I HC QUC GIA TP. H CH MINHTRNG H CNG NGH THNG TIN

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TIU LUNCng ngh truyn hnh INTERNET (IPTV)

Gio vin hng dn: Th.S Chu Tin Dng

Nhm SV thc hin: 1. Nguyn Thin

2. Nguyn Cnh Thng

3. Nguyn Ngc Minh Tn

Lp:

K2013NT

MC LC

5LI NI U

62. CC K THUT TRUYN HNH HIN C VIT NAM

62.2. Truyn hnh Analog

62.3. Truyn hnh k thut s mt t

62.4. Truyn hnh cp

72.5. Truyn hnh v tinh DTH

72.6. Truyn hnh IPTV

83. CNG NGH IPTV

83.2. Khi nim

83.2.1 IPTV (Internet Protocol Television )

83.2.2 c trng ca IPTV

93.3. T chc hot ng

93.3.1 C s h tng ca mng IPTV

103.3.2 Cu trc chc nng cho dch v IPTV

113.3.1 Vn phn phi IPTV

123.3.2 Cc k thut phn phi mng IPTV

183.4. Qun l mng IPTV

183.4.1 H thng qun l mang IPTV

193.4.2 Qun l ci t

203.4.3 Gim st thc thi v kim tra mng

213.4.4 Qun l v d phng

223.4.5 Qun l khng gian a ch IP

223.4.6 X l cc s c

233.4.7 Qun l quyn ni dung s

243.4.8 Qun l cht lng dch v

254. SO SNH GIA IPTV V VOD

254.2. Nhng im chung

254.3. Nhng im khc nhau

264.4. Tm li, so vi VOD (video theo yu cu) IPTV c cc u th

275. NG DNG

275.2. Kh nng ng dng ca IPTV Vit Nam

275.3. Nhng yu m ca IPTV

29KT LUN

LI NI UNgy nay, khi internet bng rng pht trin mnh m, to nn s thay i mnh m trong lnh vc truyn hnh. Bn cnh truyn hnh tng t, truyn hnh s, truyn hnh v tinh, truyn hnh cp, truyn hnh internet, chng ta cn bit n IPTV.

IPTV thng c cung cp cng vi dch v Video-on-Demand (VoD) v cng c th cung cp cng vi cc dch v internet khc nh truy cp Web v VoIP, do cn c gi l Triple Play v c cung cp bi nh khai thc dch v bng rng s dng chung mt h tng mng. IPTV c c hi rt ln pht trin nhanh chng khi m mng bng rng c mt khp mi ni v hin nay c hng triu h gia nh s dng dch v bng rng trn ton cu. Rt nhiu nh cung cp dch v vin thng ln trn th gii ang trin khai thm d IPTV v xem nh mt c hi mi thu li nhun t th trng hin c ca h v coi nh mt gii php t bo v trc s ln sn ca cc dch v truyn hnh cp.

Ti th trng cung cp dch v Vit Nam, dch v IPTV bt u c cung cp vi mt s dch v c bn. iu ny xem nh l c hi kinh doanh dch v mi ca cc nh cung cp dch v ti Vit Nam, khi m c s h tng mng bng rng v ang pht trin mnh m cng vi s i hi nhu cu ca khch hng ngy cng cao.

Trong bi tiu lun ny tc gi trnh by tng quan v cc dch v truyn hnh hin c Vit Nam, cng ngh truyn hnh IPTV, so snh IPTV v Vod, ng dng ca IPTV ti Vit Nam cng nh trn ton th gii.

Nhm sinh vin1. CC K THUT TRUYN HNH HIN C VIT NAM1.2. Truyn hnh Analog

Truyn hnh Analog l nguyn bn u tin ca cng ngh truyn hnh, truyn hnh Analog cn c bit n di ci tn l truyn hnh tng t. Cm t tng t y c hiu nh sau, tn hiu c pht sng t i truyn hnh, n cc my thu hnh c hnh nh v m thanh tng t nh tn hiu gc.

Nhc im: Loi hnh pht sng ny b hn ch bi khng gian, c ngha nng lc ca n ch p ng c phm vi vi chc km. V c mt iu hn ch na l loi hnh Analog rt d b tc ng bi vt cn hoc mi trng nh ting ng c xe hay cc ngun sng khc nh radio, in thoi.1.3. Truyn hnh k thut s mt t

Truyn hnh k thut s (Digital) l mt trong nhng bc t ph ln ca lnh vc truyn hnh. Cc tn hiu truyn hnh tng t c s ha, hay ni mt cch d hiu l cc tn hiu c m ha di dng nh phn (gm 2 dy s 0 v 1) trc khi truyn i. C hai loi hnh c pht l pht ln cc v tinh truyn dn, hoc pht trc tip trn mt t. Cc my thu hnh mun bt c loi hnh pht sng ny, phi nh n s h tr ca mt b gii m hay cn gi l Set Top Box, b gii m c cung cp bi cc dch v ca i truyn hnh.

u im: Loi hnh pht sng ny c u im tt hn so vi Analog, n c ph sng rng v xa hn.Nhc im: D c m ha v truyn dn tt hn, nhng sng Digital vn t nhiu b nh hng bi mi trng xung quanh.

1.4. Truyn hnh cp

y l loi hnh pht sng mi ca truyn hnh, cc tn hiu m thanh v hnh nh c truyn dn qua h thng cp quang v cp ng trc. Trn l thuyt loi hnh pht sng ny khng b nh hng bi cc tc nhn nh thi tit hay mi trng m thanh nhiu ng, nhng thc t c mt s knh nc ngoi c truyn dn t v tinh xung cc nh i, cng t nhiu b nh hng. V th khi tn hiu gc b nh hng th cc thit b thu cui m c th l mng li my thu hnh cng b nh hng theo.

u im: Hnh nh r nt, m thanh tt, khch hng c c hi xem c nhiu cc chng trnh c cht lng.

Nhc im: Cho n by gi, mng li dch v vn cn kh nh, a phn ch tp chung cc thnh ph ln. Cha p ng c nhu cu ca th trng cc vng c kh khn v a l.

1.5. Truyn hnh v tinh DTH

Truyn hnh v tinh DTH (Direct to Home), y l loi hnh kh cao cp, hnh thc pht sng ca loi hnh ny khc vi truyn hnh s mt t. Khi chui tn hiu s c pht ln v tinh v v tinh pht tr li mt t. u thu s s dng Antena Parabol thu tn hiu v u thu v tinh s thc hin gii m chuyn ha thnh hnh nh v m thanh.

Nhc im: Loi hnh ny c chi ph u t rt ln v ch ph hp vi mt b phn khch hng c thu nhp cao.

1.6. Truyn hnh IPTV2. CNG NGH IPTV

2.2. Khi nim

2.2.1 IPTV (Internet Protocol Television )

IPTV truyn hnh s dng giao thc IP l mt h thng cc dch v truyn hnh s cung cp ti cc thu bao s dng giao thc IP trn kt ni bng rng. IPTV thng c cung cp cng vi dch v VoD (Video on Demand) v cng c th cung cp cng vi cc dch v Internet khc nh truy cp Web v VolP (Voice over Internet Protocol).Khi mi bt u IPTV c gi l truyn hnh giao thc Internet hay Telco TV hoc Truyn hnh bng rng. Thc cht tt c cc tn u c s dng ni n vic phn phi truyn hnh bng rng cht lng cao hoc ni dung m thanh v hnh nh theo yu cu trn mt mng bng rng. IPTV l mt nh ngha chung cho vic p dng phn phi cc knh truyn hnh truyn thng, phim truyn, v ni dung video theo yu cu trn mt mang ring. Theo t chc Lin hip Vin thng Quc t ITU (International Telecommunications) th IPTV l dch v a phng tin bao gm truyn hnh, video, audio, vn bn, ha v d liu qua mt mng IP v c qun l cung cp mc yu cu ca cht lng dch v v s tri nghim, tnh bo mt, tnh tng tc v tin cy. 2.2.2 c trng ca IPTV

- H tr truyn hnh tng tc: Kh nng ca h thng IPTV cho php cc nh cung cp dch v phn phi y cc ng dng ca truyn hnh tng tc. Cc dng dch v IPTV c th c phn phi bao gm chun truyn hnh trc tip, truyn hnh hnh nh cht lng cao HDTV (High Denition Television), cc tr chi tng tc v truy cp Internet tc cao.

- Dch thi gian: IPTV kt hp vi mt b ghi hnh video s cho php dch chuyn thi gian xem ni dung chng trnh, y l mt k thut ghi hnh v lu tr ni dung c th xem li sau.

- Tnh c nhn: Mt h thng IPTV t kt cui n kt cui (end-to-end) h tr thng tin c tnh hai chiu v cho php cc user xem cc chng trnh theo s thch, thi quen Hay c th hn l cho cc user xem ci g h mun vo bt k lc no.

- Yu cu bng thng thp: thay th cho vic phn phi mi knh cho mi user, cng ngh IPTV cho php cc nh cung cp dch v ch phn phi cc knh m user yu cu. y l im hp dn cho php cc nh khai thc mng bo ton c bng thng ca h.

- Nhiu thit b c th s dng c: Vic xem ni dung IPTV khng gii han vic dng Tivi. Khch hng c th s dng PC ca h v cc thit b di ng truy cp cc dch v IPTV.2.3. T chc hot ng

2.3.1 C s h tng ca mng IPTV

a. Trung tm d liu IPTV

Trung tm d liu IPTV nhn ni dung t nhiu ngun khc nhau, bao gm truyn hnh a phng, cc nh tp hp ni dung, nh sn xut ni dung, qua ng cp, trm s mt t hay v tinh. Ngay khi nhn c ni dung, mt s cc thnh phn phn cng khc nhau t thit b m ha v cc my ch video ti b nh tuyn IP v thit b bo mt dnh ring c s dng chun b ni dung video cho vic phn phi qua mng da trn IP. Ngoi ra, h thng qun l thu bao c yu cu qun l h s v ph thu bao ca nhng ngi s dng.

b. Mang truy cp bng thng rng

Vic truy cp cc dch v IPTV yu cu kt ni im-im(one-to-one).Vic trin khai IPTV trn din rng th s lng kt ni one-to-one s tng ln. Do , yu cu v bng thng trn mng l kh ln. Nhng tin b v cng ngh mng cho php cc nh cung cp vin thng p ng c mt s lng ln v rng bng thng ca mng. Ring mng truyn hnh cp th s dng hn hp c cp ng trc v cp quang a ng cho vic truyn ti ni dung IPTV.

c. Thit b khch hng IPTV( IPTVCD)

IPTVCD (IPTV Consumer Device) l cc thnh phn quan trng cho php ngi s dng c th truy cp dch v IPTV. IPTVCD kt ni ti mng bng rng, chng m nhim chc nng gii m, x l cc lung tn hiu ti da trn gi IP. IPTVCD c h tr cc k thut tin tin ti thiu ha hoc loi tr hon ton nh hng ca cc vn v mng khi x l ni dung IPTV. Cc loi IPTVCD ph bin nht l RG, IP set-top-box. Trong RG l modem ADSL v modem cp trn mng truyn hnh cp hai chiu HFC (Hybrid Fiber Coaxial).

d. Mng gia nh

Mng gia nh lin kt cc thit b k thut s bn trong mt khu vc c din tch nh. N ci thin thng tin v cho php chia s ti nguyn gia cc thnh vin trong gia nh. Mc ch ca mng gia nh l cung cp quyn truy cp thng tin nh l ting ni, m thanh, d liu, gii tr, gia cc thit b k thut s xung quanh nh. Vi mng gia nh, khch hng c th tit kim tin v thi gian do vic chia s cc thit b phn cng rt tt v d dng, thng qua cc kt ni Internet bng rng.

2.3.2 Cu trc chc nng cho dch v IPTV

a. Cung cp ni dungTt c ni dung c s dng bi dch v IPTV, bao gm VoD v truyn hnh qung b s phi thng qua chc nng cung cp ni dung, cc chc nng tip nhn, chuyn m v m ha s to nn cc lung video s c kh nng c phn phi qua mng IP.

b. Phn phi ni dung

Khi phn phi ni dung bao gm cc chc nng chu trch nhim v vic phn phi ni dung c m ho ti thu bao. Thng tin nhn t cc chc nng vn chuyn v iu khin IPTV s gip phn phi ni dung ti thu bao mt cch chnh xc. Chc nng phn phi ni dung s bao gm c vic lu tr cc bn copy ca ni dung tin hnh nhanh vic phn phi, cc lu tr tm thi (cache) cho VoD v cc bn ghi video c nhn. Khi chc nng thu bao lin lc vi chc nng iu khin IPTV yu cu ni dung c bit, th n s gi ti chc nng phn phi ni dung c c quyn truy cp ni dung.c. iu khin IPTV

Cc chc nng iu khin IPTV l tri tim ca dch v. Chng chu trch nhim v vic lin kt tt c cc chc nng khc v m bo dch v hot ng cp thch hp tha mn nhu cu ca khch hng. Chc nng iu khin IPTV nhn yu cu t thu bao, lin lc vi chc nng phn phi v vn chuyn ni dung m bo ni dung c phn phi ti thu bao. Mt chc nng khc ca iu khin IPTV l cung cp hng dn chng trnh in t EPG (Electronic Program Guide), EPG c thu bao s dng chn ni dung theo nhu cu. Chc nng iu khin IPTV cng s chu trch nhim v qun l quyn ni dung s DRM (Digital Rights Management) c yu cu bi thu bao c th truy cp ni dung.

d. Chc nng vn chuyn IPTV

Sau khi ni dung yu cu t thu bao c chp nhn, chc nng vn chuyn IPTV s chu trch nhim truyn ti ni dung ti thu bao, v cng thc hin truyn ngc li cc tng tc t thu bao ti chc nng iu khin IPTV.

e. Chc nng thu bao

Chc nng thu bao bao gm nhiu thnh phn v nhiu hot ng khc nhau, tt c u c s dng bi thu bao truy cp ni dung IPTV. Mt s thnh phn chu trch nhim lin lc thng tin vi chc nng truyn dn, v d nh truy cp getway kt ni vi b ghp knh truy cp ng dy thu bao s DSLAM, hay trnh STB (b gii m) s dng trnh duyt web kt ni vi Middleware server. Trong chc nng ny, STB lu tr mt s cc thnh phn quan trng nh cc key DRM v thng tin xc thc user. Khi chc nng thu bao s s dng EPG cho php khch hng la chn hp ng truy cp v yu cu n t cc chc nng iu khin IPTV. N cng nhn cc giy php s v cc key DRM truy cp ni dung.

2.3.3 Vn phn phi IPTV

Cc kiu lu lng mng IP thi gian thc khc nhau c to ra bi cc loi dch v trn nn IP khc nhau nh VoIP v truy cp Internet tc cao. Vi mi loi dch v c nhng c im ring v ni dung, v th cn phi c nhng phng thc phn phi thch hp. Hin nay c ba phng thc dng phn phi ni dung IPTV qua mng IP l unicast, broadcast v multicast. IP Unicast: c s dng truyn d liu (hay mt gi d liu) t mt my pht (sender) n mt my thu n gin. Nhc im:+ Bng thng ca mng b lng ph.

+ Dch v rt kh m rng khi s lng my thu tng ln.

+ Khng th s dng trong cc dch v b gii hn thi gian, do s cung cp n mi my thu phi theo trnh t xp hng. IP Broadcast: c s dng gi d liu t mt my pht (sender) n ton b mt mng con Subnetwork gm nhiu my thu. T lu, hu ht cc mng m rng vic s dng cc router, nhng nu truyn broadcast th khng s dng nh tuyn. y l l do lm mng v cc thit b IPTVCD khc b trn ngp khi tt c cc knh c gi ti tt c mi ngi. IP Multicast: c s dng cung cp d liu t mt my pht n mt nhm cc my thu c ci t theo mt cu hnh thng nht, cc thnh vin ca mt nhm ny c th thuc cc mng phn tn khc nhau. - Nhc im: Cc b nh tuyn trung gian (Router) cn phi c kh nng multicast.

Yu cu cao v tnh nng thit b v nng lc qun tr mng.

Vn tin cy v kh nng kim sot li truyn d liu. Cc yu cu lin quan n cc my thu: cn c card mng v phn mm h tr IP Multicast. 2.3.4 Cc k thut phn phi mng IPTV

a. Cc loi mang truy cp bng thng rngCc nh cung cp khc nhau la chn cc h thng phn phi ty thuc vo iu kin ti nguyn mng v nhu cu thc t. C bn loi mng truy cp (c dy dn) bng rng khc nhau c kh nng cung cp cc yu cu v bng thng ca dch v IPTV l:

- Mng truy cp cp quang

- Mng DSL

- Mng cp truyn hnh

- Mng Internetb. IPTV phn phi trn mng truy cp cp quang

i vi IPTV th yu cu v bng thng ln nhng chi ph hot ng phi thp v trnh c cc can nhiu. Do , ngi ta quan tm ti vic s dng mng cp quang ang c sn trin khai cc dch v IPTV. Cc lin kt cp quang cung cp cho khch hng u cui mt kt ni chuyn dng tt nht thun tin cho vic tip nhn ni dung IPTV.

- Mng quang th ng: Mng quang th ng PON (Passive Optical Network) l cng ngh mng kt ni im - a im. Mng s dng cc bc sng khc nhau truyn d liu t trung tm d liu IPTV ti cc im ch m khng c cc thnh phn in.- Mng quang tch cc: Mng quang tch cc AON (Active optical network) s dng cc thnh phn in gia trung tm d liu IPTV v u cui ngi dng. Trong thc t, cu trc mng AON s dng cc chuyn mch Ethernet t ti v tr gia trung tm d liu IPTV v im kt cui ca mng cp quang.

c. IPTV phn phi trn mng ADSL (Asymmetric Digital Subcriber Line)Bng thng l mt vn quan trng trong vic phn phi cc dch v IPTV th h mi. Mt s mng bng rng da trn DSL hin c c k tha t cc chun DSL. Ch rng DSL l cng ngh cho php cc nh cung cp vin thng phn phi cc dch v bng thng ln trn si dy cp ng ang dng ch truyn thoi. N lm bin i h tng mng cp in thoi ang tn ti gia tng i ni ht v in thoi nh khch hng thnh ng dy s tc cao. Trong mt s trng hp n khng th gi tn hiu truyn hnh cht lng chun trn mng truy cp DSL. Vic tng qu trnh thc thi c yu cu cho IPTV c th t c bng cch trin khai cc cng ngh DSL nh ADSL, ADSL2+ v VDSL.

- ADSL ng dy thu bao k thut s bt i xng ADSL l k thut trong h xDSL c s dng rng ri nht hin nay trn cc mng vin thng th gii. ADSL l cng ngh kt ni im - im, n cho php cc nh cung cp vin thng phn phi cc dch v bng thng rng trn ng dy cp ng in thoi ang tn ti. Bng vic s dng cc k thut c trng, ADSL cho php tc downstream l 8 Mbps v tc upstream l 1,5 Mbps. Bi vy, mt kt ni ADSL ch cho ng thi hai knh truyn hnh qung b theo chun MPEG-2 v mt kt ni Internet tc cao. im tr ngi chnh ca ADSL l ph thuc vo khong cch tnh t trung tm d liu ca nh cung cp ti nh khch hng. Dch v ADSL gii hn khong cch trn l 18.000ft hay 5,5km. Cc thit b ADSL cung cp mt kt ni k thut s trn mng PSTN, tuy nhin tn hiu truyn l tn hiu tng t. Cc mch ADSL phi s dng tn hiu tng t v mng mch vng ni ht (local loop) khng c kh nng truyn cc tn hiu m ha dng s.Cc thit b c s dng trin khai dch v IPTV trn mng ADSL bao gm: Modem ADSL: Ti nh thu bao c mt b thu pht ADSL hoc modem. Modem thng kt ni bng cng USB hoc giao tip Ethernet t mng gia nh hoc PC ti ng line DSL. a s modem hin nay u c tch hp chc nng nh tuyn h tr cc dch v d liu v truy cp Internet tc cao.

B lc POTS: Ngi dng c kt ni vi Internet bng kt ni bng thng rng ADSL s s dng mt thit b gi l b lc POTS lc tn hiu d liu t cc tn hiu thoi. B lc s lc tn hiu ti thnh tn hiu tn s thp a ti in thoi v tn s cao a ti mng gia nh.

DSLAM - Digital Subscriber Line Access Multiplexer: b ghp knh truy cp ng dy thu bao s. Ti mi tng i khu vc (Regional Office) ca nh cung cp dch v IPTV, DSLAM nhn cc kt ni ca thu bao trn ng dy cp ng, tp hp chng li v kt ni tr li trung tm d liu IPTV bng cp quang tc cao da trn mng ng trc. DSLAM chu trch nhim trong vic phn phi ni dung IPTV t tng i khu vc ti cc thu bao IPTV.

DSLAM c hai loi l DSLAM lp 2 v DSLAM nhn bit IP: DSLAM lp 2: Hot ng ti lp 2 trong m hnh OSI v thc hin cc chc nng nh chuyn mch lu lng gia Ethernet v ATM, chuyn tip cc lu lng mng ngc dng (up-stream) v ngn nga can nhiu gia cc thu bao IPTV. DSLAM nhn bit IP: H tr cc giao thc IP hot ng ti lp 3 trong m hnh OSI. Cc chc nng tin tin c tch hp trong cc DSLAM nhn bit IP l ti to cc knh truyn hnh qung b v knh thc hin theo lnh.

Tc d liu: Tc ti a ca ADSL l 8 Mbps ch h tr s dng tt cho hai knh truyn hnh cht lng cao v mt s lu lng Internet, tuy nhin, n s khng th p ng c cho cc nh cung cp IPTV khi phn phi cc chngtrnh ln ti thu bao ca h. Tnh tng tc: V cng ngh ADSL tc download thp hn tc upload, do vy n s hn ch trong vic cung cp cc dch v ngang hng (peer-to-peer) yu cu bng thng download v upload bng nhau. - ADSL2 Cc chun ca h ADSL2 c a ra p ng cc yu cu v bng thng, h tr cho cc ng dng yu cu bng thng ln nh IPTV. C 3 loi khc nhau ca h ADSL2: ADSL2: Bao gm mt s ci tin so vi chun ADSL gc l t tn khc, cc tc download cao hn v khong cch t tng i trung tm ti modem ca thu bao xa hn. ADSL2+: c xy dng trn ADSL2 v cho php cc nh cung cp dch v mng a ra cc tc ln ti 20 Mbps v hot ng tt trong khong 1,5 Km tnh t tng i trung tm ti modem nh thu bao.

ADSL(Reach): c gi l ADSL m rng hay vit tt l RE-ADSL2 (ADSL- Reach). RE-ADSL2 cho php cc nh cung cp dch v IPTV tng khong cch ln ti 6 Km tnh t tng i trung tm gn nht ti nh thu bao. N l cng ngh tt nht thc thi c trong gii hn v khong cch v tc trn cc si cp ng. - VDSL ng dy thu bao s tc cao VDSL (Very high speed Digital Subscriber Line) da trn nhng nguyn l c bn nh cng ngh ADSL2+. N l cng ngh DSL mi nht v phc tp nht ti thi im ny, v n c pht trin khc phc cc khuyt im ca cc phin bn cng ngh truy cp ADSL trc y. N loi tr c hin tng tht c trai v h tr kh nng tc rt ln cho php cc nh cung cp dch v iu kin a ra cho cc thu bao IPTV rt nhiu dch v la chn bao gm c VoD v truyn hnh qung b nh dng HD. VDSL cng c thit k h tr cc truyn dn ca chuyn mch ATM v lu lng IP trn cp ng.

d. IPTV phn phi trn mng truyn hnh cp

Mng HFC (hybrid fiber/coax) l mng kt hp cp quang v cp ng trc, s dng ng thi cp quang vi cp ng trc truyn v phn phi tn hiu. Vic truyn tn hiu t trung tm n cc node quang l cp quang, cn t cc node quang n thu bao l cp ng trc. Cc mng xy dng da trn k thut HFC c mt s c tnh thun li chuyn giao cho cc dch v th h mi nh sau: - Mng HFC c kh nng truyn dn ng thi c tn hiu s v tn hiu tng t. y l c tnh rt quan trng cho cc nh khai thc mng. - Mng HFC c th chung ha gia vic tng dung lng v cc yu cu tin cy ca mt h thng IPTV. c im tng c dung lng ca h thng HFC cho php cc nh khai thc mng trin khai thm cc dch v m khng cn phi thay i ton b cu trc mng. - c tnh vt l ca cp ng trc v cp quang h tr mng hot ng tc vi Gbps. e. IPTV phn phi trn mng truyn hnh cp

Do s cnh tranh v th trng kinh doanh truyn hnh thu ph t cc nh cung cp vin thng v nhng hiu qu ln v bng thng khi s dng k thut phn phi IP, dn ti cc nh khai thc mng truyn hnh cp phi hng ti s dng m hnh mng IP phn phi ni dung ti ngi dng.

Vic chuyn mt mng da trn tn s v tuyn RF (Radio Frequency) sang mng chuyn mch video s SDV (Switched Digital Video) trn nn IP, d bng cch no th vn cn phi lp t mt s thit b mi t cc router ti b gii m IP STB (Set-top box) v cc switch tc cao. Mt s u th ca vic trin khai sang mng chuyn mch SDV: Mt s lng ln bng thng ca mng s c d tr bi v nh khai thc ch nhn c yu cu pht mt knh truyn hnh n l ti b gii m STB. Bng thng d tha cho php cc nh khai thc mng cp truyn hnh c th phn phi cc dch v v ni dung IPTV ti thu bao ca h. Nhng nh khai thc mng cp truyn hnh c th o c v gim st mt cch chnh xc ni dung xem ca mi thu bao. y l mt c tnh quan trng cho cc nh khai thc mun to thm doach thu bng qung co. f. IPTV phn phi trn mng Internet

Li dng tc bng thng rng kt hp vi cc tin b trong trong k thut nn d liu v c nhiu chng trnh la chn hn cho php khch hng xem truyn hnh qung b v ni dung video theo yu cu, l l do ti sao s lng khch hng s dng Internet tng ln. IPTV trin khai trn mng Internet c th l mt trong cc dng ng dng sau.

- Cc knh truyn hnh Internet streaming

Vic phn phi cc knh truyn hnh trn Internet l mt ng dng rng ri ca IPTV, bao gm ni dung video c streaming t mt server ti cc thit b client c kh nng x l v hin th ni dung video. Cc knh truyn hnh Internet c streaming cng c th a vo in thoi di ng hoc b gii m STB. Ni dung cc knh truyn hnh Internet c streaming cng c th c phn phi theo thi gian thc v ngi xem c th xem li theo cch xem truyn thng. Qu trnh k thut streaming knh truyn hnh Internet thng bt u ti server streaming, ti ni dung video c ng vo trong cc gi IP, nn li v pht qua mng Internet ti PC client. PC c cc phn mm, thng l mt chng trnh tm duyt (browser), gii nn ni dung video v pht ra video cn sng.

Khong thi gian t lc chn knh truyn hnh ti lc xem c thng ngn v ph thuc tc kt ni c th c gia server v client. M hnh cu trc mng c s dng phn phi knh truyn hnh trn Internet nh trn hnh

Vic trin khai tt c cc knh truyn hnh Internet s yu cu mt server streaming, server ny s h tr cc chc nng sau:

Lu tr v khi phc ni dung video ngun.

iu khin tc cc gi video IP c phn phi ti thit b ca ngi xem.

Thc hin chuyn tip v chuyn ngc cc lnh yu cu t ngi xem truyn hnh Internet.

Mt server streaming n lm vic tt khi phn phi s lng t cc knh truyn hnh ti mt s thu bao c gii hn. h tr cho vic phn phi nhiu knh ti hng trm hoc hng ngn thu bao IPTV, th cn phi trin khai mt s lng ln server streaming trn cc ng mng khc nhau.

Cng vic streaming ni dung video hu ht u cn phi bo mt v ni dung khng c lu tr trn thit b truy cp ca khch hng. V th, vic sao chp ni dung tri php cn phi c ngn chn. Mt li th khc ca IPTV l kh nng hot ng hiu qu trn cc kt ni c bng thng thp v ngi xem c kh nng bt u xem ni dung ti mi im trong lung IPTV.

- Download InternetNh tn gi, IPTV cho php khch hng download v xem ni dung theo yu cu. Hu ht cc dch v download Internet u phi tr tin hoc tr theo dung lng download, cc dch v bao gm tin tc ni b v bn tin thi tit, phim in nh, phim ni b v m nhc, ch dn gii tr v cc qung co c phn loi. Mt s v tr cng Internet trc tuyn gn y bt u tin hnh a ra cc th vin ni dung chng trnh IPTV c th download cho ngi s dng Internet. Trong hu ht cc trng hp, mi ngi u s dng PC xem cc chng trnh download, tuy nhin, mt s cng ty bt u cung cp thit b gii m STB cho nhng khch hng khng mun xem trn PC. Mt s c im ca cng ngh IPTV end-to-end da trn cc dch v download Internet:

Cc giao thc mng: Chun giao thc truyn tp tin FTP v giao thc truyn siu vn bn HTTP thng c s dng truyn ni dung IPTV t server ti client. Vic s dng cc giao thc trn gim thiu kh nng ni dung IPTV b ngn chn bi firewall.

Cng ngh server: Chun phn mm Web server thng c s dng p ng cc yu cu v ni dung video.

Tc mng: Thi gian download mt b phim trn Internet ph thuc vo tc ca kt ni bng rng v cht lng ni dung video. Cc b phim in nh nh dng SD v cc chng trnh download tng i nhanh so vi ni dung video dng HD.

Cc nhu cu v lu tr: C server v client u yu cu kh nng lu tr tin tin h tr x l cc tp tin IPTV ln. Mt s ng dng ca download Internet cho php cc thu bao IPTV ghi li mt bn copy ni dung video c download vo a DVD v xem bng u DVD.

- Chia s video ngang hng

ng dng chia s video ngang hng (peer-to-peer) cho php nhiu user xem, chia s v to ni dung video trc truyn. Vic s dng ng dng chia s video peer-to-peer khng phc tp v n thng l download v ci t mt s phn mm chuyn dng. Khi phn mm hot ng c trn PC, ngi dng ch cn click vo cc link download mt file video. Khi tin trnh download bt u, phn mm ng dng chia s video peer-to-peer c thit lp cc kt ni v bt u ly ni dung video c yu cu t cc ngun khc nhau. Khi file video c download v ghi y vo cng th c th xem ni dung.2.4. Qun l mng IPTV2.4.1 H thng qun l mang IPTV gim thiu ri ro v s c v mng, cc nh khai thc s dng h thng qun l mng NMS (Network Managerment System) gim st cu trc mng IPTV end-to-end.

Cc chc nng c thc thi bi h thng qun l IPTV c th bao gm: - Quan st mng 24/7: Mt h thng qun l mng NMS bao gm cc bn hin th thng tin cc tnh trng ca mt s thnh phn mng nh: Cc thit b v server trung tm d liu IPTV.

Cc thit b mng li IP. Cc thit b mng truy cp.

Thit b khch hng IPTV. Cc mng gia nh.

- Ti u ha mng: NMS gip qu trnh ti u ha ti nguyn mng, h tr tng kh nng tch hp cc dch v da trn nn mng IP. H tr nhn vin k thut: NMS tp hp cc bn tin li t cc thnh phn h thng IPTV end-to-end h tr nhn vin k thut nhn bit nhanh v gii quyt cc s c c th xy ra hng ngy trn mng IPTV.

Bo co: NMS tp hp cc trng thi ca cc thnh phn c bn ca mng thnh mt bo co h thng cho php ngi qun l mng IPTV: Theo di v nh gi cc on t qung ca dch v IPTV. Kim tra sc khe ca cc thnh phn mng. Nhn dng cc vn tim tng trn mng thng qua phn tch chiu hng d liu. Ghi nhn vic s dng mng trong cc giai on c bit ch .

- Minh ha cc thnh phn mng bng th: Cc giao din trc gic c trng cung cp mt th hoc bn cc trng thi c th xy ra i vi cc thnh phn h tng mng IPTV end-to-end.- Qun l cc li ca server trung tm: Cc server IPTV gi vai tr chin lc v cng quan trng trong mng truyn hnh bng rng. NMS h tr vic gim st server bng cch gi cc thng bo cnh bo v cc s c ti nhn vin k thut.- Qun l cu hnh: NMS s lu tr cc mc thng tin cu hnh ca mi thit b c kt ni vo mng IPTV trong c s d liu. Cc dng thng tin ny c th l a ch IP hay cc phin bn Middleware ca mi thit b gii m STB. NMS cho php nhn vin k thut thay i cc tham s trn.

- Qun l bng thng: IPTV l mt ng dng tn bng thng. NMS cho php cc nh cung cp dch v gi quyn iu khin cht ch vic s dng bng thng mng v ti u ha mng ca h cho cc ng dng trn nn IPTV.

- u tin ha lu lng: IPTV l ng dng nhy vi tr. ci thin cht lng dch v c phn phi ti user u cui, NMS cho php cc nh cung cp dch v u tin ha ni dung video trn cc ng dng khng nhy vi tr nh ng dng tm kim trn Internet v lu lng cc ng dng ngang hng.

- Qun l cc nht k mng: y l chc nng chu trch nhim ghi v lu tr nht k ca cc s kin xut hin trong thi gian hot ng ca mng IPTV. Thng tin nht k c lu tr gia cc NMS khc nhau, bao gm: Cc chi tit login v logout ca cc user IPTV.

Cc chi tit thay i cu hnh ca h thng v thit b IPTVCD. Cc chi tit hot ng ca thit b mng. 2.4.2 Qun l ci t

Vic ci t mng IPTV c th bao gm rt nhiu cng vic khc nhau, trong phn ny trnh by mt s ci t chung nh sau: - Phn phi a ch: Trong thc t, cc ngun video c c nh cc a ch IP, v th cc thit b IPTVCD c th xc nh chng. Vic phn phi a ch IP c ni r hn trong phn tip theo. - Ci t ngun video: y l cng vic thc hin sm nht trong tin trnh ci t v th cc thit b c th c kim tra vi video thc khi chng c ci t. Cc ngun multicast thng cn bng thng thp hn so vi cc ngun unicast gi bn sao lung video ti mi thit b ngi xem. - Ci t cc phn mm client: Hu ht cc phn mm media player mt ph u t ci t, v hu ht cc PC c kh nng ci bng tay cc chng trnh ny. - Ci t cc phn cng client: Khi cc b gii m IP-STB hoc cc thit b client c ci t, mt s nh cung cp dch v quyt nh a nhn vin k thut ti nh khc hng. iu ny cho php cc cng vic kim tra mng c thc hin y v cc h tr khc c ci t chnh xc.

- Cu hnh multicast: Nu phng thc multicast c s dng trong IPTV, mt phn ca tin trnh ci t phi kim tra li tt c cc thit b mng c kh nng to lung multicast. Tin trnh ny c th yu cu phn mm hoc cc chng trnh nng cp phn cng trong cc thit b mng, v d nh cc router. - Cu hnh h tng h thng qun l mng: Mt ci tin ln ca cc mng IPTV trn nn IP l cc mng vt l ging nhau c th c s dng gi v nhn cc lnh qun l mng v truyn dn video, vi iu kin l c cung cp kh nng thng tin hai chiu (two-way).

- Qun l vic di di v lp t li thit b: Mi ln cc thit b c di di hoc lp t li th cn phi cu hnh li h thng m bo khng c cc thng bo li v v tr vt l ca thit b. 2.4.3 Gim st thc thi v kim tra mngThng thng, vic gim st l trch nhim c thc hin bi nhiu thnh phn. u tin cc thit b s thu thp s liu v cc hot ng ca chnh bn thn mi thit b, v h thng qun l tp trung s bin dch cc d liu ny phn tch nh k. Trong mt s h thng, d liu c lu tr trn mi thit b v ch c s dng khi nhn vin k thut h thng quyt nh nhn n. Sau , b x l tp trung s phn tch d liu liu ti v thng bo cho nhn vin k thut khi thit b li. Mt s dng d liu c thu thp v phn tch bi h thng gim st thc thi nh sau: - Li bit: Mt s loi mng bao gm mt byte kim tra tng hoc kim tra chn l s ch ra cc bit hoc cc gi tin b thay i. - Cc gi mt: Trong trng hp nghn mng, mt s thit b s khng gi c ht s gi, v th lung tn hiu s b mt cc gi . Thng qua vic gim st s lng gi b mt ti cc v tr khc nhau trong mng, cc nh khai thc mng s xc nh c dung lng cn tng ln, s lng router cn xy dng thm cho dch v hoc cc lin kt cn phi c bo dng. - Cc trng thi ca thu bao: Tt c cc loi d liu thu thp v thu bao c phn tch xc nh xem c vn g xy ra vi cc kt ni t pha thu bao hay khng, t sm pht cnh bo v cc s c trn mng. - Cc hot ng ng nhp ca user : D liu ny c th ch ra cc user ang gp s c khi truy cp h thng hoc user gian ln v quyn truy cp, v d nh c nhiu user ging nhau truy cp vo h thng ti nhiu v tr khc nhau trong cng mt thi im. - Gim st h thng bo an: Thng qua vic thu thp d liu v qu trnh thc thi ca h thng bo an, cc nh khai thc c th xc nh cc firewall ang lm vic chnh xc, cc ngun tn cng mng t bn trong hoc bn ngoi, cung cp cc cnh bo v virus. Thng tin ny cng c th c s dng sau khi mt l thng bo an c xc nh tm ra cch ngn nga cc s c bo an trong tng lai. Vic gim st cht ch mng IPTV s c mt s li ch sau: - Cho php cc nh qun l mng nhn ra cc kiu lu lng mng, t cho bit s t qung hoc s gim st cht lng hnh nh sp xy ra. Vic pht hin ra cc vn tim tng lm gim bt kh nng xy ra cc on t qung ln hoc gim st t ngt cht lng video. - Sa cha ngay lp tc s t qung mng d l nh nht. - Mang n cho nhm k thut kh nng c tnh phm vi s c mng khi n xut hin. Cp nguy him ca s c s ra lnh cho cc ti nguyn no c s dng xc nh v tr s c. V d, nu s c gim st nh trong cht lng tn hiu video th chin lc sa cha s c s khc so vi cc li ca server VoD ti trung tm d liu IPTV.

m bo cc user IPTV xem c cht lng cao, c th tin hnh mt s kim tra cc thnh phn mng IPTV nh sau: - Thit b truy cp: Thng tin hnh kim tra cc thnh phn phn cng v phn mm c ci t gn nht, cc user IPTV c th c xem vi cht lng nh mong i v ti u ha vic phn phi cc dch v IPTV a im v n im. Cc ni dung tin hnh kim tra bao gm: Kim tra tc d liu di chuyn trong mng thit b truy cp thu bao. nh gi cc li v cc vn thc thi xut hin do giao thc IP, cc lp ng gi v vn chuyn video ca m hnh thng tin IPTV. - Mng li IP: Thng tin hnh kim tra tt c phn mm v phn cng c s dng phn phi cc dch v IPTV. Cc thng s cu hnh mng c th lun thay i, khi c nh hng ti cc lung IPTV c phn phi. V th cc nh qun l mng phi tin hnh kim tra nh k cc cp thc thi lung thng tin khi c s thay i xut hin trn mng. Cc thay i c th xut pht t vic mng c thm mt switch hay c s thay i firmware ca cc thit b.

- Thit b trung tm d liu IPTV: Cc thit b khc nhau c ci t ti trung tm d liu IPTV cn c kim tra y m bo n c kh nng phn phi nhiu dch v IPTV ti s lng ln thit b IPTVCD mt cch chc chn v hiu sut cao. K hoch kim tra cng cn thc hin thng xuyn trn ni dung cung cp bi cc nh cung cp ni dung m bo t c cc cp cht lng vi cc thng s tha thun. - Thit b IPTVCD: Kim tra cc thit b IPTVCD bit cc thit b IPTVCD no c s dng cung cp cho user truy cp cc dch v. Cc loi kim tra tin hnh trn thit b IPTVCD c th thay i theo cc knh c yu cu bi ngi xem, cc knh ny c iu khin t xa, l cc knh thc t nhn c m bo thi gian thay i knh khi s lng thu bao kt ni ti cc server IPTV ln. 2.4.4 Qun l v d phng

Dch v IPTV c cc yu cu v kh dng v tin cy. ngn nga cc hin tng lm t qung vic cung cp dch v th cc thit b mng v thit b trung tm d liu IPTV cn c h tr vic thay th nhanh chng cc thit b gp s c. Thi gian cn thit thay th s ch l vi giy m bo s c khng nh hng ti dch v. Cc cp d phng ca phn cng v phn mm i khi c cc nh cung cp dng gim thiu nh hng ca vic t qung dch v ln cc thu bao IPTV. Cc cp d phng c xy dng khi thit k mng IPTV s ph thuc vo loi dch v IPTV c trin khai trn mng. Cc h thng bo dng tinh vi thng c cc nh cung cp s dng theo di cc hot ng bo dng hng ngy v hng tun. Ngoi cc hot ng bo dng theo di, h thng ny cng duy tr cc chi tit d phng sn sng cho php cc nh qun l mng IPTV phn tch v ln k hoch bo dng trong tng lai. 2.4.5 Qun l khng gian a ch IP

Vic phn phi cc a ch IP s lun l vn vi cc mng c thit k truyn ti dch v. V d, trong mi trng triple-play n c th cu hnh cc IP subnet khc nhau cho mi dch v voice, truy cp Internet v IPTV. N cng c kh nng thit k mt lc a ch IP h tr vic chia s cc thit b h tng mng nh qun l DSN, OSS v cc DHCP server cho tt c cc dch v. Mt khi lc a ch IP c cu hnh trn cc thit b c chia s, th n c th chia IP subnet hoc pool a ch cho cc ti nguyn mng phn phi dch v triple-play.

V d, VoD server v IP-STB ti nh thu bao u c cu hnh nh l mt phn ca subnet dch v IPTV. Vic phn phi a ch IP trong mng IPTV l trch nhim ca DHCP server. DHCP l chc nng c yu cu trong mt s cng ty mng v cc nh cung cp dch v Internet ISP (Internet Service Provider). Vi DHCP, mt my tnh ch s dng duy nht mt a ch IP truy cp Internet. DHCP cng c tc dng khi ng dng trong mng IPTV. s dng DHCP, mi thit b IPTVCD phi tm DHCP server trong mng bng cch pht broadcast mt yu cu ti tt c cc thit b. Khi DHCP server nhn c yu cu, n s chn mt a ch IP ang sn sng c s dng v gi tr li thit b IPTVCD yu cu. DHCP cung cp cho cc nh qun l mng IPTV mt s thun li sau: Bng vic s dng DHCP, tt c cc chi tit cu hnh cn thit cho IPTVCD c b tr trc m khng cn user c bit v cc chi tit khng. Khng cn phi cu hnh cho mi thit b mt a ch IP c nh.

DHCP tp trung ha vic qun l a ch IP. Vic ci t DHCP server t ng phn phi cc a ch IP cho cc thit b trn mng IPTV thng khng phc tp. DHCP c th nh r mt dy a ch IP sn sng c dng cho tng vng ring bit. C th tch hp DHCP v OSS h tr vic cung cp cc dch v IPTV mi. 2.4.6 X l cc s c

Cc nh cung cp dch v IPTV pht trin cc h thng tinh vi tp hp cc bn tin li t thit b IPTVCD v s dng thng tin x l cc s c c th xut hin trn dch v IPTV. Cc s c thng thng bao gm cc vn v b nh m, cc trc trc v phn cng v li phn mm. Khi vng s c c nhn bit giai on tip theo l gii quyt s c, c th bao gm cc hnh ng sau: Thay i cu hnh ci cho thit b IPTVCD.

Thng bo qua in thoi cc s c xy ra cho ngi s dng v cung cp cc lnh gii quyt s c.

Cng c th s dng e-mail b sung thng tin v cc lnh.

Khi cc s c khng gii quyt c qua in thoi th nhn vin k thut bt buc phi ti nh khch hng. V cui cng khng gii quyt s c bng cc hnh ng trn ta nh phi thay th thit b mi. Mng trong nh khch hng: Cc s c nh ng i dy trong nh b hng, cp km cht lng, virus, ci t a ch IP khng ng v driver khng ph hp tt c u c th tc ng ti dch v IPTV. H thng qun l t xa kt hp vi in thoi hoc e-mail h tr thng c s dng x l cc s c xut hin trn mng trong nh khch hng.Nh cung cp ni dung bn ngoi: Vic tip nhn ni dung l nhng video c m ha km cht lng to nn cc s c v truyn dn. Khi s c c nhn bit nh cung cp th 3 ny cn c thng bo v x l s c. 2.4.7 Qun l quyn ni dung s

Qun l quyn ni dung s DRM (Digital Right Management) l mt tp hp cc nh ngha v cc c ch c s dng iu khin truy cp ni dung thng qua vic mt m hoc cc phng php khc. DRM lun lun l mt yu cu s dng trong vic cung cp ni dung video thi gian gn y trn h thng phn phi IPTV cng nh h thng truyn hnh cp v truyn hnh v tinh. Cc chnh sch DRM c th rt cht ch hoc cng c th rt bung lng; quyn s hu ni dung xc nh cc chnh sch kim sot. Mt khi cc chnh sch ny c xc nh, trch nhim ca h thng DRM l lm cho cc chnh sch ny c hiu lc.Trong h thng DRM thc t cho h thng VoD, quyn s hu ni dung c hai nhim v. u tin, ni dung phi c phn phi ti mt server m bo, ni dung c th c truy cp da trn cc yu cu ca ngi xem. Th hai, cc quy nh cho ngi xem phi c nh r. V d, ngi xem tr mt gi ch c th xem ni dung ca mt lung, ngc li th c mt s ngi c th download ni dung v xem n trong mt khong thi gian no . H thng DRM lm cc quy nh c hiu lc i vi quyn s hu ni dung, n cn c cp nht nhng ngi tham gia vo v ri khi h thng. H thng DRM chu trch nhim m bo chc chn ngi xem tr tin cho ni dung m h yu cu. Ch rng, DRM cng c th c s dng cho ni dung min ph, bo v ni dung trnh vic sao chp v bn li khng c xc thc. 2.4.8 Qun l cht lng dch v

Cht lng dch v QoS(Quality of Service) l tp hp cc ch tiu c trng cho yu cu ca tng loi lu lng c th trn mng bao gm: tr jitter, t l mt gi Cc ch tiu ny lin quan n lng bng thng dnh cho mng. vic ng b tn hiu c th thc hin c mng buc phi c qun l cht ch v cht lng dch v. thc hin c vic qun l cht lng dch v cn thit phi c: Chnh sch m bo cht lng dch v (QoS policy). Cc c ch m bo cht lng dch v ti cc nt mng: Cc thut ton xp hng (queuing), c ch nh hnh lu lng (traffic shapping), cc c ch ti u ha ng truyn, cc thut ton d on v trnh tc nghn Phng thc bo hiu QoS. Chnh sch QoS c vch ra mong mun thc hin v qun l cht lng dch v theo k hoch c th v thng qua h thng bo hiu QoS ra lnh cho cc c ch chp hnh ti cc nt mng thc hin nhim v . 3. SO SNH GIA IPTV V VOD

V tng quan, theo nh ngha: IPTV c nh ngha l cc dch v a phng tin nh truyn hnh/video/audio/vn bn/ ha/s liu truyn ti trn cc mng da trn IP c kim sot nhm cung cp mc cht lng dch v, mn nguyn, bo mt v tin cy theo yu cu, th Vod l mt dch v trong IPTV. Song trn thc t ngy nay, cng ngh truyn hnh pht trin nhanh chng, cc nh cung cp dch v trong nc nh VNPT, FPT, Viettell, SCTV cung cp nhiu gi dch v truyn hnh vi tn gi l Vod (ch khng phi l IPTV) vi hng trm knh. Vy gia IPTV v Vod c g khc v ging nhau?

3.2. Nhng im chung Chng ta thy c IPTV v Vod u l truyn hnh trn giao thc Internet, Telco TV hay truyn hnh bng rng, vi ngha truyn ti truyn hnh qung b v/hoc video theo yu cu, chng trnh pht thanh c cht lng cao trn mng bng rng. Cc nh cung cp u xy dng h tng trn c s mng truyn dn sn c ca mnh.

Tng tnh c nhn c IPTV v Vod t u cui-n-u cui h tr thng tin hai chiu v cho php cc i tng s dng la chn v thit lp vic xem TV theo s thch ring nh chng trnh v thi gian xem a thch.

Yu cu v bng thng thp - Thay v phi truyn ti tt c cc knh cho mi i tng s dng, cng ngh da trn giao thc internet cho php cc nh cung cp dch v ch cn phi pht cc knh m i tng s dng yu cu. Tnh nng hp dn ny cho php nh khai thc mng tit kim bng thng.

3.3. Nhng im khc nhau

Kh nng truy nhp trn nhiu loi thit b: Vic xem ni dung IPTV khng b gii hn l dng cho cc my thu hnh. Cc khch hng thng s dng my tnh c nhn v cc thit b di ng truy cp ti cc dch v IPTV. Cn vi Vod, khch hng ch xem c video trn my thu hnh.

Khng ph thuc thi gian: Vi kho video khng l, khch hng c th yu cu xem bt c thi gian no, c th tua tin, li ni dung mnh ang xem. C th kt hp vi my thu video s cho php to chng trnh ni dung khng ph thuc thi gian bng c ch ghi v lu li ni dung v sau c th xem li. Trong khi , IPTV chy vi thi gian thc. IPTV cng c th lu li c ni dung mong mun nhng thi lng ngn v thi gian lu hn ch.

H tr truyn hnh tng tc: Cc kh nng hot ng hai chiu ca h thng IPTV cho php nh cung cp dch v a ra mt s lng ln cc ng dng truyn hnh tng tc. Cc loi hnh dch v c phn phi qua dch v IPTV c th bao gm truyn hnh trc tip tiu chun, truyn hnh trung thc cao (HDTV), cc tr chi trc tuyn, v kt ni internet tc cao. Ngi dng cng c th gi mail, chat, download d liu trong khi vn xem truyn hnh. Cn Vod ch gii hn bi gi video theo yu cu.

3.4. Tm li, so vi VOD (video theo yu cu) IPTV c cc u th

S dng d dng, hin th trn tivi hiu qu cao hn mn my vi tnh, thao tc trn hp ghp ni + bn phm n gin, thc hin chuyn i nhanh lung cao tc/chng trnh.

D qun l, d khng ch, s dng hp kt ni lm u cui nh cung cp dch v tin hnh nh ch i vi hp kt ni khng cn n nghip v an ton v kim tra cht lng. y cng l c s k thut d thu ph. IPTV c th thc hin cc dch v multimedia. Cn c vo s la chn ca ngi dng, IPTV cung cp rt nhiu loi hnh dch v. S dng hp kt ni vi tivi, ch nhn ngi trc my n phm iu khin c th xem cc tit mc video ang hot ng, thc hin m thoi IP c hnh, nghe m nhc, tra tm tin tc du lch trn mng, gi v nhn e-mail, thc hin mua sm gia nh, giao dch tri phiu... Nh IPTV cht lng sinh hot gia nh c ci thin rt nhiu.4. NG DNG

4.2. Kh nng ng dng ca IPTV Vit Nam

Vi mng bng hp truyn thng, ch mt s dch v n gin ca IPTV l c th thc hin c. Cn c th trin khai thnh cng dch v IPTV th mng bng rng ng vai tr tin quyt, bi v ch vi mng bng rng mi c th bo m cung cp y bng thng theo yu cu cho cc dch v IPTV (nh truyn hnh, Video, Games v.v).

Cho n nay, th trng bng rng ti Vit Nam ang trong giai on pht trin, bng n nhu cu v cn rt nhiu tim nng. S lng thu bao bng rng ca Vit Nam c hng triu thu bao (trn 60% th s thu bao internet vi s tham gia ca cc nh cung cp dch v VNPT, FPT Telecom, Viettel, SPT, EVN telecom D kin trong nhng nm ti tip ni di ng, internet bng rng cng s pht trin rm r, khng ch tp trung thnh th m cn cc a phng trong huyn. ng thi vi vic trin khai cc cng ngh hu tuyn xDSL/PON v cng ngh v tuyn bng rng (Wifi/WiMAX. CDMA) ca cc nh cung cp dch v Vit Nam, th IPTV li cng c c hi pht trin mnh v bo m cho s thnh cng ca loi hnh dch r mi ny.

Hin nay trn trn th trng c hai n v cung cp dch v IPTV l VNPT v FPT vi cht lng cao v ang dn tr thnh mt xu th mi cnh tranh v cht lng v dch v. Dch v IPTV c FPT trin khai trn ton b khu vc c mng internet ca mnh, cn VNPT trin khai trn ton quc.

Vic chuyn i cu trc mng li t chuyn mch knh truyn thng theo thi gian sang mng NGN vi cng ngh chuyn mch gi l mt s chuyn i mnh m v cng ngh, ph hp vi xu th pht trin chung ca cc nc pht trin trn th gii. Do vy, cc nh cung cp dch v ca Vit Nam chn NGN lm bc pht trin tip theo trong vic tm kim cc gii php pht trin mng. Mng NGN s cho php trin khai cc dch v a dng vi gi thnh thp, gim thiu thi gian a dch v mi ra th trng, gim chi ph khai thc mng v dch v, ng thi nng cao hiu qu u t v to ngun doanh thu mi ngoi doanh thu t cc dch v truyn thng. NGN cho php tng cng kh nng kim sot, bo mt thng tin v tin cy trong khi gim thiu c chi ph vn hnh. NGN c xy dng trn tiu ch m, cc giao thc chun v giao din thn thin. NGN thng nht mang hu tuyn truyn thng v chun truyn ti m thanh, hnh nh, d liu khng dy.

4.3. Nhng yu m ca IPTV

Ngoi nhng li ch m dch v IPTV mang li, dch v ny cng cn tn ti mt s yu im sau:

V k thut: Do IPTV yu cu truyn ni dung theo thi gian thc v s dng Internet Protocol, n s d b mt gi tin hay tr. Nu kt ni IPTV khng nhanh, vic mt hay v hnh c th xy ra.

Bng thng cn b hn ch, do ng truyn cha m bo, chi ph lp t ban u l kh cao. Mt khc do mi khai thc dch v nn cc ng dng cha c p ng c nhiu nhu cu, cc chng trnh cha c phong ph, tnh tng tc cha cao.KT LUNXt trn kha cnh cng ngh, xu hng cng ngh hin nay l s hi t ca nhiu cng ngh a ra nhng loi hnh dch v tng hp (nh kt hp cc dch v thoi, s liu v bng rng) cho khch hng, ng thi tn dng c nhng c s h tng sn c gim thiu chi ph u t nng cp. Dch v IPTV chnh l mt sn phm ca s hi t khi m ch vi mt thit b u cui khch hng c th s dng rt nhiu cc loi hnh dch v con (truyn hnh qung b, truyn hnh theo yu cu, in thoi thng thng, in thoi IP, in thoi truyn hnh, truy cp internet).

Hn na vic p dng cng ngh trin khai nhng dch v vi cc chi ph nh, ti u ha h tng vin thng sn c s tng sc cnh tranh. Trong thi k kinh t th trng, khi Vit Nam ang dn hi nhp vi th gii, nhng dch v c cht lng cao, gi thnh ph hp vi i sng ngi dn s ngy mt tr thnh mt phn thit yu ca x hi. Vi nhiu tin ch mang li da trn h tng sn c, trong tng lai IPTV s ngy mt ph bin hn, cc dch v v chng trnh ngy mt phong ph hn, p ng nhu cu ca khch hng, gp phn thc y pht trin x hi.

ng thi c th khng nh vi h tng mng truy nhp hu tuyn v v tuyn bng rng trn c s mng NGN hin i m cc nh khai thc cung cp dch v ca Vit Nam v ang hng ti xy dng th vic trin khai dch v IPTV l hp l v kh nng bo m p ng yu cu trin khai dch v ny l hon ton kh thi./.