Dermot Nolan Critiques NAB/MSTV Decision to Reject COFDM in Favor of 8-VSB

000AAgain out of respect for a spunky spirit and a dedicated point of view, I bring you this critique by Dermot Nolan of the NAB/MSTV decision to endorse the continued use and further development of 8-VSB and to offer no support for acts to include COFDM in the FCC standard. Mr. Nolan offers a glimpse into a future of his own conjuring with a balustrade of points worth a ponder. There is little doubt over the political situation in the United States, however, with the most effective lobbyist in the nation--National Association of Broadcasters--now saying, with only a minor dissent, that they have made the decision to stay the course as set by the FCC, and will continue their forward march without delay to complete the digital transition. -- Dale Cripps, Editor

NAB and MSTV, a group of broadcasting interests, carried out a set of DTV tests in the US, comparing COFDM and 8VSB.

All other comparative trials of these DTV systems around the world have been supervised by independent regulatory agencies charged with making the system selection. This is made on the basis of the available field and laboratory evidence, taking into account all identified factors and issues. If problems are identified with receivers it is standard practice to investigate these, to follow up, and to ensure that the integrity of the collected field-trial data is vouchsafed.

A number of conclusions can be drawn from the reported results. The results disclose that 8VSB, as is, is an inappropriate candidate digital terrestrial television system. They also disclose that the 8VSB system does not replicate the service receivability of the current NTSC television system. Insofar as they go these results are entirely consistent with the independently conducted DTV field trials around the world.

The COFDM results are inconsistent with those found in the independently supervised field trials around the world. It has been reported that there was a problem with the tuner section of this receiver. Normal practice in independent field trials is to investigate matters of this nature. This was either not recognised or not acted upon during the course of the data collection exercise for the COFDM portion. Neither were receivers from other vendors calibrated and field-tested: in the recent independently supervised Brazilian 6Mhz comparative trials several vendors' COFDM equipment was tested during the trials.

Corollary: Given the foregoing observations the statistical confidence attached to the NAB/MSTV field trial data for COFDM is probably negligible.


A thorough investigation would have investigated multiple data sets with multiple different type receivers in order to draw statistically valid conclusions about the comparative performance of the two DTV systems in the field. This did not take place. This is surprising given that best scientific practice would be to obtain data upon which a high level of statistical confidence could be placed.

Therefore the technical report presented to the NAB/MSTV Board as a basis for decision-making likely reached conclusions based on faulty data sets.

Failure to recognise and act on this, either accidentally or by design, could have led to decisions that might otherwise not have been made.

A decision to proceed with an 8VSB system which is known to be faulty, which cannot service broadcaster requirements, which may be uneconomic to fix, and for which there is no guarantee of a fix is, at best, perilous to broadcasting as a commercial enterprise. From a due diligence perspective that is a material risk to stockholders.

More importantly this 8VSB system does not serve consumer requirements for ease of reception compared to other digital television delivery systems. At writing time fewer than 70,000 8VSB RECEIVERS had been delivered to DEALERS in the last two years whereas over FOURTEEN MILLION digital DBS receivers are in public use. Today DirecTv announced record fourth quarter numbers: up 527,000 satellite homes in Q42000. The future is digital and probably DBS.

Commercially the ATSC/8VSB television system is entirely irrelevant and has negligible market share after two years. DBS now has critical mass to compete with digital cable, sidelining 8VSB DTV entirely.

The decision by NAB/MSTV to trustingly place their future survival as a stand-alone broadcast delivery platform in the hands of silicon vendors with a proven track record of non-delivery of 8VSB 'solutions' is naive. It will undoubtedly accelerate the very visible consumer rush away from over-the-air broadcasting to wired systems such as cable and DBS.

Given the intense pressure for spectrum utilisation in the VHF/UHF bands by mobile and other telecommunications operators, the very substantial proceeds raised in spectrum auctions, it seems likely that pressure for broadcasting to vacate this 420Mhz of prized spectrum will intensify in the next few years. The number of OTA homes is shrinking below 15% of all TV homes: continued justification for broadcasting to occupy RF spectrum resources is very weak on economic grounds. This will be accentuated by the 8VSB receivability problems that, in the authors' view, are not solvable at economically viable pricepoints.

The anticipated $70 billion auction take is likely to provide a powerful regulatory and political driver to transfer US broadcasting to cable and DBS carriage. This is a form of Negroponte 'switch' occasioned by the technical failings of 8VSB, the shrinking market share of OTA services, and the economic spectrum rents derivable from termination of BOTH NTSC and 8VSB DTV broadcasting entirely.

Severe commercial problems are associated with securing cable DTV 'must-carry', however defined. There is a strong likelihood that the incoming Administration/FCC will leave these matters to free market forces based on public comments. This means it is likely that broadcasters DTV services will be carried at SDTV grade, if at all, due to cable MSO bandwidth constraints and the pursuit of other commercial priorities by MSO operators. Therefore 80% of US homes will probably not be offered HDTV service mainly on economic grounds dictated by the cable industries agenda.

NAB/MSTV have discarded the option of reinventing conventional broadcasting as a wireless multimedia business through their incomplete testing and analysis, premature rush to decision-making and foreclosed the participation of broadcasting in any future mobile DTV services.

Conventional broadcasting will likely metamorphose into a set of SDTV grade general entertainment channels carried via other MVPD players. It will have to take its place alongside other services.

The future of wireless digital video and multimedia services will, in all probability, be determined after spectrum auctions are completed. This may occur rather sooner than expected. New entrants will probably develop these services using all appropriate technologies at their disposal without the slightest hesitation.

NAB/MSTV can now pursue a new vocation: managing the orderly windup of conventional OTA broadcasting.