74.793—Digital low power TV and TV translator station protection of broadcast stations.
(a)
An application to construct a new digital low power TV or TV translator station or change the facilities of an existing station will not be accepted if it fails to meet the interference protection requirements in this section.
(b)
Except as provided in this section, interference prediction analysis is based on the interference thresholds (D/U signal strength ratios) and other criteria and methods specified in § 73.623(c)(2) through (c)(4) of this chapter. Predictions of interference to co-channel DTV broadcast, digital Class A TV, digital LPTV and digital TV translator stations will be based on the interference thresholds specified therein for “DTV-into-DTV.” Predictions of interference to co-channel TV broadcast, Class A TV, LPTV and TV translator stations will be based on the interference threshold specified for “DTV-into-analog TV.” Predictions of interference to TV broadcast, Class A TV, LPTV and TV translator stations with the following channel relationships to a digital channel will be based on the threshold values specified for “Other Adjacent Channels (Channels 14-69 only),” where N is the analog channel: N-2, N 2, N-3, N 3, N-4, N 4, N-7 , N 7, N-8, N 8, N 14, and N 15.
(c)
The following D/U signal strength ratios (dB) shall apply to the protection of stations on the first adjacent channel. The D/U ratios for “Digital TV-into-analog TV” shall apply to the protection of TV broadcast, Class A TV, LPTV and TV translator stations. The D/U ratios for “Digital TV-into-digital TV” shall apply to the protection of DTV, digital Class A TV, digital LPTV and digital TV translator stations. The D/U ratios correspond to the digital LPTV or TV translator station's specified out-of-channel emission mask.
| Simplemask | Stringentmask | |
|---|---|---|
| Digital TV-into-analog TV | 10 | 0 |
| Digital TV-into-digital TV | −7 | −12 |
(d)
For analysis of predicted interference from digital low power TV and TV translator stations, the relative field strength values of the assumed antenna vertical radiation pattern in Table 8 in OET Bulletin 69 shall be doubled up to a value of 1.0.
(e)
Protection to the authorized facilities of DTV broadcast stations shall be based on not causing predicted interference to the population within the service area defined and described in § 73.622(e) of this chapter, except that a digital low power TV or TV translator station must not cause a loss of service to 0.5 percent or more of the population predicted to receive service from the authorized DTV facilities.
(f)
Protection to the authorized facilities of TV broadcast stations shall be based on not causing predicted interference to the population within the Grade B field strength contours defined and described in § 73.683 of this chapter, except that a digital low power TV or TV translator station must not cause a loss of service to 0.5 percent or more of the population predicted to receive service from the authorized TV broadcast facilities.
(g)
Protection to the authorized facilities of Class A and digital Class A TV stations shall be based on not causing predicted interference to the population within the service area defined and described in § 73.6010 (a) through (d) of this chapter, respectively, except that a digital low power TV or TV translator station must not cause a loss of service to 0.5 percent or more of the population predicted to receive service from the authorized Class A TV or digital Class A TV facilities.
(h)
Protection to the authorized facilities of low power TV and TV translator stations and digital low power TV and TV translator stations shall be based on not causing predicted interference to the population within the service area defined and described in §§ 74.707(a) and 74.792, respectively, except that a digital low power TV or TV translator station must not cause a loss of service to 2.0 percent or more of the population predicted to receive service from the authorized low power TV, TV translator, digital low power TV or digital TV translator station.
[69 FR 69335, Nov. 29, 2004]