In February, 1993 the Federal Communications Commission's Advisory Committee on Advanced Television Service recommended that the four digital ATV transmission systems have proposed improvements made and be re-tested to determine the best system for North America. The proponents were also encouraged to form an alliance to combine the best parts of the individual systems into one superior system. The four proponents subsequently formed the "Grand Alliance" to develop a single advanced television system that would incorporate the best parts of the various proposed systems. By late fall of 1993 all aspects of the system had been determined except which transmission system to use. The Alliance proposed that the Advisory Committee participate in the testing of the proposed transmission systems to minimize the time required to review the results and agree on the recommended standard.
The tests started in early January, 1994 and were completed in early February. The results of the tests showed the vestigial sideband implementation proposed by Zenith to be better, in most respects, than the QAM implementation proposed by General Instrument. The VSB system was recommended as the ATV standard with the QAM system retained as the backup. This paper reviews the results of the cable portion of the tests.