The Association for Maximum Service Television responded to Qualcomm's opposition to its Nov. 13 Petition for Reconsideration and/or Clarification, previously covered in the Nov. 22, 2006 RF Report.
Qualcomm's opposition, available on the FCC Search Web page by typing the "05-7" docket number in the first box ("Proceeding"), refuted MSTV's argument that FCC DTV allotment table population numbers, specifically the population baseline in Appendix B of the Memorandum Opinion and Order on Reconsideration of the Sixth Report and Order, should be used for calculating the percentage of population receiving interference.
Qualcomm said, "MSTV's argument fails because Section 27.60(b)(1)(iii) of the commission's rules requires that engineering studies filed pursuant to that rule compare the 'actual parameters' of the Part 27 transmitter with the actual parameters of the TV/DTV station(s)..." and that the "1998 DTV allotments were theoretical and often do not reflect the actual parameters of DTV stations as they are now operating."
Qualcomm said that the actual population of a DTV station's noise-limited contours reflected actual parameters and that this should serve as the baseline for engineering studies pursuant to the rule.
In its response, MSTV said that a DTV station "rarely serves all persons within its noise-limited contour. Interference from other stations and sources, as well as terrain limitations, naturally prevent some 'viewers' within that contour from receiving the station's signal. Qualcomm's use of the entire population within a DTV station's noise-limited contour to measure that station's population baseline is accordingly inappropriate." MSTV noted that in measuring interference between DTV stations, the FCC "consistently calculated a station's baseline population based upon the number of potential viewers within that contour minus those persons predicted to not receive the station's signal for a variety of reasons."
MSTV provided an example illustrating the difference between the Qualcomm and FCC OET-69 approaches in determining interference. In the example, one of the stations provides service to the entire population within its noise-limited contour, while the other, even though it provides actual service to the same number of people as the other station, does not serve 20 percent of the people in its noise-limited contour due to terrain or interference. As a result, the station with the larger noise-limited contour could lose 25 percent more viewers to Qualcomm interference than the station that does not lose any viewers inside its noise-limited contour due to terrain or interference from other broadcast TV stations.
MSTV pointed out that the Qualcomm reference to the 1998 DTV Table of Allotments is a "red herring at best," saying that "So long as it is consistent, Qualcomm could use population figures from the more recent table published by the commission in December 2004. Qualcomm should not, however, be allowed to use a methodology which fails to consider the real-world factors that limit the number of viewers actually served by a station."
Even the FCC 2004 baseline population numbers are likely to overstate coverage and understate interference in some areas. This is due to OET-69's treatment of cells returning Longley-Rice Error Code 3 as receiving the desired signal and not experiencing interference regardless of what the predicted Longley-Rice signal level would otherwise indicate.
If Qualcomm actually intends to ignore the impact of terrain and interference on the population within a DTV station's noise-limited contour, it is difficult to see how this would be in compliance with Section 27.60(b)(1)(iii), as a study that ignores these elements certainly would not reflect the "actual parameters of the TV/DTV station(s)."
For those cases where a DTV station's current operation did not reflect the parameters specified in the FCC's latest DTV table, an alternative would be to calculate the DTV station's actual coverage using the parameters specified in OET-69. For the most accurate analysis it would be best to ignore Longley-Rice Error Code 3 and use actual antenna patterns for both the DTV station and the interfering stations, rather than the horizontal plane azimuth patterns and OET-69 elevation patterns.
MSTV's reply did not respond to Qualcomm's opposition to its request that market specific arguments be allowed when considering Qualcomm waiver requests. Qualcomm said in its opposition, "Opening the door to these individual 'market specific' arguments will vitiate the Qualcomm Order, will leave the commission without any real standard to apply in a consistent manner to Qualcomm's applications and, above all, will surely result in substantial delays, thereby depriving the public of the benefits of MediaFLO."
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