Welcome to RF Current, a weekly electronic newsletter focusing on Broadcast technical and F.C.C. related issues. This newsletter is part of The RF Page @ www.transmitter.com, a web site devoted to TV Broadcast RF engineering. For more information see the What is... guide to the R.F. Page site.
This page contains stories from RF Current issues published in October 1996. Links referenced in the articles were current when published but by this time may have changed. If you find a bad link, try connecting to the home page of the publication or company and look for an archive of past articles. If you find a changed link, I'd appreciate it if you'd let me know by dropping me a note indicating the new location at email@example.com.
Thomson Consumer Electronics Executive V.P. Joseph P. Clayton, speaking at a National Association of Broadcasters' news conference today predicted that "a favorable FCC vote this year will assure mid-1998 introduction of the first digital television receivers in concert with the broadcast industry." He said that adoption of the standard ""will give consumers enormous choice as they enter the digital television era. It will mean that TV receiver manufacturers, with the benefit of high-volume production, will be able to offer consumers a full range of high-performance, cost-effective and reliable digital sets, just as we have done with analog color TVs for more than four decades."
Commenting on some computer companies efforts to derail the standard, he said "those computer companies making an eleventh-hour bid to derail the standard are seeking to impose the computer industry's business model on TV-oriented consumers. Rather than high-quality, long-lasting, affordable receivers, their so-called `baseline' proposal for digital television is untested, unproven and perhaps unreal." I'll provide a link to the full text of this news release if and when it becomes available. Check the Thomson Consumer Electronics Press Release Page. (Source: Business Wire)
The Public Forum on the Economics of Mandated Standards for Digital Television, originally scheduled for October 18th has been rescheduled for Friday, November 1st. Details are available in the FCC News Release (nrmc6092.txt).
Yesterday the Mass Media Bureau, in a News Release (nrmm6028.txt) said it "approved a horizontal overscan ancillary signal system designed by Microsoft Corporation and authorized its use by broadcast television licensees without further Commission consent. The system inserts digital data in a portion of the video in an "over scanned" area located along the extreme left edge of the picture, an area that the viewer generally cannot see."
The system approved is similar to the Yes! Entertainment Corporation system approved earlier. "Timing, amplitude and frequency parameters are within those of the Yes! system," according to the Release. The Report and Order on MM Docket 95-42 indicates the Yes! system would have a maximum data rate under 20 kbps. The system transmits one bit on each horizontal line.
The FCC Cable Services said yesterday in Order DA96-1755 that the Office of Management and Budget approved information collect related to CS Docket 96-83, which preempted certain restrictions on the placement of TV, MMDS and DBS antennas. For more information on the Rule, read the Report and Order.
Friday FCC Chairman Reed Hundt spoke to the International Radio and Television Society in New York City about Digital Television. Most of the press focused on Hundt's three rules for broadcasters, mentioned before in his paper "The Communications Revolution: Stop Making Sense" , delivered in Baltimore Maryland on October 2nd and his comments against a government DTV standard. Hundt spoke for spectrum caps, clear public interest obligations and no interference. He outlined the rules he felt we didn't need: no mandate for a minimum amount of HDTV broadcasting, no constraints on DTV subscription service (with the exception of some free DTV for the public good) but paused a bit when considering a government mandated standard for DTV. He outlined the reasons for not adopting a standard -- to avoiding becoming stuck in old standard like Japan's analog IID, to not miss technical opportunities "some genius" might come up with, to promote convergence with "one of America's leading industries, the computer industry" and to avoid mandating a standard that might be "the digital equivalent of a government order that the Model T Ford is the only way a car can be built". He pointed out the there is no government standard for DBS, PCS, DARS, laser disks, CDs, CD-ROMs, ADSL , ATM, or cable set-top boxes, among other things.
What the press did not focus on were a few words that indicated Hundt would be willing to accept a standard, under certain conditions. He offered his compliments on the work of the ATSC:
"I don't oppose standards. Virtually every industry needs standards and manages on its own to set them.
Further, under certain circumstances, we should consider blessing a DTV standard by embodying it in an FCC rule. I doubt this is necessary but I'm not dead set against it. I've repeatedly praised the historic breakthrough of the Grand Alliance and Dick Wiley's Advisory Committee. They found a way to transmit terrestrial video programming digitally, flexibly and dynamically.
No other country in the world is anywhere near the United States in launching a digital terrestrial television service. We're going to issue digital terrestrial TV licenses within the next six months. The country that's closest -- the United Kingdom -- is way behind us."
He continued by outlining the type of standard he might accept:
"So if the FCC should bless or even mandate a DTV standard, then we should agree that it meets the following conditions: (1) it should be open, nonproprietary, nonexclusive;(2) it should be compatible with the business strategies of both DTV manufacturers and computer hardware and software companies; (3) it should be cost-effective both for broadcasters to transmit and consumers to receive voice, video, and data, in whatever combinations their own business strategies suggest are most likely to maximize profits and the viewing audience; and (4) it should be capable of evolving over time as compression technology and other enhancements are developed."
Refer to the text of the speech for more information on this and other DTV topics addressed by Hundt.
The broadcast industry is lining up behind the Grand Alliance standard. The Communications Workers of America and the International Brotherhood of Electrical Workers both urged quick adoption of the DTV standard to avoid losing the thousands of jobs the DTV industry could create. Nat Ostroff, Vice President of Sinclair Broadcast Group and Chairman of the ALTV Engineering Committee issued a white paper titled Facing the Final "Sign-off" Why We Need A Digital Standard in which he warns "We are at a crossroads in the history of the Broadcast Industry. The forces aligned against the Broadcaster are highly technical and ruthless competitors who have spent a lot of resources on long term strategic planning. " I'll quote one paragraph from the Paper that outlines what could happen if we don't have a standard:
"The setting of a standard creates the economic confidence in the market place to invest in the creation of hardware for the consumer. Unlike the telephone, computer and cable industry the broadcast industry does not control the entire process. The broadcasters must send a signal out into the market with the confidence that there is equipment in place to receive it. We do not supply the end use instruments like the telephone companies nor do we supply the set top decoders like the cable companies. We must rely on the TV set manufacturers to make instruments that can receive what we send. Our industry is based on a belief that no matter where you go in our county the TV receiver will receive and display the available TV signals in that area. This can only occur if the TV set manufacturers build to a standard that is ubiquitous. Multiple standards would not only create chaos but would so fragment the market so that no serious business could invest in the tooling to produce multiple standard receivers into such a market. The effect on the consumer would be to drive up their cost and perhaps render their TV set useless in anyplace but their current home town. The concept of " NO STANDARD" invites such chaos and confusion. It also sets the stage for the eventual downward spiral of the great broadcast industry that has provided the diversity of programs and viewpoints that has sustained our democracy in this highly technical society delivered free to everyone who can receive the signals."
Mr. Ostroff warns:
"Now is the time for the Broadcast industry to set aside it's internal competitive conflicts and band together in an industry wide effort to reverse the momentum that has been built up by the competitive forces of the computer industry lead by Microsoft and Bill Gates. A grass roots personalized effort by all of the broadcast industry could start with a summit meeting that leads to a White House meeting that is fully covered in our media. Continued over the air educational spots aimed at telling the public what they are about to lose could be the next step. "
This is a critical issue for broadcasters. Take time to consider the arguments and the outcome. Links to opinions from others in the industry are available elsewhere in this issue of RF Current and in the back issues listed at the bottom of the page.
On Wednesday (Oct. 16th) the FCC announced it would host a public forum on the economics of mandated standards for digital television. Later that week, it announced the forum had been canceled, but that there were plans to reschedule it. Details on the speakers are available in the original News Release (nrmc6086.txt). The cancellation is in News Release nrmc6088.txt.
Yesterday the FCC issued a Public Notice announcing a sixty day filing window for modification applications in the Instructional Television Fixed Service (ITFS) that propose co-location with an authorized wireless cable facility. The filing period commences October 24, 1996 and continues through December 23, 1996. Details are available in the Public Notice
In a Public Notice (DA 96-1720) released October 17th, the FCC allowed MDS operators who are authorized to transmit digital signals (per FCC 96-304) to "transmit Internet service from the authorized facilities to multiple receiving (subscriber) locations." No additional authorization is required from the FCC for this. Return or "upstream" digital transmissions from the subscribers are not allowed. "However," the FCC noted, "recognizing the potential value of two-way over-the-air Internet service, the Bureau has issued and will continue to issue developmental authorizations for the purpose of evaluating technical approaches, systems and related transmission parameters."
In a related story, CAI Wireless Systems announced Wednesday it had filed for authority for two-way flexible use of its MMDS wireless spectrum in Hartford, Connecticut. This would allow CAI to offer interactive services such as high-speed Internet access, home shopping and home banking.
The FCC's Inventory of Spectrum Usage Between 137 MHz. and 100 GHz. is a handy compilation of FCC frequency assignments in the upper VHF through microwave bands. The inventory is available as a zip file, which contains a WordPerfect 5.1 table (printable on 8.5 x 11 inch page in landscape mode) and associated documentation. The format is similar to but much more readable than that used in Part 2 of the FCC's Rules. It uses common terms to describe the bands (the amateur radio band from 144-148 MHz. has the commonly used description of "two-meters") and also indicates which branch of the FCC has responsibility for each service along with the FCC rule part applying to the service. The table was announced in a Public Notice (da961704.txt).
TV broadcasters today received information on regional meetings to discuss the FCC's DTV channel assignments and a possible MSTV alternative. As a starting point in this process, the NAB has made available some alternative allocation tables, which it notes are "interim working documents which do not represent the positions of any of the involved organizations."
Broadcasters are urged to study the working documents and attend regional coordination meetings. Don't ignore the information at the start of the table. A quick review shows these particular working documents base DTV coverage on DTV field strengths that are approximately 3 dB less than the values the FCC used for UHF, 4 dB more than the values the FCC used for High VHF and 1 dB more than those used for Low VHF. This has the effect of reducing DTV ERP levels for UHF, significantly increasing them for high VHF and slightly increasing them for low VHF DTV stations. Another difference is the Broadcasters' Caucus proposal takes into account the dipole effect at UHF frequencies, allowing an increase in power on higher channels. See the notes link on the page for more details.
More information is available from the NAB's Science and Technology web site at http://www.nab.org/scitech/files/DTV_educ.htm. The full interim table is also available as a text file. (The text file link on the NAB page was not working Tuesday night, but it may be fixed by now, in which case the link here may no longer work.)
While most of my readers are TV station engineers actively involved in DTV planning, as I am, before you visit the site, be aware the page clearly states "...any use of these files or the information therein for any purpose besides developing an improved table by anyone not involved in the process is expressly prohibited."
(Revised Oct. 21)
Saturday morning, something went terribly wrong during an antenna installation at KXTX's channel 39 tower site in Cedar Hill, outside Dallas Texas. The 1,500 foot TV tower collapsed, taking with it three workers from Doty-Moore Tower Service. The cause of the collapse is still under investigation, although there was speculation that either the gin pole or the load broke free and fell across a guy wire, causing the tower to collapse. In addition to KXT TV, the tower also held antennas for KRBV-FM, KOIA-FM, KYNG-FM and KEWS-FM. Killed were Dana Campbell, Joseph Kelly and John Stinson.
More details on the collapse are available in an October 12th story and photo from CNN, a story in the Dallas Morning News and a story in Saturday's Fort Worth Star-Telegram. Monday's Star-Telegram has a very moving story about Dana "Doc" Campbell, one of the Doty-Moore crew killed in the collapse. This story has been removed from the Star-Telegram's Internet site. As these are no longer current news stories, the other links listed here may also be removed before the end of the week or be replaced with other material.
I worked closely with one of the Doty-Moore crews during the installation of a new tower and antenna at KVEA on Mount Wilson, near Los Angeles. To a man they were the most professional, responsible and knowledgeable crew I've ever worked with. They are also valued friends. When the news spread through the Los Angeles Convention hall as the World Media Expo / Society of Broadcast Engineers / NAB Radio show was winding down, my thoughts immediately went to that crew and their families. Please join me in praying for the workers who died in the collapse, their families and their coworkers during this difficult time.
Last week marketing and engineering managers examined the impact of new digital technologies such as HDTV on traditional audio and video at the CEMA sponsored Digital Audio and Video Workshop. The Consumer Electronics Manufacturers Association (CEMA) news release on the Workshop included a comment from David Wachob of WorldGate Communications noting that "only 35 percent of U.S. households have PCs and only 11 percent are connected to the Web. He said that PC complexity and obsolescence are the main factors in slowing down PC acceptance in the home and offered solutions based on merging PC features with television receivers and using cable modems."
Sunday, Charles A. Pantuso, founding partner and Director of Engineering for HD VISION Inc., sent me a copy of an open letter he wrote to President Clinton and Vice President Gore regarding the computer industry's attempts to scuttle the adoption of the ATSC Digital TV standard. In it he refutes the recent John C. Dvorak article in the October 22, 1996 issue of PC Magazine. One paragraph notes the differences between the computer and television industry:
"The television viewer is not the computer user, even though the computer industry would like access to this huge market. And how big would the television audience be if they had to replace their television every two years to be able to watch the latest programs, and if rented and purchased videotapes and laserdiscs had to be upgraded every six months, at half their original cost, or they would not be viewable on the new TV? Although the computer industry is fond of applying Moore's law to all things technical, why is it that the computer I always want to purchase is the same price, year after year? And most new computer software, which is distributed on a few $1 floppy discs or a $1.50 CD-ROM, even though it typically costs more than a good color TV (about $350), cannot even be run on the best computer of a couple of years ago. If a television viewer buys the latest Pro-Scan Digital television and DVC camcorder, it is still completely compatible with all of the other television sets and recorders that he or she owns. And it is capable of reproducing, without exception, every NTSC television program ever made. There would be no television industry if its economies were like those of the computer industry. Because of the ruthless competition of television ratings and advertising rates, most of the money invested in the television industry is used for the production of programs. These programs have precisely ONE chance to achieve market acceptance. Imagine if the computer industry relied on the quality of the first release of ANY of its software."Pantuso puts forth some excellent arguments for not letting the computer industry influence the standard for Advanced TV. As with the Dvorak article, Pantuso's letter is must reading for anyone concerned with the future of free over-the-air TV.
Over a year ago the FCC removed the WAIS based search engine from its Internet site. While that one never worked particularly well, initial tests of the new FCC Web Site search engine soon after its debut shows this one works quite well. The interface is also much simpler than the original search engine. Full details are available in the News Release (nrmc6083.txt).
The FCC's International Bureau yesterday granted, in part, Directsat Corporation's request for special temporary authority to test the USABSS-4 Direct Broadcast Satellite on channels 2-32 (even) at 110 degrees WL. Although it was not available on the FCC's Web site as when this was written, the full text of DA96189 should be available within the next two weeks.
Cable Television Laboratories, Inc. (CableLabs) announced in a Press Release today that it "and its member companies have agreed upon major elements of an interoperable digital cable systems specification for North America. The specifications call for ITU-T J. 83 Annex B 64 or 256 Quadrature Amplitude Modulation (QAM), allowing data rates from 27 to 40 Mbps. MPEG-2, main profile/main level video compression and transport is specified, with Dolby Audio's AC-3 for the audio element. The release said "The service information tables for this specification will incorporate the Advanced Television Systems Committee (ATSC) specification. Having uniformity in these tables is critical for interoperability. "CableLabs also addressed broadcasters' concerns:
"The cable industry is committed to delivering broadcasters' digital video signals to cable customers. This specification is compatible with the ATSC standard definition digital video system, with the exception of modulation. The ATSC standard incorporates vestigial sideband (VSB) modulation, versus QAM.
Because of the characteristics of over-the-air transmission, versus cable transmission, and the consequent differences in bit rates, this difference in capacity is logically dealt with at the cable headend. The difference in modulation also can be dealt with at the headend, and by having this capability, cable operators will be able to handle any digital signal from whatever source and deliver those signals to cable customers."
Other Information: General Instrument Press Release on Cable Industry Digital Specifications.
The National Academy of Television Arts and Sciences awarded General Instrument Corporation an Emmy for the DigiCipher II digital video compression and transmission system. The award was for "Outstanding Achievement in Technological Development." More information is available in a press release from General Instrument.
This week the FCC released Chairman Reed Hundt's presentation "A New Paradigm For Digital Television" as prepared for delivery to Warren Publishing Company's Digital Convergence: Reshaping the Media conference in New York, September 30. This paper provides an excellent insight into Hundt's view of Digital TV and his concerns about it. It is impossible to summarize in a few words. In the talk, he expresses his concerns about the lack of a business model for Digital TV, particularly with regard to stations in smaller markets. He also questions how many people will spend $3,000 for a 60 inch TV and asks if the traditional advertisers like Pampers and Chevrolet who underwrite free TV now will be interested in reaching such a "niche audience". Chairman Hundt also tackles the battle over the ATSC standard and public interest obligations. It's essential reading.
Chairman Hundt raised some of the issues again in a paper titled "The Communications Revolution: Stop Making Sense" delivered before the National Conference of Editorial Writers in Baltimore Maryland on October 2nd. In this talk he succinctly outlined his ideas on digital TV:
"I think there should be at most only three rules for the new digital TV business: a) no one can interfere with anyone else's signal; b) no one can own too much of the spectrum; and c) anyone broadcasting digitally should promise to do at least 5% of their programming in the public interest. But no tv manufacturer or broadcaster has as yet embraced or requested this very deregulatory regime. Instead they are asking us to pass rules that mandate technology, tell them how many hours and with what resolution shows need to be shown. I just hope they do not want us to incorporate all the old, out-of-date rules for analog TV into the digital era."
In remarks delivered before the Washington Area Broadcasters Association on September 27, Commissioner Susan Ness praised the ATSC standard, calling "...a remarkable standard that has headroom for technological improvements." She said "Americans expect to be able to purchase a television set in Muncie and use it to access free over-the-air television broadcasts in Miami, in Minneapolis, and Memphis. The economics of free, over-the-air broadcasting depend upon attracting the largest number of viewers possible." However, Ness recognized the opposition to the ATSC standard, particularly from the computer industry, and asked the parties to "sit down together, to give serious consideration to each others' arguments, and to see if a joint recommendation can be made to the Commission that will benefit all." "Restoring inter-industry consensus to this process will best ensure rapid adoption and deployment of digital broadcasting, with its attendant benefits to the public." See the full text (spsn614.txt) for more of Commissioner Ness' remarks on this and other broadcast issues.
NASA's Thin-Layer Composite-Unimorph Piezoelectric Driver and Sensor, dubbed "THUNDER" , has been recognized as one of the 100 most significant technology advancements of the last year by Research and Development magazine. The technology should allow practical fabrication of piezoelectric wafers for speakers or other transducers of "any practical size from areas of a few square millimeters to several square meters and thicknesses of fractional millimeters to several millimeters." A multi-disciplinary team of researchers at NASA's Langley Research Center "have succeeded in developing and demonstrating a piezoelectric material that is superior to commercially available piezoelectric materials in several significant ways." More details are available in a the NASA Press Release on THUNDER.
Scientists at Sandia National Laboratories have been studying how phosphors (the crystalline materials used to generate pictures in conventional CRT's) emit light. By studying the green light emitted by zinc oxide, they found the amount of light does not depend on the thickness of the crystal but instead on the density of a defect in the crystal. The scientists feel this insight will allow development of portable flat panel field emitting displays that operate on as little as 500 volts instead of 25,000 volts required for CRT's. While the work focused on the odd green light from zinc oxide, the methods used to study it can be applied to other color phosphors as well. Full details are available in a media release issued last week from Sandia.
The Office of Engineering and Technology in a Public Notice (pnet6016.txt) released today said it would present a tutorial on "Progress in Optical Communications" by Dr. Harold Sobol, retired Associate Dean for Research at the University of Texas, Arlington, at 1:30 PM, November 12th. See the Public Notice for more details.
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