15 agosto 2008

Gli americani trovano l'intesa sullo standard mobile tv

Dopo qualche mese di iniziale confusione legata alla competizione tra due sistemi non interoperabili, prende piede negli USA la corsa alla versione mobile del sistema di televisione digitale ATSC (Advanced Television Systems Committee). Come dire che anche la tv digitale americana cerca il suo DVB-H per raggiungere telefonini, smartphone e altri apparati tascabili. Nei mesi scorsi (al CES di Las Vegas c'erano state le presentazioni dopo le prime submissions del maggio dell'anno scorso), LG in partnership con Harris Corp. e Samsung con Rhode&Schwarz e Nokia, avevano litigato tra loro.
Ora ci spiega questo articolo apparso su Broadcasting & Cable, sotto i buoni auspici della Open Mobile Video Coalition, è stato raggiunto un compromesso tra il sistema MPH di LG e l'A-VSB di Samsung. A luglio sono state presentate le prime bozze al consorzio ATSC e ora i broadcaster ritengono possibile una prima bozza della nuova specifica entro il prossimo autunno, con la versione definitiva attesa per il 2009.
Sembra davvero impossibile convincere gli americani a rinunciare al loro isolamento un po' altezzoso. Hanno rinunciato al DVB dopo aver portato avanti il sistema analogico NTSC contro il nostro PAL. E ora la storia si ripete. Il mondo (digitale) è bello anche perché è vario, ma certo il campanilismo tecnologico non ci rende la vita più facile.

Smooth Ride So Far for Mobile DTV
Broadcasters expect preliminary standard this fall

By Glen Dickson -- Broadcasting & Cable, 8/11/2008

Broadcasters say development of a new digital TV standard which will let them transmit video to cell phones and other portable devices is going smoothly, and that they remain on track to have a working system in place by early 2009.

The creation of a new “Mobile-Handheld” (M-H) standard has drawn strong interest from both stations and technology vendors since it was officially started by the Advanced Television Systems Committee (ATSC) in May 2007.
The mobile DTV standards process got a significant boost in May when the two large consumer electronics companies who had submitted competing technical proposals to ATSC, LG and Samsung, agreed to work together on a joint system and avoid what could have been a protracted standards battle.
That compromise between LG and Samsung was driven largely by field evaluations conducted by the Open Mobile Video Coalition (OMVC), a consortium of over 800 stations committed to creating a mobile DTV standard. According to a report the coalition delivered to ATSC, trials in San Francisco and Las Vegas slightly favored the “MPH” technology created by LG in partnership with Harris Corp. over the A-VSB system developed by Samsung, Rohde & Schwarz and Nokia.
LG and Samsung subsequently submitted a joint proposal to ATSC in early July, which mobile DTV insiders say is basically the MPH system with a few minor tweaks.
CBS affiliate and Capitol Broadcasting's WRAL Raleigh conducted successful informal tests of MPH last month, broadcasting two streams of mobile content alongside its high-definition programming to a handful of prototype receivers.
Pete Sockett, WRAL's chief engineer concedes his station's testing was decidedly unscientific, as he simply gave mobile handsets with MPH chips to station employees and told them to drive home to test the reception. But, he says, “It worked. It was pretty rock-solid within 25 to 30 miles of the transmitter. At 30-40 miles it was intermittent. Over 40 miles away we had a few successes, but that's where it dropped out.”
OMVC plans to work with ATSC to conduct more formal tests of the proposed joint LG/Samsung system, tests which could be announced as soon as this month. A key factor in the testing will be interoperability between the transmission system's exciter, multiplexer and receiver. The coalition also enlisted the research firm Horowitz Group to review mobile TV implementations internationally, to help inform consumer trials it is planning for early 2009.
While he didn't have an exact timetable for the interoperability testing, ATSC president Mark Richer says the industry should be able to ratify a formal mobile DTV standard in the first or second quarter of 2009.
“We are on track and on schedule,” says Richer. “It's nice to say that, and hopefully we stay that way.”
This month, members of the ATSC specialist group (“S4”) on mobile DTV should complete a working draft of the standard, some 800-900 pages in length, which they will meet to review in early September. Some parts of the draft standard are brand-new, while other parts are based on existing technologies such as established video and audio compression schemes. It includes some specific broadcaster requirements, such as the ability to perform audience measurement and conditional access functionality for pay-TV services, and is also intended to be updated with future versions.
On Sept. 25, the S4 group will present its draft to the larger Technology and Standards Group (TSG). It is likely to ask for the M/H draft to be raised to candidate standard status, which could happen by mid-October. It could remain as such for anywhere from three months to a year, but a likely period of time is six months. The candidate standard period is designed to encourage testing and experimentation by vendors to work out any kinks before a standard is presented to the general ATSC membership to be formally ratified, which requires the support of two-thirds of its membership.
“This working draft then becomes sort of the proving ground for the standard,” says Mark Aitken, director of advanced technology for Sinclair Broadcast Group and chair of the S4 group. “That's when third-party implementers get a view of the standard and begin to build for it.”
Samsung vice president John Godfrey says that in order to build retail products for the holiday 2009 season, his company and other manufacturers would like to have a final standard by early next year, or assurances that broadcasters were going to be using the standard.
“This is like anything in the television industry,” says Godfrey. “There's got to be some sort of coordination between the people sending the service and the manufacturers making devices to receive the service. That said, there is more momentum on ATSC Mobile-Handheld than I've ever seen on anything else.”
Sockett and other WRAL testers were impressed by the picture quality of the first-generation MPH system, and he is excited about the prospects for a commercial mobile DTV service. He says, “Everybody who saw it got the difference between typical cell phone video and what this is capable of.”

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