90.315—Special provisions governing use of frequencies in the 476-494 MHz band (TV Channels 15, 16, 17) in the Southern Louisiana-Texas Offshore Zone.
(a)
The frequency bands from 490-491 and 493-494 MHz will be available for assignment to stations governed by this part within Zone A. The boundaries of Zone A are from longitude 87°45′ on the east to longitude 94°00′ on the west, and from the 3-mile limit along the Gulf of Mexico shoreline on the north to the limit of the Outer Continental Shelf on the south. The frequency bands from 484-485 and 476-488 MHz will be available for assignment to stations governed by this part within Zone B. The boundaries of Zone B are from longitude 87°45′ on the east to longitude 95°00′ on the west and from the 3-mile limit along the Gulf of Mexico shoreline on the north to the limit of the Outer Continental Shelf on the south. The frequency bands from 478-479 and 481-481 MHz will be available for assignment to stations governed by this part within Zone C. The boundaries of Zone C are from longitude 94°00′ on the east, the 3-mile limit on the north and west, a 281 km (175 mile) radius from the reference point at Linares, N.L., Mexico on the southwest, latitude 26°00′ on the south, and the limits of the Outer Continental Shelf on the southeast. These frequencies may also be assigned to fixed stations located on shore designed to provide communications service within the zone.
(d)
Offshore stations shall afford cochannel protection to TV stations on Channels 15, 16 and 17. Station operating parameters shall be in accordance with the values given in table 1 of this section.
[In Watts] | |||
Distance from transmitter to co-channel TV station kilometers (miles) | Antenna Height above sea level meters (feet) | ||
---|---|---|---|
30.5 (100) | 45 (150) | 61 (200) | |
338 (210) | 1,000 | 1,000 | 1,000 |
330 (205) | 1,000 | 900 | 800 |
322 (200) | 800 | 710 | 630 |
314 (195) | 590 | 520 | 450 |
306 (190) | 450 | 400 | 330 |
298 (185) | 320 | 280 | 240 |
290 (180) | 250 | 210 | 175 |
281 (175) | 175 | 150 | 130 |
274 (170) | 130 | 110 | 100 |
265 (165) | 95 | 80 | 70 |
257 (160) | 65 | 55 | 50 |
249 (155) | 50 | 40 | 35 |
241 (150) | 35 | 30 | 25 |
Code of Federal Regulations
(e)
Shore stations communicating point-to-point with offshore stations will be permitted at least the same ERP as the offshore station, but only in the direction of the offshore station. A directional antenna shall be used and the rearward radiated power from the antenna in a sector ±22 1/2 ° from the line joining the shore antenna to the cochannel television station shall not exceed those shown in table 2 of this section.
Distance from transmitter to cochannel television station: kilometers (miles) | Antenna height above ground in meters (feet) | |||||
---|---|---|---|---|---|---|
30.5 (100) | 45 (150) | 61 (200) | 91.5 (300) | 152.5 (500) | 228 (750) | |
298 (185) | 320 | 280 | 240 | 190 | 125 | 90 |
290 (180) | 250 | 210 | 175 | 125 | 100 | 60 |
281 (175) | 175 | 150 | 130 | 100 | 70 | 50 |
274 (170) | 130 | 110 | 100 | 75 | 40 | 35 |
265 (165) | 95 | 82 | 70 | 50 | 35 | 25 |
257 (160) | 65 | 55 | 50 | 40 | 25 | 20 |
249 (155) | 50 | 40 | 35 | 30 | 20 | 15 |
241 (150) | 35 | 30 | 25 | 20 | 15 | 10 |
233 (145) | 25 | 20 | 18 | 15 | 10 | 7 |
225 (140) | 18 | 15 | 13 | 10 | 7 | 5 |
217 (135) | 13 | 10 | 9 | 7 | 5 | 3 |
209 (130) | 10 | 8 | 6 | 5 | 3 | 2 |
201 (125) | 7 | 6 | 5 | 4 | 3 | 2 |
193 (120) | 5 | 4 | 3 | 3 | 2 | 1 |
Code of Federal Regulations
(f)
To provide cochannel protection to television stations, no shore station will be allowed closer than 193 km miles) from the cochannel television station.
(g)
To provide adjacent channel protection to television stations, no shore or offshore station shall be allowed within 128 kilometers (80 miles) of the adjacent channel television station.
(h)
Mobile stations shall not operate closer to shore than 6.4 km (4 miles) beyond the three mile limit and shall not operate with an ERP in excess of 100 watts with 9.1 m (30 ft) maximum antenna height.
(i)
Mobile stations installed in aircraft shall operate 11 km (7 miles) beyond the three mile limit and shall not operate with an ERP in excess of 1 watt or at heights in excess of 305 m (1000 feet) AMSL.
(j)
(1)
The following frequency bands are available for assignment in all services for use in the Zones defined in paragraph (a) of this section.
Zone | Transmit (or receive) | Receive (or transmit) |
---|---|---|
A | 490.01875-490.98125 | 493.01875-493.98125 |
B | 484.01875-484.98125 | 487.01875-487.98125 |
C | 478.01875-478.98125 | 481.01875-481.98125 |
(2)
Only the first and last assignable frequencies are shown. Frequencies shall be assigned in pairs with 3 MHz spacing between transmit and receive frequencies. Assignable frequency pairs will occur in increments of 6.25 kHz. The following frequencies will be assigned for a maximum authorized bandwidth of 6 kHz: 478.01875, 478.98125, 484.01875, 484.98125, 490.01875, 490.98125, 481.01875, 481.98125, 487.01875, 487.98125, 493.01875, and 493.98125 MHz.
(k)
Fixed stations operating point-to-point shall be assigned frequencies beginning with 490.025/493.025 MHz (Zone A), 484.025/487.025 MHz (Zone B) and 478.025-481.025 MHz (Zone C) and progressing upwards utilizing available frequencies toward the end of the band. Offshore base/mobile stations shall be assigned frequencies beginning at 490.975/493.975 MHz (Zone A), 484.975/478.975 MHz (Zone B) and 478.975/481.975 MHz (Zone C) and progressing downwards utilizing available frequencies toward the beginning of the band. All frequency assignments are subject to the conditions specified in § 90.173.
[50 FR 12027, Mar. 27, 1985; 50 FR 14389, Apr. 12, 1985, as amended at 58 FR 44959, Aug. 25, 1993; 60 FR 37277, July 19, 1995; 72 FR 35198, June 27, 2007]