IPTV u CG

[zanzibar]

Sve se vise prica o IPTV...najavljuju je iz naseg dragog T-coma...

interesuje me vase misljenje:

treba li posebna licenca za IPTV?
usvakom slucaju jeste distribucija TV signala...doduse drugom tehnologijom...vec se uveliko spore oko toga...

i hoce li T-Com uspjeti da pruzi kvalitetan servis?
ukoliko se ne varam, potrebne su znacajno vece brzine ADSL-a od postojecih...morace se ici ka ADSL2(+)...ako krenu kao sa ADSL-om na pocetku bice veselo...

[Don_Sharky]

ukoliko se ne varam, potrebne su znacajno vece brzine ADSL-a od postojecih...morace se ici ka ADSL2(+)...ako krenu kao sa ADSL-om na pocetku bice veselo...

Pogledaj ovo: http://www.hrt.hr/hdtv/video/20.zip
tako hdtv treba da "izgleda". Znaci: oko 20 MB za 10 sekundi snimka ili 2MB po sekundi. Sa xl paketom za prebacivanje 2MB je potrebno 8 sekundi ako se ne varam. Tako da bi trebala 8puta brza veza za hdtv, ne? ADSL2 ide do 12mbps sto bi znacilo da je potreban ADSL2+ (do 24)

[zanzibar]

koliko se sjecam, a mogu provjeriti potrebno je 6MB/s za TV...

znaci bez ADSL2(+) vrlo tesko, ili nemoguce je izvesti IPTV..sto znaci nove DSLAN-ove koliko ja znam...

sad zamislite situaciju, narucite film, uredno ce vam to naplatiti...i u trenutku gledanja filma zagrmi...malo zabudali ADSL...sto je sada redovno...i sta onda?

[Don_Sharky]

da, moze se kvalitet smanjiti da je moze opsluzivati i ovaj xl paket ali za hd je potrebno 16 (uz pretpostavku da je kompresija koju koristi hrt standard u svijetu)

[Sale]

X/XL/XXL i ostali paketi nemaju veze sa IPTV

[Maveric]

da, moze se kvalitet smanjiti da je moze opsluzivati i ovaj xl paket ali za hd je potrebno 16 (uz pretpostavku da je kompresija koju koristi hrt standard u svijetu)

Niko ni ne pominje da ce da uvedu HD. Vjervatno ce za kompresiju koristiiti MPEG-2

Za HDTV trebaju izmedju ostalog i drugi risiveri koji su skuplji tako da za jedno vrijeme to nam vjerovatno nece ponudit.

[Jocker]

How it works

First things first: the venerable set-top box, on its way out in the cable world, will make a resurgence in IPTV systems. The box will connect to the home DSL line and is responsible for reassembling the packets into a coherent video stream and then decoding the contents. Your computer could do the same job, but most people still don't have an always-on PC sitting beside the TV, so the box will make a comeback. Where will the box pull its picture from? To answer that question, let's start at the source.

Most video enters the system at the telco's national headend, where network feeds are pulled from satellites and encoded if necessary (often in MPEG-2, though H.264 and Windows Media are also possibilities). The video stream is broken up into IP packets and dumped into the telco's core network, which is a massive IP network that handles all sorts of other traffic (data, voice, etc.) in addition to the video. Here the advantages of owning the entire network from stem to stern (as the telcos do) really come into play, since quality of service (QoS) tools can prioritize the video traffic to prevent delay or fragmentation of the signal. Without control of the network, this would be dicey, since QoS requests are not often recognized between operators. With end-to-end control, the telcos can guarantee enough bandwidth for their signal at all times, which is key to providing the "just works" reliability consumers have come to expect from their television sets.

The video streams are received by a local office, which has the job of getting them out to the folks on the couch. This office is the place that local content (such as TV stations, advertising, and video on demand) is added to the mix, but it's also the spot where the IPTV middleware is housed. This software stack handles user authentication, channel change requests, billing, VoD requests, etc.—basically, all of the boring but necessary infrastructure.

All the channels in the lineup are multicast from the national headend to local offices at the same time, but at the local office, a bottleneck becomes apparent. That bottleneck is the local DSL loop, which has nowhere near the capacity to stream all of the channels at once. Cable systems can do this, since their bandwidth can be in the neighborhood of 4.5Gbps, but even the newest ADSL2+ technology tops out at around 25Mbps (and this speed drops quickly as distance from the DSLAM [DSL Access Multiplier] grows).

So how do you send hundreds of channels out to an IPTV subscriber with a DSL line? Simple: you only send a few at a time. When a user changes the channel on their set-top box, the box does not "tune" a channel like a cable system. (There is in fact no such thing as "tuning" anymore—the box is simply an IP receiver.) What happens instead is that the box switches channels by using the IP Group Membership Protocol (IGMP) v2 to join a new multicast group. When the local office receives this request, it checks to make sure that the user is authorized to view the new channel, then directs the routers in the local office to add that particular user to the channel's distribution list. In this way, only signals that are currently being watched are actually being sent from the local office to the DSLAM and on to the user.

No matter how well-designed a network may be or how rigorous its QoS controls are, there is always the possibility of errors creeping into the video stream. For unicast streams, this is less of an issue; the set-top box can simply request that the server resend lost or corrupted packets. With multicast streams, it is much more important to ensure that the network is well-engineered from beginning to end, as the user's set-top box only subscribes to the stream—it can make no requests for additional information. To overcome this problem, multicast streams incorporate a variety of error correction measures such as forward error correction (FEC), in which redundant packets are transmitted as part of the stream. Again, this is a case where owning the entire network is important since it allows a company to do everything in its power to guarantee the safe delivery of streams from one end of the network to the other without relying on third parties or the public Internet.

Though multicast technology provides the answer to the problem of pumping the same content out to millions of subscribers at the same time, it does not help with features such as video on demand, which require a unique stream to the user's home. To support VoD and other services, the local office can also generate a unicast stream that targets a particular home and draws from the content on the local VoD server. This stream is typically controlled by the Real Time Streaming Protocol (RTSP), which enables DVD-style control over a multimedia stream and allows users to play, pause, and stop the program they are watching.

The actual number of simultaneous video streams sent from the local office to the consumer varies by network, but is rarely more than four. The reason is bandwidth. A Windows Media-encoded stream, for instance, takes up 1.0 to 1.5Mbps for SDTV, which is no problem; ten channels could be sent at once with bandwidth left over for voice and data. But when HDTV enters the picture, it's a different story, and the 20-25Mbps capacity of the line gets eaten up fast. At 1080i, HDTV bit rates using Windows Media are in the 7 to 8 Mbps range (rates for H.264 are similar). A quick calculation tells you that a couple of channels are all that can be supported.

The bandwidth situation is even worse when you consider MPEG-2, which has lower compression ratios. MPEG-2 streams will require almost twice the space (3.5 Mbps for SDTV, 18-20 Mbps for HDTV), and the increased compression found in the newer codecs is one reason that AT&T will not use MPEG-2 in the rollout of its IPTV service dubbed "U-verse."

Simultaneous delivery of channels is necessary to keep IPTV competitive with cable. Obviously, multiple streams are needed to support picture-in-picture, but they're also needed by DVRs, which can record one show while a user is watching another. For IPTV to become a viable whole-house solution, it will also need to support enough simultaneous channels to allow televisions in different rooms to display different content, and juggling resulting bandwidth issues is one of the trickiest parts of implementing an IPTV network that will be attractive to consumers.

[Don_Sharky]

X/XL/XXL i ostali paketi nemaju veze sa IPTV

vjerovatno ce iskoristiti svoju t magiju i uvesti ga preko nekog jos nama neznanog servisa?

@Maveric
...tako da za jedno vrijeme to nam vjerovatno nece ponudit.

slazem se

[Iggy]

vjerovatno ce iskoristiti svoju t magiju i uvesti ga preko nekog jos nama neznanog servisa?


slazem se

ADSL podrzava brzine prenosa do 8mbps, i nezavisno od Internet paketa koji koristis, njima ostaje "slobodno" jos 6mbps za IPTV. Naravno, kroz ovo se ne moze provuci HDTV

Testovi za ADSL2+ su vec odradjeni po opstinama, tako da je to priprema terena za HDTV.

Ocigledno da ce im trebati licenca za distribuciju TV kanala, jer tu oblast pokriva ARD (Agencija za RadioDifuziju) a ne Agencija za Telekomunikacije, na ciju se oni licencu pozivaju.

Ako ARD zadrzi cvrst stav, bojim se da ce T-Com morati da saceka sledeci tender za KDS i MMDS, ili ce ponuditi toliko jaku cifru za licencu da ce im je ovi izdati preko reda

[Jocker]

Ako ARD zadrzi cvrst stav, bojim se da ce T-Com morati da saceka sledeci tender za KDS i MMDS, ili ce ponuditi toliko jaku cifru za licencu da ce im je ovi izdati preko reda

Ili će se utalit da T-com nastavi da naplaćuje radio-difuznu pretplatu, koju prema ugovoru od 30. juna više nije obavezan da naplaćuje, u zamjenu za žmirkanje na jedno oko.

Ustvari, ako malo bolje razmislite o slijedu događaja, potpuno je logično da je ARD potegao pitanje licence za emitovanje TV over IP kao oblik pritiska na T-com (za šta imaju punu zakonsku osnovu), zbog toga što im ugovor o naplati radio-difuzne pretplate ističe krajem ovog mjeseca.

S druge strane, ako T-com ostane čvrst u tom stavu da više ne naplaćuje pretplatu, taj potez će veoma ozbiljno ugroziti finansijski opstanak RTCG i nekih manjih, a kvalitetnih, privatnih radio stanica. Msilim, ugroziće i opstanak manjih TV kuća ali nešto me za Monten-u, MBC, Panramu i sl... baš ono...

[Iggy]

Sve u svemu, T-Com nece proc onako lagano kao sto su mislili da prodju pozivajuci se na Licencu za telekomunikacione service, i svrstavajuci emitovanje RTV programa kroz IP u telekomunikacioni servis ...

[Jocker]

Pošto vam je dosadno da čitate ono gore što sam postovao na engleskom evo extract:

A Windows Media-encoded stream, for instance, takes up 1.0 to 1.5Mbps for SDTV, HDTV bit rates using Windows Media are in the 7 to 8 Mbps range

[vukg]

X/XL/XXL i ostali paketi nemaju veze sa IPTV

Ali mozda ima veze sa ovim: http://www.ehomeupgrade.com/entry/39...mediaroom_iptv

Hint 1: Pogledati MPEG-4 part 10

Hint 2: vecina TV-a u CG jos nije spremno za HDTV. Doci ce sa metro ethernetom.

Hint 3: Zakon o radio difuziji i pravilnik o KDS/MMDS sistemima (http://www.ard.cg.yu/dokumenti/20070...d_dokumeta=196) ne regulise IPTV servis, cak sta vise decidno definise kablovske sisteme kao DVB-C only, tako da po tom pravilniku i zakonu ne moze ni izdati bilo kakvu licencu za IPTV sistem.

Hint 4: Zakonom (http://www.ard.cg.yu/dokumenti/20040...id_dokumeta=16) se regulise radio difuzija, kablovski sistemi su ostavljeni podzakonskom aktu koji propisuje gradnju i koristenje KDS, a ne predvidja IPTV gdje se ne radi o gradnji mreze, vec o isporuci servisa preko broadband telekomunikacione mreze.

Hint 5: Regulativa generalno ne definise jasno ove sisteme (http://www.preiskel.co.uk/Articles/PDF6.pdf) sto znaci da u postojecem rregulatornom okviru mogu da se grade i eksploatisu do konacne regulacije (primjer copyright, prije donosenja zakona mogao je da postoji legalni DVD klub sa piratskim filmovima, nakon donosenja zakona morali su da se uklope u regulativu)

Hint 6: Prava distribucije se regulisu i ugovoraju sa kanalima pojedinacno, za sta postoje ugovori.


Eto malo za razmisljanje...

... i za uzivanje: http://www.microsoftmediaroom.com/ i http://www.microsoft.com/tv/default.mspx ))

[Jocker]

Vuče,

Hint 4: Zakonom (http://www.ard.cg.yu/dokumenti/20040...id_dokumeta=16) se regulise radio difuzija, kablovski sistemi su ostavljeni podzakonskom aktu koji propisuje gradnju i koristenje KDS, a ne predvidja IPTV gdje se ne radi o gradnji mreze, vec o isporuci servisa preko broadband telekomunikacione mreze.

U Zakonu o radio-difuziji, u dijelu koji se tiče nadležnosti Agencije, piše i da Agencija:

Utvrđuje visinu naknada za izdavanje i korišćenje dozvola za prenos i emitovanje radio-difuznih signala i dozvola za izgradnju i korišćenje distribucionih sistema;

A kablovski distribucioni sistem je definisani kao: telekomunikaciona mreža koja se gradi, održava i koristi za prenos radio i televizijskih programa i drugih telekomunikacionih signala prema savremenim tehničko-tehnološkim rješenjima

Na osnovu Zakona, ono što Agencia treba da uradi je samo da donese podzakonski akt, kao što je i pravilnik koji pominješ, u kojem će odrediti visinu naknade za distribuciju RTV signala over DSL ili 3G tehnologijom.

I još jedna stvar koja mi pade na pamet, a tiče se regulisanja ili deregulisanja nekih oblasti. VOIP našim zakonima i njihovim podzakonskim aktima nije bio regulisan kada je Telekom poslao u zatvor onu dvojicu iz Budve (otac i sin) zbog navodne štete koju su nanijeli Telekomu, a u najgorem slučaju su mogli da "leže" zbog utaje poreza.

[helpdesk]

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