HDTV systems to present united front


The four HDTV systems vying for Federal Communications Commission approval have agreed to cooperate in placing before the FCC's Advisory Committee on Advanced Television Service a single digital high-definition television (HDTV) system.

That announcement, made in Washington on Monday, May 24, by the FCC, involves MIT.

Professor Jae Lim is director of the Advanced Television Research Program, located in the Research Laboratory of Electronics.

MIT and General Instrument Corporation, which have been cooperating in placing a system before the FCC, are among the groups which have agreed to focus on a single system.

The proposed system, if recommended by the Advisory Committee and adopted by the FCC, could place the US in the forefront of high definition video technology, said the FCC announcement. An all-digital standard, which would facilitate interoperability with computer and telecommunications technologies, has worldwide potential, the announcement said.

Advisory Committee Chairman Richard E. Wiley, who had encouraged the complex negotiations leading to the agreement, said, "I believe the Grand Alliance proposal, subject to Advisory Committee and ultimate FCC approval, will help to conclude a process that has fostered the development of highly advanced digital HDTV technology. The members of the Alliance should be commended for their accomplishments."

Important aspects of the "alliance" proposal include the use of progressive scan transmission (where entire picture frames are transmitted sequentially) and the use of so-called "square pixels" (where the dots on a TV screen are arranged in equally spaced rows and columns.) Both of these design aspects are important for the "interoperability" of HDTV with computers, telecommunications and other media and applications, the announcement said.

The agreement calls for all large-screen HDTV receivers (34 inches in diagonal and above) to incorporate a 60 frame-per-second, 787.5 line or higher progressive scan display mode. Progressive display would be optional at first for smaller screen receivers. There was also agreement that transmission of film material will be in a progressive scan format starting with the commencement of HDTV service. The alliance members also agreed to endorse the objective of moving the standard to a high line number progressive scan transmission as soon as feasible and will work together to eliminate interlaced scanning format from the transmission path in the future.

A version of this
article appeared in the
May 26, 1993

issue of MIT Tech Talk (Volume
37, Number
34).


Topics: National relations and service

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