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 May 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.
The FCC today released its Report on Experimental Applications granted during April. Two items looked interesting. One was KS2XFP granted to 3M Corporation "to use 905 and 5810 MHz for weathering tests of dielectric materials subjected to RF power." Locations are in Phoenix, AZ; Miami, FL; and Cottage Grove, MN. The other interesting application was KF2XDA granted to Alliant Techsystems, Inc. "to operate on 909.75-919.75 MHz to test and develop a system that detects and locates gunfire."
The FCC today made the full text of its Fifth Further Notice of Proposed Rule Making in MM Docket No. 87-268, Advanced Television System and Their Impact Upon the Existing Television Broadcast Service. As expected, the NPRM proposes adoption of the ATSC DTV "Grand Alliance" standard. This NPRM contains a wealth of background and historical information on how the Rule making has changed since it was first initiated in 1987. Some concrete technical proposals are included in fifth NPRM. These include allowing measurement of DTV RF power over the channel using an RMS averaging power meter and use of a precision offset of 5.082138 MHz., plus or minus 3 Hz. between the upper adjacent ATSC DTV pilot carrier and the lower adjacent NTSC visual carrier.
The NPRM requests comments on a wide range of technical standards and includes a lengthy list of part 73 regulations the Commission is considering modifying. An DTV emission mask is also proposed, along with mention of a 12 dB difference in operating level of ATSC DTV stations' average power level and NTSC peak power levels on adjacent channels.
This is an important document and the arguments are well thought out. It deserves comment from any broadcaster with an interest in the future of over the air television. I'm pleased to report that the FCC has acknowledged a role for Low Power TV in the body of the NPRM, requesting commenters consider the impact of their proposals on LPTV operations.
In a press release issued yesterday WRC-TV said the Model HDTV Station project had selected it as the host station for the project. WRC-TV is located in Washington DC and operated by NBC. The Model HDTV station project is sponsored both by broadcasters and the "professional consumer electronics industry". The release noted that
While the project is under way, the station will serve as a source of encoded digital television signals to aid equipment manufacturers in the development of their new lines of professional and consumer electronic equipment. It also will provide broadcast demonstrations in the Washington area to permit the public to view High Definition Television and to train broadcast station technical personnel in the new technology.David Sarnoff Research Center was selected to implement the facility. More details and quotes from industry officials involved with the project are in the Press Release.
Last week Senator Pressler put forth a Spectrum Reform Discussion Draft that, if enacted, would have a major impact on most users of the RF spectrum, particularly TV broadcasters. In the opening statement of the draft, Pressler challenges the way spectrum had been allocated, noting that digital communications technologies make it possible to use different frequencies and even share spectrum through a concept he refers to as an "overlay". He offered this explanation:
Another good example of why today's technology requires increased spectrum flexibility occurs in spread spectrum and digital overlay. These techniques make it possible for multiple communications pathways to be established within the same radio frequency channel. In other words, using this technology, broadcasters could transmit communications in addition to video and sound signals. Radio broadcast channels today, for example, already provide local links for paging operations. Government policy must allow multiple, more intensive use of radio frequency resources where there is no perceptible adverse technical impact.
Other publications have noted the Draft's proposal to charge TV stations for the second channel, then reimburse the amount paid, minus interest, when the original NTSC channel is returned. What has not been widely reported is that the Draft also appears to allow stations to continue broadcasting NTSC on their original channel as long as they want or switch to digital on that channel, noting:
An NTSC licensee will also be given flexibility within its assigned channel and service area to provide any services, without imposition of economic fees as required in the Telecommunications Act of 1996, other than standard NTSC service subject to technical limits imposed by the FCC to prevent interference to DTV and other NTSC assignments. Before any NTSC service may be reduced or discontinued, however, the NTSC licensee must have provided a comparable free replacement for such service including necessary receiving equipment to allow such service to be displayed on standard NTSC receivers.If you noticed that that paragraph did not include any reference to the ATSC DTV system or the Grand Alliance system, you are correct. Another provision of this Draft stated:
FCC is specifically precluded from mandating an HDTV or digital television (DTV) standard for broadcast licensees or establishing a requirement that all TV sets sold or imported must be digital compatible by a date certain.
This is a serious piece of legislation and it warrants reading. If you have difficult linking to the Spectrum Reform Discussion Draft, let me know and I will post it on the RF Page.
The Commission said today, that, in accordance with Section 403 (1) of the Telecommunications act of 1996,
"the license of any broadcast station that remains off-the-air for any consecutive 12-month period will expire as a matter of law, notwithstanding any provision, term, or condition of the license to the contrary. The first such licenses will expire on February 9, 1997. These rules will apply to all classes of broadcast stations, commercial and noncommercial, as well as to the remote pick-up and auxiliary stations licensed to the silent station."Report MM 96-21 also noted that the expiration will not be affected by a silent station's applications on file. The Commission warned anyone purchasing a silent broadcast station to "make sure that sufficient time exists, before automatic expiration of the license, to return the station to the air."
The FCC today released the Report and Order - WT Docket 95-102 establishing a "very short distance two-way voice radio system", called the Family Radio Service or FRS. It will be regulated under Part 95 of the Commission's Rules. The radios will be limited to 500 mW ERP and must use F3E emission with a peak deviation not exceeding plus or minus 2.5 kHz. External amplifiers, antennas and internal modifications to FRS units are prohibited. Connection to the Public Switched Network (PSN or telephone system) are not allowed.
In the second of three Notices on the transition of TV broadcasting from analog to digital, the FCC today announced in a News Release (nrmm6019.txt) that it proposed "requiring broadcasters that transmit digitally to use the ATSC DTV Standard." This standard has also been referred to as the "Grand Alliance" proposal. Recognizing the rapid rate of technological development, the FCC offered several options to promote development, including a sunset provision on the standard, a commitment to review the the Standard at some future time or reliance on "current processes to consider any future changes if circumstances warrant...". The FCC said the third and final notice will consider the allocation and assignment of channels. This notice will probably be released towards the end of the summer.
In a NEWSReport (nrin6014.txt) released today the FCC proposed a "uniform legal framework for permitting users in the United States to access satellite systems licensed by other countries ("non-U.S. satellite systems")." While the report's title indicates access will be easier, it notes that the licensing requirement for fixed satellite service receive only stations that communicate with non-U.S. satellites will be maintained. Receive only stations that obtain signals from foreign countries via U.S. satellite systems would be deregulated. In addition, "the Commission will generally permit non-U.S. satellites to provide mobile, fixed, or direct-to-home satellite services if there are no de jure or de facto barriers that prevent U.S. satellite systems from providing analogous services in the non-U.S. satellite's home market and some or all of its route markets."
Business Wire today had a release from Loral indicating the FCC had granted Loral approval to build and launch two satellites for "digital voice, data and television services to commercial and individual users in the United States, Puerto Rico and the Virgin Islands." The new satellites will be located at 77 degrees and 129 degrees west longitude. The satellites will have 24 C band transponders and 32 Ku band transponders with powers of 20 watts and 110 watts respectively. Loral calls the system "LoralSat". This is, to the best of my knowledge, Loral's first venture into the realm of commercial satellite operation. The company has extensive experience with satellite construction for defense and other governmental applications.
Earlier this year the FCC amended its regulatory policies governing domestic fixed satellites and separate international systems, making it easier for domestic satellite operators to access foreign markets. Apparently some foreign governments were not aware that "the FCC will no longer require or issue separate authorizations for transborder transmissions using U.S.-licensed satellite." Report SPB-45 summarizes the amendment on a one page form, which should make consultation with some foreign agencies easier.
Todays FCC Daily Digest announced the FCC had authorized "without opinion the construction, launch, and operation of eleven satellites" and assigned them orbital locations. In related news, FCC International Bureau Chief Scott Blake Harris praised the assignment plan for KA-Band, saying "Today the U.S. satellite industry is another step closer to providing a variety of seamless satellite services to customers world-wide".
Businesswire carried a news release from Marshall Electronics describing the SECURECam I. The SECURECam I is a digital color camera that plugs directly into a standard telephone line to allow remote viewing by any PC with a modem and Windows software. Single frame resolution is 640x480 with 24 bit color. The image can be viewed at a 2 FPS rate at lower resolution. This should make it the ideal device for monitoring remote transmitter sites. News departments may find it useful for monitoring traffic congestion and weather. The story noted that up to five or more cameras can use the same phone line. Suggested retail price was quoted at $599 for a SECURECam I, with slave cameras listed at $299 each and the multi-camera adapter box at $199. Marshall Electronics is located in Culver City, California.
Yesterday the FCC issued a News Release (nrwl6021.txt) outlining the final results of 184 rounds of bidding for 493 licenses. The spectrum auctioned was 30 MHz. of frequency block C, 1895-1910 MHz. paired with 1975-1990 MHz. One of the winning bidders was NextWave, which detailed its plans in a Press Release last week.
The FCC today released the full text of the Notice of Proposed Rule Making - ET Docket 96-102.. The NPRM proposes limiting peak EIRP to -10 dBW (0.1 watt), which the Commission believes will provide communications at distances up to 100 meters. The Commission decided not to allow higher power devices, saying they would pose "unacceptable interference risks" and limit the number of unlicensed stations in a local area. The Commission left open to comment future higher powered (1 watt transmitter power) operations in the 5.725 to 5.875 GHz. band.
Out of band emissions would have to be attenuated by at least 50 dB or to emission limits specified in Section 15.209. The FCC decided not to propose a channel plan, but invited comment on whether it should set a maximum band width and/or spectrum limitation on operations.
The NPRM leaves several issues open to comment, including development of an "etiquette" for usage. Comments are due 60 days after publication in the Federal Register.
Today the FCC released the First Report and Order and Further Notice of Proposed Rule making (WT Docket 95-157). See the April 1996 RF Current for a summary of this R&O.
Ever wonder what your community looked like in the 60's and 70's? You now have a chance. The U.S. Geological Survey has begun distributing photos from declassified U.S. intelligence satellite spy missions in the '60's and '70's. More information is available from the U.S. Geological Survey's declassified photos web page. Information and browse images can be accessed through the Global Land Information System. If you are only interested in the spy photos, jumping directly to the search form will save you a substantial amount of time navigating the menus.
When using the form, you can search for photos using either manually entered coordinates or by outlining an image on a map. If you use the map, don't forget to set the radio buttons at the top of the page. You will probably want to first "pan" the map to the area you want, then select "zoom" to zoom in on the air and, finally, select the area to search. Images can be view on line (not full screen) and ordered for the cost of reproduction ($8 to $18 according the the USGS page).
The FCC last week issued the Final rule; Third Order on Reconsideration and Order to Clarify "Private Operational-Fixed Microwave Service, et. al.; 2.1 and 2.5 GHz Frequency Use". Previous rule making enlarged the protected service area for MDS stations from an area equal to a circle with a 15 mile radius to one with a 35 mile radius. It also set rules for serving interference studies on affected ITFS stations and clarified the use of frequency offsets for interference protection. The rule heading notes "In this Third Order on Reconsideration and Order to Clarify, the Commission also provides clarification of provisions set forth in the MDS Report and Order in MM Docket No. 94-131 and PP Docket No. 93-253, including the interference study requirements for pending ITFS applications and the statement of intention to be filed by some winning bidders in the MDS auction." Refer to the document linked to above for the complete text.
In a press release issued today Andrew Corporation claimed credit for engineering the antenna system at the "highest broadcasting station" in North America - the KRQE - Channel 13 / KASY -Channel 50 tower on Sandia Crest in Albuquerque, New Mexico. The structure is interesting in that the mast is designed to support over 11 tons of radial ice and 130 mph winds. The wind thrust at these levels is "equivalent of the thrust produced by four 727 jet aircraft engines." Jump to the press release at the Andrew Corporation Web Site for more details on this interesting project.
Business Wire carried a release today from Acrodyne announcing Acrodyne Industry, Inc.'s introduction of 10, 20, 50 and 100 watt MMDS wireless cable transmitter units.
The following item is from John O'Neill, Secretary of the BWA
The BROADBAND WIRELESS ASSOCIATION (BWA) emerged from a call for an industry initiative to promote wireless technologies during the 1st Digital MMDS European Workshop (May'95) hosted by TDF in Metz, France. This workshop formed part of a European Union research project entitled Digital Microwave Multi-point /Multi-Channel Propagation undertaken by an consortium comprising STAR Telematics, North West Labs, TeleDiffusion de France (TDF) and THOMSOM CSF. North west Labs operates the Irish National Wireless Cable (MMDS) Test-bed.
The BWA comprises manufacturers, telecommunications operators, service providers, network operators and researchers from eight European countries.
Technical, Commercial and Regulatory Committees are being formed to address the BWA work programme. The intent is to draw-on and complement the work of other groups such as DVB and CEPT in fostering a strong industry.
More information is available from John O'Neill.
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Last modified May 24, 1996 by Doug Lung email@example.com
Copyright © 1996 H. Douglas Lung