RF CURRENT

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.

Issues are dated each Monday, although recently I've needed an extra day(week) or two to complete each issue. Articles may be posted earlier if time permits or if there is a major, breaking story.

<<< Back to November 22 - Issue 241

December 4, 2000 - Issue 242 Final Edition

TECHNOLOGY - WJ Communications Says It Can Break Shannon's Law (Dec. 1)
WJ Communications, Inc. announced scientists at its R&D labs have proven that the theoretical limits postulated by mathematician C.E. Shannon on information that can be transmitted in a given bandwidth can be exceeded. While such claims have been made before, this time the scientists have been able to demonstrate transmission of data at 155 Mbps in an occupied bandwidth of less than 4 MHz using hardware and software developed at WJ Communications.

Research team leader Max Martone, PhD., presented the results at the Globecom communications research conference. Experiments were conducted using frequencies in the 2.5 GHz range in outdoor, non-line-of-sight multipath environments. The WJ Communications Press Release said "Custom low cost RF hardware developed by WJ Communications has demonstrated data transmission in the range of 60-155 Mbits/sec occupying a bandwidth of 2-4 MHz at MMDS type frequencies."

The Press Release did not explain how the system achieved the extra data capacity, but a comment provided a clue: "The creation of extra-dimensionality between transmitter and receiver is achieved by properly sampling the wavefield space created by the multipath propagation environment." There were few other technical details in the announcement.

Malcom Caraballo, President and CEO of WJ Communications, said, "We believe this breakthrough will revolutionize the communications industry by offering a tremendous increase in spectral efficiency. Our technology will allow users to achieve broadband data rates in a non line of sight environment through narrow spectrums." Skip Hoover, Senior Vice President said, "The WJ designed solution can be achieved at comparable cost to currently deployed systems while delivering five times the data throughput in the same bandwidth."

Additional information may be available on the WJ Communications web site.

DTV - Survey Shows Increasing Consumer Interest in DTV (Dec. 1)
A survey of 1,000 adult American consumers by eBrain Market Research found interest in digital DTV was increasing. A new TV with a "crystal clear picture, twice as sharp as their current TV" was a somewhat or very appealing concept to fifty percent of these consumers. Interest increased if the TV had "a wide, rectangular screen, like a movie theater". Sixty-one percent said surround sound audio would increase their interest in DTV.

There was also interest in interactive features such as Internet browsing, email and shopping. Overall, the survey found 54 percent of those surveyed were very or somewhat interested in buy DTV, up from 33 percent in September 1999.

Copies of the survey, Consumer Perspective of Digital Television are available free to Consumer Electronics Association (CEA) member companies and members of the media. It can also be purchased for $499 at www.eBrain.org. Information on the study is available in a CEA Press Release, accessed through the CEA Newsroom web site.

INDUSTRY - Dielectric Communications Purchases Central Tower (Nov. 30)
Dielectric Communications announced it has agreed to purchase Central Tower Inc. and Ryan Construction Inc. The acquistion will allow Dielectric to offer complete turnkey broadcast systems including antennas, transmission line, towers, RF systems and system checkout. It also gives Dielectric a customer base in PCS and wireless. Tower services offered include installation, tower construction, modification, maintenance and inspection. Central Tower and Ryan Construction facilities will remain in Newburgh, Indiana.

Lewis Kling, President of Dielectric, commented, "This acquisition allows Dielectric to offer a fully integrated broadcast system package, and with this new expertise in the engineering, design and installation of custom towers it will significantly improve our offerings to our current and future customers." Ray Ryan, current CEO of Central Tower and Ryan Construction said, "This partnership will provide to the broadcast industry a strong platform of unique integrated offerings to prepare for the expedited implementation of DTV and new wireless communication services. In addition, Dielectric's strength in system engineering will bring new innovation to satisfy the growing demands of our wireless customers."

This information is from the Dielectric Press Release Growth continues at Dielectric. In the past, Dielectric has changed links to news releases. Check the Dielectric web site if the link above doesn't work.

FCC Sets Rules for Broadcast Signal Carriage on Satellite (Nov. 30)
Local TV stations are available via direct broadcast satellites (DBS) in some TV markets. As of November 27, 2000, DirecTV carries some local channels in 38 markets and Echostar has local channels available in 34 markets. This service, termed "local into local" does not allow viewers to see local channels outside their market, even though they are transmitted from the same satellite. The Satellite Home Viewer Improvement Act of 1999 (SHVIA) requires satellite carriers, effective January 1, 2002, "to carry upon request all local television broadcast stations' signals in local markets in which the satellite carriers carry at least one television broadcast station signal." On November 29, 2000 the FCC adopted a Report and Order in the Matter of: Implementation of the Satellite Home Viewer Improvement Act of 1999- Broadcast Signal Carriage Issues - Retransmission Consent Issues. Non-technical portions of the Report and Order are not covered here. Refer to text of the Report and Order, available as text file fcc00417.txt or Word document fcc00417.doc for additional information.

The rules adopted by the FCC closely parallel those for must-carry and retransmission consent for cable carriage. However, satellite carriers will be required to carry all local TV stations that request carriage and meet certain signal quality standards. Cable companies with more than 12 channels are not required to devote more than one-third their capacity to local stations. Commercial TV stations must request carriage by making an election by July 1, 2001, for carriage to commence on January 1, 2002. Refer to the Report and Order for the dates for future elections and for the timeframes when a new station begins service or a satellite carrier commences new local-into-local service.

Satellite carriers are required to carry all local TV stations in a contiguous manner on its channel line-up. Stations that elect mandatory carriage must be treated the same on electronic program guides as stations that elect retransmission consent. Satellite carriers must offer stations that elect mandatory carriage to subscribers on comparable price terms as it offers TV stations that elect retransmission consent. The satellite carrier must also carry the primary video and accompanying audio of local TV stations, including all program-related material contained in a TV station's vertical blanking interval, "unless carriage of such data is technically infeasible". A satellite carrier must provide the same degree of picture quality to stations that elect mandatory carriage as it provides to those that elect retransmission consent.

The FCC did not address digital TV carriage issues. The Report and Order stated, "We refrain from addressing the merits of such requirements and state that the satellite digital carriage issues will be addressed at the same time the Commission considers cable digital carriage issues."

As is the case with cable TV, broadcasters must provide a satisfactory signal to the "local receive facility" where a satellite carrier collects the signals of local television stations. This facility must be located inside the local market, unless fifty percent of the broadcasters in the relevant market agree to a location outside the local market. The quality standards for the signal a broadcaster delivers to the local receive facility are the same as those for cable TV. (See Doug Lung's RF Technology Column for September, 1993 for information on signal level requirements.) The Report and Order states "a satellite carrier does not have an obligation to carry a television signal that does not meet the Commission's good quality signal standard, until the time when the television station pays to cure the signal strength deficiency."

DTV - Philips Announces Single-Chip DVB-T Receiver (Nov. 29)
Philips said its new TDA10045 DVB-T Channel Receiver is now available in quantities of 100,000 units. The TDA10045 supports COFDM 2K and 8K demodulation modes and includes forward error correction. It is designed to be used with Philip's Nexperia line of home entertainment chips.

The Philips Press Release had little technical information. The TDA10045H Product Information Page was not working when the press release was issued but may be available now.

FCC Releases Report on Satellite Home Viewer Distant Signal Eligibility (Nov. 29)
As required by the Satellite Home Viewer Improvement Act of 1999 (SHVIA), the FCC has provided a Report to Congress "evaluating whether the signal intensity standard used to determine the eligibility of satellite television subscribers to receive retransmitted distant signals of network stations should be modified or replaced."

In response to a Notice of Inquiry, commenters asked that the standard be modified to include a time fading factor and requested a planning factor for multipath interference. The FCC recommended that "the time fading planning factor be modified to replace the existing fixed values with the distance-sensitive values determined for the actual receiving locations using the Individual Location Longley-Rice prediction model." With regard to multipath, the FCC found "the effects of ghosting cannot be effectively included in a revised distant network signal eligibility standard at this time, because we have been unable to identify a reliable methodology for predicting multipath at an individual location. In addition, on-site measurements that are capable of incorporating multipath interference, as proposed by one of the commenters, cannot be made in an inexpensive and simple manner. A predictive methodology is necessary to keep costs low when determining the eligibility of satellite television subscribers to receive retransmitted distant signals of network stations under SHVIA. We continue to believe that consumer efforts to use and properly orient antennas designed to ameliorate multipath interference is an excellent way to minimize the ghosting phenomenon. In view of the absence of any technical solutions for the inclusion of this impairment, we do not recommend modification of the Grade B signal intensity standard to include multipath interference."

The Report noted "A clear consensus of comments proposed deferring adoption of an eligibility standard for DTV signals, because adoption of a standard at this time would be premature." Commenters from the satellite industry generally wanted higher signal intensity values, since, they claimed, "changes in technology, demographics, and viewer expectations of picture quality have rendered the existing values obsolete." Broadcast industry commenters proposed retention of the current signal intensity values and argued, "improvements in technology could support a decrease in the overall Grade B signal intensity values, but that it is preferable to retain the existing values, which will provide households with a "safety margin" providing greater assurance that they will receive pictures of acceptable quality."

The FCC agreed with broadcasters and stated that, "technological developments over the years have led to an increased "safety margin" in television receivers so that the actual quality of reception is probably somewhat better than predicted by the methodology and assumptions underlying the creation of the Grade B signal intensity values." However, they declined to lower the Grade B signal intensity level, saying "These positive developments have not been studied in sufficient depth or scale as to warrant any decrease in the values of the Grade B signal intensity standard, but they do weigh against increasing those values for any but scientifically supported reasons."

FCC Accepts Application from SpaceData International to Operate TDRSS (Nov. 27)
SpaceData International, LLC (SDI) filed an applicaiton to operate the NASA Tracking and Data Relay Satellite System (TDRSS) for six months on a time-share basis for transmitting data to and from ships conducting ocean floor surveys searching for potential oil and gas deposits. SDI said no commercial satellite system is technically capable of meeting SDI's service requirements. SDI is currrently using TDRSS undeer an Special Temporary Authority (STA) and an Experimental License, which limited it to communicating with no more than three vessels for 180 days solely for the purposes of testing its service.

The proposed frequencies do not conform with the Table of Frequency Allocations. A waiver is requested to allow operation on frequencies around 15 GHz for uplinks. Downlink frequencies fall between 13.4 GHz and 14.1 GHz. Precise frequency bands and additional information is in FCC Satellite Policy Branch Report SAT-00060.

FCC Authorizes DirecTV and EchoStar Satellite Constellation Modifications (Nov. 27)
In a Memorandum Opinion and Order - DA 00-2382, the FCC granted EchoStar Satellite Corporation authority to make minor changes in its DBS satellite constellation and allowed a waiver of Section 100.21 with respect to power limits. EchoStar is allowed to operate its new, higher capacity EchoStar 6 satellite at 119 degrees West Longitude, allowing it to relocate EchoStar 1 from 119 degrees WL to 148 WL. EchoStar 4 will be relocated to 118.9 degrees WL and EchoStar 2 will be located at 119.35 degrees WL. This will expand the total number of channels available to serve Alaska and Hawaii. EchoStar 6 will also provide backup to EchoStar 4, which has experienced technical problems and is expected to have a limited life. The State of Hawaii did not oppose the application, but requested it be subject to four specific conditions to improve EchoStar's service to Hawaii. The State of Alaska filed similar comments. The FCC denied the requests from these states. Refer to the Memorandum Opinion and Order for details.

In an Order and Authorization - DA 00-2381, the FCC granted DirecTV Enterprises, Inc. authority to launch and operate direct broadcast satellite, DirecTV 5, at the 119 degree W.L. orbital location. The FCC denied the State of Hawaii's petition to deny the application and the State of Alaska's request to condition the authorization on providing service to Alaska that is comparable to service provided elsewhere. Refer to the Order and Authorization for details.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Orono, ME (Dec. 4)
Maine Public Broadcasting Corporation (MPBC), licensee of station WMEB-TV, NTSC Channel 12 in Orono, Maine has requested the substitution of DTV Channel 9 for its assigned DTV Channel 22. MPBC claims that, "substantial hardship will be inflicted upon WMEB-TV if it were required to activate its DTV channel *22 because of the power levels of 990.7 kW will result in additional electrical power costs of approximately $262,800 per year." MPBC also stated "because VHF channel *9 power levels are lower, it is less susceptible to terrain and vegetation blockage, which would allow WMEB to replicate its existing coverage area from the beginning without a substantial cost investment."

The FCC has found this channel change would meet its requirements and warrants consideration. However, because WMEB-TV is located within 400 km of the U.S.-Canadian border, Canadian government concurrence must be obtained. The technical parameters of the modified allotment on Channel 9 would specify an effective radiated power of 15 kW at a height above average terrain of 375 meters.

Interested parties may file comments on or before January 25, 2001. Reply comments are due on or before February 9, 2001. Refer to the Notice of Proposed Rule Making (MM Docket 00-243) for details on the request and information on filing comments.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Charlottesville, VA (Nov. 28)
Central Virgina Educational Telecommunications Corporation (CVETC), licensee of station WHTJ, NTSC Channel 41 in Charlottesville, Virginia, has requested the substitution of DTV Channel 46 for its assigned DTV Channel 14. CVETC stated that, "the proposed change will obviate the possibility of WHTJ interfering with public safety and commercial land-mobile operations which operate on frequencies located adjacent to UHF-TV channel 14." CVETC estimated it may have to spend $500,000 to $1,000,000 to construct and operate on channel 14 without causing interference to land-mobile and aural STL licenses. Shenandoah Valley Educational Television Corporation, licensee of translator station W19BB, filed comments supporting the channel substitution and requesting the FCC retain DTV channel 14 as an unassigned, reserved channel so that it may apply for it to upgrade its translator service to full-power status. CVETC said these comments are procedurally defective and if they are not dismissed without consideration, they should be considered in a separate rule making proceeding. The FCC agreed and stated that, "to the extent that Shenandoah wishes to pursue, on a separate track, both its displace translator operations and the assignment of an additional full-service DTV channel at Charlottesville, it must file both a displacement application and a separate rule making petition with an engineering statement demonstrating compliance with Section 73.653(d) of the Commission's rules."

The FCC has found the channel change requested by CVETC would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 46 would specify an effective radiated power of 50 kW at a height above average terrain of 352 meters.

Interested parties may file comments on or before January 19, 2001. Reply comments are due on or before February 5, 2001. Refer to the Notice of Proposed Rule Making (MM Docket 00-240) for details on the request and information on filing comments.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Weston, WVA (Dec. 1)
Withers Broadcasting Company of West Virginia (Withers), licensee of station WDTV, NTSC Channel 5 in Weston, WVA has requested the substitution of DTV Channel 6 for its assigned DTV Channel 58. Withers stated that, "the National Radio Astronomy Observatory ("NRAO") has filed an objection to Withers' "checklist" application for its proposed digital facilities on Channel 58." In addition, Withers contends that "operation on DTV channel 6 should eliminate the NRAO's concern. Withers also states that station WDTV(TV)'s allotment is the outside the "core" digital spectrum." The proposed change would resolve both issues and save Withers from expending considerable resources. Withers submitted an engineering study demonstrating that no interference would be caused to existing FM radio stations on FM channels 200-220.

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 6 would specify an effective radiated power of 10 kW at a height above average terrain of 253 meters.

Interested parties may file comments on or before January 22, 2001. Reply comments are due on or before February 6, 2001. Refer to the Notice of Proposed Rule Making (MM Docket 00-242) for details on the request and information on filing comments.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Hastings, NE (Dec. 1)
Nebraska Educational Telecommunications Commission (NETC), licensee of station KHNE, NTSC Channel 29 in Hastings, Nebraska, has requested the substitution of DTV Channel 28 for its assigned DTV Channel 14, to alleviate any interference issues with land mobile operations adjacent to Channel 14. NETC also stated that, "that the proposed substitution will allow NETC to preserve the Nebraska taxpayers' resources." NETC contends the expensive of installing the filter for DTV channel 14 will cost "upwards of $500,000" as well as approximately $50,000 to expand the KHNE transmitter building.

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 28 would specify an effective radiated power of 200 kW at a height above average terrain of 366 meters.

Interested parties may file comments on or before January 22, 2001. Reply comments are due on or before February 6, 2001. Refer to the Notice of Proposed Rule Making (MM Docket 00-241) for details on the request and information on filing comments.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in La Crosse, WI (Nov. 24)
QueenB Television, LLC (WKBT), licensee of station WKBT, NTSC Channel 8 in La Crosse, Wisconsin, has requested the substitution of DTV Channel 41 for its assigned DTV Channel 53. WKBT stated that, "its assigned DTV channel 53 is not within the core group of television channels to be retained for broadcast use following the end of the DTV transition period. WKBT contends that its station would be required to either switch its DTV operation to Channel 8 (its present NTSC channel) at the end of the transition period or shift its DTV operation to a totally new channel to be determined by the Commission." It also noted that, "the desirability of channel 8 for permanent DTV broadcasting is at this point uncertain owing to what may prove to be greater susceptibility obf DTV reception to electrical noise on the high band VHF channels."

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 41 would specify an effective radiated power of 1,000 kW at a height above average terrain of 446 meters.

Interested parties may file comments on or before January 16, 2001. Reply comments are due on or before January 31, 2001. Refer to the Notice of Proposed Rule Making (MM Docket 00-236) for details on the request and information on filing comments.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Reno, NV (Nov. 24)
Broadcast Development Corporation (BDC), licensee of station KAME-TV, NTSC Channel 21 in Reno, NV has requested the substitution of DTV Channel 20 for its assigned DTV Channel 22. BDC stated that, "the use of lower adjacent channel 20 for KAME-DT would facilitate the use of a common transmission site for analog and digital operations for KAME-TV as well as less complex filtering in order to prevent disturbance of the KAME-TV aural signal." BDC also said substitution of DTV channel 20 for DTV channel 22 would make it possible for KAME-TV and KAME-DT to use a single antenna.

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 20 would specify an effective radiated power of 50 kW at a height above average terrain of 189 meters.

Interested parties may file comments on or before January 16, 2001. Reply comments are due on or before January 31, 2001. Refer to the Notice of Proposed Rule Making (MM Docket 00-234) for details on the request and information on filing comments.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Lead, SD (Nov. 24)
Duhamel Broadcasting Enterprises (Duhamel), licensee of station KHSD-TV, NTSC Channel 11 in Lead, South Dakota, has requested the substitution of DTV Channel 10 for its assigned DTV Channel 30. Duhamel stated that, "the allotment of a VHF channel, rather than a UHF channel, is necessary to facilitate the introduction of digital television service to the vast, sparsely populated, rural area served by KHSD-TV." Duhamel also contended it would require a new tower, which would require local zoning and aeronautical approval. Duhamel said the increased cost to build the new tower and operate the UHF facility "presents a real impediment to the implementation of digital television in a small television market, an impediment that be removed by adopting KHSD-TV's channel substitution. " The proposal channel change would also result in service to a greater number of people.

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 10 would specify an effective radiated power of 34.8 kW at a height above average terrain of 576 meters.

Interested parties may file comments on or before January 16, 2001. Reply comments are due on or before January 31, 2001. Refer to the Notice of Proposed Rule Making (MM Docket 00-235) for details on the request and information on filing comments.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Fort Walton Beach, FL (Nov. 24)
Television Fit-For-Life, Inc. (WFGX), licensee of station WFGX, NTSC Channel 35 in Fort Walton Beach, Florida, has requested the substitution of DTV Channel 50 for its assigned DTV Channel 25. WFGX stated that, "its proposal would allow station WFGX(TV) to provide 100 percent replication of its NTSC service area during the DTV transition period," and that "the adoption of the channel substitution will afford WFGX the flexibility to upgrade its DTV facilities by eliminating the restrictive protection requirements on its presently allotted DTV channel 25."

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 50 would specify an effective radiated power of 1,000 kW at a height above average terrain of 221 meters.

Interested parties may file comments on or before January 16, 2001. Reply comments are due on or before January 31, 2001. Refer to the Notice of Proposed Rule Making (MM Docket 00-233) for details on the request and information on filing comments.

FCC Grants Change to DTV Table of Allotments in Richmond, VA (Dec. 1)
The FCC has granted the request of Central Virginia Educational Telecommunications Corporation, licensee of WCVE-TV, NTSC Channel 23 in Richmond, VA to substitute DTV channel 42 for channel 24.

The FCC agreed the public interest would be served by the substitution since "it would eliminate the potential for interference between WTVR-DT, Channel 25, Richmond, Virginia, and station WCVE-TV's operation on DTV channel *24. In addition, the channel substitution would permit CVETC to operate-commonly owned DTV stations WCVE-DT and WCVW-DT, both located in Richmond, from a common antenna and reduce intermodulation effects between local channels 22, 23, 24, 25, and 26." Parameters of the Channel 42 DTV allotment to Richmond specify an effective radiated power of 100 kW at a height above average terrain of 327 meters serving a population of 1,097,000. Reference coordinates are 37-30-46 N and 77-36-06 W.

This information is from the Report and Order (Proceeding Terminated)(MM Docket 00-97).

FCC Grants Change to DTV Table of Allotments in Redding, CA (Nov. 24)
The FCC has granted the request of California Broadcasting, Inc., licensee of KRCR-TV, NTSC Channel 7 in Redding, California to substitute DTV channel 34 for channel 14.

The FCC agreed the public interest would be served by the substitution since "it would enable station KRCR-TV to avoid potential interference problems to land mobile operations." Parameters of the Channel 34 DTV allotment to Redding specify an effective radiated power of 166 kW at a height above average terrain of 1,106 meters serving a population of 318,000. Reference coordinates are 40-36-10 N and 122-39-00 W.

This information is from the Report and Order (Proceeding Terminated)(MM Docket 00-115).

FCC Grants Change to DTV Table of Allotments in Scottsbluff, NE (Nov. 24)
The FCC has granted the request of Duhamel Broadcasting Enterprises, licensee of KDUH-TV, NTSC Channel 4 in Scottsbluff, Nebraska, to substitute DTV channel 7 for channel 20.

The FCC agreed the public interest would be served by the substitution since "it enable station KDUH-TV to cover the entire community of Scottsbluff with the requisite 36 dBu signal strength." Parameters of the Channel 7 DTV allotment to Scottsbluff specify an effective radiated power of 32.4 kW at a height above average terrain of 592 meters serving a population of 95,000. Reference coordinates are 42-10-21 N and 103-13-57 W.

This information is from the Report and Order (Proceeding Terminated)(MM Docket 00-140).

OTHER Items of Interest

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