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 or two to complete each issue. Articles may be posted earlier if time permits or if there is a major, breaking story.

<<< Back to February 21 - Issue 202

February 28, 2000 - Issue 203 Final Edition

FCC Mass Media Bureau Puts Consolidated Database System On-Line (Feb. 28)

The FCC Mass Media Bureau officially released the Consolidated Database System (CDBS) on the Internet. The introduction is a mixed blessing. The introduction of the new database caused problems for software that depended on the FCC's flat-file engineering, antenna and facility databases. On the other side, the CDBS provides a much greater range of data than the old database, which hasn't been updated since December 31, 1999 due to Y2K problems. For example, the new TV Engineering Database has separate entries for mechanical and electrical beam tilt on antennas, as well as the direction of the tilt. This information is important because it is often possible to optimize coverage by mechanically tilting the antenna in a different direction than the azimuth pattern peak or angle of symmetry. On the negative side, because the CDBS depends on data that may have been filed over twenty years ago which wasn't stored with this information, the new fields are available only for more recent applications. Generally, entries for applications filed after Stptember 1, 1999 will include the new fields.

While it was easy to import the old flat-file engineering databases into a spreadsheet, the CDBS is a relational database that requires linking with other databases to be useful. To make it easier for people to obtain engineering data on TV stations, I've merged several files from the CDBS into one Excel 5.0 spreadsheet. The spreadsheet contains technical information on existing TV stations, TV applications and TV construction permits. Information from the FCC DTV Table of Allotments is not included unless it appears in an actual application. I plan to make tools to extract TV antenna pattern data available in the future. Check the information at the top of the RF Page for links to the latest TV Engineering Database and a smaller, DTV only, subset. Both spreadsheets are compressed into ZIP files to speed downloading. Your comments on the format are appreciated.

Preliminary information explaining the CDBS and the fields in each database are available from the FCC FTP site in the Engineering Database Description (Adobe PDF) and readme.txt file. The RF Page spreadsheets use the same field names as the FCC database. Note, however, that items such as comm_city and station_ch are different in the facility.dat and application.dat databases. In the spreadsheets, where the field was repeated. information from the application.dat database was used as that usually reflects the latest filing. Note, however, that I have found some errors in the application.dat database. In one case, a station in San Antonio was given a comm_city of San Francisco. The engineering coordinates, however, are correct. Given that multiple relationships are needed to link the database, such errors were not unexpected. The CDBS is still evolving.

If technical data is not needed, the CDBS database can be searched on the FCC web site at http://svartifoss.fcc.gov:8080/prod/cdbs/pubacc/prod/cdbs_pa.htm. The spreadsheet version of the files at www.transmitter.com includes both the application and facility ID numbers. These can be used to speed the search for data on application status or ownership with the on-line FCC access to CDBS. To download the database files, visit http://www.fcc.gov/Bureaus/Mass_Media/Databases/cdbs/. For many applications submitted after September 1, 1999, the information contained in FCC Form 301, 314, 315 and 316 can be viewed at this link. An FCC Public Notice (da000414) cautions that Internet users must have a web browser such Netscape version 3.04 or Internet Explorer version 3.51 or later.

FCC Reminds Licensees of Deadline for Ensuring Compliance with RF Exposure Rules (Feb. 25)

The FCC has released a Public Notice (pnet0005) advising licensees that "All existing transmitting facilities, operations and devices regulated by the Commission must be in compliance with the requirements of paragraphs (b)(1) through (b)(3) of this section by September 1, 2000, or, if not in compliance, file an Environmental Assessment as specified in [47 CFR] 1.1311." The FCC notes that if an Environmental Assessment is required, "the obligation to file it would fall upon the licensee presently holding the permit or license to transmit, or the party presently holding the grant of equipment authorization." The FCC also reminded licensees that if their antenna is located on a fixed structure, non-RF environmental issues must be addressed in any Environmental Assessment filed with the FC.

The FCC warned that, "After September 1, 2000, if any facility, operation or device is found not to be in compliance with the Commission's RF exposure guidelines, and if the required EA has not been filed, the Commission will consider this to be a violation of its rules resulting in possible fines, forfeiture or other actions deemed appropriate by the Commission." Also, for antennas on fixed structures, the licensee, not the tower owner, is responsible for undertaking the environmental evaluation and filings, as required, "due to non-compliance with our RF rules." Even facilities, operations or devices categorically excluded from routine evaluation for RF exposure under Section 1.1307(b)(1) must still comply with the FCC's exposure guidelines.

Visit the FCC RF Safety Web page at www.fcc.gov/oet/rfsafety for more information.

FCC Technological Advisory Council to Meet March 24 (Feb. 25)

The Technological Advisory Council will hold its fourth meeting Friday, March 24, at 10 AM in Room TW-C305 at the FCC, 445 12th St. S.W., Washington, DC. The Council was formed to provide recommendations to the FCC on technological developments in the communcations industry.

The March 24 meeting will include discussions on: "(1) the current state of the art for software defined radios, cognitive radios, and similar devices; future developments for these technologies, and ways that the availability of such technologies might affect the FCC's traditional approaches to spectrum management in light of existing and future electromagnetic noise levels; (2) current technological trends in telecommunications services, including changes that might decrease, rather than increase, the accessibility of telecommunications services by persons with disabilities, and ways by which the FCC might best communicate to designers of emerging telecommunications network architectures, the requirements for accessibility; (3) telecommunications common carrier network interconnection scenarios that are likely to develop, including the technical aspects of cross network (i.e., end-to-end) interconnection, quality of service, network management, reliability, and operations issues, as well as the deployment of new technologies such as dense wave division multiplexing and high speed packet/cell switching; (4) additional issues that the Council may choose to address in the future."

More information is available in the FCC Public Notice (da000376).

TOOLS - US Geological Survey and Microsoft Offer Topographic Maps On-Line (Feb. 25)

The USGS said digital versions of its topographic maps are available on the Microsoft TerraServer at http://www.terraserver.microsoft.com. Details on accessing the service may be found in the USGS release USGS's Most Popular Maps Now Available Online.

The maps are quite detailed, but if you are used to spreading a topo map across your desk, you may find the constraints of the PC monitor difficult to detail with. However, for taking a quick look a the terrain around a transmitter site, http://www.terraserver.microsoft.com deserves a place in your bookmark/favorites list.

FCC Experimental Actions for December 1999 and January 2000 (Feb. 22)

The FCC Office of Engineering and Technology has released its report on Experimental Actions from 12/1/99 to 2/1/00. Many of the grants were for scientific efforts such as remote data collection. Grants involving new technologies includes one to Orbital Services Corporation to use various frequencies in the 451-457 MHz range, 806-824 MHz, 851-869, 896-902 and 935-941 MHz for "test, development, and demonstration of automatic vehicle location system." Several licenses were granted to the State of California Air Resources Board for wind profiler radar on 915 MHz. ArrayComm, Inc. received a license to operate on 1850-1910, 2305-2320 and 2345-2360 MHz "to perform engineering field tests of adaptive antenna technology" in San Mateo County, CA. Los Angeles County received a license to use 2402-2412, 2414-2424, 2426-2436 and 2438-2448 for "demonstration of airborne video transmission system for public safety use" in and around the City of Los Angeles.

One interesting grant was license WB2XBC to Joseph A. Bobier to operate on 2450 MHz "for testing of nonconventional signal methods" mobile in St. Mary's, West Virginia. Anyone have more information on this?

OTHER Items of Interest

TWICE article - CEA, NCTA Reach Digital Cable Agreement - article by Greg Tarr

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