MSTV/NAB DTV Test Aftermath: 8-VSB vs. COFDM and the Future of U.S. Terrestrial Broadcasting
Summary
The $3 million MSTV/NAB comparative tests failed to resolve the 8-VSB versus COFDM modulation debate, instead revealing that 8-VSB delivers up to 50% loss of service receivability in many cases. European critic Dermot Nolan argues the results confirm 8-VSB is unfit to replace NTSC, while editor Dale Cripps warns consumer frustration threatens the entire DTV rollout.
So, I have included this piece from Dermot Nolan into our "record" because, as Mark Schubin once said to me, "he won't shut up" anyway, and because he always brings some substance to the table. His words are not vapid salesmanship, but rather from a watch dog who sees that his point is never buried by someone else's prejudice. As one who has substantial investments in the current H/DTV roll-out through our HDTV MAGAZINE (please subscribe), I do NOT endorse any delay of any kind. It is not my intention to bring up arguments that will cause this nation to fumble or stumble, for I would be forced to also fumble and stumble. But the truth can only come from careful examination of all arguments, and if something has not been done in the MSTV tests to represent all of the facts, then we are not yet able to settle on the issue and to move on. Indeed, enough questions were raised by the MSTV tests that the entire move into digital broadcasting (costing billions upon billions of dollars!) should be reviewed. I did not like saying that, but you will anyway. I might add, that none of my calls to Victor Tawill at MSTV have been answered. I welcome a response from him, and from Lynn Claudy of the NAB, who also has been dodging my calls (five calls--no call back). The NAB is one organization who is not fairing well under the division of their members over this difficult argument. Manufacturers are hunkering down not delivering decoders into the marketplace until the issue is cleared. Customers--the beating heart of the movement--are fed-up with the industry's inability to settle this issue, and are turning against both broadcasters and the manufacturers. Look to my forum to see just how poisonous this has become. And trust me, I am closer to the end-users than most through our HDTV Magazine, and, as the canary in the mine, can tell you that there are some gasses escaping that can put an end to this DTV roll-out. I know we are on the horns of a dilemma. There is no set of magic words able to resolve the issue without dictatorial methods employed, but we must come to realize that time is no longer on our side as far as the last driving force in digital broadcast is concerned--the consumer. Dale Cripps THE MSTV/NAB DTV TEST AFTERMATH: ANY FUTURE FOR US TERRESTRIAL BROADCASTING? Dermot Nolan 1?Indecisive outcome Three million dollars (est.) spent and the MSTV/NAB comparative 8VSB/COFDM tests have not resolved the US DTV modulation debate. Instead the tests reveal that the proposed ATSC 8VSB DTV system is a poor substitute for the current analog NTSC system: leading to severe loss of SERVICE RECEIVABILITY, UP TO 50% IN MANY CASES. The MSTV tests have exposed to a domestic audience the reality determined elsewhere by 'Johnny Foreigner' engineers in six countries that the 8VSB system does not meet the basic requirements for an over-the-air digital terrestrial television system. PERIOD. The initial results are a free commercial for cable and DBS platform operators in the United States revealing that 'Neither DTV system in its current implementation will meet all broadcasters or viewers needs'. This is a wonderful marketing by-line for broadcaster competitors that can be used again and again. Over-the-air DTV is simply not a saleable product given that it is a work in progress. Who would risk a purchase given the technological uncertainties that abound: DTV now enters the deep freeze 2?Commentary on MSTV report The present author does not intend to dwell at length on the MSTV testing. The results for 8VSB speak for themselves: it is unfit to serve as a replacement to NTSC. The results for COFDM appear to have been strongly influenced by the choice of receiver made by the testers, acknowledged by the authors, and by the fact that the receiver had a broadband front-end without any filtering. EXTRAORDINARY. The present author was aware of these facts in November 2000 and is entirely unsurprised by the outcome: if you are handed the DTV equivalent of a leaky sieve you can expect the worst! Without a receiver specifically designed for 6Mhz markets, with the right tuners, and the right filters you can expect RF overload. PERIOD. This, of course, has a major impact on the outcome. A structural concern with the testing methodology is that it appears to have not tested a wide array of receivers from both camps in the field. This has the advantage that any receiver specific problems are identified early in comparative testing allowing corrective steps to be taken. In the other recent comparative tests of 6Mhz DTV systems undertaken by ABERT/SET in Brazil an array of 8VSB and COFDM receivers were tested in the lab and field: COFDM came out way ahead! The tests also appear to have been driven by latest technology considerations. The latest Zenith receiver was tested (and again the same 8VSB dismal performance was found) and the testers chose a COFDM mode (64QAM FEC 3/4 GI 1/16) which actually requires a minimum THEORETICAL C/N of around 22dB in a RAYLEIGHIAN channel. In a good receiver this would probably be around 24dB in practice to decode, leading to a possible receivability C/N gap of 9dB. Sinclair highlighted their reservations last Friday and given the known problems with this receiver the results are completely unsurprising. Computer predictions in the report indicating that COFDM would reduce the total viewing population by 5.9%, probably based on 30 ft outdoor antenna predictions, are very difficult to reconcile with MSTV field test data. These indicate that SERVICE RECEIVABILITY (the real-world measure) of either system at ground-floor level was only 50% given the available receivers. This conflicting field-test data must be reconciled with the theoretical predictions. A fair criticism is that MSTV were ill served by the then available 6Mhz COFDM receivers: a factor recognised by Sinclair and rectifying steps taken as now disclosed. Given this combination of factors who can be surprised that the outcome fell as it did. This leaves US broadcasting in greater disarray than ever and at the mercy of competitors, factionalism, declining markets, and technology uncertainty. The almost touching faith of the NAB/MSTV report in eventual delivery of 8VSB salvation chips from the merry mirage chip men is an example of 'Grand Old Duke of York syndrome' and ignores the commercial reality that the market share of over-the-air broadcasting is diminishing daily. Currently fewer than 15% of TVHH in the US depend on OTA delivery which means that the addressable universe for 8VSB DTV is likely capped to under 15 million units and it is unlikely to ever be adopted in sizeable markets outside the US. Economically and given the commercial dominance of COFDM around the world this means 8VSB is unattractive to global silicon vendors and its importance will recede further. 3?DTV MARKET FUNDAMENTALS UNALTERED Irrespective of the outcome of the initial MSTV/NAB DTV testing the ATSC/Grand Alliance/FCC/Zenith DTV strategy has failed. THE US is a market with 70% cable connections, 15% DBS connections, and a society where the outdoor antenna is a curio except in rural and some suburban areas. To date CEA is unable to provide accurate estimates of the NUMBER of 8VSB STB's and TELEVISION SETS WITH BUILT-IN 8VSB RECEPTION CAPABILITY WHICH ARE IN CONSUMER HANDS. WHY? Under 200 8VSB DTV stations are probably being RECEIVED by fewer than 100,000 viewers with OTA DTV capability. Other estimates place this number at less than 50,000. This is less than the number of Tivo receivers sold in the United States, which is a service with a monthly ongoing cost. On the basis of current performance, the residual market of 15,000,000 NTSC homes, it will take decades to retrieve the NTSC spectrum. This is unsustainable, given the relentless pressures in the United States for spectrum retrieval in the VHF/UHF bands for use by mobile communications providers. These providers could, of course, provide mobile DTV services usurping the present position of OTA broadcasting. Therefore once the current policy failure is recognised a course correction is inevitable. 4?RADICAL DTV TRANSITION: COMPLETE CLOSURE OF TERRESTRIAL BROADCASTING The initial MSTV/NAB test outcome, the failure of the ATSC/Grand Alliance/FCC business model and technology, the inability of the broadcasting industry to speak with one voice and the insatiable demand for spectrum by trillion dollar mobile industries point towards a radical DTV transition. The United States as a society lends itself to a RAPID transition in which cable and satellite carry broadcasting services EXCLUSIVELY. Both NTSC and OTA DTV services are abandoned as all broadcasting services are carried as SDTV services via cable and DBS either as a mandated FCC program or by commercial agreement. This is made substantially easier for cable operators if NTSC service is terminated as these channels are then 'liberated'. The 15 million homes with OTA NTSC are given DBS receivers as part of a spectrum auction with obligations to convert residual analog viewers. This would probably cost around $3 billion, peanuts compared with the projected VHF/UHF auction take of between $30 and $70 billion. A financially engineered DTV transition of this nature has certain advantages: This vision also means that OTA broadcasting will disappear in the United States with the networks metamorphosing into multiplatform content providers and local television services will secure carriage on local cable and MMDS systems. It also means that portable indoor antenna reception will be abolished, that broadcasters will not partake as of right in any mobile DTV future, and that broadcasters will be strategically dependent on third party platform operators. This is undoubtedly a super attractive scenario for non-broadcast industries and it is the ultimate nightmare scenario for broadcasters: eviction from any gifted spectrum exploitation and inability to reinvent themselves in a digital era. What happens next may determine how quickly this scenario comes to pass or whether OTA broadcasting in the United States has any future. 5?THE BURNING QUESTION The results of the MSTV tests determined that 8VSB is a consumer turkey whichever way you cut it. No one is going to erect a 30ft outdoor antenna and revert to armstrain from the use of a rotor: NOT WHEN CABLE AND DBS PROVIDE SIMPLE ALTERNATIVES. Equally the results of the MSTV tests determined that a COFDM receiver had a 'documented but unexplained RF anomaly' in field-testing. The results of tests with a COFDM receiver DESIGNED for use in the US could be very different. Therefore the issue, given the failure of 8VSB to provide a replacement for NTSC, is SIMPLE: 'What happens with a properly designed DVB-T/COFDM receiver in the US market?' This is the question that needs to be answered. If it is not answered now, for whatever reason, it will return like Banquo's ghost very soon. 6?WHAT HAPPENS TO OTA BROADCASTING? Three possible outcomes are likely and I would like to highlight the probable consequences of each set of actions. 1) NAB/MSTV vote to halt the process and retain the status quo: As the business fundamentals are unaltered nothing changes. Sinclair will fight on and may eventually triumph, too late. The window of opportunity for OTA DTV shrinks as cable opposes DTV 'must-carry' tooth and nail. The wired DTV future scenario above becomes a realistic proposition given the failure of the DTV strategy. OTA broadcasting disappears in the US. 2) NAB/MSTV vote to continue the process: New DVB-T receivers are tested. These either do or do not meet the expectations of NAB/MSTV and COFDM proponents. If they do then pressure to adopt COFDM becomes unstoppable. If they do not the status quo is retained and OTA broadcasting disappears in the US. However even if COFDM is adopted in the US the central issue of a viable DTV business model remains to be tackled. Pressure to retrieve the spectrum intensifies 3) NAB/MSTV are deadlocked This means essentially that the status quo is endorsed as broadcasting remains a house divided. Again OTA broadcasting disappears over time because this is a recipe for inaction. PREFERRED SOLUTION: FREE MARKET FORCES IN DTV In my view the preferred solution to this seemingly intractable problem which has dogged the US since the early 1990's is a free market forces DTV solution. Quite simply the only two commercially available DTV systems are ATSC and DVB-T/COFDM. The MSTV tests demonstrated one interesting fact: the difference between COFDM and 8VSB in interference to the existing NTSC service would be minimal. Therefore either system could be used in the US within the existing Table of Allotments. Permitting either of the two systems to be used in the US has a number of strategic benefits. It introduces a competitive dynamic given that without it the ATSC/8VSB camp have no survival incentive and will simply push for cable carriage as the solution to 8VSB's failings. It give broadcasters and consumers a choice, it will ensure that the DVB camp come up with the goods to ensure US acceptance, and it opens the door to service flexibility. In addition the DVB-T hierarchical mode offers the surest route to REPLICATION OF NTSC COVERAGE AND RECEIVABILITY AT 480i. From a timing perspective an Americanized DVB-T system can be brought in within a year whereas the speculative and unproven claims of the merry mirage chip men cannot be delivered before 2003 according to the MSTV report. It's now all about who has the fastest route to market with a solution to the problems. Evidence from related industries that competition is a good thing is overwhelming: we need only look at cellular, telecommunications, computing and other branches of CE. Those worried about the use of two standards can consider the fact that there are AM/FM radios, triband cellular phones etc. In practice one standard may dominate because of its consumer adoption, time to market advantages and fitness for purpose. My conviction is that standard would be DVB-T/COFDM. However, there remains the small matter of the viable business model for US DTV. That has to change and I am sure that US broadcasters left to their own devices would have the commercial nous to do the business. Either they will or they will not survive. In the end markets do adjudicate on controversial technology matters because consumers make the decision. The evidence is clear that 8VSB has been rejected by the US public and that high-end HDTV display devices are, in essence, a niche market for aficionados. It is equally clear that the current DTV strategy will not lead to spectrum retrieval for decades. Therefore let the market decide between 8VSB and COFDM. Kind Regards, Dermot Nolan PS, I actually suspect that for political reasons NAB/MSTV will vote for the status quo. We may be witnessing the rapid decay and death of over-the-air broadcasting in the United States as the mobile industries and spectrum auctioneers move center stage in the great US DTV debate. With my telecommunications industry hat on that would be economically efficient. Whether it is desirable from other public policy perspectives is a matter for intense debate.
Editor's Note: One voice from Europe has constantly warned all who would listen that the U.S. was on a slippery path with 8-VSB. His attacks upon the ATSC and their methods have often been brutal, certainly painful to read, and invariably anger-provoking. He is not above "polishing the truth" to emphasize the virtues of his "beloved" DVB, nor beneath a kick in the groin to all who come against his conclusions. He seeks global uniformity in the modulation standards, taking that as an insurance against higher costs and consumer inconvenience. Some think he is a paid hack by the DVB interests, and if not, he certainly missed his calling.
