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A Little History
By August of last year the modulation debate broke into open battle pitting historical partners--broadcasters and manufacturers--in a Martin Luther vs. Catholic Church--like conflict. Sinclair--the Martin Luther role--was charged with being an infidel by CEA, and one pretty short of money at that. More accurately CEA charged that the Sinclair tests were used to slow the process because they had a weakened financial condition and couldn't hack the FCC schedule. "They are even selling off their best assets," asserted one Washington-based CEA spinner.
Sinclair did sell their radio holdings shortly after the Baltimore test. Their stock was also depressed. CEO David Smith assured everyone in interviews with HDTV News and others that his motive was not to delay but to alert everyone so they could fix the problem--either the receivers or the standard--before it was too late. "Do you believe everything you are told?" asked Zenith barely masking their sarcasm? Anyone looking at his balance sheet, Smith asserted, would know he could do what was required for DTV for all of his stations. Acrodyne--a transmission vendor--was scooped up in part by Sinclair, Smith said, as part of their commitment to digital. More-over Smith claimed he wanted to participate as fast as he could in the digital revolution. The world is racing to wireless, he reasoned, and he is in a wireless business. If one missed the Internet play, you absolutely don't want to miss the wireless one.
Zenith stopped short of calling the Sinclair tests "rigged," choosing instead to say that not enough data points were taken to make the kind of assessments they did. Austria and Smith ignored their criticism and appealed to other broadcasters in a satellite teleconference on September to join them in correcting the problem. They would march on Washington.
Even before the test/demonstrations in Baltimore Motorola, NxtWave, and Broadcom were alerted to the shortcomings of early 8-VSB receivers. They independently initiated development on new chips to address the dynamic multipath problem. A self-training or "blind" equalization scheme was used rather than relying on the inadequate training signal in the standard. Even while on the brink of massively increases computer power no vendors have proved yet their case to Sinclair (or anyone else). Broadcom rounded up the best talent in the business for their try. They told a broadcaster recently that what they have now is their best shot. But it still doesn't match COFDM in multipath handling. According to our source they will not invest in more 8-VSB development.
Philips in Eindoven supports 8-VSB and COFDM. They are "working hard" on third generation 8-VSB chips. "We certainly think it's possible to get indoor reception working to a reasonable level."
Motorola surfaced at almost the same time as NextWave a little after the Baltimore tests. The Sinclair guys thought that a little to cosmic in timing. Both vendors claimed to have met the criteria originally set by broadcasters. They have matched the multipath handling characteristics of COFDM, they said. Data is available on the Motorola web-site http://mot-sps.com/adc/MCT2100test.html which has not convinced the industry of those claims. They quickly acknowledge that the new criteria being discussed--fast mobile the prime example--is not answered with their current chip, nor from its software upgrade. The company pointed out to HDTV News that they are a major COFDM vendor--the first and biggest in fact--and authoritatively say that the new criteria of rapid mobile reception will come with a payload price to both 8-VSB and COFDM.
The Sinclair team (by this time including other group broadcasters) became more and more biased towards COFDM and asked cynically for hard proof about these so-called improvements from those "miracle chips. "Send us your samples and we will test them," they asked repeatedly.
But if COFDM is so good why is Motorola--by far the largest producer of COFDM chips--devoting a department of 13 PHDs to their 8-VSB development? "Because that is the US standard," explained the Director of Digital Television products, Bob Stokes. He says they do not want to influence anyone as to what standard should or should not be used, but only want to make money selling the best chips for the standard that is in use. Sounds simple enough.
Back to the saga...CEA told HDTV News when the first new chips appeared that Sinclair was not the appropriate place to test them since the first test were, after all, biased and completely bogus. Why subject the hard-won new improvements to such PR risks? But such reluctance only deepened the suspicion at Sinclair that 8-VSB was just unfixable--a non-competitive standard for the needs of broadcasters in the 21st century. COFDM was right until otherwise proven wrong with only cold hard facts being acceptable.
A charge that sticks to Sinclair is the one which says they see more than an HDTV future for broadcasting. They have spoken up at speeches and before Congress for multiple channels, datacasting, fast mobile applications, and still talk to me wholesomely about doing HDTV. This brings up the obvious question of how? If you are sending so many bits to other causes, where do you get enough to still do HDTV? To be sure, MPEG decoding is not going to advance in efficiency with the alacrity of Moore's law. But that does not mean that coding efficiencies will not, or have not inched forward. But what do the heavy-weight experts say about that now?
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"In Europe most of the digital SDTV transmissions are at 4.5 Mbit/s," we are informed by no less than the founder and Chairman of the MPEG standardization group, Leonardo Chiariglione. "The video portion is about 4 Mbit/s. If you have 1440 x 1080, 16 Mbit/s are a perfect match for the video portion (audio contributes very little: at 320 kbit/s gives you transparent 5.1 audio). The1920 x 1080 is another story, but I would be surprised if the system would break down. Users are likely to perceive more degradations from the break down of the physical layer (be it 8-VSB or COFDM) than from coding artifacts. All this is under the assumption that you use good old MPEG-2. MPEG-4 will give you some improvement in efficiency (don't expect wonders, though). The real advantage for terrestrial broadcasters would be the ability to provide real multimedia (scene composition of objects). But this (Mark Twain would say at this point) is another story and should probably wait for another round."
For that alternative progressive format of 720p, a coding of around 12 Mbit/s has been reported to be adequate.
COFDM advocates are quick to boast about their hierarchical modulation capability too (to be on display at this year's NAB), where two separate datastreams are modulated onto a single one. One stream--the High Priority (HP)--is embedded in a Low Priority LP) stream. Receivers with good reception conditions get both streams, but in poorer conditions they get the High Priority stream. Broadcasters can target two different types of receivers with different services. Typically, the LP stream has a higher bitrate, but less robust than the HP. Could this be employed while still sending HDTV or two or more SDTV programs? These are the kind of questions the Task Force will undoubtedly address.
The sharpest in our era say that DTV is not merely TV. It is the centerpiece for e-commerce, for e-business-to-business, and is by far the biggest and best consumer window on the cyber and real worlds of tomorrow delivering the contents form any IP aware device in the world. "We are in a staggering revolution," noted Ross Perot in a speech to the medical community this week in Washington, DC, "but hindered by legacy protectionism." Perot said that was very natural thing but "legacy" is another word for "obsolete." To survive now everyone must let the obsolete go while embracing the new.
Engineers and market pundits on Internet forums attack 8-VSB as being formed from legacy protectionism tethered to the old analog ways--hardly a forward looking standard in their critical eyes. COFDM advocates leap to their feet when hearing such words and deliver a hard pitch for their own modern baby, Again, Leonardo Chiariglione sums up the global situation from his perspective: "ATSC tries to save a future for terrestrial broadcasters. DVB caters to the interests of old guard European broadcasters, and new aggressive service providers. The EBU is the last bastion of European terrestrial broadcasters. OpenCable protects the interest of cable operators."
Some of the engineers and marketing pundits squawking the loudest show themselves to be not as concerned over the modulation part of the ATSC standard as it might appear from their undying support of overthrowing it. They use that issue to advance their cause, which can only come if the standard is opened for revision at the FCC level. That is the way they can incorporate their "futuristic" ideas in a newer, more evolved standard...even at the expense of several years delay for the DTV movement. They use hot-button terms to provoke agreement like, "We must take time to get it right." To believe the rhetoric one would conclude the entire ATSC standard was beyond hope, made up of musk-melon rinds and manipulated by a few fat cats with dead ideas protecting old men hoping for another go at the gate--completely out-of-touch with the new realities that Perot and others have so eloquently pointed to.
The ATSC has had to answer every challenge, and there have been many, with carefully worded documentation and papers replete with scholarly theory pointing to hard test data. At the CES in Las Vegas Zenith showed their latest improvements to a select group, including the Office of Technical Assessment from the FCC. A demonstration of "recorded" multipath signal, attenuated to replicate distance, came with a booklet of graphs and charts which again "showed the superiority" of 8-VSB. Who could doubt the advances coming in science and technology? All we have to do is stay the course and benefit from the lower power--a financial benefit to the broadcaster that should last the lifetime of the standard.
COFDM advocates were unimpressed and claim Zenith's CES demonstration (later given in Washington on Snowy February afternoon) were "optimized" to show only what they wanted. The battle between the two camps seemed never to quiet down and onlookers asked the kind of questions no one wanted to hear: Why are these partners fighting in public?
Nat Ostroff was determined to hold 8-VSB's feet to the fire, at least until companies either delivered on the improvements promised, or they caved in to his initiative for including COFDM in the FCC standard.
To keep the fire hot Sinclair filed a petition with the FCC in the Fall of 99 requesting that COFDM be included in the FCC standard. Ostroff was determined to carry the issue to Congress if the FCC didn't act to his liking. The ATSC fully realized then that Sinclair had become a force to deal with.
But what could the FCC do? The Office of Engineering and Technology (OET) listened to industry spokespersons then wrote an opinion saying there are, of course, merits to both sides, but the 8-VSB was still the right choice for America. The FCC should stay the course it concluded. OET was attacked, of course, for being no more than a lackey of the ATSC lobby.
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