp su. Em mong mun c tip thu kin ca cc thy c gio em c c kin thc v bn n c hon thin hn.

Em xin chn thnh cm n!

H Ni, ngy 10 thng 08 nm 2011

Sinh vin thc hin

Nguyn Thi Sn

CHNG 1. GII THIU CHUNG V CNG NGH IPTV

1.1. Tng quan v cng ngh IPTV

1.1.1. nh ngha

IPTV l tn vit tt ting anh ca cm t Internet Protocol Television, biu din ni dung video s, bao gm v tuyn truyn hnh, c phn phi qua vic s dng giao thc Internet (IP). nh ngha IPTV ny khng ch rt n gin m cn nhn mnh rng Internet khng ch cn thit cho vic thc hin vai tr trong truyn pht tn hiu truyn hnh hoc l bt c loi ni dung video khc. V vy, IPTV cp ti cch dng IP l c ch c th s dng Internet, trnh by mng cng cng trn c s IP, hoc IPTV s dng truyn pht ni dung video qua mt mng ring trn c s IP.

V IPTV yu cu dng IP khng ch l mt c ch truyn pht, IP c th c s dng truyn pht cc loi ni dung khc nhau qua c mng Internet v mng ring trn c s IP. V d ni dung IPTV c th gii hn t nhc hnh ti cc cuc biu din trn truyn hnh, phim, v nhiu s kin c bit khc, nh l bng . iu ny c ngha l nh ngha ngn gn ca IPTV bao gm mt di rng c cc chng trnh ang c v chng trnh c kh nng pht trin. Ngoi cc dch v truyn hnh qung b thng thng, Video theo yu cu (Video on Demand VoD), IPTV cn h tr s tng tc gia ngi xem vi chng trnh v y cng chnh im c bit v hp dn nht ca IPTV. Khng nh truyn hnh cp truyn thng, IPTV l mt tng th chui cc dch v truyn hnh c tnh tng tc. Ngoi vic t do la chn chng trnh truyn hnh hay phim mun xem, NSD c th tham gia cc cuc hi tho t xa, chi game, mua hng qua TV hoc vit blog video (vlog), nhn tin qua TV thng qua my vi tnh PC hoc my thu hnh cng vi hp phi ghp set topbox.

1.1.2. M hnh kin trc h thng cung cp dch v IPTV

IPTV l cng ngh truyn dn hnh nh k thut s ti ngi s dng (NSD) qua Internet bng rng. Ngoi cc dch v truyn hnh qung b thng thng, Video theo yu cu (Video on Demand VoD), IPTV cn h tr s tng tc gia ngi xem vi chng trnh v y cng chnh im c bit v hp dn nht ca IPTV. Khng n thun l truyn hnh nh truyn hnh cp truyn thng, IPTV l mt tng th chui cc dch v truyn hnh c tnh tng tc. Ngoi vic t do la chn chng trnh truyn hnh hay phim mun xem, NSD c th tham gia cc cuc hi tho t xa, chi game, mua hng qua TV hoc vit blog video (vlog), nhn tin qua TV

Ta c th chia h thng IPTV t ngun ni dung ti u cui ngi dng lm cc khi chc nng c bn nh sau: h thng cung cp ni dung, h thng Head-end, h thng Middleware, h thng phn phi ni dung, h thng qun l bn quyn s (DRM),

n tt nghip i hc Chng 1

mng truyn ti, h thng qun l mng v tnh cc, Set-top Box (STB). S khibiu th thnh phn nh hnh 1.1 sau y:

Hnh 1.1. M hnh kin trc h thng cung cp dch v IPTV

H thng gm cc khi chc nng chnh nh sau:

- H thng cung cp ni dung: cung cp ngun d liu thu, nhn v x l cc d liu chng trnh t cc ngun khc nhau nh v tinh, truyn hnh mt t v cc ngun khc chuyn sang h thng Head-end.

- H thng Head-end: Thu, iu ch v gii m ni dung hnh nh v m thanh t cc ngun khc nhau v s dng cc thit b m ha (encoder) chuyn i ni dung ny thnh cc lung d liu IP khun dng m ha mong mun. Hin nay tn hiu video ch yu c m ha MPEG-4/H.264 m bo tc kh thp, cho php trin khai tt trn mng truy nhp xDSL. Cc chng trnh sau khi c m ha s c phn phi ti khch hng trn cc lung IP Multicast qua mng truy nhp v mng li IP. Cc chng trnh ny c th c mt m bi cc h thng bo v ni dung. Ty vo chng trnh c chn, STB ca khch hng s chuyn ti lung multicast tng ng s dng giao thc Internet Group Management Protocol (IGMP). u vo ca h thng Video Headend l cc chng trnh truyn hnh qung b, cc knh truyn hnh mua bn quyn thu t v tinh, cc knh truyn hnh cp, cc phim t cc ngun khc nh t sn xut, t cc thit b VCD/DVD player, v.v..

- H thng Middleware: Cung cp kh nng qun l thu bao, ni dung v bo co hon chnh cng vi cc chc nng qun l EPG v STB, ng thi vn duy tr tnh m cho vic tch hp cc dch v trong tng lai. Middleware l mt giao din ca h thng cung cp dch v IPTV vi ngi s dng, n xc nh danh tnh cho ngi dng. Hin th mt danh sch cc dch v m thu bao c th s dng v tr gip la chn dch v ny sau khi xc thc danh tnh ca ngi dng. Middleware lu li mt profile cho tt c cc dch v. Middleware m bo cc hot ng bn trong ca dch v truyn hnh mt cch hon ho. Middleware s khng gii hn bt k hot ng ring r no trong h thng, nhng s giao tip trc tip vi mi thnh phn c h thng h tr. Middleware h tr API cho php m rng cc chc nng mi v truyn d liu gia cc h thng.

- H thng phn phi ni dung: Bao gm cc cm my ch VoD v cc h thng qun l VoD tng ng, cho php lu tr cc ni dung c m ha v thit lp cc chnh sch phn phi ni dung mt cch mm do. H thng ny thng c thit lp phn tn, cho php nh khai thc m rng mt cch kinh t, ph hp vi ti v yu cu dch v ca cc thu bao. My ch VoD s lu ni dung thc v cung cp cho thu bao khi n nhn c s xc thc danh tnh t Middleware. N cho php cc thu bao t v xem nhng b phim cht lng cao v chng trnh theo yu cu (chng trnh ny c lu trn my dch v v truyn ti theo yu cu). H thng ny cng cung cp nhng chc nng iu khin VCR nh fast-forward, pause, v rewind tng t nh xem qua u DVD.

- H thng qun l bn quyn s (DRM): DRM gip nh khai thc bo v ni dung ca mnh, nh trn cc tn hiu truyn hnh hay m ha ni dung VoD, khi truyn i trn mng Internet v tch hp vi tnh nng an ninh ti STB pha thu bao. DRM dng bo mt ni dung cc kha gii m ca cc thu bao. Nhng ni dung c ti trn nhng my ch ni dung s c m ha trc bng h thng DRM v n cng ch m ha ni dung broadcast bo mt s phn b n Set-top Box (STB). H thng c kh nng h tr chc nng m ho trong cc Headend tng ng v cung cp kho mt m cho cc Headend ny. H thng DRM cha kho cho phn ni dung ca mt c s d liu kho ng thi b mt phn phi c s d liu ny ti STB. H thng DRM cng s h tr thm vo phn ni dung cc chc nng th thut trong khi xem (tua nhanh, tua li, v.v...). H thng DRM s da trn cc khi nim ca h thng c s h tng kho cng cng (Public Key Infrastructure, PKI). PKI dng cc th k thut s X.509 xc nhn mi thnh t trong h thng DRM ng thi m ho an ton d liu c dng cc kho chung/ring.

- Mng truyn ti: Mng truyn dn ng vai tr quan trng nht trong ton b h thng cung cp dch v IPTV. Kh nng p ng v bng thng ca mng truyn ti s quyt nh n s thnh cng cho dch v IPTV cung cp. H tng mng IP bng rng

truyn dch v t nh cung cp dch v IPTV n khch hng. Mng truy nhp s tn dng phn h tng mng xDSL c sn. cung cp dch v vi cht lng tt v tiu th t bng thng khi c ng thi nhiu truy nhp n h thng, mng truy nhp bng rng (B-RAS/MSS v DSLAM) cn phi c h tr multicast. i vi DSLAM, ngoi h tr multicast, DSLAM cn cn h tr IGMP version 2. Ngoi ra, B-RAS/MSS v DSLAM cng cn h tr cc giao tip Ethernet chun (FE, GE). Mng cng phi c kh nng h tr QoS t u cui n u cui, m bo c bng thng cn thit v u tin cho cc knh truyn hnh qung b cng nh cc phin Video theo yu cu ang s dng (phi t c mt gi v jitter ti thiu). Bng thng xDSL do cc DSLAM cung cp n khch hng phi c kh nng ln n 4-5 Mbps.

- H thng qun l mng v tnh cc: H tr qun l mng v tnh cc cho dch v IPTV ca khch hng.

- Set-top Box (STB): Thit b u cui pha khch hng, cho php thu, gii m v hin th ni dung trn mn hnh TV. STB cn h tr cc chun MPEG-4/H.264. Ngoi ra, STB cng c th h tr HDTV, c kh nng kt ni vi cc thit b lu tr bn ngoi, video phone, truy nhp web (Walled garden), v.v... STB cung cp cc ng dng truyn thng v gii tr. STB s h tr kt ni gia thit b tivi v mng in thoi, cng nh Internet v th vin nh o ca nh cung cp dch v. N c th gii m nhng chui d liu v hnh nh n da vo a ch IP, ng thi th hin cc hnh nh ny trn TV. STB s h tr chun H.264/MPEG-4 Part 10 v phn mm client Middleware ca n s c da trn mt cu trc thick client, iu c ngha l ng dng v d liu th hin s lu trn STB. i km theo B gii m l mt thit b cm tay remote control. Remote khng ch thc hin cc chc nng iu khin t xa nh thng thng m con tch hp cc tnh nng tng tc chuyn bit nh: Xem lch chng trnh truyn hnh, t lch xem theo s thch, to album ring, gi tin nhn (tr chuyn), voting (bnh bu), Vi thit b ny chc chn khch hng s khng cn cm gic th ng mi khi ngi trc mn hnh TV.

Hnh 1.2. Mt loi Set-top Box

1.2. Cc phng thc truyn dn tn hiu IPTV

IPTV c hai phng thc truyn pht tn hiu chnh. Tiu chun MPEG-2 l phng php ph bin nht c dng truyn pht tn hiu video qua mt mng IP, v RTP cng l phng php cn thit cho vic truyn pht video.

C ba phng php truyn pht tn hiu qua mt mng IP. Nhng phng php ny bao gm truyn mt file - khng xt thi gian thc, qung b v video theo yu cu (VoD), ti tnh thi gian thc. phn ny ta s tp trung vo vic s dng k thut pht qung b v video theo yu cu.

Cc phng thc truyn pht IPTV c m t nh trong hnh v di y:

Hnh 1.3. Cc phng thc truyn pht IPTV

Pht qung b: Khi video c pht qung b, mi ng dn c cung cp mt knh duy nht cho php mt set-top box nhn ng dn thit b iu khin c nhn xem. Ngun pht qung b c th l cc b phim trc c lu trong server cng nh mt ng dn trc tip t mt trm truyn hnh v tuyn truyn hnh trn chung kt gii bng chuyn Olympic ma h, mt chng trnh nhiu tp trn truyn hnh, hoc l cc chng trnh khc. Mi ngun u vo b gii m qung b c ng gi lung video, gm vic thit lp mt knh v nhm a ch multicast ti thit b set- top box s tham gia bt c khi no ngi xem chn knh s dng thit b.

H thng pht qung b c coi l mt chui cc server phng tin dn mt s lung qung b. Cc server phng tin h tr vic truyn pht c multicast v unicast, sau s dng cho vn hnh VoD. H thng qun l thu bao c dng thc hin tnh cc thu bao, h thng qun l thu bao s cung cp thm cc chc nng: h tr

cc c im tng tc set-top box, cung cp cc ni dung c la chn ti cc thu bao nh l mt sn phm VoD.

Video theo yu cu: VoD hi p thc mc c pht ra bi mt thu bao qua thit b set-top box hoc PC, cc lung hi p l mi chui cc gi unicast ti a ch IP ca thit b set-top box hoc my tnh c nhn. in hnh, trm qun l thu bao s hin th mt danh sch cc s kin VoD t mt thu bao c th la chn chng trnh. Tuy nhin, cng c th cho nh vn hnh IPTV chn thm mt th vi ha n hng thng ca thu bao, ha n c th lit k hng trm s kin, gi cc v m truy nhp ly li cc s kin c la chn. Cng phng php nh vy, lung gi d liu IP s biu din mt truyn dn unicast ti thit b set-top box hoc my tnh c nhn ca thu bao.

1.2.1. S dng MPEG-2

Mt trong cc phng php c s dng truyn pht IPTV qua ng gi MPEG-2 s dng UDP ti lp truyn ti. Khi vic ng gi xy ra, UDP c th la chn s dng RTP cung cp khung lp ng dng xc nh ti c truyn v cung cp chui cho mi gi d liu RTP, cho php cc gi b mt c pht hin.

UDP/RAW v UDP/RTP: video cng c th c truyn trc tip trong cc gi UDP m khng phi s dng RTP. Lc , lung truyn c gi l UDP/RAW. Khi UDP/RAW c dng, vi li v iu kin thng tin c th c pht hin, bao gm: b gi thay i, bytes ng b li, kch thc gi sai, qu thi gian, jitter qu mc, tc UDP khng ph hp.

Hnh 1.4. Truyn pht MPEG-2 qua IP

Khi RTP c s dng vi UDP, nh hnh 1.4, cc gi c th ng gi thi gian v xc nh qua vic s dng mt chui s. iu ny cho php pht hin mt vi kt ni li nm ngoi kh nng pht hin khi m UDP/RAW c s dng. Cc iu kin li pht hin mi ny s dng gm c UDP/RTP:

- Xc nh cc gi nhn c sai;

- Pht hin cc gi b nhn i;

- Xc nh nu mt gi b mt;

- Xc nh cc gi c mt kch thc khng ng.

C UDP/RAW v UDP/RTP c th c dng truyn hnh nh, sau cung cp kh nng n b cho nhng iu kin li nh cc gi c nhn hng, cc gi sai kch c, hoc cc gi b nhn i. Thm na, v UDP/RTP cho php b thu xc nh nu b mt gi, v cng cho php b n b khi thy s mt gi. Ph thuc vo phn mm c s dng bi mt b thu, n c th khng lm g trong sut thi gian mn hnh xut hin trng khng hoc lp cc khung nhn trc . Tip theo, v cc khung c nhn tip theo c th hoc khng th xem xt khc t cc khung c lp li, kt qu c th l s chuyn tip trn chu hoc b ngt qung.

Mt nhn thi gian cho php b thu thc hin ng b cng nh phn gii jitter v tr mt gi qua mt mng.

1.2.2.Giao thc truyn ti thi gian thc RTP

RTP c xc nh trong mo u UDP vi gi tr 5004 trong trng cng. RTP cung cp chc nng truyn ti mng u cui d dng cho truyn ti d liu thi gian thc nh audio, video, v d liu m phng qua dch v mng unicast hoc multicast. RTP cung cp chui v nhn thi gian d liu, nhng khng c nh a ch d tr ngun cng nh m bo cht lng dch v (QoS) cho d liu thi gian thc. V vy, cc nh vn hnh mng phi cu hnh xp hng nh tuyn u tin xc nh trc lu lng cho php video thi gian thc nm bt c ch ca n vi tr ti thiu.

1.2.3.Giao thc iu khin truyn ti thi gian thc RTCP

Giao thc iu khin truyn ti thi gian thc cung cp thng tin v ngi tham gia vo phin ang pht trin cng nh mt c ch iu khin cht lng dch v. Thng tin v cc thnh phn tham gia vo phin c th thay i t cc trng hp khng c thnh phn hin iu khin phin yu cu iu khin mi quan h thnh phn chi tit. RTCP thc hin qua on truyn dn ca cc gi iu khin ti tt c cc thnh phn ca phin theo cng phng php phn phi l s dng cho cc gi d liu. V chc nng gc ca RTCP cung cp hi p cht lng ca s phn b d liu, n thc hin chc nng nh l phn vai tr RTP nh l giao thc truyn ti. Thc t, thng tin c cung cp bi RTCP c th c dng xc nh ni nghn c chai khi phng thc multicast xut hin, lm cho d dng qu trnh gii quyt vn .

SV: Nguyn Thi Sn - H09VT329

1.2.4.Giao thc lung thi gian thc - RTSP

RTSP (Real Time Streaming Protocol) c nh ngha bi IETF RFC 2326 m t tp iu khin VCR cho streaming media. Thng cc bn tin RTSP c gi t khch hng n server, i khi cng c ngoi l, gi t server n khch hng. Trong cc h thng IPTV, RTSP c s dng trong cc ng dng VoD khch hng truy cp, iu khin ni dung lu tr ti VoD server. VoD thc cht l lin lc mt-mt c to ra s dng unicast. Unicast cho php thc hin dch v VoD v gi n khch hng n l.

Client

Describe Setup Play

Teardown

Server

Content

Hnh 1.5. Giao thc RTSP

1.2.5.Giao thc qun l nhm Internet - IGMP

IGMP (Internet Group Management Protocol) c nh ngha bi mt s IETF RFC, phin bn mi nht l RFC 3376. IP Multicasting c nh ngha l s truyn pht gi tin IP ti mt nhm ch (host group). Nhm ch ny l mt tp cc host c nhn dng bi mt a ch IP n. Trong h thng IPTV, nhm ch s l mt tp cc thu bao mun nhn chng trnh c th no .

Trong thc t, cc h thng truyn dn s dng IGMP khng gi ton b ni dung n ton b ngi s dng. Hot ng Multicast, s dng IGMP, cho php iu khin nhng ni dung no n ngi dng no v do iu khin lng d liu c gi thng qua mng ti mt thi im bt k.

IGMP l giao thc c s dng x l chuyn knh trong h thng IPTV. p li lnh iu khin t xa, chui cc yu cu IGMP c a ra ri multicast hin thi v tham gia vo dch v khc. Thi gian cn thc hin cc yu cu ny s nh hng trc tip ln thi gian chuyn knh. Cc nh cung cp Middeware ang lm vic trn nhiu m hnh khc nhau ci thin thi gian hi p chuyn knh.

1.3. Cc dch v c bn cung cp bi IPTV

Kh nng ca IPTV gn nh l v hn v ha hn mang n nhng ni dung k thut s cht lng cao, theo cc nh ngha v xut ca hip hi vin thng quc t (ITU), vic phn loi da theo cc dch v c bn ca IPTV nh bng sau:

Bng 1. Cc dch v c bn cung cp bi IPTV

Nhm dch vTn dch vM t v dch v

Dch v qung b (Broadcast Service)Truyn hnh qung b (Linear/Broadcast TV )Dch v pht cc knh truyn hnh qung b thng thng. V d: cc knh qung b VTV1, VTV2, HTV7, HTV9,

Linear Broadcast TVwith Trick ModesTruyn hnh qung b cho php ngi dng tm dng, xem li, xem tip, b qua cc on qung co, ghi li chng trnh bng cc u ghi.

Multi-angle serviceDch v cung cp cho ngi dng xem nhiu gc quay ca mt phim (nh 3D) hoc mt trn bng

Electronic ProgramGuide (EPG)Dch v hng dn trc tip trn mn hnh v lch pht sng, danh sch cc phim, cc phvv

Qung co truyn hnh truyn thngQung co km theo cc chng trnh truyn hnh truyn thng

Dch v theo yu cu (On Demand Service)Phim theo yu cu - Video on Demand (VoD)Cho php khch hng la chn phim a thch v c tr ph

Nhc theo yu cu - Music on Demand (MoD)Cho php khch hng la chn cc video clip, bn nhc a thch v c tr ph.

Game theo yu cu - Game on Demand (GoD)Cho php khch hng la chn cc game a thch v c tr ph.

Thanh ton theo ni dung (Pay Per ViewPPV,OPPV, IPPV)Xem cc chng trnh phi tr ph (ng k cc chng trnh theo lch pht hoc l chng trnh mi)

Dch v tng tc (InteractiveThng tin chung ( T- information )Cc dch v thng tin thng thng trn truyn hnh nh tin thi s, thi tit, gi c th trngvv

Service)

T-communicationDch v thng tin qua truyn hnh cung cp cho khch hng kh nng trao i thng tin thng qua IPTV di cc hnh thc nh email, tin nhn, chat, duyt web, Video conferencinfvv

Thng mi (T- commerce)Dch v giao dch ngn hng, mua sm, t ch khch sn, tu, my bay, v xem ca nhc vv ti nh

Dch v votingCho php ngi xem tham gia trc tip cc tr chi trn truyn hnh.V d: Thamgia tr chi Hugo t thit b iu khin t xa ca tivi,

Gii tr (T- entertainment )Cc tr chi, karaoke, xem nh, s x, nht k in tvv. C th chi 1 mnh hoc nhm

Thng tin chnh sch(T-government)Cc thng tin v ch , chnh sch x hi lin quan n chnh ph, thnh ph, phng, qun

Interactive ProgramGuide (IPG) Electronic ContentsGuide (ECG)Dch v hng dn tm kim, tra cu ni dung trn TV theo cc ch m khch hng la chn (tng tc).

Qung co chn lc (Targeted Advertising)Qung co theo yu cu ca doanh nghip (tp trung vo mt s i tng khch hng nht nh, khng qung b ton mng).

1.4. u Nhc im ca IPTV

1.4.1. u im

- Tch hp a dch v: Trn mt ng kt ni Internet ngi dng IPTV c th c s dng cng mt lc rt nhiu dch v khc nhau nh truy cp Internet, truyn hnh, in thoi c nh v di ng, VoIP (Voice over Internet Protocol)...mang li cho ngi dng s tin li trong qu trnh s dng.

- Tnh tng tc cao: IPTV s mang li cho ngi dng tri nghim xem truyn hnh c tnh tng tc v c nhn ha rt cao. V d, nh cung cp dch v IPTV c th tch hp mt chng trnh hng dn tng tc cho php ngi xem c th tm kim ni dung chng trnh truyn hnh theo ta hoc tn din vin. Hoc nh cung cp dch v c th trin khai chc nng hnh-trong-hnh (picture-in-picture) cho php ngi dng xem nhiu knh cng mt lc. Ngi dng cng c th s dng TV truy cp n cc ni dung a phng tin khc trn PC nh hnh nh hay video hoc s dng

in thoi di ng iu khin TV nh ghi li mt chng trnh a thch no ...Mt phng thc tng tc khc m nh cung cp dch v IPTV c th trin khai l cung cp cc thng tin m ngi xem yu cu trc tip trong qu trnh xem chng trnh. V d ngi dng c th nhn thng tin v i bng m h ang xem thi u trn mn hnh chng hn.

Trn thc t tnh tng tc cao hon ton c th xut hin cc loi hnh truyn hnh s khc nh truyn hnh v tinh hay cp. Song trin khai c th cn phi c s kt ni tng tc gia u pht sng v b thu sng. y l iu m truyn hnh v tinh v cp khng c c. Mun trin khai th hai hnh thc truyn hnh ny buc phi kt hp vi cc h tng mng khc nh Internet hoc in thoi di ng.

- Cng ngh chuyn mch IP: Hu ht ngi dng u khng bit rng truyn hnh cp v v tinh thng gi i tt c tn hiu ca mi knh cng mt lc cng mt thi im nhm cho php ngi dng chuyn i knh tc thi nh chng ta vn thy. iu ny dn ti s lng ph bng thng cn thit.

IPTV s dng cng ngh chuyn mch IP loi b hn ch ny. Mi d liu chng trnh truyn hnh c lu tr ti mt v tr trung tm v ch c d liu knh m ngi dng yu cu xem l c truyn ti i. iu ny s cho php nh cung cp dch v c th b sung thm c nhiu dch v cho IPTV hn v bng thng khng cn phi l vn qu kh gii quyt na.

- Mng gia nh: Kt ni vo mng Internet trong gia nh khng ch c TV m cn c cc PC khc. iu ny s cho php ngi dng c th s dng TV truy cp n nhng ni dung a phng tin trn PC nh nh s, video, lt web, nghe nhc... Khng nhng th mt s mn hnh TV gi y cn c tch hp kh nng vn hnh nh mt chic TV bnh thng. Tt c lin kt s tr thnh mt mng gii tr gia nh hon ho.

- Truyn hnh s: IPTV c th c xem nh i din ca cng ngh pull-push" nh mt thu bao a ra yu cu ti nh cung cp dch v i vi lung hnh nh ring. Do truyn hnh c s ho th c cc nh cung cp gii tr thng thng cng nh ph hp nn v mng qua IPTV, n l cng ngh ng dng s cp. Thm vo do nh cung cp dch v c th phi ch truyn nhng g c yu cu, khng ging vi truyn hnh cp v v tinh, IPTV theo l thuyt cung cp mt s lng gii hn knh xem, m cho php nh cung cp dch v cung cp nhiu loi ni dung so vi i th cnh tranh m truyn qung b ng thi nhiu knh khng ch ti ngi xem chng. Do , s khc nhau v cu trc gia IPTV v truyn hnh qung b cho php nh cung cp nhiu ni dung hn, nh cung cp c th ginh c ni dung ng k xem yu cu ca thu bao.

- Truyn hnh kinh doanh pht ti mn hnh: Mc d th trng s cp ca IPTV l cc khch hng l h gia nh ring r, cng ngh cng ph hp tt i vi cng vic kinh doanh. Trong mi trng kinh doanh mi trm lm vic LAN c th c gn mt a ch IP ring bit v vy to ra a ch c th i vi lung hnh nh khc nhau c a ti ngi khc nhau. V d, mt s ngi phi yu cu truy nhp tc thi n CNBC tri li nhng ngi khc c th yu cu truy nhp ti Bloomberg, Reuters, hay chng trnh v ti chnh. Do IPTV c th c chia t l trn mn hnh, n tr nn c th gip ngi xem nhn thy knh kinh doanh c yu cu hoc nhiu knh trong khi ang thc hin theo tc my tinh s dng mt phn khc ca mn hnh PC.

- Video theo yu cu - Video on Demand (VOD): VOD l tnh nng tng tc c th ni l c mong i nht IPTV. Tnh nng ny cho php ngi xem c th yu cu xem bt k mt chng trnh truyn hnh no m h a thch. V d, ngi xem mun xem mt b phim c cch y vi nm th ch cn thc hin tm kim v dnh thi gian xem hoc ghi ra a xem sau. Mc d thu truyn hnh cp v v tinh c cp nhiu nm thu li nhun mi on phim v s kin th thao, bi m nht so vi truyn hnh theo yu cu do c th c cung cp qua cng ngh IP. Nguyn nhn chnh ti sao truyn hnh theo yu cu IPTV c th xem nh ng u trong thu li nhun v trong thc t nh cung cp trc IPTV pht chng trnh khng gii hn tri li cc nh cung cp IPTV gii hn mt nhm knh qung b.

- Hc t xa: Trong mt mi trng i hc n c th l ti hai ni cng thi gian giao tip qua sc mnh ca s tin dng hc t xa. Trn thc t, ti trng ta gio vin s dng hc t xa ging dy kha hc truyn thng d liu truyn tc thi qua mn hnh, hnh nh trn Internet.

Mc d hc t xa c th c hon thnh qua s dng thit b truyn hnh hi ngh thng thng, khi thc hin thng qua vic s dng hiu qu IPTV c kt hp vi sinh vin xa c th tng ln ng k. l do hc t xa thng thng da trn s dng thit b hi ngh truyn hnh dn n mn hnh trung tm ti v tr xa. Khng ch lm m tt c sinh vin phi tp trung v mn hnh n, nhng thm vo, mt micro phi m bo c phm vi bi gim th ti mi v tr ti sinh vin m s ni vi gio vin. So snh, s dng IPTV c th ci thin ng k vic hc t xa do hnh nh ca gio vin c trc tip n mn hnh PC ca mi trm lm vic sinh vin trong khi micro c kt ni ti mi my tnh cho php sinh vin chat vi gio vin khng phi ch micro a n lp hc.

Nhng u im ng k khc ca IPTV trong mi trng vic hc t xa trn thc t, ging nh tho lun trc v truyn hnh kinh doanh ti mn hnh, n c chia t l trn mn hnh PC. iu ny cho php kha hc t xa trn chng trnh v ch khc c sinh vin c xem v nghe gio vin trong khi h thc hin cc bi tp khc. Do

phn mm c pht trin cho php gio vin thy c hot ng ca sinh vin, tc cng vic ca sinh vin c th c gio vin nhn thy. Tng t, vi chng trnh thch hp, gio vin c th thy n lc ca phn bi tp cho ring mt sinh vin trn mn hnh PC, nh x l ng k s tng tc gia gio vin v sinh vin.

- Lin lc trong cng ty : Trong hu ht cc t chc, ch tch hay ngi ng u cng ty thng xuyn cn a ch ca nhn vin. Trong mi trng thng thng yu cu ny thng thng tha mn bi lch trnh s dng mt hoc mt s phin hp dnh cho thnh gi trong thi gian m ngi ng u gii thch l do ti sao tin li li ln hoc xung, hiu qu ca dng sn phm mi, thay i k hoch tr cp cho nhn vin, hoc cc vn khc cn c ph bin ti ton th nhn vin.

Thng thng s dng mt phng dnh cho thnh gi thng bo mt chnh sch mi hoc a ra cc s kin gn y c yu cu tng thi gian ng k v n lc . Nu phng c a vo lch trnh t trc vi cc s kin khc, sau b phn hu cn chuyn s kin vo thi gian khc v ni t chc c xem xt sau.

- Kim sot ti a chng trnh TV: VOD ni chnh xc cng l mt phn li th ny. y l tnh nng m ngi dng s cm thy thch th nht IPTV bi n cho php h c th kim sot ti a chng trnh truyn hnh. Khng cn th ng phi xem nhng g m nh cung cp dch v pht i nh truyn hnh truyn thng hay v tinh m gi y ngi dng s c tri nghim kh nng kim sot ti a nhng ni dung m h mun xem. Vi VOD ngi dng c th chn la nhng chng trnh thch hoc ghi n ra a xem v sau ny.Nh m thit b iu khin t xa ca IPTV s c y tnh nng nh iu khin mt chic u a. Khi ang xem chng trnh nu gp phi mt on no hay ngi dng c th tua xem li, dng pht chng trnh hoc tua nhanh v pha trc ... iu ny cng n gin bi ni dung c cung cp duy nht theo yu cu ca ngi xem ch khng cung cp rng cho tt c mi ngi dng nh truyn hnh truyn thng.

- Truyn hnh cht lng cao HD: Xu hng ni dung cht lng cao hin hin hin thc t. Nh kt ni bng thng rng nn c th ni ch trong tng lai khng xa IPTV s ch pht truyn hnh cht lng cao. iu ny ng ngha vi vic ngi dng s thng thc cc chng trnh c cht lng hnh nh v m thanh cao.- Nhu cu thc t ca IPTV : Theo nhm nghin cu a phng tin (MRG )trong D on IPTV ton cu nm 2005-2009: tc pht trin IPTV rt cao: gn1000%. Th trng IPTV trn th gii pht trin mc tng kp hng nm 78% ln ti36.9 triu ngi s dng vo nm 2009. Doanh thu dch v cn tng nhanh hn trong cng thi k, t 880 triu USD ti 9.9 t USD.

Theo Informa: tc pht trin IPTV tng nhanh vo 5 nm ti v t 25.9 triu thu bao IPTV vo cui nm 2010.

Theo nguyn cu TDG: Doanh thu IPTV ton cu s t trn 17 t USD vo nm2010.

V trn thc t, dch v IPTV c trin khai v t dc thnh cng nhiu nh Italy ( Fast Web), Hng Kng (PCCW), Canada ( Manitoba) v Japan (Yahoo BB).

Ti th trng Trung Quc, IPTV bt u c trin khai t nm 2004 vi 2 nh cung cp hng u l CHINA Telecom v ZTE cng vi nhng nh cung cp khc.S lng thu bao c th tng ln ti 3-6 triu vo nm 2010.

IPTV c trin khai vi bng thng 2M vi k thut nn MPEG-4 part 10 cho TVthng v 6M i vi HDTV.

Cc dch v trin khai trn IPTV n vi ngi dng:

+ LiveTV: truyn hnh trc tuyn;

+ VoD: truyn hnh theo yu cu;

+ RoD: Dch v ghi hnh theo yu cu;

+ NVoD: Xem chng trnh theo lch pht sng.

1.4.2. Nhc im

- Cht lng dch v: c trng phn bit dch v IPTV vi truyn hnh Internet chnh l kh nng m bo cht lng dch v ca IPTV. Tuy nhin vi h tng mng khng ng nht, cht lng mng truy nhp khng tt, kh nng x l khi s thu bao tng vt cha p ng c l cc yu t dn n hin nay cht lng ca dch v IPTV cha tho mn c yu cu ca khch hng. Khi cht lng ca IPTV cha tng ng c vi dch v ca truyn hnh cp th IPTV vn cha th chim u th c.

- Vn an ninh: Vic kt ni vi Internet cng nh kh nng kt ni vi khch hng khc trong mng em li tnh hp n c bit ca dch v IPTV. Tuy nhin n cng cha nguy c tim tng cho s an ton ca ngi s dng, v cc giao dch ca khch hng rt d b li dng, nh cp ti khonNgoi ra cc vn xy ra vi mng Internet nh kh nng ly nhim virut, tn cng t chi dch vcng l cc yu t gy nghi ngi cho ngi s dng.

- Vn bn quyn ni dung: V vic m bo bn quyn ca cc chng trnh m nh cung cp ni dung cho php s dng khng b s dng bt hp php cha hon ton to c tin cy, cc nh cung cp ni dung cha sn lng cung cp ni dung cho dch v ny.

- Vn chun ho: Hin nay hu ht cc gii php ca cc hng vn ang di dng ng, c tng i t kh nng lm vic vi cc nh cung cp thit b, ni dung khc nhau. y l mt yu t hn ch kh nng pht trin rng ri ca dch v IPTV.

- Chi ph trin khai dch v: trin khai dch v IPTV end to end cn phi c mt chi ph kh ln ban u. Nu khng phi l nh khai thc vin thng c sn h tng bng rng th chi ph ny c th l mt tr ngi rt ln. K c i vi nhng nh khai thc vin thng c sn li th ban u th vn phi nng cp mng bng rng v IPTV l mt dch v yu cu bng thng kh ln. Ngoi ra chi ph ca khch hng cn b ra mua STB cng l mt ro cn trin khai dch v ny.

1.5.Kt lun chng 1

Chng ny gii thiu tng quan v IPTV. Gii thiu nh ngha, c im, kin trc, cc phng thc truyn ti v giao thc s dng trong mng IPTV. ng thi cng vi kin thc v IMS c cp chng II l nn tng xy dng dch v IPTV trn nn IMS/NGN.

CHNG 2. PHN H A PHNG TIN IMS

2.1.Tin trnh pht trin IMS

Vin Tiu chun K thut Chu u (ETSI) - t chc tiu chun ha nh ngha h thng ton cu v lin lc di ng Global System for Mobile Communications (GSM). ETSI cng nh ngha kin trc mng dch v v tuyn gi chung - General Packet Radio Service (GPRS). Tiu chun GSM mi nht c nh ngha nm 1998, v cng nm cc t chc tiu chun t Chu u, Nht, Nam Triu Tin, USA v Trung Quc hp tc to ra 3GPP ch r h thng di ng 3G cu thnh truy nhp v tuyn a truy nhp phn chia theo m/phn chia theo thi gian (TD-CDMA) v a truy nhp nhn chia theo m bng rng (WCDMA) v mng li GSM pht trin.

2.1.1.3GPP phin bn 99

Phin bn u tin phin bn nm 1999 phi mt ti gn 1 nm mi hon thnh. Tiu chun ca phin bn ny hon thnh thng 12 nm 1999. 3GPP pht trin cc dch v, kin trc h thng, cc truy nhp v tuyn WCDMA v TD CDMA, v mng li chung. ETSI SMG pht trin GSM/t l d liu nng cao cho truy nhp v tuyn pht trin ton cu (EDGE).

Truy nhp v tuyn WCDMA l s nng cao c ngha nht i vi h thng 3G c s GSM trong phin bn 1999. Cng vi WCDMA, mng truy nhp v tuyn mt t UMTS cng a ra giao din Iu. So snh vi giao din A v Gb, c hai im khc bit u tin, m ha thoi Iu c thc hin trong mng li. Trong GSM, theo logic th Iu c chc nng trm chuyn tip thu pht c s. Th hai, m ha v qun l di ng mc t bo ca Iu hon thin trong b iu khin mng v tuyn (RNC). Trong GSM, cc chc nng cng hon thnh trong node h tr dch v GPRS (SGSN) cho cc dch v GPRS.

Hnh 2.1 sau y m t vai tr ca IMS trong cc mng chuyn mch gi:

n tt nghip i hc Chng 2

Hnh 2.1. Vai tr ca IMS trong cc mng chuyn mch gi

2.1.2.3GPP phin bn 4

Sau phin bn 1999, 3GPP bt u xc nh phin bn 2000, c gi l ton IP, sau c i tn thnh IMS. Phin bn 2000 c chia thnh hai phin bn l phin bn 4 v phin bn 5.

Phin bn 4 c th hon thnh m khng c IMS. Chc nng mi quan trng nht trong 3GPP phin bn 4 l: khi nim trung tm chuyn mch di ng (MSC)cng a phng tin (MGW), cc giao thc mng li truyn ti IP, nng cao dch v nh v (LCS) cho UTRAN, bn tin a phng tin, truyn ti IP ti mt phng ngi dng Gb.3GPP phin bn 4 chnh thc hon thnh thng 3 nm 2001. Yu cu tng thch nn cho s thay i, cn thit cho giao din v tuyn, c hiu lc cui thng 12 nm 2002.

2.1.3.3GPP phin bn 5, 6 v 7

T bng 2 di y c th thy 3GPP nh ngha kin trc gii hn cho b my dch v a phng tin IP trn nn SIP, cha chc nng ca cc yu t logic, m t lm th no cc yu t kt ni c vi nhau, la chn cc giao thc v cc tin trnh.

Bng 2. Cc c im IMS

SV: Nguyn Thi Sn - H09VT339

Phin bn 5Phin bn 6Phin bn7

Kin trcCc thc th mng v cc im tham chiu bao gm cc hm tnh cc.Lm vic tng tc (CS, cc mng IP khc, WLAN) v mt vi, thc th mi v cc im tham chiu.Cuc gi thoi lin tc gic min CS v PS, kt ni di rng c nh ti IMS.

Bo hiuCc nguyn l nh tuyn chung, ng k, khi to phin, thay i phin, lm t phin, cc lung phin khi to mng/ xa khi danh sch. Nn Sip gia mng IMS v UE. Truyn d liu gia b lu thng tin khch hng (HSS) v cc thc th iu khin phin (CSCF); Truyn d liu gia b lu thng tin khch hng (HSS) v server ng dng (AS).Cc thc th nhm nh tuyn, a ng k.Cc phin cnh bo, SMS h tr s dng SIP, kt hp cc cuc gi CS v cc phin IMS.

Bo mtIMS AKA cho cc khch hng c nhn thc v mng, bo v ton b cc bn tin SIP gia mng IMS v UE, bo mt min mng.bo v cn mt cc bn tin SIP, nhn thc trn nn IP, kin trc nhn thc chung.tng thch truy nhp bng rng, h tr TLS.

Cht lng dch viu khin chnh sch gia mng truy nhp GPRS v IMS, iu kin quyt nh v du hiu nhn thc.Cc lung a phn chia ca cc phin ring bit trong cng ni dung PDP.Cn i iu khin tnh cc v chnh sch, khng c du hiu nhn thc QoS.

Cc dch vS dng cc server ng dng v im tham chiu iu khin dch v IMS.Hin din, bn tin, hi ngh, Push to talk, over cellular, qun l nhm, cc dch v ni.Cc dch v b sung trong SIP.

2.2.Kin trc phn h a phng tin IMS

2.2.1.Yu cu kin trc

- Cc phin a phng tin IP

Cc mng lin lc ang tn ti c th yu cu cc loi dch v thoi, video v tin nhn s dng chuyn mch knh bin. Dch v khch hng cui khng b t chi khi khch hng chuyn t min chuyn mch gi sang bt u s dng IMS. IMS s lin lc vi mc trn bng cch yu cu cc iu kin lin lc c nng cao cht lng. Ngi dng c th tch hp thoi, video, vn bn, chia s ni dung v hin din l mt phn trong phin lin lc v c th thm vo hoc loi i dch v cng nh vy khi m h chn.

-Kt ni IP

Yu cu nn tng l thit b phi c kt ni IP c th truy nhp. Cc ng dng ngang hng yu cu s nm bt u cui ti u cui v kt ni ny c th t c d dng nht vi phin bn IPv6, v IPv6 khng thiu a ch. Do vy, 3GPP sp xp cc vn v IMS h tr ring cho IPv6. Vic b sung v thc hin IMS ban u c th s dng IPv4. 3GPP a ra cc lu v vic cc phin bn IP kt ni cng vic vi nhau c x l nh th no trong IMS. Kt ni IP c th t c t mng nh ln mng khch. Hnh di ch ra la chn kt ni IMS khi NSD chuyn vng.

Cc la chn kt ni IMS khi mt ngi dng ang chuyn vng c m t nh hnh v sau:

Hnh 2.2. Cc la chn kt ni IMS khi mt ngi dng ang chuyn vng

-m bo cht lng dch v cho cc dch v a phng tin IP

Trong mng Internet cng cng, tr c xu hng cao v a dng, cc gi ti b hng v mt vi gi b mt hoc b loi. Vi IMS th trng hp ny s khng cn tn ti lu na. Cc mng truy nhp v tuyn ti c bn cng vi IMS cung cp cht lng dch v u cui ti u cui (QoS). Theo IMS, UE sp xp cc kh nng v nhn mnh cc yu cu v QoS trong sut phin giao thc khi to phin (SIP) hoc qu trnh thay i phin. UE c th sp xp cc tham s nh sau:

oLoi phng tin, hng lu lng.

oTc bit loi phng tin, kch c gi, tn xut truyn ti gi

oS dng ti RTP cho cc loi phng tin

oTng thch bng thng

-Lin lc m bo

Bo mt l yu cu c bn trong mi h thng vin thng v IMS khng phi ngoi l. IMS c cc c ch cho php v nhn thc gia UE v mng IMS thm vo th tc mng truy nhp (mng GPRS). Hn na, tnh tin cy ca bn tin SIP hoc la chn c cung cp gia UE, mng IMS o v gia cc thc th mng IMS m khng quan tm ti mng li c s ( l RAN v GPRS). V vy, IMS cung cp t nht mc bo mt l GPRS tng ng v cc mng chuyn mch knh.

-iu chnh tnh cc

Tng quan v tnh cc trong IMS c m t nh hnh v di y:

Hnh 2.3. Tng quan v tnh cc trong IMS

Kin trc IMS cho php s dng cc m hnh tnh cc khc nhau. Gm, kh nng tnh cc bn tham gia gi i hoc tnh cc ca c pha gi n v gi i trn c s ngun c dng mc truyn ti. Sau ngi gi c th b tnh cc trong ton b phin mc IMS: c th s dng cc s tnh cc khc nhau ti mc IMS v mc truyn ti.

Trong phin IMS c th gm thnh phn a phng tin (thoi v video), yu cu IMS cung cp iu kin tnh cc mi thnh phn phng tin. iu ny cho php kh nng tnh cc pha b gi nu h thm vo thnh phn phng tin mi trong phin, v cng yu cu cc mng IMS khc nhau c th thay i thng tin trong tnh cc c p dng vo phin hin ti.

Kin trc IMS h tr c kh nng tnh cc online v offline. Tnh cc online l tin trnh tnh cc m thng tin tnh cc c th nh hng trong thi gian thc m dch v a ra, v vy, tng tc trc tip iu khin phin/dch v. Hnh 2.3 ch ra ci nhn n gin v vic tnh cc thng thng trong mi trng IMS. R rng cha kha y l: IMS thm kh nng tnh cc cho lu lng IP ngi dng hn l cch trc y.

-H tr chuyn vng

Ngi dng c th truy cp vo dch v ca mnh m khng xt n v tr a l. c im chuyn vng lm cho ngi dng c th s dng dch v thm ch khi khng nhng vng trong vng dch v ca mng nh.

Hnh 2.4. Cc thay i chuyn vng IMS/CS

-Lm vic tng tc vi cc mng khc

IMS h tr lin lc vi PSTN, ISDN, khch hng Internet v di ng. Thm vo , c th h tr cc phin vi cc ng dng Internet thc hin khng thuc v t chc3GPP.

-S pht trin dch v

Quan trng l c nn dch v m rng v a ra dch v mi nhanh chng, ngha l cch tiu chun ha b dch v t xa, ng dng v dch v b sung. V vy 3GPP ang tiu chun ha cc dch v tim nng. Kin trc IMS gm khung lm vic dch v cung cp kh nng h tr thoi, video, a phng tin, tin nhn, chia s, truyn d liu, v cc dch v b sung c bn trong IMS.

-Thit k phn lp

3GPP quyt nh tip cn cc lp thit k kin trc, c ngha l cc dch v bin v truyn ti l ring bit vi mng bo hiu IMS v cc dch v qun l phin.Kin trc cc lp v IMS c m t nh trong hnh v di y:

Hnh 2.5. Kin trc cc lp v IMS

Cc lp c s c lp ti thiu cho php cc mng truy nhp mi vo h thng d . Mng vng ni ht khng dy (WLAN) truy nhp vo IMS c thm vo 3GPP phin bn 6 v truy nhp bng rng c nh ti IMS l tiu chun trong phin bn 7.

Khi thu bao ang s dng in thoi di ng hoc khch hng s dng PC lin lc, cng nhm v hin din lit k cc chc nng trong IMS s c dng. Cc dch v khc nhau c nhng yu cu khc nhau. Bao gm: bng thng, hi t, x l cng sut trong thit b.

Chc nng a truy nhp c xy dng trong kin trc IMS, gii php hi t di ng v c nh ca cc nh vn hnh mng di ng v c nh. iu ny s cho php

cc nh cung cp dch v s dng cc kh nng v c im ca cc thit b c la chn hin ti v phng php truy nhp mng .

-Truy nhp c lp

IMS c thit k truy nhp c lp v vy cc dch v IMS c cung cp qua cc mng kt ni IP (GPRS, WLAN). Tuy nhin, cc tiu chun IMS phin bn 5 c vi c im ring ca GPRS. Trong phin bn 6 (GPRS) vn truy nhp ring c chia t cc m t IMS v kin trc IMS tr li trng thi gc (truy nhp c lp).

2.2.2.M t cc chc nng v cc thc th trong IMS

Nhng thc th trong IMS c th c phn thnh su loi: Qun l phin v nh tuyn (CSCFs), c s d liu (HSS, SLF), cc dch v (server ng dng, MRFC, MRFP), cc hm lm vic tng tc (BGCF, MGCF, IMS MGW, SGW), cc chc nng h tr (PDF, SEG, THIG), tnh cc.

Cc chc nng iu khin phin cuc gi (CSCF)

C ba loi chc nng iu khin phin cuc gi (CSCF): i dinCSCF (P- CSCF), dch v-CSCF (S-CSCF) v truy vnCSCF (I-CSCF). Mi CSCF c cc nhim v ring. Thng thng tt c CSCF thc hin mt vai tr trong sut tin trnh thit lp phin v ng k v to b my nh tuyn SIP. Hn na, tt c cc khi chc nng c th gi d liu tnh cc ti mt khi chc nng tnh cc offline.

PCSCF v SCSCF u c th gii phng phin trn danh ngha ngi dng (v d, khi S-CSCF pht hin ra mt phin ang b treo hoc P-CSCF nhn lu rng mt phng tin bin b mt) v c th kim tra ni dung ca ti giao thc m t phin (SDP) v kim tra khi no n cha loi phng tin hoc gii m, m khng c cho php khch hng. Khi xut ca SDP khng ph hp vi chnh sch ca nh vn hnh, CSCF t chi yu cu v gi mt bn tin li SIP ti UE.

Chc nng iu khin phin cuc gi y quyn (P-CSCF)

Khi chc nng iu khin phin cuc gi y quyn (P-CSCF) l im lin lc u tin ca ngi dng trong IMS, c ngha l tt c lu lng bo hiu SIP t UE s c gi ti P-CSCF. Tng t, tt c cc u cui bo hiu SIP t mng c gi t P- CSCF ti UE. C bn nhim v ring c ng k cho P-CSCF: nn SIP, kt hp bo mt IPSec, tng tc vi chc nng quyt nh chnh sch (PDF) v pht hin phin khn cp.

P-CSCF chu trch nhim duy tr kt hp bo mt (SAs) v p dng bo v ton b v tin cy cho bo hiu SIP. iu ny c thc hin trong sut phin ng k SIP v

UE v P-CSCF iu chnh IPSec SAs. Sau khi bt u ng k P-CSCF c th p dng bo v ton b v tin cy bo hiu SIP.

Chc nng iu khin phin cuc gi truy vn (I-CSCF)

Chc nng iu khin phin cuc gi truy vn (I-CSCF) l im lin lc trong mng nh vn hnh cho tt c cc kt ni xc nh ch ti thu bao ca nh vn hnh mng . I-CSCF c bn nhim v:-t c tn ca next hop (hoc l S-CSCF hoc l server ng dng) t server thu bao nh (HSS).-Phn cng cho S-CSCF da trn cc kh nng nhn c t HSS.

-nh tuyn cc yu cu n ti S-CSCF c phn cng hoc ti server ng dng.-Cung cp chc nng cng lin mng n cu hnh (THIG).

Chc nng iu khin phin cuc gi dch v (S-CSCF)

Chc nng iu khin cuc gi dch v (S-CSCF) - im trng tm ca IMS l khi chu trch nhim x l qu trnh ng k, to quyt nh nh tuyn, duy tr trng thi phin, v lu c im dch v. Khi ngi dng gi yu cu ng k. n s c nh tuyn ti S-CSCF, ti d liu nhn thc t HSS. Trn c s d liu nhn thc pht lnh ti UE. Sau khi nhn hi p v kim tra, S-CSCF chp nhn ng k v bt u gim st trng thi ng k. Sau qu trnh ny ngi dng c th bt u v nhn cc dch v IMS. Hn na, S-CSCF ti v c im dch v t HSS l mt phn ca qu trnh ng k.

S-CSCF s dng thng tin gm h s dch v quyt nh khi no v server ng dng no c lin lc khi ngi dng gi mt yu cu SIP hoc nhn mt yu cu t ai khc. Hnh 2.6 m t vai tr ca S-CSCF trong cc quyt nh nh tuyn. S-CSCF cn c th gi thng tin lin quan ti khon ti h thng tnh cc online cho cc mc ch tnh cc online ( l h tr cho cc thu bao tr trc).

Thit lp phin IMS c bn v nh tuyn S-CSCF c m t nh trong hnh v sau y:

Hnh 2.6. Thit lp phin IMS c bn v nh tuyn S-CSCF

C s d liu

C hai c s d liu chnh trong kin trc IMS: server thu bao thng tr (HSS)v chc nng nh v thu bao (SLF).

HSS l b lu d liu chnh cho tt c cc thu bao v d liu dch v lin quan ca IMS. D liu chnh c lu trong HSS bao gm cc nh dng ngi dng, thng tin ng k, cc tham s truy nhp v thng tin bt u dch v. Nhn dng khch hng gm 2 loi: nhn dng khc hng cng cng v ring. Cc tham s truy nhp IMS c s dng thit lp cc phin v gm cc tham s ging nh nhn thc ngi dng, cho php chuyn vng v ch nh tn S-CSCF. Thng tin bt u dch v cho php thc hin dch v SIP.

Hnh 2.7. Cu trc HSS

SLF c dng nh l c ch gii quyt cho php I-CSCF, S-CSCF v AS tm kim a ch ca HSS nm gi d liu thu bao ca thc th ngi dng a ra khi HSS c th xc nh nhiu a ch v ring r c thc hin bi nh vn hnh mng.

Cc chc nng dch v

C ba chc nng c a ra l cc chc nng lin quan dch v IMS l: b iu khin chc nng ngun a phng tin (MRFC), b x l chc nng ngun a phng tin (MRFP), v server ng dng (AS).

ASs c m t y l mt phn cc chc nng IMS v ASs l cc thc th cung cp cc dch v a phng tin gi tr gia tng trong IMS, nh hin din v Push to talk qua di ng. AS nm trong mng gia nh ca khch hng hoc l v tr bn th ba. Bn th ba y c ngha l mng hoc l AS ng mt mnh. Cc chc nng chnh ca AS l: C th x l v nh hng phin SIP ti nhn c t IMS, c kh nng pht cc yu cu SIP, c kh nng gi thng tin ti khon ti cc chc nng tnh cc.

IM-SSF c gii thiu trong kin trc IMS h tr cc dch v k tha c pht trin trong CSE. N dn ra cc c im mng v lin mng vi giao din phn ng dng CAMEL (CAP.)

Hnh 2.8. Mi quan h gia cc loi server ng dng

AS SIP l server trn c s SIP, dn mt di rng cc dch v a phng tin gi tr gia tng. AS SIP c th c dng cung cp cc dch v hin din, bn tin, Push to talk qua di ng v hi ngh. Hnh 1.13 ch ra cc chc nng khc nhau kt ni nh th no. Tng lai ca AS SIP S-CSCF, server kh nng dch v OSA v IM-SSF a ra cng c tnh im tham chiu.

MRFC v MRFP cng cung cp cc c ch cho cc dch v lin quan ti bin nh l hi ngh, thng bo ti mt khch hng hoc chuyn m bin trong kin trc IMS.Cc thc th GPRS

o Node h tr dch v GPRS (SGSN)

Node h tr dch v GPRS (SGSN) lin kt RAN ti mng li gi, c nhim v thc hin c chc nng iu khin v x l lu lng cho min PS. Phn iu khin cha hai chc nng chnh: qun l ng v qun l phin. Qun l ng gii quyt v tr, trng thi UE, nhn thc c thu bao v UE. Phn iu khin ca qun l phin gii quyt iu khin tha nhn kt ni v bt c thay i no trong cc kt ni d liu ang tn ti. N cng qun l cc dch v v ngun mng 3G. SGSN m bo cc kt ni nhn QoS ph hp. Thm vo , SGSN pht thng tin tnh cc.

o Node h tr cng GPRS (GGSN)

Node h tr cng GPRS (GGSN) cung cp s nh hng vi cc mng d liu gi ngoi. Chc nng gc ca GGSN l kt ni UE ti cc mng d liu ngoi, ni cc ng dng da trn c s IP v cc dch v c tr. Mng d liu ngoi c th l IMS hoc Internet. Ni cch khc, GGSN nh tuyn cc gi IP cha bo hiu SIP t UE ti P-CSCF, v ngc li. Thm vo, GGSN quan tm ti vic nh tuyn cc gi IP phng tin IMS ti mng ch (v d, GGSN trong mng u cui). Ngoi ra GGSN a ra chnh sch v gim st vic s dng ni dung PDP cho lu lng phng tin IMS v pht thng tin tnh cc.

2.3.Cc giao thc s dng trong IMS

2.3.1. Giao thc khi to phin SIP Session Initiation Protocol

SIPgiao thc khi to phin l giao thc lp ng dng c s dng thit lp, thay i v xc nh u cui cc phin a phng tin trong giao thc Internet (IP). Cc ng dng gm: thoi, hnh nh, tr chi, tin nhn, iu khin cuc gi v hin din.

SIP da trn giao thc truyn ti vn bn (HTTP) v giao thc truyn th n gin(SMTP). Hnh 2.9 ch ra ni SIP ph hp trong ngn xp giao thc.

SV: Nguyn Thi Sn - H09VT348

Hnh 2.9. Ngn xp giao thc

SIP c to ra vi cc mc ch thit k sau:

- Giao thc truyn ti trung lp cho php chy giao thc tin cy (TCP, SCTP) v giao thc khng tin cy (UDP).- Yu cu nh tuyn trc tip (hiu nng) hoc nh tuyn y quyn(iu khin).

- Phn chia m t bo hiu v phng tin c th thm cc ng dng hoc phng tin mi.- Kh nng m rng.

- Tnh di ng c nhn.

2.3.2.Giao thc m t phin SDP Session Description Protocol

Giao thc m t phin SDP-giao thc c s vn bn, l giao thc lp ng dng tham gia vo m t cc phin a phng tin. Khi m t mt phin ngi gi v ngi c gi ch ra cc kh nng nhn tng ng, cc nh dng phng tin v a ch/cng nhn. Thay i kh nng c th c thc hin trong sut qu trnh thit lp phin hoc trong sut phin l, trong khi phin ang c tin hnh.

Ni dung bn tin SDP:

Mt bn tin SDP cha ba mc thng tin:

- M t mc phin iu ny bao gm b nhn dng phin v cc tham s mc phin khc, nh l a ch IP, tn, thng tin lin lc v phin v/hoc ngi to ra.

- M t on thi gian thi gian bt u v kt thc, thi gian lp li, mt hoc nhiu m t mc phng tin.- nh dng v loi phng tin giao thc truyn ti v s cng, cc tham s mc phng tin khc. Ch rng a ch phng tin c th khc vi a ch bo hiu.

Ba mc thng tin phi xut hin theo th t c m t nh trn. Bn tin SDP l la chn ca cc dng SDP.

2.3.3.Giao thc truyn ti thi gian thc RTP

Giao thc truyn ti thi gian thc RTP l giao thc s dng cho vic truyn pht d liu thc u cui ti u cui. N cng cha cc dch v truyn pht u cui ti u cui cho cc d liu thi gian thc: nh ngha loi ti (codec), s chui, nhn thi gian v iu khin truyn pht. RTP khng cung cp cht lng dch v (QoS); tuy nhin cung cp iu khin QoS s dng giao thc iu khin RTP (RTCP).

RTP s dng cho truyn pht d liu thi gian thc: Cc trng mo u c nh RTP:

Cc trng RTP hin ti trong mt gi RTP trnh by nh sau:

-Phin bn (V) phin bn ca RTP. Lun c thit lp l 2.

-m (P) nu c thit lp, th gi RTP cha octet m. m c th cn thit cho mt vi thut ton m ha vi kch thc khi c nh hoc cho cc gi RTP a mang trong mt gi giao thc lp thp hn.-S m rng (X) nu c thit lp, th l mt s m rng mo u RTP.

-m CSRC (CC) s ngun phn b (CSRC) IDs theo mo u c nh.

-nh du (M) s gii thch ca n c nh ngha bi mt profile.

-Loi ti (PT) nhn dng nh dng ti (codec).

-S chui tng 1 cho mi gi d liu RTP. B thu s dng s chui ny yu cu li cc gi ti khng nm trong chui v s chui ny gip b thu xc nh khi no cc gi b mt.-Nhn thi gian ch thi gian khi m octet u tin trong ti c lm mu.Trng ny cng c dng theo vi s chui loi b jitter.

-Ngun ng b (SSRC) RTP khng ph thuc vo cc giao thc diInternet v v vy s dng trng ny xc nh ngun ca cc gi RTP.

-Ngun phn b (CSRC) trng ny mang mt danh sch SSRC ch ra cc ngun c phn b trn cc lung phng tin, nu b trn i km, cho

php gia 0 v 15 SSRCs. Nu c hn 15 ngun phng tin, th ch 15 ngunc xc nh. B trn hi ngh thoi l mt v d tt.

Hnh 2.10. nh dng gi RTP

2.3.4.Giao thc iu khin RTP RTCP

Cc gi giao thc iu khin RTP c truyn nh k ti tt c cc thnh vin tham gia trong mt phin. C 4 chc nng RTCP:-Cung cp hi p trong QoS phn b d liu thi gian thc.

-Mang b nh dng lin tc ca ngun RTP (c gi l CNAME).

-Cho php mt on phn b gi RTCP c th thay i (on thng bo).

- kho st thng tin iu khin phin.

Cc loi gi RTCP

-SR thng bo b gi, cung cp thng k nhn v truyn dn, c gi bi cc b gi phng tin hot ng.-RR thng bo b nhn, cung cp thng k nhn, c gi bi cc b gi khng hot ng.-SDES cc m t ngun, nh l CNAME.

-BYE ch kt thc tham gia.

-APP cc chc nng ng dng ring (c nh ngha bi mt h s).

2.4. Kt lun chng 2

Chng 2 gii thiu v tm hiu v m hnh IMS v cc phn t chnh nh CSCF, HSS, MRCF Cc giao thc quan trng s dng trong IMS nh khi to phin SIP, m t phin SDP, truyn ti thi gian thc RTP v iu khin RTP.Cc ni dung ny l nn tng lm c s nghin cu thm v vn IMS/NGN h tr cc dch v IPTV m bo mng a phng tin cng vi mng tch hp hi t v di ng trong chng sau.

CHNG 3. CNG NGH IPTV TRN NN IMS NGN

3.1. Gii thiu chung

Khch hng tng lai mong i cc dch v TV ca h c c nhn ha theo nguyn ca h, c tng tc, vi cht lng cao v truy nhp c t bt k thit b no, cho d l my thu hnh, my in thoi di ng (TD) hay my tnh c nhn. Gii tr ngy hm nay l cc cng dn s qu quen thuc vi cc phng tin truyn thng x hi, vi video theo yu cu (VoD) v Web di ng. H bt u quen vi vic kt ni ti cc dch v Internet v cc ni dung s ca h t bt k loi thit b no, vo bt k lc no v ti bt k ni no h ang c mt. Trong khi cc khch hng ang mua sm cc my thu hnh mi c phn gii cao (HDTV) vi cc hp STB (set-top box) s nh km c th thu c truyn hnh s. n lc cc nh khai thc vin thng phi thm nhp cc cung on th trng mi bng s tr gip ca cc dch v truyn hnh. Bn cnh xu hng pht trin mng th h sau NGN hin nay l chuyn t Softswitch sang IMS do IMS em li kh nng cung ng dch v a phng tin cho ngi s dng u cui m khng b ph thuc vo v tr, cng ngh truy nhp mng v vo thit b u cui ca ngi s dng. IMS h tr cc loi hnh dch v khc nhau (thoi, d liu, hnh nh v kh nng tch hp ca c ba loi hnh dch v ni trn - Tripple Play m in hnh l dch v IPTV).

Nhiu nh cung cp dch v bt u trin khai cc dch v triple play trn DSL, trong IPTV l mt thnh phn dch v quan trng. Gii php pht trin dch v l rt cn thit gi chn khch hng, pht trin th trng chia s v tng li nhun cho cc dch v qung b trn th trng bng rng ang cnh tranh ngy cng d di. Tuy nhin mi dch v trong nhm dch v triple play ny (nh IPTV, VoIP) li c c cu iu khin dch v, cc h thng h tr tnh cc v iu hnh ring ca n, iu ny lm tng s phc tp ca ton th kin trc dch v triple play. Hn na, cc nh cung cp dch v cn phi phn bit dch v ca mnh vi cc nh cung cp dch v khc c cng nhm dch v. Trong phn ny s nghin cu v cc nn tng tng tc dch v IPTV v IMS nhm lm gim phc tp ca mng v m hnh kin trc ca IPTV trn nn IMS.

Kin trc IPTV trn nn IMS c th cung cp cc dch v IPTV c iu khin v x l bi IMS v c th chuyn tip c lp cc dch v IPTV vi mng truyn ti IP bn di. tm hiu r hn v kin trc ny, trc ht ta tm hiu qu trnh pht trin ca IPTV theo hng NGN.

Vi TV da trn IMS, IMS/NGN c tiu chun ho, cc nh khai thc c th cung cp cc dch v TV c nhn ha c trin khai ti c nhn ngi dng vi cc ni dung TV tng tc, cng nh cc dch v kt hp truyn thng v gii tr. Cui cng,

n tt nghip i hc Chng 3

iu ny dn n cc dch v TV hi t m chng cho php ngi dng chuyn cc phin truyn hnh gia cc thit b, th d nh tip tc xem mt chng trnh truyn hnh t my thu hnh sang chic TD.

TV da trn IMS, IMS/NGN c xy dng trn mt kin trc Bng rng y Dch v (Full Service Broadband) cho php cc nh khai thc st nhp cc mng di ng v c nh ca h. IMS cung cp vic iu khin thng nht, s qun l nng ng h tr tt c cc dch v truyn thng, gii tr v thng tin m mt nh khai thc chn cung cp d qua truy nhp di ng hay c nh. Chng ny tm hiu v IPTV trn nn IMS/NGN, kin trc chc nng cc thnh phn, v tm hiu v dch v VoD trn nn IMS/NGN lc truyn tn hiu.

3.2. S pht trin kin trc IPTV theo hng IMS - NGN

Nn IPTV trn c s IMS c th c nh ngha nh sau: nn IPTV trn c s IMS l kin trc nn dch v cho php cung cp cc dch v IPTV c iu khin v x l bi phn h li IMS v truyn pht c lp vi cc mng truyn ti IP c s. Tn ti t nht 3 mc pht trin kin trc IPTV. S pht trin ny bao gm mt qu trnh gm bn bc nh trong Hnh 3.1 di y:

Hnh 3.1. Cc bc pht trin chnh ca IPTV

Kin trc non-NGN-based IPTV :

Cc gii php IPTV trn c s non-NGN (hu ht cc gii php c gi tr hin nay u c mt trn th trng). Vi hot ng tng tc vi NGN, nhng hu ht lp iu khin dch v v ng dng ring bit c thc hin cho cc dch v IPTV (IPTV middleware).

Kin trc IPTV da trn NGN non-IMS:

Kin trc IPTV trn c s NGN. Cho php tng tc v hp tc lm vic qua cc im tham chiu chun gia cc ng dng IPTV v vi thnh phn NGN chung ang tn ti. Nhng thnh phn ny gm cc yu t iu khin truyn ti cho vic tha nhn ngun v iu khin phn h (RACS) hoc phn h gn vi mng TISPAN (NASS). Cch tip cn ny s dng mt phn h dnh cho IPTV trong NGN cung cp tt c cc chc nng yu cu IPTV cn thit.

Kin trc IPTV da trn IMS-NGN

Kin trc IPTV trn nn IMS. Xc nh cc chc nng IPTV c h tr bi phn h IMS v thc hin nhng chc nng ny cho php ti s dng cc chc nng IMS v cng to s khi to dch v v iu khin trn c s SIP (giao thc khi to phin).

Kin trc hi t ca non-IMS va IMS IPTV

y l kt hp v hi t gia hai kin trc IPTV da trn IMS v non-IMS trong mt cu hnh chung cung cp cc kiu hi t ca cc dch v IPTV.

Cc dch v IPTV c th c phn chia thnh ba nhm dch v chnh (nhng khng gii hn trong tng lai):

- Cc dch v pht qung b (BC): truyn hnh trc tip v cc knh v tuyn cung cp broadcasted hoc multicasted qua mng- Ni dung theo yu cu (CoD): cc dch v unicast thng thng c cung cp theo yu cu ca thu bao pht cc ni dung c yu cu (nh mt b phim, mt bi ht,)- Cc dch v ghi hnh c nhn (PVR) gm cc dch v cho php ghi, dng hoc chuyn thi gian cho cc ni dung pht trc tip (c th c cung cp bi mng hoc UE).

Li ch ca IPTV trn nn IMS NGN

IPTV da trn IMS-NGN c nhiu u im nh h tr tnh nng di ng, tng h vi cc dch v NGN, c nhn ho dch v, tng thch phng tin v cc dch v di ng nh cc dch v quadruple-play.Hn na, vi vic ng dng v ti s dng c tnh IMS sn c h tr cc dch v IPTV, c th ti u ho v ti s dng cc c tnh NGN v nhng vn sau:

- ng k v nhn thc ngi dng tch hp (v d, bo pht sign-on n, nhn dng ngi dng ng nht).

-Qun l thu bao in thoi ca ngi dng, tp trung h s ngi dng, chnh sch ngi dng linh hot v c nhn ho dch v.-Qun l phin, nh tuyn, khi u dch v (service trigger), nh s.

-Tng tc vi cc nh cho php dch v (hin din, nhn tin, qun l nhm).-H tr Roam (chuyn vng) v Nomadic (Lu ng).

-Cht lng dch v (QoS) v iu khin ngang hng.

-Ghi cc (billing) v tnh cc ng nht.

Ngoi ra, IPTV da trn IMS-NGN cn cho php tng thch gia lung d liu IPTV vi cc ti nguyn mng sn c v kh nng kt cui ngi dng. Do vy, ngi dng c th truy nhp dch v IPTV khng ch nh m c khi di chuyn s dng mt u cui di ng. Do , IMS-NGN-based IPTV cng cho php hi t gia c nh v di ng.

IPTV da trn IMS-NGN cng cho php iu khin linh hot cc dch v IPTV nh vic iu khin phin s dng giao thc SIP. Chng hn, mt ngi dng c th s dng mt u cui IMS iu khin b ghi IPTV ca n t xa. Vic chuyn giao cc phin IPTV tch cc (active) gia cc mn hnh khc nhau, t mt laptop ti mt thit b truyn hnh cng l mt nhn t thu ht khch hng s dng cc dch v IPTV.

3.3.Kin trc IPTV trn nn non-NGN v non-IMS

3.3.1.Kin trc IPTV trn nn non-NGN

Kin trc triple play thng thng thng bao gm cc phn sau:

-Min nn dch v:

+ Middleware IPTV (non-NGN);

+ NGN dnh cho nn IPTV (IPTV NGN trn nn non-IMS);

+ Nn IPTV trn c s IMS (IPTV NGN trn c s IMS).

-Mng truyn ti;

-Mng truy nhp;

-Mng gia nh v CPEs (thit b gia nh khch hng). Kin trc IPTV thng thng c m t nh hnh v sau y:

Hnh 3.2. Kin trc IPTV thng thng

Min nn dch v cho vic cung cp cc dch v triple play thng cha mt vi hoc t hn s c lp cc phn kin trc dch v triple play phc tp:

- Phn h thu ni dung cho php nhn, x l v m ha ni dung t cc ngun m rng nh ngha m ha phng tin v ng gi (b thu v b m ha, IPTV u cui, u vo v tin x l VoD).

- Phn h phn phi ni dung c nhim v phc hi, bo v, phn phi, lu tr v truyn pht ni dung bng cch c a thch hn ti h thng ngi dng u cui (thit b ngi dng).

- Middleware IPTV cha cc server ng dng iu khin v qun l ton b cc thit b IPTV (cc server, c s d liu, cc h thng kt cui trc v sau, giao din h thng m rng, v d h thng h tr hot ng v h thng h tr kinh doanh), ngi dng, v cc dch v. Phn nn dch v cng c th l cc ng dng IPTV thm vo hoc cc cng cho php hot ng tng tc gii hn vi cc h thng khc (v d, VoIP, NGN).

- La chn dch v v phn h c tm ra cho php mt ngi dng c v tm kim, qua cng TV ngi dng, gn vi ni dung hoc thng tin dch v (metadata) m h mun xem (c th l mt phn ca middleware IPTV).

- VoD, nPVR, hoc cc phn h khc to thnh cc thit b phn h chun ha c yu cu cho cc dch v chuyn dng (v d, VoD hoc dch v ghi hnh c nhn trn c s mng).

V triple play cha ba loi dch v - video, thoi, v d liu kt ni ti cc dch v Internet v mt nn dch v thoi (nh, qua cng VoIP) cng c yu cu.

3.3.2. Kin trc IPTV NGN trn nn non-IMS

NGN dnh ring kin trc phn h IPTV tip cn thm vo phn h IPTV chun ha l min chc nng ti kin trc R2 NGN TISPAN. y l s tch hp vo NGN qua cc im tham chiu tiu chun v truyn pht cc yu cu mc dch v, trong khi cho php thc hin ni linh hot v m rng cc loi dch v mi.

3.4.Kin trc IPTV trn nn IMS/NGN

Trong phn ny, chng ta trnh by nn IPTV trn c s IMS/NGN cho php cung cp cc dch v IPTV c iu khin v x l bi IMS v truyn pht cc dch v IPTV c lp vi cc lp mng truyn ti di IP. IPTV trn c s IMS c mt s u im, nh l h tr tnh di ng, tng tc vi dch v NGN, cc dch v c nhn, v s thch nghi phng tin, cng nh s tch hp cc dch v thoi, d liu, hnh nh v di ng l cc dch v quadruple play. Hn na, bng vic thc hin v ti s dng cc chc nng IMS ang tn ti h tr cc dch v IPTV, ta c th dng li cc khi nim NGN cho cc vn sau:

-ng k v nhn thc ngi dng c tch hp (cho vic truy nhp n, ng nht thc th ngi dng);-Qun l thu bao di hn ca ngi dng, tp trung ha profile ngi dng, v c nhn ha dch v v chnh sch ngi dng linh hot;-Qun l phin, nh tuyn, dch v trigger, nh s;

-Tng tc vi cc dch v NGN (hin din, tin nhn, qun l nhm, );

-H tr chuyn vng;

-iu khin QoS v bin;

-ng nht tnh cc v ha n.

Hn na, IPTV trn nn IMS/NGN cho php s tng thch cc lung d liu IPTV vi cc ngun mng c gi tr v kh nng ca cc u cui ngi dng. V vy, ngi dng c th truy nhp cc dch v IPTV khng ch ti nh m cn khi ang di chuyn s dng mt thit b di ng. V vy, IPTV trn nn IMS cho php IPTV hi t c nh v di ng.

IPTV trn nn IMS/NGN cng cho php iu khin linh hot cc dch v IPTV, nh iu khin phin trn c s SIP. V d, ngi dng c th s dng u cui IMS iu khin b ghi IPTV t xa. S chuyn vng ca cc phin IPTV hot ng gia cc mn hnh khc nhau v d, t mt laptop ti mt thit b TV c th l mt cch dng a thch khc ca cc dch v IPTV trn nn IMS/NGN.

3.4.1. Kin trc chc nng trn c s IMS/ NGN s dng cho cc dch v IPTV

Kin trc chc nng ca IPTV trn nn IMS c trnh by trong phn ny cha cc khi chc nng chnh v cc im tham chiu nh ngha trong ni dung IPTV trn nn IMS/NGN ETSI TISPAN (bao gm cc chc nng iu khin dch v, cc chc nng iu khin phng tin, v cc chc nng phn phi phng tin). Kin trc chc nng IPTV trn nn IMS (hnh 3.4). Kin trc chc nng pht trin ng dng IPTV trn IMS-NGN bao gm cc chc nng chnh v cc im tham chiu c nh ngha trong ETSI TISPAN bao gm cc chc nng iu khin dch v, chc nng iu khin v phn phi phng tin (Hnh 3.3).

SDF

SCF

ISC

SV: Nguyn Thi Sn - H09VT359UPSF

S-CSCF

Mw Mw

SSF

I-CSCF

Mw P-CSCF

MCF

Gm Mp

UEXd

MDF

Hnh 3.3. Kin trc IPTV trn IMS/NGN n gin ca TISPAN

Hnh 3.4. Kin trc IPTV trn nn IMS/NGN

Thit b ngi dng (UE) c th giao tip vi cc server ng dng IPTV (bao gm cc chc nng iu khin dch v) thng qua nhiu giao din khc nhau thc hin cc mc ch khc nhau, c th, thng qua giao din Gm ti li IMS qun l phin, thng qua giao din Ut cu hnh h s dch v, hay qua giao din Xa tng tc vi cc tnh nng la chn dch v.

Mi UE c t nht bn giao din dnh cho vic iu khin phng tin thng qua Xc v phn phi phng tin thng qua Xd, cng nh giao din Gm ti IMS-NGN v giao din o Xt ti cc my ch ng dng IPTV. Cc giao din Ut v Gm hon ton tng thch vi cc c tnh k thut ca 3GPP IMS. My ch ng dng IPTV s dng giao din iu khin dch v IMS (ISC) giao tip vi cc chc nng iu khin dch v IMS-NGN. Cc chc nng iu khin phng tin (MCF) c th iu khin cc chc nng phn phi nng lng qua im tham chiu Xp cho php xy dng mt c s h tng phn phi phng tin c cp pht v c th thay i phm vi h tng.

3.4.1.1. Cc thnh phn chc nng

Cc thnh phn chuyn dng cho IPTV trn IMS-NGN bao gm cc chc nng c trnh by c th di y.

a)Chc nng iu khin dch v a phng tin (MSCF)

Chc nng ny x l yu cu v IPTV, n ng vai tr l phn t iu khin phin v dch v ca tt c cc dch v IPTV. Thnh phn chc nng ny cng chu trch nhim tng tc vi li IMS-NGN trn lp iu khin dch v. Chc nng iu khin dch v cha tt c cc chc nng phc v cho mi dch v IPTV v do c th s dng li nh cc chc nng server ng dng IPTV c th, hay nh cc phn t c chc nng ring bit ph thuc vo kh nng thc hin. (Do , chng ta s dng thc th chc nng ring bit gi l Chc nng iu khin dch v a phng tin - MSCF).

Nhim v chung ca MSCF l:

- Thit lp phin v iu khin dch v cho cc ng dng IPTV;

- Tng tc vi li IMS v S-CSCF thc hin cc yu cu IPTV (tip nhn, ph chun v thc hin cc yu cu dch v IPTV ca ngi dng);- Cho php dch v v ph chun yu cu ngi dng v ni dung c la chn da trn thng tin h s ngi dng;- La chn cc chc nng iu khin/phn phi phng tin IPTV ph hp;

- Thc hin iu khin tn dng.

MSCF c th s dng h s IPTV iu chnh theo yu cu khch hng. Chng hn, c th s dng danh sch knh c t mua lc ra danh sch cc knh gii thiu cho khch hng.

b) Chc nng iu khin phng tin IPTV (IMCF)

Chc nng phng tin IPTV bao gm chc nng iu khin phng tin (MCF) v chc nng phn phi phng tin (MDF). Mt nguyn l thit k quan trng i vi chc nng ny l kin trc phn phi phng tin phn cp v linh hot.

Chc nng chnh ca cc MCF nh sau:

- La chn cc MDF thch hp;

- Truyn b ni dung ti cc mng phn b;

- Qun l vic phn b quyn s hu (mt gi ni dung) gia cc MDF v thit b ngi dung;- Chc nng iu khin bo v ni dung (chnh sch cp php iu khin quaIMDF), ph chun vic ng k ni dung c bit cho ngi s dng);

- p dng chnh sch qun l phn b (theo gii hn v khng gian ring hoc tm thi);- Qun l lu tr trong h thng phn phi;

- nh x ID ni dung v v tr ni dung trong IMDF ring;

-Qun l tng tc vi UE (v d, x l cc lnh ghi hnh hay cc lnhIGMP);

- Qun l vic gi li cc s kin ang chiu trc tip (Ghi hnh c nhn mng PRV, dch thi mng TV time-shift);

- La chn thng tin thng k v vic s dng dch v;

- Pht thng tin tnh cc.

c) Chc nng phn phi phng tin IPTV (IMDF)

Ban u MDF ch chu trch nhim phn phi phng tin ti thit b ngi dng (trong min IPTV, phng tin c th l video, voice, data). Hin nay tnh nng phn phi phng tin c m rng thnh 3 phn t chc nng sau:

- Interconnect (I-IMDF): chc nng ny x l ni dung phng tin v nhp ni dung CoD, metadata v nh cung cp dch v, ng thi tip nhn cc lung trc tip t u cui IPTV hay tip nhn trc tip t cc ngun ti nguyn ca nh cung cp ni dung.

- Serving (S-IMDF): chc nng ny x l quy trnh ca ni dung (m ho, bo v ni dung, chuyn m sang cc dng thc khc), lu tr ni dung v metadata cng vi vic truyn b thng tin ni dung trong IPTV IMS.

- Primary (P-IMDF): chc nng ny l im lin lc s cp, n cung cp cc tnh nng streaming cho tt c cc dch v theo nh dng, cht lng yu cu vi phng thc pht c th (pht a im/ pht duy nht/qung b).

Chc nng phn phi phng tin c th c phn chia theo loi dch v (Qung b: BC; Ni dung theo yu cu: CoD; Ghi video c nhn: PVR) hoc theo cc chc nng ph. Do , chc nng ny bao gm cc ni dung ph sau:

- Metadata: c s dng cung cp thng tin ngi dng, m t ni dung, asset (s hu) nh d liu SDS, EPG, hoc VoD. N c th cung cp bt k loi metadata no, c chun ho thch hp.

- Assets: CoD-MDF c thit k phn phi assets ti thit b ngi dng. Cc asset ny c truyn b trc ti P-/S-IMDF nh IMCF ph thuc vo kh nng sn c, tnh ph bin v vng ni dung bao hm trong n.

d) Chc nng la chn v pht hin dch v

Chc nng pht hin v la chn dch v (SDF v SSF) cung cp thng tin yu cu i vi mt UE la chn dch v. Cc chc nng ny cng chu trch nhim cung cp thng tin v cc dch v IPTV c kh nng truy cp, thng tin ny i km vi dch v. Trong IMS-NGN-based IPTV, c th s dng mt hay nhiu SSF cung cp thng tin dch v cng nh thng tin u tin ngi dng c nhn. Ngoi ra cn yu cu thng

tin ch dn chng trnh in t hay ch dn chng trnh phc v cha metadata vthng tin v ti nguyn phn phi phng tin.

IP.

Nhim v ca SDF:

- Cung cp thng tin i km vi dch v;

- Pht hin dch v c nhn;

Thng tin i km dch v bao gm cc a ch SSF di dng cc URI hoc a ch

Nhim v ca SSF:

- Cung cp thng tin la chn dch v c nhn v thng tin cn thit c th ho vic la chn dch v. SSF c th pht thng tin ny mt cch tu . N cng c th nhn v chuyn tip thng tin ny. Trng hp thng tin la chn dch v l thng tin c nhn th n phi c phn phi qua ch unicast. Ngc li, thng tin ny s c phn phi qua ch multicast hoc unicast;- Cung cp thng tin trnh din la chn dch v mt cch tu chn. Thng tin ny c c th ho khi n c chuyn tip qua ch unicast.

e) Chc nng iu khin dch v

Chc nng iu khin cc dch v (SCF) ng dng my ch SIP chnh. Nhim v bao gm:-y quyn cho ngi s dng yu cu dch v IPTV;

-Kim sot tn dng v np thng tin k tip;

-La chn MCF (c th MDF).

f) UPSF HSS ca TISPAN

Trong NGN, cc thng tin lin quan n user khng c lu trong HSS, m c lu trong UPFS. C 2 giao din ng dng server qua giao din ng knh/Sh v CSCF qua giao din ng knh/ Cx v UPSF v HSS c gi tr tng ng nhau trong lun n. V vy cc thng tin lin quan n vic p dng HSS cho UPSF l tt. Nh vi IMS, mt SLF c th c s dng khi c nhiu UPSF.UPSF lu tr h s ngi dng IMS v d liu h s chuyn dng cho IPTV. N giao tip vi thc th chc nng iu khin dch v IPTV ti im tham chiu Sh v vi li IMS-NGN ti im tham chiu Cx. Li IMS-NGN v ISCF c th s dng cc dch v ca thc th chc nng cp pht thu bao in thoi tm a ch ca UPSF. SLF giao tip vi ISCF ti im tham chiu Dh v vi li IMS-NGN ti im tham chiu Dx.

g) MF IPTV tng thch MRF

Mc d MRFC v MRFP cng cung cp cc phng tin chuyn m, trn v streaming media (MRFP) v qun l ca chng (MRFC), Nhng mc tiu ca MRF trong IMS nh l cho php hi ngh truyn hnh, thay v cho php cc dch v IPTV. Do , TISPAN gii thiu chc nng mi trong kin trc IPTV ca h. Cc chc nng ny l Chc nng iu khin Media (MCF) v chc nng phn pht media (MDF) v chng cng nhau to thnh nhng g c gi l cc chc