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.

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May 15, 2000 - Issue 214 Final Edition

DTV Philips and Eldon to Develop Low Cost iDTV Reference Design (May 15)

Philips Semiconductors, an affiliate of Royal Philips Electronics, and Eldon Technology, a subsidiary of EchoStar Communications Corporation, have reached an agreement to work together to develop a low cost, intelligent integrated Digital TV (iDTV) reference design. The goal is to provide a design that will enable analog TV set manufacturers to produce their own iDTV models for the middle to low-range DTV market.

The Philips Semiconductors Press Release said the reference design "will incorporate all aspects of an analog colour television chassis and will support both free-to-air digital terrestrial transmissions and proprietary transmissions via it's Common Interface. The design will also address the lengthy time-to-market and substantial software resource issues involved in developing iDTV receivers, accelerating the penetration of digital technology into the middle and lower segments of the receiver market."

The agreement builds on Philips Semiconductor's expertise in system-on-silicon solutions for analog television and Eldon Technology's software capabilities. Philips will supply its intelligent iDTV "Bolt On" solution, based on its "Ultimate One Chip" family of devices.

The system makes use of Philips' SAA7240 de-multiplexer/MIPS and the SAA7215 MPEG decoder/graphics engine. Digital channel reception and demodulation is handled by a single hybrid tuner and a TDA10045 COFDM device.

FCC Issues NPRM Regarding Ultra-Wideband Transmission Systems (May 11)

The Notice of Proposed Rule Making - ET Docket 98-153 Revision of Part 15 of the Commission's Rules Regarding Ultra-Wideband Transmission Systems proposes to amend the FCC Rules to "pave the way for new types of products incorporating ultra-wideband (UWB) technology." The NPRM said it appears UWB devices will be able to operate on spectrum occupied by existing radio services without causing interference. The NPRM, however, cautioned that "Further testing and analysis is needed before the risks of interference are completely understood." The FCC said it will provide "ample opportunity to complete these tests and ensure that analyses of the test results are submitted in the record for public comment before adopting any final rules in this proceeding." Broad comment on the Notice was invited.

The NPRM outlines some of the applications for UWB technology, including secure communications and communications at high data rates over short distances without problems from multipath. The FCC also noted, "Some parties believe that UWB technology would be useful for outdoor wide area communication systems." A more common use for UWB is short range radar.

Given the wide range of applications, it isn't surprising that the technical characteristics of UWB devices varies widely. U.S. Radar Inc., Geophysical Survey Systems, Inc. and the U.S. Geological Survey indicated their devices would operate with center frequencies up to 3 GHz with bandwidths up to 2 to 3 times the center frequency. Lawrence Livermore National Laboratories expected their UWB devices would operate with a center frequency anywhere between 20 MHz and 60 GHz with bandwidths ranging from 150 MHz to 30 GHz. Time Domain said GPRs and long range military communications will tend to operate below 1 GHz. Devices such as law enforcement and emergency motion and imaging devices, high performance microphones, security fences will use the 1 - 2 GHz region. Road and runway inspection radars, law enforcement and emergency service mobile imagers, buried victim rescue, RF Asset ID and tracking devices, collision avoidance sensors, etc. will operation in the 2 - 8 GHz region and above, according to Time Domain.

Power levels also vary widely between applications. The U.S. Government has radars with up to 200 mW average power and 1 kW peak power. One commenter, MSSI, anticipated that commericial UWB applications can be met with the same power levels given for spread spectrum and UNII devices - 1 W transmitter output power and a 6 dBi gain antenna.

In the NPRM, the FCC observed most near-term applications for UWB involve relatively low powers and short operating ranges and are intended to be mass marketed to businesses and consumers, making individual licensing of each device impractical. The FCC tentatively concluded that is is appropriate to regulate low puwer UWB devices intended to be mass marketed to businesses and consumers under Part 15 of the rules.

The NPRM contains more technical information on UWB than it is possible to cover here. Simply defining UWB is a complicated exercise. The FCC has proposed to define UWB devices as any device where the fractional bandwidth is greater than 0.25 or occupies 1.5 GHz or more of spectrum. Refer to the NPRM for the definition of bandwidth.

The FCC stated it had significant concerns about the operation of UWB devices, except for GPRs and possibly through-wall imaging devices, in the region of the spectrum below approximately 2 GHz. Critical safety systems, such as GPS, must be protected from harmful interference. Comment was invited as to whether and at what levels, if any, the FCC should permit operation in the restricted bands below 2 GHz for devices that can operate using extremely low signal levels. The NPRM noted that, "Even though we are considering restricting the operation of UWB devices from use below approximately 2 GHz, we will consider allowing access to this spectrum provided that test results and detailed technical analyses are submitted demonstrating that there is no risk of harmful interference to GPS, to other services operating in restricted frequency bands, or to TV broadcasting."

Please refer to the Notice of Proposed Rule Making, available either as a text file - fcc00163.txt or Word document - fcc00163.doc on the FCC web site. Comments will be due 90 days after publication in the Federal Register and reply comments are due 120 days after publication in the Federal Register. The NPRM is summarized in a FCC News Release - New Public Safety Applications and Broadband Internet Access Among Uses Envisioned by FCC Consideration of Ultra-Wideband Technology. Also see the EE Times article linked to in the Other Items section.

FCC Notice of Proposed Rule Making to Modify DTV Table of Allotments in Urbana, Illinois (May 8)

The University of Illinois Board of Trustees (University), licensee of station WILL-TV, NTSC Channel 12 in Urbana, Illinois, has requested the substitution of DTV Channel 9 for its assigned DTV Channel 33. The University stated that the use of channel 9 "will allow station WILL-TV to preserve its limited resources", noting that the cost of physical plant changes would be $500,000 higher for a channel 33 DTV facility than the proposed channel 9 facility. It also said ongoing operating and maintenance could be over $125,000 greater for the UHF channel. The University said the savings could be applied to the station's other public interest responsibilities with no decrease in signal quality for its viewers.

The FCC has found this channel change would meet its requirements and warrants consideration. The technical parameters of the modified allotment on Channel 9 would specify an effective radiated power of 30 kW at a height above average terrain of 302 meters.

Interested parties may file comments on or before July 3, 2000. Reply comments are due on or before July 19, 2000. Refer to the Notice of Proposed Rule Making (MM Docket 00-76) for details on the request and information on filing comments.

OTHER Items of Interest

FCC NPRM on Advanced Digital Communications in the 118-137 MHz band - FCC would modify rules to promote transition to high-capacity digital communciations systems for future requirements of air traffic control for civial aviation and implementation of Flight Information Services.
FCC Wireless Telecommunications Bureau Implements ULS Filing via the Internet - this Public Notice contains information on using the ULS, including software requirements. Note that the FCC program uses the standard (non-Microsoft specific) implementation of Java applets and thus requires Netscape Navigator.
FCC Releases Tips for Applicants Filing Paper Forms for Authorizations in the Microwave Radio Services - Note that the manditory electronic filing requirement for certain Microwave Services becomes effective June 1, 2000.
New Orders for Acrodyne Products Mark a Successful NAB Show - press release - New technology Quantum IOT based transmitter product line receives strong approval from buyers
First Andrew STACKER(tm) Optimized Antenna Structure Installed for Capitol Broadcasting's WRAL-DT and WRAZ-DT - press release - Nice photo of the tower with the STACKER installed. John Green, VP, Capitol Broadcasting, said "our early tests are showing consistently good performance on the channel 53 antenna."
This Week in Consumer Electronics article - Time/ABC Fight Gives Antennas Quick PR Boost - story by Steve Smith
EE Times article - Ultra-wideband might operate without a license - story by George Leopold
EE Times article - STMicro adds Turbo coding to satellite TV chip set - story by Crhis Edwards - also see the press release STMicroelectronics Reinforces Digital Satellite Leadership with Turbo Code Technology. The system involves a new form of forward error correction that could be used for satellite modems, hard disc drives and UMTS wireless telephony.
EE Times article -

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