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 29, 2000 - Issue 216 Final Edition

FCC Issues NOI on Change in TV Signal Intensity Standard for SHVA (May 26)
In a Notice of Inquiry (NOI) released May 26, the FCC explained, "In this proceeding, we are opening an inquiry to obtain information for 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. The existing standard uses the Grade B signal intensity values that have long been used within the television broadcast service. We are not considering alteration of the Grade B standard for any purpose other than determining eligibility to receive retransmitted distant network signals."

The NOI includes a detailed explanation of the history of the FCC's signal intensity standards, including the parameters used in determining them and an explanation of the role statistics on variability played in determining the standards. For example, the NOI notes that the values chosen for Grade B signal intensity account for location and time variability factors and predict that at least 50 percent of the locations along the Grade B contour will receive an acceptable picture 90 percent of the time. In this case, acceptable picture was considered to be TASO Level 3, defined as "(passable) - The picture is of acceptable quality. Interference is not objectionable." The specific level of signal to noise ratio at the receiver that delivered the level 3 picture was determined and, using planning factors, a required signal level intensity was calculated.

The FCC NOI asks "whether there have been any technological developments in television system equipment, over-the-air television viewer installations or picture quality expectations that would warrant a significant modification to the planning factors on which the current Grade B standard for household eligibility for distant TV network signal reception under SHVA is based." (SHVA = Satellite Home Viewers Act) For example, the FCC asked if "any of the planning factors for Grade A [are] more appropriate than the corresponding Grade B factors for determining distant signal reception eligibility?" Parties responding to the NOI were cautioned, however, that their comments "should be supported by technical showings evidencing the need to make the suggested changes." It also invited "submission of evidence that documents any significant changes in the television reception environment, and significant changes in viewer expectations, that have not been documented in previous Commission proceedings."

Specific technical areas open for comment include 1) Receiver Noise Figure; 2) Signal-to-Noise Ratio and Service Quality; 3) Transmission Line Loss and Antenna Gain; 4) Dipole Factor; 5) Field Strength Variability; 6) Environmental Noise; and 7) Multipath Interference. In Item 3, for example, the FCC noted that the original analog TV planning factors were developed for 300-ohm twin-lead, which while it had less attenuation was prone to picking up more electrical noise and RF interference. Today most antenna systems use 75-ohm coaxial cabling. NTIA Report 81-68 studied 50 sites between Chicago and Peoria, Illinois and found the median antenna system gain for systems using a 75-ohm transmission line was lower than that for systems using 300-ohm twin-lead. In addition, the median estimated antenna system gains were less than the system gains that were applied as planning factors in defining required field strengths for Grade A or Grade B service area.

The FCC requested comment on "whether the DTV noise-limited service contour values shown in Table 3 above are valid for the purposes of determining whether a DTV viewer is eligible to receive satellite transmissions of distant network signals under the SHVA. If not, what specific modifications to this standard should be considered?" Please refer to the Notice of Inquiry for the tables showing analog and digital TV planning factors. The Notice of Inquiring (ET Docket 00-90) is available on-line as a text file fcc00184.txt and Microsoft Word file fcc00184.doc. Information on how to file comments and reply comments are included in the NOI.

DTV - Philips Demos DVB-S Reception Using Microsoft BDA (May 29)
Philips announced it was the fist company "to have successfully ported and demonstrated a PCI-based DVB-s (digital video broadcast) receiver card into Microsoft's new Broadcast Driver Architecture (BDA)." The demonstration used the Philips SAA7146A Multimedia PCI-bridge. In addition to satellite DVB-S applications, the design is also applicable to cable and terrestrial digital broadcast reception on PC architectures.

Martin Maloney, International Product Marketing Manager for Infotainment Systems, Philips Semiconductors, commented, "This is an important step forward in bringing digitally broadcast television to the PC. Ultimately PC users will benefit from access to broadcast media from their PC, whether at home or in the workplace." Kevin Unangst, group production manager, marketing, Digital Media Division, Microsoft, explained, "Our architecture enables our hardware vendors to write drivers that use a standard set of interfaces to deliver content from different broadcast signals. This first implementation by Philips Semiconductors for DVB is a significant step forward in bringing digitally broadcast television to PC users." He said, "Our Broadcast Driver Architecture system has been developed to enable broadcast networks and receiver hardware vendors to create drivers for digital reception by millions of users of Microsoft Windows."

This information was obtained from Philips Semiconductors Technology News article Philips Semiconductors demonstration of DVB satellite reception on Windows using Microsoft's new PC Broadcast Architecture.

FCC Satellite Policy Branch - Applications Accepted for Filing (May 24)
In Report SAT-00043, the Satellite Policy Branch of the FCC International Bureau listed applications accepted for filing. GE Americom requested authority to launch and operate its GE-6 satellite at 72 degrees instead of 101 degrees West Longitude. GE-6 is a Hybrid Replacement Satellite for Satcom SN-4. The move to 72 degrees reflects the reassignment of SN-4. GE Americom's application said it does not seek to provide extended Ku-band services from the 72 degree location and will limit the coverage area of the satellite to North America and the Caribbean.

DIRECTV filed an application to launch and operate a direct broadcast satellite, DIRECTV 5, at 119 degrees West Longitude, colocated with the USABSS-7 satellite. After a successful launch of DIRECTV 5, DIRECTV proposes to keep the USABSS-7 satellite at 119 degrees as an in-orbit spare. DIRECTV 5 proposes to launch this satellite in September 2000.

EchoStar COmmunications and DBS Industries, Inc. filed an application for Transfer of Control of the non-voice, non-geostationary mobile satellite service license held by E-Sat, Inc. from EchoStar Communications to DBS Industries.

Telesat Canada has requested ANIK F-1 at 107.3 degrees W.L. be added to the "Permitted Space Station" list created by the FCC in the DISCO II First Reconsideration Order. For details on this and other proceedings listed here refer to the Satellite Policy Branch Report SAT-00043 (Adobe Acrobat is required to view this link.)

OTHER Items of Interest

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