Download pdf - Chuyen de Iptv- Ptit

B THNG TIN V TRUYN THNG HC VIN CNG NGH BU CHNH VIN THNG VIN KHOA HC K THUT BU IN

Gii thiu chuyn :

TNG KT CC TIU CHUN CHO IPTV

H ni 2009

Chuyn Tng kt cc tiu chun cho IPTV

Ni dung 1 Gii thiu v l do la chn chuyn ..........................................................................4 2 Cc ch vit tt ...............................................................................................................4 3 Tng quan v h thng cung cp dch v IPTV/VoD ....................................................7 3.1 3.2 3.3 4.1 Kin trc h thng ..................................................................................................7 u im ca IPTV .................................................................................................9 Nhc im ca IPTV .........................................................................................11 Chc nng ca cc module ..................................................................................11

4 Cc module chc nng c bn ca h thng cung cp dch v IPTV/VoD .................11 4.2 Cc yu cu i vi cc module trong h thng cung cp dch v IPTV/VoD ...14 4.2.1 Cc yu cu v vic bo v v qun l ni dung IPTV .................................14 4.2.2 4.2.3 EPG 4.2.4 4.2.5 4.2.6 Cc yu cu i v cht lng ca cc dch v IPTV ...................................15 Cc yu cu cho h thng DBM (Data Broadcast Middleware) v Enhanced .......................................................................................................................15 Cc yu cu v Metadata ca cc dch v IPTV ...........................................17 Cc yu cu v m ha cho IPTV .................................................................18 Cc yu cu v bo mt ni dung ((DRM/CAS) ..........................................19

5 Phn tch nhng yu t nh hng n cht lng dch v IPTV/VoD ......................21 5.1 C ch m ha, tc bt v ni dung hnh nh ..................................................21 5.2 Gii hn v bng thng ........................................................................................22 5.3 Mt gi .................................................................................................................22 5.4 Nghn trn server .................................................................................................23 5.5 Jitter v timing drift..............................................................................................23 5.6 Mng li, mng truy nhp v mng ti thu bao..................................................24 6 Tng kt cc tiu chun k thut v cht lng dch v IPTV/VoD trn th gii.......24 6.1 DSL Forum ..........................................................................................................24 6.2 MPEG...................................................................................................................25 6.3 ETSI .....................................................................................................................25 6.4 ITU .......................................................................................................................26 6.5 ATIS .....................................................................................................................30 6.6 Open TV Forum ...................................................................................................31 6.7 Broadband Services Forum (BSF) .......................................................................31 6.8 IPDR.....................................................................................................................32 6.9 ISMA ....................................................................................................................32 6.10 Nghin cu b tiu chun ca Chu u p dng cht lng dch v cho IPTV/VoD ......................................................................................................................32

Trang 2/36


6.11 Nghin cu b tiu chun ca M p dng cht lng dch v cho IPTV/VoD .33 7 Ti liu tham kho ........................................................................................................36

Trang 3/36


1

Gii thiu v l do la chn chuyn IPTV (Internet Protocol Television) l h thng cung cp dch v truyn hnh s

bng cch s dng giao thc IP qua h tng mng, c th l thng qua mt kt ni bng rng. nh ngha chung v IPTV l ni dung truyn hnh thay v c truyn i thng qua cp hay qung b truyn thng th s c chuyn n ngi xem thng qua cc cng ngh s dng cho mng my tnh. Khng ging nh cc dch v streaming s dng kt ni best-effort trn internet, IPTV thng c xy dng da trn mng c qun l tt m bo cht lng video. IPTV thng c cung cp km vi dch v Video on Demand v c th cng vi cc dch v Internet nh dch v truy cp web v VoIP cho ngi s dng. Gi cc dch v IPTV, VoIP v truy nhp Internet c gi l dch v Triple Play (nu b sung thm cho di ng th gi l Quadruple Play). V vy dch v IPTV s l dch v thit yu v quan trng nht cho cc nh cung cp Triple Play n ngi s dng. Dch v IPTV ang rt thnh hnh cc nc Chu u v s khch hng s dng dch v IPTV ngy cng tng ln. Hn na nhiu nc ang c k hoch gii thiu dch v IPTV n Chu u v Nam M. V vy, hin nay IPTV vn ang l mt ch nng c bn lun v nghin cu xy dng tiu chun trn cc din n quc t cng nh cc t chc tiu chun trong vn cht lng dch v IPTV ang c quan tm v ch trng nhiu nht. Chuyn ny tng kt cc tiu chun v cht lng dch v IPTV trn th gii bao gm cc ni dung sau: Tng quan v h thng IPTV Cc module chc nng c bn Nhng yu t nh hng n cht lng dch v IPTV Tng kt cc tiu chun v cht lng dch v IPTV trn th gii. 2 Tn tt AVP Cc ch vit tt Ting Anh Audio-Visual Profile Nghia

Trang 4/36


BCG BGMP CDP

Broadband Content Guide Border Gateway Multicast Protocol Content Delivery Protocols Dynamic Host Configuration

DHCP DNS DVB

Protocol Domain Name System Digital Video Broadcasting Digital Video Broadcasting -

DVB-H ESG EPG

Handheld Electronic Service Guide Electronic Program Guide European Telecommunications

ETSI FEC

Sdandards Institute Forward Error Correction File Delivery over Unidirectional

FLUTE FTP HTTP ICMP IETF IGMP IP IPDC IPTV LC

Transport File Transfer Protocol Hypertext Transfer Protocol Internet Control Message Protocol Internet Engineering Task Force Internet Group Management Protocol Interent Protocol IP Data Cast Internet Protocol TeleVision Layered Coding

Trang 5/36


LCT

Layered Coding Transport Multimedia Broadcast/Multicast

MBMS MLD MPEG MSDP

Service Multicast Listener Discovery Moving Picture Experts Group Multicast Source Discovery Protocol Organization for the Advancement of

OASIS PIM RFC RP RTCP RTP RTSP STB SIP SNTP SM SSM TCP TLS TS UDP

Structured Information Standards Protocol Independent Multicast Request for Comments Rendevous Point Real-Time Control Protocol Real Time Protocol Real Time Streaming Protocol Set-Top-Box Session Initiation Protocol Simple Network Time Protocol Sparse Mode Source-Specific Multicast Transmission Control Protocol Transport Layer Security Transport Stream User Datagram Protocol Universal Mobile

UMTS

Telecommunications System

Trang 6/36


WSBN

Web Services Base Notification

3

Tng quan v h thng cung cp dch v IPTV/VoD 3.1 Kin trc h thng H thng IPTV bao gm bn thnh phn chnh, tt c cc thnh phn ny l

chung cho bt k kin trc h thng ca nh sn xut no.

Hnh 1: Cc thnh phn ca mng IPTVVideo Head End Cng nh vi h thng truyn hnh v tinh s hay truyn hnh cp, dch v IPTV cng cn c h thng video head end. y l ni m ni dung linear (v d broadcast TV) v on-demand (v d phim) c ghi li v nh dng truyn qua mng IP. V c bn th u vo ca b head end l cc chng trnh c thu qua v tinh hoc ly trc tip t cc b broadcast hay cc chng trnh qua b aggregator. Mt head end mang mt knh ring v m ha n di nh dng video s, nh MPEG2. Hin nay cc nh cung cp dch v broadcast cng bt u s dng m ha MPEG4 v n c mt s u im hn so vi MPEG2 nh yu cu tc b bit thp cho c tn hiu truyn hnh SD v HD. Sau khi m ha, mi knh c ng gi IP v c truyn qua mng. Cc knh ny l cc dng IP multicast in hnh, tuy nhin mt s nh sn xut cng s dng lung IP unicast. IP multicast c rt nhiu u im v n cho php nh cung cp dch v truyn mt lung IP trn knh broadcast t video head end n mng truy nhp ca nh cung cp dch v. Cch ny c rt nhiu u im khi nhiu ngi s dng mun s dng cng mt knh broadcast ti cng thi im (v d hng nghn ngi xem cng mun xem mt s kin th thao) Mng Core/Edge ca nh cung cp dch v

Trang 7/36


Nhm cc lung video m ha c truyn qua mng IP ca nh cung cp dch v. Mi nh cung cp dch v c mt mng ring ca h v mng ny thng bao gm thit b t nhiu nh sn xut. Cc mng ny c th l mt hn hp ca mng IP hin c v mc ch l xy dng mng IP cho vic truyn video. Ti Edge, mng IP kt ni vi mng truy nhp. Mng truy nhp Mng truy nhp l lin kt t nh cung cp dch v n thu bao khch hng. Kt ni bng rng gia nh cung cp dch v v khch hng c th s dng nhiu cng ngh khc nhau. Nh cung cp dch v vin thng s dng cng ngh DSL phc v cho thu bao khch hng. Nh cung cp dch v cng bt u s dng cng ngh quang nh PON (passive optical network) kt ni n khch hng. Mng IPTV s dng ng truyn ADSL v VDSL cung cp bng thng m bo cho hot ng ca dch v IPTV n thu bao. Nh cung cp dch v s thay th thit b (nh DSL modem) ti thu bao phn pht kt ni Ethernet n mng ca khch hng. Mng ti thu bao Mng ti thu bao cung cp dch v IPTV n khch hng. C rt nhiu loi mng ti thu bao khc nhau nhng dch v IPTV yu cu bng thng cao ti mng ca thu bao. im cui trong mng ca thu bao m TV c kt ni n l set top box. Middleware: b cho php thc hin dch v IPTV Thut ng IPTV Middleware c dng m t cc gi phn mm lin quan n vic phn pht dch v IPTV. C rt nhiu nh sn xut thc thi gi phn mm ny, mi nh sn xut c cch tip cn ring i vi IPTV. Middleware do nh cung cp dch v s dng c th nh hng n kin trc ca mng IPTV. Middleware c kin trc client/server in hnh, trong client nm STB. Middleware nh ngha cch khch hng tng tc vi dch v. V d giao din ngi s dng v dch v sn c cho khch hng s dng (nh EPG Electronic Program Guige, VoD hay PPV) c thc hin v iu khin thng qua Middleware. Tnh d dng trong qun l nhiu dch v l mt chc nng ca mng IP hai chiu. Kin trc IP ny cung cp tiu chun cho cc ng dng v dch v c tch

Trang 8/36


hp vo trong mng, IPTV ch l mt dch v trong cc ng dng ny. Nhn t phn bit trong m hnh dch v IP l tnh hi t. Bi v cu trc chung cho cc ng dng v dch v, tnh hi t c th c hin thc ha cho cc thnh phn mng, ng dng, h thng h tr hot ng (OSS/BSS). V vy qun l a dch v tr thnh bi ton qun l cng cc dch v qua mng v phn b chng n nhiu mi trng ngi dng u cui khc nhau. IPTV Video on Demand (VoD) Video on Demand hot ng theo cch khc so vi dch v broadcast TV v h thng IPTV s cung cp cho thu bao mt lung unicast ca chng trnh c cc chc nng VCR bao gm pause, fast forward, rewind. IPTV middleware s iu khin giao ien ngi s dng v c th c m rng phc v cc dch v nh Subcription VoD v PVR. 3.2 u im ca IPTV H thng IPTV da trn IP nn c nhng u im ng k, bao gm kh nng tch hp truyn hnh vi cc dch v IP khc nh truy nhp internet tc cao v VoIP. Mng IP cng cho php truyn nhiu thng tin hn v vi nhiu chc nng hn. Trong mng v tinh hay TV truyn thng, s dng cng ngh broadcast th tt c ni dung c truyn lin tc n mi thu bao, thu bao chuyn knh ti set top box. Thu bao c th la chn t nhiu la chn nh cng ty v tinh, cp, truyn thng a lung thng tin v nh. Mng IP lm vic khc. Ni dung c gi trn mng v ch nhng ni dung khch hng la chn l c gi n nh thu bao. iu ny s tit kim bng thng v s la chn ca khch hng t b gii hn bi ng ng dn n nh thu bao. iu ny cng c ngha l tnh ring t ca khch hng c m bo hn so vi h thng v tinh v TV truyn thng. Tnh tng tc H thng IPTV cho php ngi xem c c hi xem cc chng trnh TV c tnh tng tc hn v c nhn hn. V d nh cung cp dch v c th cung cp chc nng tng tc cho php ngi xem la chn ni dung xem theo tn phim hay tn ca din vin hay chc nng picture in picture cho php ngi xem c th chuyn knh

Trang 9/36


m khng phi ri b chng trnh h ang xem. Ngi xem cng c th xem trng thi ca ngi chi trong khi ang xem mt chng trnh th thao, hay ngi xem c th thay i gc quay camera. Ngi xem cn c th truy nhp vo album nh v kho nhc trn PC ca h t mn hnh TV, s dng in thoi t lch ghi li cc chng trnh TV yu thch. Ngoi ra h cn c th s dng chc nng gim st iu khin (parent control) cm con ci xem mt s chng trnh TV khng ph hp. VoD VoD cho php khch hng duyt mt chng trnh trc tuyn hoc mt danh sch cc b phim xem qua v sau l la chn chng. V mt k thut, khi khch hng la chn mt b phim, th mt kt ni point-topoint c thit lp gia b gii m ca khch hng (Set top box hoc PC) v server phn pht lung ni dung. Bo hiu v cc chc nng nh pause, backward/forward c m bo bi giao thc RTSP (Real Time Streaming Protocol). Dng m ha chung nht c s dng cho VoD l MPEG2, MPEG4 v VC-1 trnh hin tng n cp bn quyn ni dung phim th ni dung ca VoD thng c m ha. Vi cng ngh IPTV vic m ha c thc hin hiu qu thng qua h thng DRM (Digital Rights Management). Vi h thng ny nu khch hng la chn xem phim trong thi gian 24 gi th sau 24 gi ni dung film s khng th xem c na Cc dch v hi t da trn IPTV Mt u im khc ca mng IP l kh nng tch hp v hi t. Cc dch v hi t y ni n kh nng tng tc ca cc dch v hin c theo cch trong sut to ra cc dch v gia tng mi. V d l dch v On-Screen Caller ID, nhn Caller IP trn mn hnh TV v kh nng x l (gi n voice mail). Cc dch v da trn IP s cung cp kh nng cho khch hng c th truy nhp bt k u, bt k khi no n ni dung thng qua TV, PC hay in thoi ca khch hng, v kh nng tch hp cc dch v v ni dung gn cht chng vi nhau.

Trang 10/36


3.3 Nhc im ca IPTV V IPTV yu cu truyn d liu thi gian thc v s dng giao thc IP nn rt nhy cm vi mt gi v tr nu kt ni IPTV khng nhanh v gy ra v hnh nh nu d liu khng tin cy. Vn v hnh nh l vn nghim trng nu c gng truyn lung IPTV qua cc lin kt khng dy. Vic ci tin cng ngh khng dy ang c bt u to ra cc thit b gii quyt vn ny. 4 Cc module chc nng c bn ca h thng cung cp dch v IPTV/VoD 4.1 Chc nng ca cc module

Hnh 2: Cc module chc nng c bn ca h thng IPTV Mng truy nhp bng rng 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

Trang 11/36


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 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 Video Headend. H thng Video Headend 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 IP multicast khun dng m ha mong mun. Yu cu phi c thit b u cui cho vic pht ni dung qung b. Thit b u cui ny c kh nng m ho mt chui cc hnh nh theo thi gian thc bng k thut nn dng MPEG-4 Part 10 hoc H.264. Hnh nh m ho c th ly t v tinh, truyn hnh cp, h thng truyn hnh mt t, my ch video, tape playout, v.v... Sau khi m ho, cc chui (nh dng ASI, SPTS) truyn MPEG s c ng gi bng cch s dng IP Streamer. Sau s truyn nhng chui gi IP bng cch s dng giao thc UDP/IP. 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.

Trang 12/36


H thng phn phi ni dung Bao gm cc cm my ch VoD v 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 cng 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. 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 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. H thng qun l mng v tnh cc H thng ny qun l v tnh cc dch v truy cp ca thu bao IPTV. 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

Trang 13/36


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. 4.2 Cc yu cu i vi cc module trong h thng cung cp dch v IPTV/VoD 4.2.1 Cc yu cu v vic bo v v qun l ni dung IPTV Cc yu cu chung C ch bo v IPTV phi linh hot v c th m rng. C ch bo v IPTV c th h tr bo v nhiu mc: bo v ton b hay ch mt s phn ca ni dung IPTV. C ch bo v IPTV phi cho php nh sn xut c cch thc thi ring. Tc l c ch no c th c m t theo cch tiu chun, thng qua cch m t chun ny nh sn xut c teer c cch thc thi ring ca h trong khi vn ph hp vi c ch bo v m t. C ch bo v IPTV c kh nng s dng ton b im mnh ca mng do bn cht ca cng ngh IPTV mang li. N c c ch ti v nhng cng c thc thi c ch bo v cn thiu. IPTV phi c m hnh ch ra s qun l ni dung. Vic qun l gip u cui IPTV xc nh c liu ni dung ang s dng khng c bo v hay khng. Cng vi c ch bo v, c ch qun l cung cp mt ni dung c bn quyn hon chnh. C ch qun l cn h tr nhiu m hnh kinh doanh p dng cho ni dung IPTV (v d m hnh thu bao, m hnh pay per view ). Cc yu cu c th Cch m t c ch bo v c th c biu din di dng metadata XML.

Trang 14/36


Cch biu din di dng XML ny cn t bo v c d liu metadata ca chng (bo v phn cp). Metadata cng c xem nh l mt ni dung c gi tr cn c bo v. C th IPTV multicast vi ch d liu metadata. C th IPTV multicast d liu metadata cng vi ni dung AV ca cc chng trnh IPTV. C th bo v thng tin c nhn trong metadata. 4.2.2 Cc yu cu i v cht lng ca cc dch v IPTV IPTV s b sung nhiu ng dng mi trong th trng dch v Multimedia vi linh hot v a dng ngy cng tng. V ni dung multimedia c truyn qua mng IP nn d liu multimedia c th b tr hoc mt, dn n lm suy gim cht lng ca tn hiu audio, video. Hn na mc suy giam ph thuc vo trng thi v tnh trng nghn mng. Ngoi ra mt s dch v IPTV thng mi yu cu cht lng audio/video phi chp nhn c. V vy IPTV phi gii quyt cc vn v cht lng sau: Phng php gim st cht lng video ca b nhn m s dng bng thng b sung t nht. Phng php gim st thi gian thc cht lng video b nhn. Phng php gim st cht lng audio b nhn s dng bng thng b sung t nht. Phng php gim st thi gian thc cht lng audio b nhn. 4.2.3 Cc yu cu cho h thng DBM (Data Broadcast Middleware) v Enhanced EPG Phn ny s m t cc yu cu i vi h thng DBM (Data Broadcast Middleware) nhn v thc hin nhiu dch v IPTV khc nhau bao gm cc dch v thi gian thc nh VoD, PPV v endhanced EGP h tr cch la chn v tm kim mt cch d dng dch v IPTV. Cc yu cu i vi DBM Cc dch v cable/satellite/terrestrial hin c s dng cc chc nng khc nhau ca middleware cung cp dch v. h tr cc dch v broadcast hi thoi cn c

Trang 15/36


cc ng dng java yu cu thng tin AV cht lng cao. V vy DBM cn h tr chc nng tru tng ha v kch hot ng dng t lung broadcast d liu nhn c thng qua IP Tuner cung cp DBS trong IPTV. Cn phi c s chun ha trong phng php s dng cc ni dung broadcast khc nhau h tr tnh lin thng gia cc middleware broadcast hin c. Yu cu: IPTV DBM cn cung cp mt framework nhn v x l cc dch v broadcast d liu (Data Broadcast Service). Chc nng nhn cc dng d liu broadcast: Chc nng ny c nhim v phn tch v qun l thng tin dch v t broadcast d liu thi gian thc thng qua mng bng rng. Chc nng bo hiu cho ng dng broadcast d liu: Chc nng ny cung cp cch ng gi ng dng lin quan n thng tin m tru tng t lung d liu broadcast cng nh h tr thc thi cc mi trng ng dng. DBM API: Chc nng ny cung cp mt API chun cho cc ng dng broadcast d liu truy nhp cc chc nng DBM khc nhau. Yu cu i vi Enhanced EPG (Electronic Program Guide) IPTV s h tr cc dch v tng tc tm kim v la chn thng tin theo cc c tnh ca ng dng ISP. Tuy nhin thng tin EPG hin c ch p dng cho cc dch v broadcast thi gian thc v cung cp chc nng tm kim v la chn thng tin cho cc dch v nh VoD v PPV. V vy Enhanced EPG cn phi cung cp cch qun l hiu qu v cung cp thng tin knh tch hp trn cc dch v broadcast, VoD, PPV trong dch v IPTV Yu cu: Cn phi cung cp mt framework cho broadcast d liu thi gian thc, VoD, PPV v cc dch v lung d liu khc bao bm c offline media vi cc ng dng ca n. nh ngha lc m t dch v IPTV: chc nng ny yu cu nh ngha ra mt lc cho EPG tch hp t thng tin ca cc dch v khc nhau trong IPTV. Giao thc truyn ti thng tin dch v IPTV: cn c giao thc truyn ti cho vic phn pht thng tin ca Enhanced EPG gia client v server.

Trang 16/36


Chc nng la chn v tm kim dch v IPTV: chc nng ny s pht hin ra dch v v la chn dch v s c thc thi thng qua enhanced EPG cng nh l mt chc nng tch hp vi IPTV middleware. 4.2.4 Cc yu cu v Metadata ca cc dch v IPTV Vi s pht trin ca mng vin thng, ngi ta c th cung cp cc dch v d liu media thng qua mng IP. Trong qu kh, mng broadcast truyn thng l phng tin duy nht phn pht d liu media n khch hng, v d nh dch v cung cp ni dung video vi cht lng SD hay HD. Tuy nhin ngy nay mng IP tr nn c tnh cnh tranh hn v mt cung cp bng thng v tnh tng tc ti ni dung. Hn na s lng ni dung multimedia ngy cng tng v rt nhiu ni dung c th c truyn qua mng IP n thit b u cui ca khch hng. Dch v IPTV hin ti tp trung vo vic phn pht ni dung audio-video n khc hng. d dng tm kim, la chn v duyt cc ni dung IPTV m ngi s dng a thch th cn phi c dch v metadata i km vi vic cung cp ni dung audio-video. V vic chun ha phng php tm kim ni dung trn nhiu dch v IPTV khc nhau l c bit cn thit. V vy metadata cho IPTV c th cung cp nhng thng tin cn thit v ni dung chng trnh nh tiu chng trnh, th loi, o din, din vin trong phim, thng tin v bn quyn, ngy sn xut, ngy pht hnh T nhng thng tin cn thit trong metadata c th xy dng nn cc ng dng lc v tm kim thng minh cho cc dch v IPTV. Cc yu cu chung Cung cp metadata IPTV: metadata s c cung cp cng vi ni dung audio-video ca chng trnh IPTV. S dng metadat IPTV: C th s dng IPTV metadata trn u cui IPTV v vy c th truy nhp d dng n cc chng trnh IPTV c th v cc thng tin c lin quan. Cn xem xt li nhng chun hin c ng dng cho metadata ca cc chng trnh TV thch ng vi cc ng dng IPTV, trnh vic phi tm ra metadata mi.

Trang 17/36


Metadata cn linh hot v c th m rng cho cc dch v IPTV trong tng lai, metadata IPTV c th lin thng tt nht vi metadata ca cc dch v broadcast truyn thng. Cc yu cu c th Metadata IPTV c biu din theo lc XML. C th tng tc n metadata IPTV. C th cung cp metadata mulitcast i km vi ni dung audio-video ca cc chng trnh IPTV. C th cung cp metadata multicast m khng cn i km vi ni dung audiovideo ca chng trnh IPTV. C c ch bo v metadata. C c ch bo v thng tin c nhn trong metadata. 4.2.5 Cc yu cu v m ha cho IPTV ITU-T v MPEG ang tin hnh chun ha c ch m ha video. ITU-T a ra chun H.26x nh H.261 v H.263 trong khi MPEG a ra chun MPEG1, MPEG2 v MPEG4. Thut ton m ha ca hai t chc ny l tng t nh nhau nhng mc ch l khc nhau. H.26x c pht trin cho video telephony trong khi MPEG c pht trin ch yu cho cc ng dng broadcast video cht lng cao. T nm 2000, hai t chc ny cng nhau pht trin ra H.264/AVC hay MPEG-4 Part10. Hin ti y c coi l c ch m ha video hiu qu nht.

.

Trang 18/36


Hinh 3: Lch s v xu hng pht trin ca m ha video Mt s yu cu i vi c ch m ha video phn gii nn nm trong phm vi t kch thc PDA n kch thc HDTV. phn gii tm thi c th nm trong khong t 7.5 frame/giy n 60 frame/giy. Mc v cht lng c th la chn nn l ln hn 3 mc. Cc tham s cho lu lng video c th thch hp vi cc tham s lu lng s dng trong chun Internet, v d RSVP. C ch m ha video c th c km vi cc cng c b li s mt gi C ch m ha video c th bao gm ch tr thp (v d tr nh hn 50ms gy ra bi b gii m video) IPTV da trn SVC c th thc hin c ch layered multicast Thng tin metadata cho mt knh c th bao gm mt nh x gia knh ni dung v cc a ch multicast tng ng thuc v knh ni dung . Tnh phc tp ca vic thch ng video vi cc iu kin khc nhau phi nh nht c th bi v s thch ng ny thng c thc hin trong thit b mng trung gian (proxy, gateway, router) phn ng li vi nhng rng buc thay i theo thi gian trong thi gian thc. Tnh linh hot trong vic thch ng video c th to ra nhiu gii php p ng c cc rng bu v truyn dn v tiu th ti nguyn khc nhau. 4.2.6 Cc yu cu v bo mt ni dung ((DRM/CAS) Cn phi thc thi vn bo mt ni dung bo v quyn tc gi cho cc ni dung IPTV. C hai cch tip cn vn bo mt ni dung l CAS (Conditional Access System) cho cc dch v broadcast ty bin v DRM (Digital Rights Management) cho cc dch v Internet cn c cung cp mt c ch bo mt ni dung tch hp trong mi trng ubiquitous v hi t s. V l do ny nn c ba yu cu chnh i vi vn bo mt ni dung IPTV nh sau:

Trang 19/36


Yu cu 1: Dch v IPTV c th cung cp c ch bo v quyn tc gi cho cc ni dung broadcast v s dng vic bo mt ni dung h tr nhiu m hnh kinh doanh khc nhau. Bo v ni dung: chc nng ny cung cp c ch bo v c bn cho ni dung IPTV bao gm m ha thi gian thc, c ch to ra key tc c o, phn b key v cc phng php v in du vn tay. iu khin truy nhp: chc nng ny iu khin truy nhp ca ngi s dng bo v ni dung IPTV bao gm qun l v nhn thc thu bao, ng gi ni dung, qun l cp php, giao din IPMP (Intellectual Property Management and Protection). M t quyn: chc nng ny m t quyn bng XML (eXtensible Mark-up Language) nhm h tr tnh lin thng. XrML (eXtensible Rights Mark-up Language) hay ODRL(Open Digital Rights Language) cng c thc thi trn th gii. Qun l min: chc nng ny cung cp cch qun l hiu qu ni dung khi ngi s dng iu khin nhiu thit b c h tr cc cng ngh nh: device certification, cu hnh min o - virtual domain configuration, gia nhp v ri b ming (domain join & leave), Phn pht thng tin quyn - rights information delivery v enforcement within the domain technology. Yu cu 2: Bo mt ni dung trong bo v quyn tc gi ca ni dung IPTV c th hot ng trong min bo mt tin cy. Bo mt ni dung IPTV cn h tr hot ng bo v quyn tc gi trong mi trng tin cy v c th b tn cng t cc thit b ca i th. Yu cu 3: Bo mt ni dung trong bo v quyn tc gi ca ni dung IPTV cn h tr tnh lin thng m khng ph thuc vo cng ngh. S khng tng thch c th xy ra gia cc nh sn xut khc nhau s dng cch bo mt ni dung khc nhau khi ph thuc vo mt cng ngh c th. V vy cn c mt framework bo mt ni dung h tr tnh lin thng c tt.

Trang 20/36


5

Phn tch nhng yu t nh hng n cht lng dch v IPTV/VoD5.1 C ch m ha, tc bt v ni dung hinh nh Ni dung hnh nh Video thng c m ha v nn di dng MPEG2,

MPEG4 Part10/H.264, Microsoft WMV9/VC1 v mt s dng khc. Cc dng m ha video thng h tr nhiu tc nn khc nhau nhm p ng yu cu tha hip gia cht lng video v bng thng. Phn ln cc dng nn xut pht t vic s dng m ha s khc nhau gia cc khung hn l bng cch gi i tng khung video ch nhng khc nhau gia mt khung v khung trc . C ch nay flm vic nu nu c t s thay i v hnh nh c truyn i nhng nu c s chuyn ng ng k ca hnh nh th hoc bng thng s phi tng thm hoc cht lng video b suy gim. Cng c nhiu c ch m ha cho php m ha hoc vi tc bt khng i (trong trng hp cht lng video c th thay i) hoc vi tc bt thay i (trong trng hp cht lng video t thay i). Cc c ch m ha hnh nh ni chung thng s dng t hp cch m ha intra-frame v inter-frame. Vi cch m ha intra-frame (I frame) khung hnh nh c chia thnh cc khi block sau s dng thut ton Discrete Cosine Transform chuyn i tng block thnh tp cc h s ri p dng m ha vi chiu di thay i. Nhm cc block c t hp vo trong mt thc th n gi l slice, i khi slice ny c mang i trong mt gi n. Nu c li truyn dn xy ra th ton b nhm block s b mt to thnh mt k sc khi gii m hnh nh. iu ny c th xy ra bi v cc h s DC trong mi block c m ha d on t block u tin trong slice , khi c mt li xy ra lm cho thng tin ny khng cn ng na i vi ton b phn cn li ca slice. Mt s li c th lm hng c cu trc ca frame v lm ton b frame khng cn gi tr na. Vi m ha inter-frame hoc m ha da vo s chuyn ng, cc vector chuyn ng c xc nh v m ha cho tng block. Nh cch m ha intraframe cc li xy ra c th lm hng ton b slice hoc lm frame b sai i. Trong cc h thng m ha inter-frame n gin nu b mt i mt frame th c th lm cho cc frame tip theo tr nn v ngha cho n khi nhn c khung I frame

Trang 21/36


tip theo. iu ny dn n lm hnh nh b dng li hoc ton b mn hnh nhn c l trng. Trong phn ln cc trng hp th cc chun m ha hnh nh u c s linh hot ng k cho c b m ha v gii m, cho php thc hin tha hip gia gi c v hiu nng. 5.2 Gii hn v bng thng Gii hn v bng thng thng xy ra trong lin kt truy nhp c th l kt ni cp hay DSL. Nu khng c bng thng cho dng video th b m ca router s b qua mt s gi dn n suy gim cht lng video. Mt vn nghim trng hn c th xy ra do tc truyn gi thay i nhiu v kch thc cc khung I, B, P l khng ging nhau. Tc truyn gi nh xy ra trong khi truyn khung I c th dn n mt gi v vy lm suy gim cht lng hnh nh. 5.3 Mt gi Mt gi xy ra c th do nhiu nguyn nhn khc nhau: nghn mng, t lin kt, khng bng thng, li truyn dn Loi suy gim cht lng xy ra do mt gi ph thuc vo giao thc s dng mang tn hiu video: Nu s dng giao thc UDP th mt gi s nh hng trc tip n cht lng hnh nh, v d nh mt s phn ca lung hnh nh s b thiu Nu s dng UDP ng tin cy (Reliable UDP) th nhng gi b mt c th c truyn li, tuy nhin nu truyn li vn gy ra mt gi th s khng c truyn li mt ln na, v vy cht lng hnh nh cng b nh hng. C th s dng FEC km vi UDP thay th nhng gi b mt, tuy nhin nu t l mt gi qu ln (v d trong qu trnh bng n s mt gi) th FEC cng khng c hiu qu. Nu s dng TCP th mt gi s dn n vic truyn li, tc l c th dn n s dng ht b m ca set top box v gy ra dng hnh nh.

Trang 22/36


Vi lung video s dng UDP mt gi c th lm mt phn hoc ton b frame b sai lc. V mt khung thng gm nhiu gi v lung video tiu chun bao gm cc khung c ni suy v vy vi mt t l mt gi xc nh th c th dn n t l mt khung cao hn gp 6 ln (minh ha hnh 4)

Hinh 4: nh hng ca t l mt gi i vi t l li/mt khung MPEG 5.4 Nghn trn server Khng phi tt c mi vn lin quan n cht lng video u do mng IP. Nu server khng c h tr phc v s lng ti a ngi dng c nhu cu s dng th s dn n nghn trn server. Li ny thng dn n dng hnh nh. Nu s dng cc giao thc nh UDP Multicast th c th gip gim bt ti cho server, tuy nhin iu ny ph thuc vo c nhiu thu bao cng xem mt ni dung ti cng thi im hay khng. 5.5 Jitter v timing drift Network jitter l s thay i v thi gian n ca cc gi tin, thng nguyn nhn l do nghn mng. Set top box ca h thng IPTV thng b m nhn gi sau 5-20 giy mi pht hnh nh, y l iu cn thit mc jitter thng thng t nh hng n cht lng hnh nh. Nu tr ln hn, v d do nghn

Trang 23/36


trn server th c th gy ra vn thiu b m, v vy nh hng n cht lng ca hnh nh. Timing drift xy ra khi ng h u cui gi v u cui nhn chy vi tc khc nhau. iu ny c th c khc phc bng cch iu chnh tc ng h ca tng bn cho nh nhau trnh gii quyt vn . 5.6 Mng li, mng truy nhp v mng ti thu bao ng truyn IP thng bt u ti mt video server v kt thc set top box. iu ny c ngha l gi tin s i qua nhiu mng, thng c s hu bi nhiu nh cung cp dch v khc nhau. Mng li IP thng l mng quang c dung lng ln, hot ng tt di nhiu mc nghn v v vy khi c vn xy ra th thng l do mng truy nhp hay mng pha thu bao.

6

Tng kt cc tiu chun k thut v cht lng dch v IPTV/VoD trn th giiTng t nh truyn hnh cp v v tinh, IPTV cng cn c b cc tiu chun

cng nghip nhm xc tin qu trnh cnh tranh, gim gi thnh cho cc thu bao, gim thiu s hn lon trong th trng, nng cao cht lng qu trnh cung cp dch v IPTV. Qu trnh tiu chun ha IPTV l nhim v phc tp, v c rt nhiu thnh phn v h thng t cc nh cung cp thit b khc nhau to nn mt h thng IPTV u cui-ti-u cui. Tuy nhin, cng nh i vi mt cng ngh mi xut hin, qu trnh tiu chun ha IPTV cn c s tham gia ca cc c quan tiu chun v hip hi cc nh xn xut cng nghip. Sau y gii thiu cc t chc tiu chun ha IPTV v cc tiu chun m h a ra: 6.1 DSL Forum DSL Forum l t chc c thnh lp trn c s s hp tc phi li nhun nhm to ra cc hng dn, nguyn tc ch o cho qu trnh trin khai v pht trin h thng mng DSL. T chc ny thit lp mt s khuyn ngh di dng cc bo k thut (TR-xxx). Khuyn ngh lin quan ti cht lng dch v IPTV ca DSL Forum l TR-126 Triple-Play Services Quality of Experience (QoE) Requirements. Ti liu ny a ra cc yu cu i vi cc dch v triple-play, bao hm c thoi, video, s liu vv quy nh kh chi tit cht lng dch v i

Trang 24/36


vi IPTV. c thm thng tin v cc ti liu tiu chun hin ti ca DSL Forun, tham kho http://www.broadband-forum.org/technical/trlist.php 6.2 MPEG MPEG (Moving Pictures Experts Group) l mt nhm cng tc ca ISO/IEC chu trch nhim nghin cu v xut cc tiu chun quc t cho qu trnh nn, gii nn, x l v hin th cc nh ng, m thanh m ha v t hp ca chng. MPEG ang pht trin mt s cc tiu chun lin quan n IPTV. Nhm cng pht trin tiu chun middleware a phng tin ISO/IEC 23004 (MPEG-E M3W) cng vi nhiu loi tiu chun m ha video khc nhau. MPEG-E bao gm mt s cc giao din chng trnh ng dng (APIs) c quy nh trong 8 phn ring bit ca bng sau y: Part Number ISO/IEC 23004-1 ISO/IEC 23004-2 ISO/IEC 23004-3 ISO/IEC 23004-4 ISO/IEC 23004-5 ISO/IEC 23004-6 ISO/IEC 23004-7 ISO/IEC 23004-8 6.3 ETSI Nm 2003, ETSI thnh lp nhm TISPAN (Telecom & Internet converged Services & Protocols for Advanced Networks) pht trin cc ch tiu k thut cho cc h tng mng c nh v di ng th h sau. TISPAN ln lt cu trc thnh cc nhm nghin cu a ra cc ch tiu k thut c bit quan trng i vi cng nghip IPTV t cc mng ring v bo mt n qun l v nh a ch mng. Cui nm 2005, TISPAN a ra cc ch tiu k thut i vi NGN phin bn R1 v hin ang nghin cu xut phin bn R2. Phin bn 2 tp trung vo tnh lu ng, cc dch v mi v phn phi ni dung vi kh nng qun l v Part (API) Description Architecture Multimedia API Component model Resource and quality management Component download Fault management System integrity management Reference software

Trang 25/36


bo mt c tng cng. IPTV l mt trong nhng dch v mi c nghin cu trong phin bn 2 v TISPAN tin hnh nhng bc ban u trong vic quy nh mng h tr IPTV. Hin nay TISPAN a ra mt s tiu chun k thut lin quan ti IPTV nh sau: a) TS 181 014 Requirements for network transport capabilities to support IPTV services: bao gm cc yu cu mc cao v iu khin qun l, h tr multicast/unicast, bo mt, tnh cc b) TS 181 016 Service Layer Requirements to integrate NGN services and IPTV: bao gm cc yu cu mc cao v tm dch v, phn phi dch v, gim st u cui, QoE, tng tc ca IPTV vi cc dch v khc nh video telephony c) TS 182 027 IPTV architecture; IPTV function supported by the IMS subsystem: quy nh r cu trc chc nng ca h thng IPTV s dng cu trc phn h a phng tin (IMS) v cc c trng ca n d) TS 182 028 IPTV architecture; Dedicated subsystem for IPTV functions: m t cc chc nng IPTV trong cu trc NGN, bao gm cc lnh vc nh qu trnh xc thc v cp php, bo v ni dung, trao i kh nng qun l ti nguyn, tnh cc e) ETSI TR 101 290 Digital Video Broadcasting (DVB); Measurement guidelines for DVB systems: cung cp cc hng dn o kim trong h thng qung b video s. Ti liu ny c lin quan n vic o kim cht lng hnh nh trong dch v IPTV. 6.4 ITU Nm 2006, ITU thnh lp nhm tiu im v IPTV (ITU-T FG IPTV) , thng gi l FG IPTV phi hp v y mnh s pht trin cc tiu chun IPTV ton cu, kt hp vi cc cng vic hin ti ca cc nhm ngin cu ITU v cc c quan tiu chun khc nh ATISS v ETSI. FG t di s ch o ca ITU-T Study Group 13, nhm ng u NGN. Mc ch ca FG IPTV bao gm xc nh cu trc IPTV v cc yu cu dch v, phi hp vi cc t chc tiu chun ha khc, lm hi ha s pht trin ca cc tiu chun mi v tng cng

Trang 26/36


kh nng phi hp hot ng vi cc h thng hin ti. FG IPTV c 6 nhm lm vic chu trch nhim trong cc lnh vc khc nhau nh sau: WG1 : Architecture and Requirements WG2 : QoS and Performance Aspects WG3 : Service Security and Contents Protection WG4 : IPTV Network Control WG5 : End Systems and Interoperability Aspects WG6 : Middleware, Application and Content Platforms T khi thnh lp, FG IPTV tin hnh hp 7 ln. Trong cc ln hp FG tho lun 1100 Contributions v hon thin 20 vn bn [12]. Cng vic ca FG kt thc sau k hp cui thng 12 nm 2007, cc bo co v trao i c chuyn ti cc nhm nghin cu ca ITU-T qua SG 13 i vi nhiu lnh vc khc nhau ca IPTV v c th ti v min ph t website ca ITU ti a ch: http://www.itu.int/md/T05-FG.IPTV-071211/sum/en. Qu trnh tip tc cc cng vic v IPTV ca cc nhm lin quan c thc hin di s iu khin ca IPTV GSI. Iptv-GSI s phi hp cc k hoch hot ng v ng t chc cc cuc hp cho cc nhm nghin cu lin quan pht trin cc cng vic v IPTV. S kin u tin ca IPTV-GSI din ra vo thng 1 nm 2008 ti Hn quc. Ti y, cc cuc tho lun v cc vn nghin cu lin quan ti IPTV t cc nhm nh sau: a) SG 9 (Integrated broadband cable networks and television and sound transmission) b) SG 11 (Signalling requirements and protocols) c) SG 12 (Performance and quality of service) d) SG 13 (Next generation networks) e) SG 16 (Multimedia terminals, systems and applications) f) SG 17 (Security, language and telecommunication software) Cc vn bn lin quan ti cc vn QoS/QoE c tho lun trong WG2 ca FG-IPTV bao gm:

Trang 27/36


(a) QoE requirements for IPTV (b) Traffic management mechanism to support IPTV services (c) Application layer reliability and error recovery mechanisms for IPTV (d) Performance monitoring for IPTV Cc mc (a) v (d) c chuyn ti Question 13 trong SG12 (Q.13/12), (b) v (c) c chuyn ti SG13 v SG16. Mc (a) m t cc yu cu v QoE i vi cc dch v IPTV v by gi c tn gi G.IPTV-QoE di dng mt khuyn ngh phc tho [16]. Cc yu cu ny bao gm cht lng video, audio, text, v graphics, cng nh cht lng ca cc chc nng iu khin nh chuyn knh, kim tra chnh xc ca siu d liu, chc nng ca chng trnh EPG v trnh duyt. Mc (d) quy nh cc im gim st cht lng, cc tham s cht lng mng cn gim st ti cc im v phng php nh gi QoE t cc tham s cht lng thu o c. Nhm SG12 s tiu chun ha cc im gim st cht lng, nh nu trong khuyn ngh G.IPTV-PMP. Tip theo , nhm s to ra mt h cc khuyn ngh quy nh cc vn cn li trong vn bn hin ti. Bng sau l tm tt ni dung mt s cc khuyn ngh ca ITU-T v IPTV. Trong bng ny, chng ta thy hai khuyn ngh lin quan chnh n cht lng dch v IPTV l hai khuyn ngh mi ang trong qu trnh hon thin G.1080 v G.IPTV-PMP, ni dung ca hai khuyn ngh ny l cc yu cu v cht lng dch v IPTV v gim st cht lng dch v IPTV. Khuyn ngh ITU-T (for QoS) Rec.J.241 Tm tt ni dung Khuyn ngh v cht lng qung b IP; m t cht lng truyn ti cc lp IP v cht lng hnh nh trn Set Top Box. Rec.J.200, J.202 (for J.200 m t kin trc tng th ca API l thnh phn khng thiu c cho vic chuyn i ni dung thng xuyn. J.201 m t cc phng tin cho vic phn phi ni dung. J.202 xc nh cc

ITU-T J.201, API)

Trang 28/36


Khuyn ngh

Tm tt ni dung nh dng ni dung th tc c pht trin mi.

ITU-T DRM) ITU-T AN)

J.197

(for

Khuyn ngh ny a ra khi nim v Digital Rights Management Bridge trn mt mng gia nh.

J.281

(for

Cc yu cu i vi qung b IP s dng FTTH Khuyn ngh i vi kin trc h thng qung b IP Khuyn ngh ny cp n kin trc mng IP

ITU-T Rec.J.mcvifarch (for AN)

ITU-T

Rec.J.resil-

multicast c hiu lc cao duy tr cht lng dch v mt cch hiu qu i vi vic truyn hnh nh trn IP. J.192 to ra mt Residential Gateway bng cch cung cp mt tp hp cc c tnh da trn nn tng IP, cc c tnh ny c a vo mt Cable Modem hoc c kt hp vo mt thit b ng ring bit. J.179 m t vic trin khai cc dch v Multimedia bng cch a ra cc nh ngha v cc giao din bo hiu da trn nn tng IP.

ipmulti (for AN)

ITU-T

Rec.J.192,

J.179 (for RGW)

ITU-T core-a,

Rec

J.stb-

J.stb-core-a m t chc nng cu trc ca STB th h tip theo. J.stb-mi-a khuyn ngh i vi kin trc ca STB cho qung b IP. J.stb-cable-a m t thnh phn kin trc mng cp ca STB th h tip theo. Khuyn ngh ny xc nh mt tp hp cc thnh phn cu trc c bn c kt hp mt cch linh hot trong mt tp hp cc cu hnh thch ng

J.stb-mi-a,

J.stb-

cable-a (for STB)

ITU-T Rec.J.190 (for HN)

Trang 29/36


Khuyn ngh

Tm tt ni dung vi s a dng ca cc gii php mng gia nh.

Y.1541

Khuyn ngh v phn loi cht lng mng IP. Ph lc IX cp n cht lng qung b IP. Khuyn ngh i vi cc dch v audio/video on-

F.741

demand. Mt s cp v N-VOD v IPTV.

F.750 G.1080 TD PMP) 45 (G.IPTV-

Khuyn ngh khung lm vic siu d liu. Cc yu cu cht lng dch v IPTV Gim st cht lng IPTV

6.5 ATIS ATIS (The Aliance for Telecommuniction Industry Standard) l t chc cng nghip vin thng bao gm 350 cng ty ch yu l cc nh cung cp dch v. pht trin hn na qu trnh tiu chun ha i vi lnh vc cng nghip IPTV, ATIS thnh lp nhm IPTV Interoperability Forum (IIF). Vn ch yu ca IIF l xy dng cu strucs chun ha chung pht trin cc dch v IPTV, tp trung ch yu vo bn lnh vc chnh, thit b h tng mng, bo mt ni dung, kim tra kh nng phi hp hot ng v cht lng dch v. hin nay, nhm ban hnh mt s hng dn trong lnh vc qun l bn quyn v cu trc: ATIS-080001: ti liu ny quy nh cc ch tiu k thut kh nng phi hp hot ng i vi qu trnh thc hin cc h thng IPTV DRM. T chc ny d nh s dng tiu chun ny lm c s cho vic to lp ch tiu k thut kh nng phi hp hot ng DRM/bo mt trong tng lai. ATIS-0800002: ti liu ny cung cp cc hng dn cho cc nh cung cp ni dung v dch v v cu trc yu cu truyn ti cc dch v IPTV.

Trang 30/36


ATIS-0800003: ti liu c xut bn nm 2006 ny t ra mt l trnh gm mt s giai on tiu chun ha cu trc cc h thng IPTV. ATIS-0800004: ti liu ny quy nh mt khun kh cho qu trnh gim st cc tham s QoS i vi nhiu loi hnh dch v IPTV. ATIS-0800005: ti liu k thut ny bao hm ch mt gi qua qu trnh trun ti qua h tng mng IPTV. Cng vi vic xc nh r cc nguyn nhn gy mt gi khc nhau, ti liu cn cp n vic gim tc ng ca mt gi trong mi trng lin kt mng IPTV. ATIS tha thun chia s cc tiu chun ny vi cc t chc tiu chun ha IPTV khc nh ITU-T FG IPTV nhm m bo kh nng hot ng tng thch gia cc cng ngh khc nhau. ATIS cng ln d nh thit lp qu trnh cp chng nhn cho cc nh sn xut phn cng v phn mm trong tng lai. c thm thng tin tham kho www.atis.org. 6.6 Open TV Forum Nm 2007, cc hng ch to thit b mng, cc nh cung cp thit b in t dn dng, cng phi hp thit lp hip hi tiu chun ha c tn Open IPTV Forum. Mc ch ca din n ny l cng cng tc vi cc t chc tiu chun ha hin c quy nh cc ch tiu k thut qu trnh truyn ti cc dch v IPTV u cui-ti-u cui qua nhiu cu trc mng khc nhau. c thm thng tin tham kho www.openiptvforum.org. 6.7 Broadband Services Forum (BSF) BSF l mt din n cng nghip nhm h tr cho vic trao i, pht trin cng vi cc cng c v thng tin nhm gii quyt cc vn c bn v cng ngh v kinh doanh mang tnh cht sng cn i vi s pht trin ca cng nghip truyn thng bng rng. Hip hi cc cng ty ny c c bit tp trung vo IPTV v s thc y nghnh cng nghip ny qua nhng ng gp ca mnh trong nhiu din n v trin lm thng mi. c thm thng tin tham kho www.broadbandservicesforum.org

Trang 31/36


6.8 IPDR IPDR ((The Internet Protocol Detail Record Organization) l mi hip hi cc nh cung cp dch v v cc nh cung cp thit b tp trung vo vic pht trin v dn xp cc tha thun trao i s dng cc tiu chun dch v IP th h sau. T chc ny chu trch nhim quy nh cc tiu chun phi hp hot ng cc h thng tnh cc, qun l mng... bit thm thng tin tham kho www.ipdr.org. 6.9 ISMA c thnh lp nm 2000, ISMA (Internet Streaming Media Alliance) l lin minh phi li nhun ca cc cng ty cng nghip. Nhim v ca lin minh l lm cho thun tin v xc tin vic chp thun mt cu trc m i vi qu trnh truyn ti m thanh v hnh nh trn cc mng IP. T chc pht trin mt s ch tiu k thut t ci tin thi gian chuyn knh i vi cc h thng IPTV cho n qu trnh ng b hnh nh v s liu vi ni dung video. Cc ch tiu k thut m lin minh a ra cho n nay to ra s ng dng rng ri cc tiu chun Internet m do IETF xut. bit thm thng tin, truy cp www.isma.tv. 6.10 Nghin cu b tiu chun ca Chu u p dng cht lng dch v cho IPTV/VoD 1. Tiu chun ETSI-TS-181-014 V2.0.0 - Requirements for network transport capabilities to support IPTV services. Tiu chun ny bao gm nhng ni dung sau: Quy nh cc yu cu chung cho dch v IPTV Nhng yu cu v mng truyn ti Admission Control Multicast and Unicast Support Security User data Accounting NAT Traversal

Trang 32/36


2. Tiu chun ETSI TS 182 028 V2.0.0 - IPTV Architecture, Dedicated subsystem for IPTV functions Tiu chun ny bao gm nhng ni dung sau: NGN IPTV subsystem NGN dedicated IPTV subsystem functional architecture Operational framework Security Management User data IPTV profiles User data location IPTV delivery modes Operational modes Service initialization Nomadism

Charging Procedures Linear TV Multimedia content on demand (CoD) Media broadcast with trick modes Near CoD

6.11 Nghin cu b tiu chun ca M p dng cht lng dch v cho IPTV/VoD ATIS l t chc tiu chun ha trong lnh vc truyn thng v cng ngh thng tin ca M. ATIS c cng nhn bi Vin tiu chun quc gia Hoa K (American National Standards Institute - ANSI). B cc tiu chun v IPTV ca ATIS: 1. ATIS-0800001 - IPTV DRM Interoperability Requirements

Trang 33/36


Description: This document defines the requirements for the interoperability of systems and components in the IPTV DRM/security environment. The requirements defined in this document shall be used to create an IPTV DRM/security interoperability specification during the next phase of the IIF DRM TF 2. ATIS-0800002 - IPTV Architecture Requirements Description: IPTV is a suite of secure, reliable, managed video-related services. This document provides an initial industry consensus view on the requirements for an end-to-end architecture to support these services 3. ATIS-0800003 - IPTV Architecture Roadmap Description: The IPTV Architecture Roadmap is intended as a companion to ATIS-0800002, IPTV Architecture Requirements. This document is intended to help guide the architecture specification development work of the IIF. The Roadmap provides an industry consensus perspective on the prioritization and scoping of the specification development efforts of the IIF. 4. ATIS-0800004 - IPTV QoS Framework Document Description: This document provides an initial industry consensus view of scope, definitions, and tools to support the creation of IPTV QoS metrics and measurements within ATIS IPTV Interoperability Forum (IIF). 5. ATIS-0800005 - IPTV Packet Loss Issue Report Description: The IPTV Packet Loss Issue report is a technical report that explores a range of potential solutions to the problem of packet loss and makes recommendations regarding their applicability for an IPTV service. 6. ATIS-0800006 - IIF Default Scrambling Algorithm Description: This document provides the IIF Default Scrambling Algorithm (IDSA) Interoperability Specification. It supports interoperability by specifying a default scrambling/de-scrambling algorithm for the MPEG-2 Transport Stream and the scrambling algorithm signaling 7. ATIS-0800007 - IPTV High Level Architecture

Trang 34/36


Description: This document provides a high level architectural framework for end-to-end systems implementation and interoperability for the supporting network design Theo b tiu chun ny th h thng DRM s bao gm cc thnh phn sau:

Hinh 5: Thnh phn ca h thng DRM Tiu chun cung quy nh nhng nh ngha v d liu v c ch chia s thng tin gia cc vng trong h thng cung cp dch v IPTV:

Hinh 6: IPTV MetaData

Trang 35/36


7[1].

Ti liu tham khoS. A. Karunasekera and N. G. Kingsbury, A distortion measure for blocking artifacts in images based on human visual sensitivity, IEEE Trans. Image Processing, vol. 4, no. 6, pp. 713-724, June 1995. H. R. Wu and M. Yuen, A generalized block-edge impairment metric for video coding, IEEE Signal Processing Letters, vol. 4, no. 11, pp. 317-320, Nov. 1997. A. B. Watson, J. Hu, and J. F. McGowan III, DVQ: a digital video quality metric based on human vision, Journal of Electronic Imaging, vol. 10, no. 1, pp. 20-29, Jan. 2001. M. C. Q. Farias and S. K. Mitra, No-reference video quality metric based on artifact measurement, in Proc. ICIP 2005, vol. 3, pp. 11-14, Sept. 2005 E. Ong, X, Yang, W. Lin, Z. Lu, and S. Yao, Perceptual quality metric for compressed videos, in Proc. ICASSP05, vol. 2, pp. 581-584, Mar. 2005. S. Winkler, A. Sharma, D. McNally, Perceptual video quality and blockiness metrics for multimedia streaming applications, in Proc. International Symposium on Wireless Personal Multimedia Communications, pp. 547-552, Sept. 2001 K. T. Tan and M. Ghanbari, A multi-metric objective picture-quality measurement model for MPEG video, IEEE Trans. Circuits Syst. Video Technol., vol. 10, no. 7, pp. 1208-1213, Oct. 2000. High quality compression for film and video, PRESTO, Sept. 2002. framework for QoS metrics and measurements supporting IPTV services, ATIS-0800004, Nov. 2006. User requirements for perceptual video quality monitoring of IPTV, FG-IPTV-ID0013, Geneva, 10-14 July 2006. Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN);IPTV Architecture; IPTV functions supported by the IMS subsystem, ETSI TS 182 027 V2.0.0 (2008-02) Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IPTV Architecture; Dedicated subsystem for IPTV functions, ETSI TS 182 028 V2.0.0 (2008-01) Shinji Ishii, et al., Report on ITU-T FG IPTV International Standardization Activities NTT Technical Review, 2007 http://www.itu.int/ITU-T/IPTV/ http://www.etsi.org http://www.atis.org/ http://www.tek.com/ http://www.home.agilent.com/agilent http://www.spirent.com/ http://www.sunrisetelecom.com http://www.ixiacom.com/ http://www.ineoquest.com/ http://www.agama.tv

[2]. [3].

[4]. [5]. [6].

[7].

[8].

[9]. [10].

[11].

[12]. [13]. [14]. [15]. [16]. [17]. [18]. [19]. [20]. [21]. [22].

Trang 36/36