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2	Analog spacings Co-Channel Separations – in km Zone Ch. 2-13 Ch. 14-69 I 272.7 248.6 II 304.9 280.8 III 353.2 329.0 1 st Adjacent Separations – in km Ch. 2-13 Ch. 14-69 95.7 km 87.7 km
3	Analog Protected/Service Contours
4	Analog I.F. Taboos + -8 I.F. Beat 31.4 km +-2, 3, 4, 5 Intermod 31.4 km +-7 Oscillator 95.7 km +-14 Sound 95.7 km +-15 Picture 119.9 km
5	Maximum TV Analog Power Channel 2-6 100 kW Channel 7-13 316 kW Channel 13-69 5,000 kW
6	Class A and Translator Protections
7	Class A and Translator Interference Ratios
8	DTV Noise Limited Contours F(50-90) Channels 2-6 28 dBu Channels 7-13 36 dBu Channels 14-69 41 dBu – dipole factor 20 log (615/channel mid-frequency)
9	DTV Principal City Contour City Grade Noise limited +7 dB Deadline for requirement Commercial 12/31/05 Public 12/31/06*
10	Maximum DTV Radiated Power
11	Maximum DTV Radiated Power
12	Maximum DTV Radiated Power
13	Allocation Standards - New DTV
14	Allocation Standards -New DTV
15	Protection to Land Mobiles Co-chan <250 km from center LM Adjacent <176 km from center LM
16	Planning Factors Characterize the equipment and include antenna systems used for home reception. Determine the minimum field strength for DTV reception as a function of frequency Developed in 1997 for prototype receivers
17	Planning Factors Assumptions
18	Front-to-Back Ratios (dB) for Receiving antennas
19	Vertical Pattern % Field Assumed (Based on depression angle)
20	Longley-Rice Variables - FCC
21	OET 69 Refractivity Assumption 301 N-Units – mid USA value used Higher refractivity values occur on coasts Great lakes area are prone to higher refractivity during certain times of year Humidity increases refractivity values
22	Refractivity Chart
23	Ground Conductivity Chart
24	Interference Criteria for co and adjacent channels D/U
25	DTV Allocation Rules OET-69
26	DTV Allocation Rules
27	Evaluation Procedure Area subject to calculation is boxed in latitude and longitude. Coordinates every 5 degrees around compass point are calculated and this defines box size. Box then divided into square cells approximately 2 km on a side (or smaller) 1990 Census used to determine number of population centroids within each cell. Longley-Rice is used at cell centroid point to determine interference level.
28	Interference Evaluation Procedure Cells are examined for threshold reception. Qualifying cells are examined for interference A cell has interference when D/U ratio qualifies it, considering any possible interference source and receiving antenna directivity For an analog station, if cell already has interference from another analog station, it is not counted as an interference cell (masking)
29	Interference Application Rules Comparisons use 1990 US Census No More than 2% population interference can be caused any one station – (use current interference levels) No additional interference can be caused NTSC stations that have a total percent lost of 10% . DTVs that are not check-listed are considered Surrounding NTSC stations are considered in the 10%
30	Interference Application Rules No new interference can be caused stations that have DTV Service less than 90 percent of analog service Interference to DTV stations from changes in NTSC facilities is not allowed – de minimus = 0 .4999% Translators and Class A stations must cause no more than de minimus interference or 0 .4999% 1990 Population Base - Appendix B - 6th Report & Order Class A stations are protected from new interference
31	Typical Output After Analysis Results for: 18A VA ROANOKE DTVPLN DTVP0331 PLN HAAT 610.0 m, ATV ERP 605.0 kW POPULATION AREA (sq km) within Noise Limited Contour 1 429251 44584.2 not affected by terrain losses 1255716 38531.0 lost to NTSC IX 21455 898.4 lost to additional IX by ATV 10715 395.3 lost to ATV IX only 17688 602.9 lost to all IX 32170 1293.7 Potential Interfering Stations Included in above Scenario 20 18N KY LEXINGTON BLCT 19850221KF LIC 18N NC CHARLOTTE BLCT 791128LG LIC 18N OH ZANESVILLE BPCT 20010808AAS CP 17A VA ROANOKE DTVPLN DTVP0285 PLN 18A SC GREENWOOD BPEDT 20000501AGM CP Percent Service lost without proposal: 0.9 to DTVPLN DTVP0331 Percent Service lost with proposal: 1.1 to DTVPLN DTVP0331
32	Problems with OET 69 Are planning assumptions valid? Are depression angle assumptions valid? Longley-Rice tends to over-predict on line-of-sight paths Longley-Rice does not fully implement Tech Note 101 FCC assumes KWX errors are non-interfering points.
33	Problem Assignments WMVS-DT à WOOD-TV – Grand Rapids, MI WMVS-DT à WOOD-TV – Grand Rapids, MI – KWX WKOW-DT à WGBA-TV – Green Bay, WI WKOW-DT à WGBA-TV – Green Bay, WI – KWX WHRO-DT à WBOC-TV – Salisbury, MD
34	Interference is Minimal - Now Vast majority of DT stations operating at STA powers (Minimization.) Full impact may not be known until all DTV operate at authorized powers DTV to DTV Interference not fully tested Matched pair DTV-Analog channel swaps.
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