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 June 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.
Thursday the IEEE Standards Activity Board ratified IEEE Standard 802.11 for wireless Local Area Networks (LANs). The new standard will allow wireless LAN products from different vendors to work together. A Lucent Technologies Press Release described the key features of the standard:
802.11 defines both the Physical (PHY) and Medium Access Control (MAC) protocols for wireless LANs. The PHY specification encompasses three transmission options: one infrared (IR) option and two radio frequency (RF) options (Direct Sequence Spread Spectrum and Frequency Hopping Spread Spectrum). These three options enable wireless LANs to satisfy multiple price/performance requirements in a broad range network environments, from a single room to an entire campus.
The MAC protocol, known as Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), works seamlessly with standard Ethernet, making wired and wireless nodes on an Enterprise LAN logically indistinguishable. This compatibility makes wireless LAN products easy to install, operate, and manage when integrated with a wired Local Area Network. Many advanced features are incorporated into the MAC protocol, such as roaming and power management.
Another company, Netwave-Wireless has a more detailed technical explanation of the standard on its 802.11 Industry Standards: IEEE Backgrounder page.
The FCC list of broadcast applications released today showed the Commission had accepted for filing several commercial digital television station applications. These included KTVD-DT on channel 19 in Denver, CO with 860 kW ERP (average) and a Dielectric TFU-30GTH antenna, WESH-DT on channel 11 in Daytona Beach, FL with 45 kW ERP and a Dielectric THV-6A11 antenna, KCCI-DT on channel 31 in Des Moines, IA with 1000 kW ERP and a Dielectric TFU-30GTH, KETV-DT with 1000 kW on channel 20 also using a Dielectric TFU-30GTH antenna and KOAT-DT, channel 21 in Albuquerque, NM with 280 kW and another TFU-30GTH. More information can be found in the FCC Public Notice.
Another item of interest in the same Public Notice was an application from Global Broadcasting Company, based in New York City, for a new developmental broadcast station "for experimentation with and development of event broadcasting." The application proposes operation through the United States, including the U.S. Virgin Islands and Puerto Rico, with 40 watts anywhere in the AM band, 10 watts anywhere in the FM band and 10 watts on any channel 2 through 13. Call letters are KF2XBF.
INTELSAT said that it successfully launched INTELSET 802 on June 25th from Kourou, French Guiana. The satellite will be deployed at 174 degrees East and serve the Pacific region. Coverage includes parts of Australia, various Asian regions and the west coasts of the United States and Canada. The satellite has 44 transponders on C and Ku band. Two of the Ku-band spot beams are independently steerable and can be reconfigured in-orbit. The satellite is scheduled to begin service the end of August, 1997. For more information see the INTELSAT Press Release.
The Academy of Television Arts and Sciences (ATAS) will present a Primetime Engineering Emmy to the Digital HDTV Grand Alliance for its role in developing the technology upon which the new U.S. standard for over-the-air DTV broadcasting is based. The ATAS said the Grand Alliance is "primarily responsible for developing and standardizing the transmission and technology for the upcoming digital television revolution by establishing a system that delivers a flexible mix of high-resolution television, multiple standard-resolution programs, multiple-channel digital audio and data for advanced applications." In a joint statement, the seven members of the Grand Alliance said "We're extremely proud to have been selected for this prestigious award, which over the years has been conferred on many of the industry's most distinguished innovators. Grand Alliance technology will propel America into the digital age, and redefine the medium of television for the 21st century."
The FCC's Office of Engineering and Technology released its list of Experimental Actions for May 1997 this week. Amateur Radio operators around Ashburn (Loudoun) Virginia may want to tune a bit above two meters to check out WA2XHS, an experimental station license granted to COMSAT RSI on 149.61 MHz. to test LEO (Low Earth Orbiting satellites) antennas. Lockheed Martin Corporation was authorized for mobile operations in the 420-450 MHz. band to test a sensor subsystem of an advanced air defense system. If there are any UHF TV stations operating on channel 39 or higher in White Bear Lake, Minnesota, they may be interested in an experimental authorization granted to Underground Imaging, Inc. to operate in the 620-960 and 3100-3400 MHz. bands. In Santa Clara, California, Netro Corporation was allowed to operate fixed and mobile transmitters on 38 GHz. for propagation studies.
Fearing consumers will hold off purchasing large screen TV's until DTV sets are available, Zenith pledged that "consumers may trade in any large-screen Zenith TV set purchased between Aug. 1 and Dec. 31, 1997, applying the original purchase price toward a new Zenith digital high-definition television (HDTV) set, planned for introduction late next year." The HDTV set must be purchased from an authorized Zenith dealer no later than Dec. 31, 1999. Large-screen is defined as 32 to 60 inches. Refering to the digital HDTV sets, Zenith Sales Company President William J. Sims said "...initially those new sets will be quite expensive - perhaps more than $7,000 - and digital programming will be limited for many years." Sims added that today's big-screen sets are a "tremendous value." Saying reports that analog TV sets will be useless after digital programming begins are erroneous, he commented that "The TV sets we're selling today will likely never become obsolete. They'll continue to receive analog broadcasts until 2006, and they'll accept cable, satellite, VCR and DVD signals for years after that. And if people add a converter box, those sets will receive digital TV broadcasts."
There are restrictions and limitations on the trade-in. Zenith is also offering a coupon for converter box purchases. For full details, see the Zenith Press Release. In other digital video news, a Consumer Electronics Manufacturers Association News Release said more than 27,000 DVD players were shipped to dealers in May while "sales of laserdisc players plummeted 81 percent to some 1,800 units."
Last week the FCC imposed a forfeiture of five thousand dollars on each of the nineteen licensees renting space on a tower owned by Bowen-Smith Corporation. The Compliance and Information Bureau did not take action against the owner, noting that "At the time of the violations, [December 7, 1992]licensees on an antenna structure were solely responsible for violations of the terms of their license. Although Congress authorized the Commission to impose forfeitures on non-licensee tower-owners, this change did not alter a licensee's ultimate responsibility for compliance. An FCC licensee may not delegate its responsibility to comply with the Commission's rules, and is held responsible for the acts of its agents and similarly situated persons."
The Order also noted "Furthermore, a licensee is required to comply with the provisions in its license and the FCC's rules, and 'oversight or failure to acquaint itself with the Commission's requirements will not excuse' a violation." "Moreover, violations that result from inadvertence, omissions, or mistakes are equally subject to monetary forfeiture penalties." "Therefore, we find no reason to change the field office's determination to hold the licensees responsible."
Refer to the Memorandum Opinion and Order for more information. The FCC Rules outline procedures licensees should follow if a tower owner refuses to properly maintain tower lighting or markings. See my FCC Links page for sources of FCC Rules.
Press reports last week made reference to rejection of Representative Markey's attempt to ban the sale of analog only TV's after 2002. This, however, was not the only story. While many TV broadcasters focused on outlining the flaws in the FCC's 5th and 6th Report and Orders on Advanced TV (details on that in next week's issue), the House of Representatives worked on legislation that will affect the future of DTV and even today's analog TV.
The details are in the Committee Prist, Proposed Reconciliation Provision as Approved by the Subcommittee on Telecommunications, Trade and Consumer Protection on June 10, 1997, Title III, Committee on Commerce, Subtitle D - Communications. An Adobe Acrobat PDF File of it is available on the House Commerce Committee's web site. Key points are that "initial licenses or construction permits assigned by the Commission to existing terrestrial broadcast licensees for new terrestrial digital television services" are excluded from auction requirements. It also appears the life of analog TV may be extended beyond 2006:
"A television license that authorizes analog television services may not be renewed to authorize such service for a period that extends beyond December 31, 2006. The Commission shall grant by regulation an extension of such date to licensees in a market if the Commission determines that more than 5 percent of households in-such market continue to rely exclusively on over-the-air terrestrial analog television signals."
LPTV stations that air at least 3 hours a week of locally produced programming and that are on the air at least 18 hours a day were also given protection under this bill. It states "Prior to making any allocation or assignment under this section the Commission shall assure that each qualifying low-power television station is assigned a frequency below 746 megahertz to permit the continued operation of such station."
Refer to Subtitle D... for details. Refer to The Subcommittee on Telecommunications, Trade, & Consumer Protection Web Site for current news.
Will TV ownership consolidation go as far as radio has? The Local Television Competition and Diversity Act, introduced last week by Congressman Cliff Stearns increases the chances for multiple ownership of two TV stations in the same market. However, it would not allow the a single owner to own more than two stations. He said
"The heart of the legislation would allow a person or company to own two stations in a local market, but one would have to be a UHF station. Therefore, such an entity could own two UHF stations or a VHF-UHF combination. Notwithstanding, however, the FCC still would have an override of that duopoly condition if they significantly harm diversity in their opinion. This bill also would allow the FCC, under unusual and compelling circumstance, to allow a person or company to own two VHF stations."
See the full text of the Local Television Competition and Diversity Act of 1997 for more details.
Scientific-Atlanta (SA) in a Press Release issued today Theodore R. Wieber, Jr., president of SA's Electronic Systems Division, said
"Acquisition of the first five IRIDIUM satellites represents a number of technology 'firsts' for the satellite communications industry. It marks the first time five commercial communications satellites have been launched and placed in orbit together and the first time such a deployment has been tracked by five separate ground stations strategically located around the world to monitor them. Also of key importance to the IRIDIUM program is our ability to meet the significant challenge of using Ka band (20-30 GHz) frequencies for system control segment functions. Obviously, Scientific-Atlanta is proud to play an important role in support of the IRIDIUM System."
IRIDIUM is a system of low earth orbiting satellites providing a worldwide wireless telecommunications network for telephone, paging, facsimile and data services to subscribers using handheld telephones and pagers. The service is scheduled to be made available in late 1998, after the entire 66 satellite network is operational. SA is under contract to build 57 earth terminals for the system, 43 of which will be used in communications gateways linked to the public switched telephone networks. The others will be used to regulate the orbit of the satellites.
The Consumer Electronics Manufacturers Association (CEMA) asked the House of Representatives' Commerce Subcommittee on Telecommunications to kill a proposal by Representative Edward Markey (D-MA) that would effectively ban the sale of analog TV sets after the year 2002. Markey's amendment would require all TV receivers, VCRs and set top boxes sold after 2002 be able to receive a digital signal.
Gary Shapiro, CEMA's president, commented that
"Thankfully, Congress did not consider laws like this when television was first introduced. If this type of logic had prevailed then we wouldn't have radio today. This effort of Congressman Markey's to spotlight the foolishness of the budget allocation for [TV] spectrum auctions is laudable, but doing it at the expense of consumers and manufacturers is outrageous. Each year, Americans buy more than a million black and white televisions because they are adequate to meet the needs of many Americans. Similarly, we expect analog-only sets and VCRs to be in great demand for years to come. The free-market works - consumers want choice and they want the freedom to express that choice. Black and white television did not become obsolete then, and it along with NTSC color and VCRs, will not become obsolete tomorrow. This amendment is anti-consumer and anti-choice."
CEMA also criticized Representative John Dingell's (D-MI) amendment to the budget bill that would require language on all analog TV sets sold in the US stating that they would be "obsolete" after 2006. More details are available in the CEMA News Release.
The FCC's monthly listing of experimental license grants included three items that I thought readers might find interesting. Ford Communications, Inc. was granted an experimental license to test Digital Audio Radio Services (DARS) receivers for foreign markets in the 226 to 230 MHz. band. Of interest to Channel 13 TV stations in the area, Syntron, Inc. was granted a license to operate between 216 and 220 MHz. to test and develop a remote sensing system for acquistion of seismic information in Huntsville and Matagorda Texas. Sprint Corporation, LLC, was given permission to use 27.5 GHz. to 28.35 GHz. for test and development of a Local Multipoint Distribution System.
E-Town News carried an article today saying that Day Sequerra, a manufacturer of high end audio tuners, would be marketing indoor antennas designed to replace rabbit ears and allow direct to home satellite users the ability to receive local TV stations. The antennas are omnidirectional, slender, almost flat panels designed to be wall mounteded. Prices for the TV antennas range from $129 to $159. Refer to the E-Town News article for more details on this product.
RCA also announced it has developed a new 18-inch satellite dish that contains an imbedded TV antenna for the reception of local programs. This dish allows owners of RCA digital satellite systems to receive local channels without an additional antenna.
It will be interesting to hear how these antennas work in urban environments where multipath is often a problem. Please drop me a note if you have an opportunity to test one of them. Also interesting is that, so far, I have not seen any announcements from companies using the innovative indoor antenna funded by NAB research.
The National Association of Broadcasters (NAB) and the Association for Maximum Service Television (MSTV) asked the FCC "to adopt a rule preempting certain state and local government restrictions on the placement, construction and modification of broadcast transmission facilities." While the main purpose of the Petition was to provide relief for TV broadcasters trying to meet an aggressive DTV build--out schedule, it also sought preemptive relief for radio stations as well.
NAB President/CEO Edward Fritts said "The FCC should be sensitive to legitimate local interests. But, in order to meet the DTV build-out schedule to which television broadcasters are dedicated -- and to let all broadcasters improve their service -- somelocal and state restrictions may need to be overridden. The FCC has this authority and we hope that this rule making will go forward expeditiously." MSTV President Margita White noted that "Issues such as RF radiation, interference concerns, tower appearance and tower height are matters of federal regulation. Television stations simply will not be able to meet the DTV build-out schedule if local procedural rules stymie the alteration of existing towers or the siting and construction of new ones.
More information is available in the NAB Press Release.
In a speech to Commission employees, FCC Chairman Reed Hundt said he had asked President Clinton to begin searching for a replacement for his position. He outlined what the FCC had accomplished during his term, listing items such as:
He also said the Commission had more work to do, including ensuring that "digital television is launched rapidly and with rules that guarantee that digital television programming will serve the public interest." In the midst of all changes his term has brought, it is useful to step back and look at the big picture. This speech provides a good view of that picture. Many of the reforms he instituted will not be felt until the new technologies hit the market over the next few years. It will be interesting to see how his successor handles the climate of revolutionary change Hundt instilled in the FCC. A RealAudio® version of his speech is also available from the FCC's audio archive.
NASA's Langley Research Center, working with a consortium led by TRW Space and Electronics Group, plans to demonstrate "in flight a weather-piercing camera that has allowed researchers to see through fog, smoke and clouds." The system uses millimeter radio waves to generate a visual image of the forward scene in low-visibility conditions. The NASA press release didn't describe the illumination source, but said "The sensor uses a focal plane array of about 1,000 receivers made up of monolithic millimeter wave integrated circuits developed by TRW. Each of these complex circuits, formed on a sliver of gallium arsenide, replaces bulky, heavy and costly components, resulting in a compact device."
MOre details are available in the NASA Press Release.
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Last modified June 30, 1997 by Doug Lung dlung@transmitter.com
Copyright © 1997 H. Douglas Lung