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 July 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.

July 28 - Issue 79 Final Edition

INDUSTRY - Judge Awards COMARK Up to $18M In Harris Patent Suit (July 24)
COMARK Communications released news late Thursday that a Federal judge in Philadelphia affirmed an earlier jury finding that Harris Corporation's Broadcast Division willfully infringed on COMARK's patent for its Aural Carrier Corrector. As reported in the April 28th RF Current, the jury awarded COMARK $7.7 million. Now, according to the release carried on Business Wire, the judge doubled the judgement against Harris to $15.4 million because the infringement was "knowing and intentional". In addition, the judge ordered Harris to pay prejudgement interest of $745,000 and granted a request from COMARK for reimbursement of its attorneys' fees, which COMARK estimated at $2.6 million. See the COMARK Press Release for more information.

The April 28th RF Current also reported on Harris' response to the original jury verdict. In that response, Richard Ballantyne, Harris vice president and general counsel, said Harris would appeal the ruling to the Federal Court of Appeals if necessary. Harris' response to today's ruling wasn't available as this was written but will be reported in RF Current as soon as it becomes available.

FCC Releases Report And Order on Sky Station 40 GHz. Application (July 23)
Today the FCC posted its Second Report and Order (FCC97153) on amending parts 2, 15 and 97 of the Commission's Rules to Permit Use of Radio Frequencies Above 40 GHz. for New Radio Applications, International Harmonization of Frequency Bands Above 40 GHz. and the Petition of Sky Station International, Inc. for Amendment of the Commission's Rules to Establish Requirements for a Global Stratospheric Telecommunications Service in the 47.2 - 47.5 GHz. and 47.9 - 48.2 GHz. Frequency Bands.

While the Report and Order contains information and decisions useful to other applicants wishing to establish communications systems in the bands above 40 GHz., the core of this document is its descriptions of the Sky Station global wireless telecommunications service. RF Current outlined the Sky Station system in the May 12th issue. This Order provide more details on the service, called the Global Stratospheric Telecommunications Service or GSTS, which is based on a network of platforms in the stratosphere, kept aloft by hydrogen or helium elements about 18 miles above the earth and propelled by Corona Ion Engines that use the surrounding atmosphere and the sun as a fuel source.

The system is designed to provide data, voice and video communications at a 64 kbps. data rate to small personal receivers or PC cards. The system would also provide wireless Internet access. Lasers would link the stratospheric platforms to each other.

USSB was concerned that the Sky Stations would interfere with reception of DBS-TV satellites. The FCC decided to defer USSB request that the Commission accept a service rule requirement that would protect DBS-TV from Sky Station interference. The FCC said it would consider the requested restriction when it considers the need for other use restrictions "to ensure the performance of the authorized services under appropriate service rules."

HCI (Hughes Communications, Inc.) and Motorola argued that there are many open technical, financial and safety concerns that must be addressed before the FCC acts on this. In particular, HCI and Motorola argued that "there are significant public safety risks posed by the use and size of the platforms, their untested technology, and their location over major metropolitan areas and in aircraft flight paths."

The full text of this Report and Order presents an almost sci-fi version of future telecommunications. It makes interesting reading.

FCC Preempts Meade Kansas Satellite Dish Ordinance (July 22)
After declining to preempt several ordinances (see RF Current for July 14), the FCC today granted a Petition for Declaratory Ruling filed by Star Lambert and the Satellite Broadcasting and Communications Association of America.

The FCC Ruling found problems with the city's permit and fee requirements, the penalties for non-compliance and the city's antenna location requirements. One interesting aspect of this case is that although the city repealed the ordinance prior to the FCC's decision and replaced it with another one, the FCC rejected Meade's contention that the Petition is now moot. The FCC instead based its decision on the new ordinance.

This case makes interesting reading for anyone interested in the battle between local governments and the FCC over the right to regulate over the air reception devices. Full details are available in the Memorandum Opinion and Order (DA971554).

FCC Acts on Satellite Applications in 2 and 40 GHz. bands (July 22)
The FCC's International Bureau announced in a Public Notice (DA971551) that it found the application by Motorola for its M-Star system was acceptable for filing. The M-Star system is a global network of 72 non-geostationary satellites. Uplinks will operate in the 47.2 to 50.2 GHz. band and the downlinks (satellite to earth) will operate in the 37.5 to 40.5 GHz. band. Intersatellite links will operate between 59 and 64 GHz. and 65.0 to 71.0 GHz. Up to six tracking, telemetry and control sites will use the uplink bands. The service will provide voice and data services at data rates ranging from 2.048 Mbps. to 51.84 Mbps using earth stations with antenna aperture sizes ranging from 0.66 to 1.5 meters. The FCC invited filings by new applications for satellite systems in the 40 GHz. band. More information is available in the Public Notice.

In another action, the International Bureau established a cut-off for additional space station applications in the 2 GHz. band. Public Notice (DA971550) invited

"(1) amendments to existing applications and (2) new applications for authority to construct, launch and operate U.S.-licensed geostationary and non-geostationary satellite system and (3) letters of intent to use non-U.S. licensed space stations in providing mobile satellite service to, from and within the United States to be considered in the First 2 GHz. Band Processing Round in accordance with the Commission's 2 GHz. Allocation Order released March 14, 1997."

The frequency bands allocated for the service are 1990 to 2025 GHz. and 2165-2200 MHz. Refer to the Public Notice for more details.

OTHER Items of Interest

July 21 - Issue 78 Final Edition

TV - Larcan-TTC Approves Merger with Larcan Inc. (July 18)
Larcan-TTC, based in Louisville, Colorado, announced it had approved a definitive merger agreement with Canadian based Larcan, Inc., currently a 78.4 percent shareholder. If approved by Larcan-TTC shareholders, the company will become a wholly owned subsidiary of Larcan, Inc.

For more information on Larcan, see its web site at http://www.larcan.com. Information on Larcan's parent company, LeBlanc and Royle, is available at http://www.leblanc-group.com.

FCC Experimental Actions (July 18)
The FCC has released its list of experimental application granted in June. Interesting licenses include WA2XLT, to Tracor Aerospace Electronic Systems, Inc. for operation on 74.7, 140, 225, 450 and 959.995 MHz. to do radiation hazard and antenna tests under a Government contract. The station will be located in Lansdale, PA. Radian International was granted three licenses to operate wind profiler radars on 915 MHz. in Temecula, Riverside and Palm Springs California.

A complete listing of all experimental applications granted in June is available from the FCC in Public Notice PNET7016.

FCC Moves To Allow Non-U.S. Satellites to Serve the U.S. (July 17)
The FCC has released a "Further Notice of Proposed Rulemaking" seeking additional comment on a framework to allow satellites licensed by other countries to provide service in the United States. The News Release noted that the FCC would retain its proposed ECO-Sat tests for satellite licensed by non-World Trade Organization members, for intergovernmental organizations and for services such as direct-to-home TV, direct-broadcast satellite TV and digital audio radio.

More information is available in the FCC News Release NRIN7026. The full text of of the Further Notice of Proposed Rule Making is available in the International Bureau's Notices directory under FCC97252 .

SPACE - Human Planetary Travel Will Require New Technologies (July 15)
A report from the Natonal Research Council said today's technologies would not be able to sustain crews affordably on missons beyond Earth's orbit. Even though there are no immediate plans for such exploration, that situation is likely to change in the next two decades. The report recommended focusing programs on key priorities such as a self-contained life support system and spacesuits designed for use on planet surfaces.

See the Press Release from the National Research Council for more information on this NASA funded study.

OTHER Items of Interest

July 14 - Issue 77 Final Edition

FCC Proposes Reallocating TV Channels 60-69 To Other Services (July 9)
The FCC today released a Notice of Proposed Rulemaking that would allocate 24 MHz. of spectrum now used by TV channels 63, 64, 68 and 69 (764-776 MHz. and 791-806 MHz.) for use by Public Safety radio systems. The remaining 36 MHz. would be allocated to fixed, mobile and possibly broadcasting. Existing full power stations would be protected from interference, although the criteria for this protection was not specified. While the FCC welcomed comments on how to mitigate the impact on LPTV and translator stations, the NPRM also states: "We emphasize, however, that any accommodation of low power operations should not impede public safety use of the spectrum nor reduce the opportunity for other services to use this spectrum." One alternative suggested was to defer allocation of some of this spectrum until after the DTV transition period ends in 2006.

For more details, see the FCC's Web Page on this issue at www.fcc.gov/oet/dockets/et97-157/. For information on public safety radio spectrum requirements, see the Public Safety Wireless Advisory Committee page.

FCC Declines to Preempt Local Zoning Regulation for Some Sat Dishes (July 9)
Today the FCC released several Memorandum and Order relating to requests that it preempt local governments and allow certain satellite dish installations. The FCC declined a request from Hughes Network System that it preempt the zoning ordinances of Coconut Creek and Coral Gables Florida and allow VSAT dishes on the roof tops of some service stations. The reason given was that Hughes had not shown that it had "exhausted all local administrative remedies". Full details are available in International Bureau Order DA971365.

In another case, the FCC declined a request from TerraStar, Inc. to have its new C-band satellite dish system covered under the Commission's rules on over-the-air reception devices. The TerraStar system is interesting in that instead of using the conventional two to three meter dish for C band reception, it instead uses a linear array of three adjacent parabolic dishes, each 0.53 meters in size. The total length is greater than the one meter allowed dishes to qualify under the over-the-air reception devices laws. While the FCC declined this request, it said it would consider instituting a Notice of Proposed Rulemaking to deal with these "significant issues." Full details are in International Bureau Order DA971364.

The FCC's collection of decisions in several satellite receive dish cases were released on the Internet Wednesday. To find additional cases, check http://www.fcc.gov/Bureaus/International/Orders/1997/ and look at the files surrounding the Orders listed earlier.

OTHER Items of Interest

July 7 - Issue 76 Final Edition

CONSUMER - AITECH Introduces 2.4 GHz. Wireless Link for the Home (July 7)
AITECH announced its new PC/TV Airlink, a device which connects to a PC, scan converts the video, then transmits it to a receiver connected to a TV set up to 300 feet away (100 feet through obstructions). In addition to providing a wireless link from the PC's video monitor and sound board to the TV, it also comes with a wireless keyboard / mouse that uses an IR link to communicate with the set-top receiver box and back to the computer. AITECH says the keyboard / mouse combination was designed for laptop use while sitting on a couch or easy chair. Although designed for the home, don't be surprised if this unit turns up in some business settings. The 2.4 GHz. transmitter has a PLL synthesizer with four channels. See the AITECH PC/TV Airlink page for more information. Suggested retail price is $399.

SCIENCE - Pathfinder Lands On Mars (July 6)
For the first time in over twenty years, a spacecraft from Earth has landed on Mars. As one would expect, the images are sharper and coming in much faster than the first pictures from Viking. NASA has teamed up with Silicon Graphics, Compuserve, Sun Microsystems and other Internet servers around the world to cover the Mars landing and exploration. Choose the server nearest you at http://mpfwww.jpl.nasa.gov/. You'll find updates seem to run about half a day behind event. Want more pictures? Check out the Imager For Mars Pathfinder (IMP) Page. (Original story dated July 3, Revised July 6)

FCC Considers Reallocation Of TV Channels 60-69 At Open Meeting (July 2)
According to the Agenda.released Thursday, the Federal Communications Comission will consider the reallocation of television channels 60-69, the 746 to 806 MHz. band, at its open meeting Wednesday, July 9th. Recent bills introduced in Congress require the Commission to allocate 24 MHz. of spectrum as soon as possible for public safety use. See Senate Bill 705, introduced by Senator McCain.

The audio portion of the meeting, scheduled to start at 9:30 AM EDT, can be heard via the Internet, using RealAudio. Visit http://www.fcc.gov/realaudio/ for directions.

The long wait is over. The FCC's Office of Engineering and Technology released OET Bulletin 69, titled Longley-Rice Methodology for Evaluating TV Coverage and Interference. Longley-Rice is a very flexible program designed to cover a wide range of applications and locations. OET-69 provides the parameters needed to provide the results needed for FCC TV broadcast applications under the new rules released in the FCC's 6th Report and Order on DTV. (See the April 21, 1997 RF Current).

OET-69 is available from the FCC Office of Engineering and Technology Web Site in WordPerfect or Adobe Acrobat format.

OET-69 doesn't address all the issues put forth by Dr. Oded Bendov in his paper Understanding the Requirements for DTV Construction Permit Application or the Petition for Reconsideration filed by Hammett and Edison (Acrobat File - 508k). The outline at the front of the Bulletin, for example, mentions "grid cells over water" but the text doesn't contain any information on this. In spite of these limitations, OET-69 provides much of the key information missing in the FCC's 5th and 6th Report and Order on DTV. Resolution of some of the issues raised in the two papers mentioned earlier will likely require higher level approval at the FCC. OET should be commended on their efforts to clearly define a complex process.

The FCC in general and OET in particular should be complimented on their decision to make the Fortran source code of the FCC's computer program for DTV coverage and interference analysis available on the FCC Internet site, along with a database of DTV antenna patterns. Neither of these were available July 2nd, when OET-69 was released. The Longley-Rice program or, more accurately, the Irregular Terrain Model, Version 1.22, has been available on the Internet for sometime. You can find the source code in Fortran along with documentation and a very limited capability DOS program at http://elbert.its.bldrdoc.gov/itm.html. I'll have more on Longley-Rice in my August 1997 RF Column in TV Technology magazine.

WIRELESS - Warp Drive Networks to Use UHF LPTV Channel For Internet Service (July 2)
According to a story on Business Wire today, Warp Drive Networks has been granted permission by the FCC to use a transmitter operating in the low power UHF TV spectrum to transmit its wireless Internet Access Service. The service will provide coverage in Silicon Valley. The same company will also use MMDS frequencies, in a cellular configuration, to provide coverage in the Seattle market.

The LPTV transmitter provides the path from the Internet to the user. The return path will still require another Internet connection, such as a dial up phone line. This is similar to how Hughes DirectPC service currently operates. Monthly fees will start at $150 / month for 128k of bandwidth.

More details are available on the FAQ page at Warp Drive Networks home page. While the manufacturer of the equipment wasn't mentioned, both ITS Corporation and EMCEE showed wireless Internet solutions at the recent WCA convention in California and both sell UHF LPTV transmitters and MMDS equipment. Use the links in the previous sentence to visit their home pages.

OTHER Items of Interest

Other Issues Available:



1995 and 1996

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Last modified July 28, 1997 by Doug Lung dlung@transmitter.com
Copyright 1997 H. Douglas Lung