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 March 1997. 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 dlung@transmitter.com.
The FCC's Office of Engineering and Technology today released its list of Experimental Actions during February. Interesting items included a license to Rockwell Collins for tests in the shortwave (HF) bands for "test and development of a HF Data Radio." Meteor Communications was authorized to operate on 44.5 MHz. "to test a vessel tracking system." From the frequency and name this looks like it might be a system relying on bouncing signals off of meteor trails. Surprising enough, there are actually enough of these to allow transmission of short messages, provided 100% availability isn't essential.
The Notice of Proposed Rule Making on 37.0 to 50.2 GHz. allocations for Fixed Satellite. mobile and wireless services is now available on on the FCC's web site. See the March 17th RF Current (below) for a summary of this NPRM.
According to the NPRM, broadcasters' use of 40 GHz. frequencies licensed under Operational Fixed rules for window-ledge and point to point relays shouldn't be affected. The NPRM stated:
17. Many of the frequencies we have designated or are planning to designate for terrestrial wireless services are consistent with our prior proposals regarding fixed terrestrial services in these bands, as well as proposed operations, such as Sky Station. For example, we have already issued licenses for fixed operations throughout the 38.6-40.0 GHz band and have proposed to continue to license these services in that band. These wireless broadband point-to-point systems provide local access and backhaul services in primarily industrial areas, with more multimedia applications anticipated for the future.
ITS Corporation to Demo over-the-air DTV at NAB
ITS Introduces ITS-8800 5 kW Solid State UHF DTV Transmitter
FCC Order to Relocate Digital Electronic Message Service to the 24 GHz. Band (Mar. 28)
Hubble Telescope Images of Hale-Bopp Comet Surprise Astronomers (Mar. 27)
Have you ever wondered if you could run your transmitter site on solar power? Engineers at the Georgia Institute of Technology are studying solar power using the country's largest rooftop, solar-powered energy system connected to a utility power grid. The system is in use at the Georgia Tech Aquatic Center, used in the 1996 Summer Olympics. The array, which covers 3/4 of an acre, generated up to 342 kilowatts of power. More details on the system are available in a News Release from the Georgia Institute of Technology.
Two days after Chairman Hundt's speech to the NCTA (see below), broadcasters seemed closer to an accelerated schedule for implementing DTV in the top 10 TV markets. The National Association of Broadcasters and the Association of Maximum Service Television (MSTV) proposed that 31 station in the top 10 markets would begin broadcasting DTV within 2 years.
The Consumer Electronics Manufacturers Association wants Digital TV for Christmas 1998. In a press release issued today, it endorsed the broadcasters' proposal. "We are encouraged by the broadcasters' accelerated schedule for DTV roll-out," said Gary Shapiro, president of CEMA. "We stand ready to work with the broadcasters and the FCC to make HDTV a reality, and this announcement brings us one step closer to that goal." The press release said that "by providing a digital signal, broadcasters will enable TV manufacturers to begin selling HDTV sets in late 1998."
FCC Chairman Reed Hundt, speaking before the National Cable Television Association convention in New Orleans yesterday, said "The total cost of the dirt and the tower will average less than a million dollars a station, making DTV one of the cheapest ways to deliver digital TV in local markets that anyone can imagine." He asked "So why do we have to push broadcasters to push the build-out? " He commented that "UHF broadcasters" (Sinclair? ALTV?) "suggested we pretend to adopt a plan allotting channels to all broadcasters but then tell everyone it's not final until we do another two years of testing."
Chairman Hundt said that "As long as broadcasters think this Franchise is analog TV transmission and forever will be, they are putting the Franchise up for grabs." This, he said, creates an opportunity for cable to "grab the franchise away."
The strong wording and threatening stance of the Chairman's speech are a wake up call to broadcasters who want to stay in the analog world. Take time to read the full text of Hundt's speech.
The FCC today posted its First Report And Order And Further Notice of Proposed Rulemaking In the Matter of Amendment of Section 2.106 of the Commission's Rules to Allocate Spectrum at 2 GHz for Use by the Mobile-Satellite Service on the www.fcc.gov web site. The Commission allocated 70 MHz. of spectrum in between 1990-2025 MHz. and 2165-2200 MHz. for the Mobile-Satellite Service. Because this spectrum is used for Broadcast Auxiliary, Cable Television Relay Service, Local Television Transmission Services and other Fixed Services (FS), the FCC proposed reaccommodation of these existing services.
Broadcast Auxiliary spectrum at 2 GHz. was reduced from 120 MHz. in the 1990 - 2110 MHz. band to 105 MHz. between 2025 - 2130 MHz. The FCC, drawing on comments filed by the Society of Broadcast Engineers (SBE), did not propose reducing the number of channels in this band. Instead, the bandwidth of each channel would be reduced to 15 MHz. from the existing 17 or 18 MHz. The new channel plan will be secondary during the transition, but would become primary around January 1, 2000. Any users operating under the old plan would not be allowed to interfere with those using the new channel plan. The FCC invited comment on whether or not a more flexible plan, with narrower channels for digital use, should be adopted.
Moving Broadcast Auxiliary into the 2110 - 2130 MHz. band will require clearing Fixed Service licensees from the band. Therefore, the new plan would not become primary until after the last FS licensee was relocated. The FCC allowed that sharing between FS and MSS may be possible, but if it wasn't, the FS licensee would move to bands above 5 GHz. The new MSS operators would have to share the cost of relocation of the existing services. The FCC invited comment on whether or not it should grant any new Broadcast Auxiliary licenses in the MSS bands or issue them only on the condition that the Broadcast licensee bear the cost of relocation.
This Report and Order is also available in WordPerfect and Adobe Acrobat formats.
FCC Releases HTML Version of Expanded AM Band Allotment Plan (Mar. 24)
Comark and Lin Television Sign DTV Agreement (Mar. 24)
Comark NAB Products (Mar. 24)
FCC Releases HTML Version of Expanded AM Band Allotment Plan (Mar. 24)
Full Text: FCC Report And Order On Teledesic Satellite System (Mar. 18) (See March 17 RF Current, below, for summary)
In a Press Release INTELSAT announced today that it had completed the latest round of interoperability testing for digital video compression equipment from ten different manufacturers. The tests focused on single channel systems used for digital SNG (satellite news gathering). California Microwave/STS, DiviCom, NDS/DMV, Magnitude Compression Systems, Inc./General Instruments, Scientific-Atlanta Inc., Tadiran Scopus DVC, Tandber Television AS, Thomson Broadcast Systems, Tiernan Communications Inc.,, and Wegener Communications participated in the test.
Unlike the tests last year, this round of tests looked at "plug and play" operation for both NTSC and PAL. at several different parameter sets. For "plug and play" test the only adjustments allowe there those "by means accessible to the typical user (i.e., front panel control or PC set-ups)."
INTELSAT is correlating and refining the test data. It will be released April 8th at the NAB Convention in Las Vegas. See the Press Release for more details.
The FCC today posted a News Release (nrin7008.txt) outlining the Order issued Friday March 14th authorizing "Teledesic Corporation to construct, launch, and operate a satellite system in a non-geostationary satellite orbit to provide domestic and international fixed-satellite servics in the Ka-band." Teledesic is based in Seattle, WA and backed by Craig McCaw and Bill Gates. The news release said
Teledesic proposes an innovative satellite constellation that will comprise an "Internet in the sky." The satellite system will link computers around the world with high-speed connections. The Teledesic network will also offer other information services, from high-quality voice channels to broadband channels supporting videoconferencing, interactive multimedia, and real-time, two-way digital data.
The system will consist of 840 satellites in non-geostationary orbit about 435 miles above the earth, which, as proposed, will provide "24 hour seamless coverage to over 95% of the Earth's surface and almost 100% of the Earth's population. " In the U.S. Teledesic was authorized to use 28.6 - 29.1 GHz. and 27.6 - 28.4 GHz. for uplinks. Downlinks will be in the 18.8 - 19.3 GHz. and 17.8 - 18.6 GHz. bands. The authorization "is conditioned on it [Teledesic] complying with the service rules to be adopted in a forthcoming Commission action on rules for the Ka-Band satellite services."
In a Public Notice released today it was releasing a Memorandum Opinion and Order which rescinds the allotment plan set forth in the March 22, 1996 Public Notice. The revised plan provides for 88 AM radio stations in the expanded AM band from 1605 to 1705 KHz. The Public Notice "identifies the stations eligible to apply for authorization and the specific allotments for which they may apply."
Yesterday the FCC released its Second Report and Order, Order on Reconsideration, and Fifth Notice of Proposed Rulemaking on the Local Multipoint Distribution Service (LMDS). The FCC envisions licensees providing a variety of services, "such as multichannel video programming, telephony, video communications and data services.", and "wireless competition to both local exchange carriers and cable television systems, even in urban areas."
A News Release posted on the FCC's web site today summarized the rules. The Order provides spectrum for LMDS in the 27.5-28.35 GHz., 29.1-29.25 GHz., and 31.0-31.3 GHz. bands. The spectrum will be licensed by Basic Trading Areas, with two licenses (one for 1150 MHz. and the other for 150 MHz. of spectrum) awarded for each BTA. Local exchange carriers and cable TV operators will have to wait three years to before obtaining in-region 1150 MHz. licenses. Licensees have to provide "substantial service" in their service areas within ten years. Existing users, such as state and local governments using the 31 GHz. for traffic control systems, will be able to continue operations, but will receive protection from LMDS only in the 31.0-31.75 GHz. and 31.225-31.300 GHz. portions of the bands. They will have 75 days to apply to modify their licenses to move to this part of the band and 18 months to implement the move.
The Report and Order outlined the technical details of the service. A uniform polarization scheme will be required within 20 km. of service area boundaries. Except those facilties operating in the 29.1-29.250 GHz. band, the maximum equivalent isotropically radiated power (EIRP) for LMDS hubs is set at 30 dBW/MHz. As much as 42 dBW/MHz. is allowed for point to point transmission paths. Required frequency tolerance is 0.001 percent, except for existing users in the 31 GHz. band.
More details are available in the Second Report and Order, Order of Reconsideration, and Fifth Notice of Proposed Rulemaking . It is available at the FCC's web site in both text and WordPerfect formats.
What is the upper frequency limit for satellite services? The FCC, in a Notice of Proposed Rule Making adopted yesterday, proposes to allocate spectrum for fixed satellite services in the 36 to 51.4 GHz. band. Services could include cellular and PCS backhaul, private data distribution, private line networks and backup and disaster recovery. The allocations would include both geostationary and non-geostationary Fixed Satellite Services. Downlinks would be in the 37.5 to 38.5 and 40.5 to 41.5 GHz. bands. Uplinks would be assigned frequencies in the 48.2 to 50.2 GHz. band.
The Notice of Proposed Rule Making sought comment on the extent to which terrestrial services could share spectrum with satellite operations. The Notice includes a proposed fixed allocation at 46.9 to 47.0 GHz. and an upgrade from secondary to primary status of the fixed and mobile service allocations in the 40.5 to 42.5 GHz. band.
A News Release summarizing the NPRM is available on the FCC's web site. The Notice of Proposed Rule Making is now available.
Thursday Scientific Atlanta announced that its PowerVu MPEG-2 encoders had passed CableLabs Conformance testing. A Press Release from Scientific Atlanta said that more than 100 system transport stream elements and over 70 video screen elements were checked to determine compliance with the MPEG-2 Main Profile / Main Level definition. Last year, Scientific Atlanta provided PowerVu MPEG-2 compresson equipment for interoperability testing by Intelsat. Details on the tests were reported in the September 1996 RF Current. and the September Intelsat Broadcaster.
The Consumer Electronics Manufacturers Association (CEMA) has put together a concise reference on the "V-Chip" parental control device to be included in TV receivers to receive information on program content from broadcast, cable and satellite TV providers. The What is A V-Chip? page includes general information as well as some technical details.
The FCC Order adopted March 4 and released yesterday did not change the transmission standard for digital television adopted in last year's Fourth Report and Order. The amendment included some non-substantive changes in language referencing material from the ATSC. The changes were requested by the Director of the Federal Register and replace the wording used in the Fourth Report and Order.
Scientific-Atlanta To Demo Digital Delivery of HITS and Other Digital Feeds at NCTA - Press Release.(3/17)
FCC & NTIA Agree to Relocate DEMS from 18 GHz. to 24 GHz. - News Release
Loral Space & Communications Completes Acquisition of AT&T Skynet - Press Release
FCC Proposes Rules to Streamline Equipment Authorizaiton Process - News Release
FCC Amends Rules for 220-222 MHz. Operation and LIcensing - News Release - Report and Order
In an Electronic Engineering Times article available on the 'Net, Junko Yoshida and George Leopold say the "key question is whether broadcasters can deliver the goods to parlay digital TV into the next big thing in consumer electronics. The only way to find out, regulators say, is to get digital TV on the air -- the sooner, the better -- and let consumers vote with their remotes."
The article provides an excellent overview of the problems facing consumer electronics manufacturers and broadcasters in providing HDTV products and programming. This article is must reading for anyone concerned about the future of broadcasting.
The FCC issued a Public Notice on March 6th announcing the auction of two nationwide licenses in the satellite Digital Audio Radio Service (DARS). One license will be for the spectrum from 2320-2332.5 MHz. and the other for 2332.5 to 2345 MHz. Participation will be limited to four entities - American Mobile Radio Corporation, Digital Satellite Broadcasting Corporation, Primosphere Limited Partnership, and Satellite CD Radio, Inc.
HDTV Newletter carried a news release dated March 5th announcing that Oregon Public Broadcasting was the first in the state to transmit digital television. The release indicated OPB's Portland TV station was transmitting DTV signals using a low power transmitter from Harris Corporation. Information on these transmissions was not available from either the Oregon Public Broadcasting or Harris Corporation web sites.
In a Notice of Proposed Rule Making released last week, the FCC proposed amending the Amateur Radio Service rules to eliminate the rules that restricted amateur radio stations to transmitting only frequency hopping and direct sequencing spreading techinques. Some Part 15 equipment suppliers, including Metricom, which operates a wireless Internet service in some areas were concerned high power amateur spread spectrum transmissions could interfere with their equipment. The NPRM addresses this by including a requirement that the transmitter power of an amateur station using spread spectrum emissions not exceed 100 watts under any circumstances. If the transmitter power is over 1 watt, it must be "automatically adjusted to maintain an Eb/ (N0 + 10) ratio of no more than 23 dB at the intended receiver."
Comments in this Rule Making are due May 5, 1997. Reply comments must be submitted by June 5, 1997.
Yesterday the FCC issued a Report And Order, Memorandum Opinion and Order And Further Notice of Proposed Rule Making on the Establishment of Rules and Policies for the Digital Audio Radio Satellite Service in the 2310-2360 MHz. Frequency Band. Copies are available from the FCC's web site in both Text and WordPerfect formats.
The Report and Order is quite detailed, covering competitive, public service and technical issues. Some of the key points: The FCC did not feel it was necessary to require the services be subscription based, increasing the possibility that satellite delivered radio could compete with terrestial broadcasters for advertisers. Full coverage of the continental US is required. Coverage of Hawaii, Alaska and territories is optional but encouraged. No specific value of service link margin for a given geographical area will be required. The FCC set no single transmission standard but will require that " a satellite DARS applicant, in its application, certify that its satellite DARS system will include a receiver design that will permit users to access all licensed DARS systems that are operational or under construction." No specific power flux density limit was imposed, however, stations will have to be coordinated and this may impose some limits. A request from Cornell University for tighter out-of-band emission limits than those required by Section 25.202(f) to protect radio-astronomy operations was rejected, but satellite operators were encourage to take deep space operations into account when designing their systems. Finally, of interest to TV broadcasters, feeder links will be licensed in the 7025 to 7075 MHz. band. This band is currently used for broadcast auxiliary operations such as studio transmitter links and electronic news-gathering. Satellite DARS earth station applications would have "to demonstrate that their Earth station operations would not affect other co-primary users of the band."
The "Further Notice of Proposed Rule Making" concerns the regulation of terrestrial gap-filler transmitters. Comments are due May 2, 1997 with reply comments due May 23, 1997.
In this week's issue, I'm introducing a new feature. During the week I uncover many interesting news reports and stories that I simply don't have time to summarize here. There are also items that lie outside the technical side of broadcasting, but which may still interest broadcast engineers, who often have to deal with FCC issues outside their area of expertise. I welcome your comments on this feature. Use the mailto link at the top or bottom of this page. Here are some of the links that didn't make it into the final edition:
Commission Proposes FY 1997 Regulatory Fee Schedule - News Release (Mar. 5)
FCC FY 1997 Regulatory Fee Schedule - Text or WordPerfect (recommended) format
Experimental Actions - January 1997
LIN Television Corporation Signs with Dielectric (Mar. 7)
Augmenting Reality (Virtual Sets and more...) (Mar. 7)
The first of the new Intelsat 801 series spacecraft was successfully lauched on Thursday, February 27 aboard an Ariane 44P launch vehicle. The satellite will be deployed at 64 degrees east and will serve customers throughout the Indian Ocean Region. The Lockheed Martin satellite has 46 transponders providing a mix of Ku and C-band services. New on this satellite are two independently steerable Ku-band spot beams that can be reconfigured in orbit. The series of commands needed to maneuver the satellite into geostationary orbit are supposed to be completed on March 7th. The solar arrays are scheduled to be deployed on March 9th and the C and Ku band reflectors on the 10th. After testing, the satellite should begin service in May 1997.
More details and hyperlinks to additional information are available in the Press Release on the Intelsat home page.
The FCC today released Commissioner Susan Ness' remarks before the Michigan Association of Broadcasters last week. While the remarks reflected Commissioner Ness' opinions, they also provide a glimpse of the future envisioned by the FCC. Ness started by stating she believed in free-over-the-air broadcasting, calling it an "insurance policy for democracy".
Commissioner Ness emphasized that "The DTV transition is unlike the introduction of prior broadcast services. FM did not replace AM radio. Color was added to black and white television. But DTV will replace analog NTSC transmission. In the long term we do not have enough spectrum to do both." She said the FCC hoped to complete a schedule of station allotments and the rules for DTV service by April. Regarding the early removal of some spectrum from broadcast TV, she commented "I am pleased that MSTV and the FCC staff are working out the differences in their tables so that a portion of the channels from 60 to 69 can be made available for other services, including public safety. Call this early return of analog spectrum as a 'down-payment' on the eventual return of all of the analog channels."
Some questions were left open for discussion. Ness asked "Should the FCC specify in advance the length of the transition, or should the transition be tied, say, to the percentage of households that purchase the new digital sets or have converter boxes? Or should we wait for a period, perhaps five years, and then set the conversion date?" She offered that she is "committed to preventing a break in service to consumers", but noted that "at the same time, I want to set in motion the rapid return of the analog spectrum. So, my decision, for example, on a simulcasting requirement will be based upon whether it is likely to delay or accelerate the transition to digital."
Commissioner Ness also addressed the Digital Radio issue. Referring to the CEMA request for a separate band for digital terrestrial broadcasting (see the CEMA News Release and Washington Post Ad), she said she prefers "to use the existing bands for terrestrial digital radio and support efforts to re-engineer them." She did allow that "...if these bands are not adequate, we must work together to see how radio broadcasters will get into the digital world."
Refer to Commissioner Susan Ness' remarks for more details.
Its power source is degraded and its ability to send data is almost non-existent, but Pioneer 10, launched on March 2, 1972, continues to function. NASA scientists expect to continue to be able to receive its faint radio beacon for at least another year. Pioneer 10 was the first man-made artifact to "leave the Solar System" when, on June 13, 1983, it passed beyond the orbit of the farthest known planet. It is currently over 6 billion miles away! NASA said "Pioneer 10 is now searching for the solar wind termination shock and the edge of intersellar space."
Pioneer 10 is a tribute to its designers and engineers. Consider that it has passed through an asteroid belt, survived the intense radiation from Jupiter and functioned without maintenance for 25 years and 6 billion miles! NASA is justifiably proud of this accomplishment. Take time to visit NASA's Pioneer 10 web page and also peruse the Pioneer 10 Mission Profile. These are well done web pages and include links to other archives.
Return to The RF Page @ www.transmitter.com
Last modified April 3, 1997 by Doug Lung dlung@transmitter.com
Copyright © 1997 H. Douglas Lung