Goto Section: 90.313 | 90.317 | Table of Contents
FCC 90.315
Revised as of October 2, 2015
Goto Year:2014 |
2016
§ 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.
(b) Offshore base/mobile, and offshore and shore fixed stations may be
authorized.
(c) F2, F3, F4, F9, and A2, A3, A4, and A9 emissions may be authorized.
(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.
Table 1—Protection of Cochannel Television Stations by Offshore Stations
Operating in the Southern Louisiana-Texas Offshore Zone (65 dB Protection);
Maximum Effective Radiated Power
[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
Note: To determine the maximum permissible effective radiated power:
(1) As specified in § 73.611 determine the distance between the proposed
station and the cochannel television station. If the exact distance does not
appear in table 1 of this section, the next lower distance separation is to
be used.
(2) Opposite this distance figure ERPs are given that may be used for
antenna heights of 30.5, 45 or 61 meters (100, 150 or 200 ft) ASL. If the
exact antenna height is not shown, the ERP allowed will be that shown for
the next higher antenna height.
(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 ±221⁄2 ° from the
line joining the shore antenna to the cochannel television station shall not
exceed those shown in table 2 of this section.
Table 2—Maximum Rearward Effective Radiated Power Allowed for Shore
Stations; Rearward Effective Radiated Power (in Watts) From Shore Antenna in
a Sector <±>221/2° From the Line Joining the Shore Antenna to the Cochannel
Television Station
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
Note: As an example of the use of tables 1 and 2, assume an offshore station
located 290 km (180 mi) from TV Channel 17 located in Bude, Miss. with an
antenna height of 30.5 m (100 ft). Table 1 allows this station to operate
with 250 W ERP. Now assume the shore station communicating with the offshore
station is 48 km (30 mi) from the offshore station and 241 km (150 mi) from
Bude, Miss. The shore station antenna height is 152.5 m (500 ft) above
ground. The shore station will be allowed the same ERP as the offshore
station (250 W) in the direction of the offshore station. Table 2 indicates
that the effective radiated power in a sector <±>221⁄2 ° from the line
joining the shore antenna to Bude, Miss. can only be 15 W. Consequently, a
directional antenna must be used whose minimum front-to-back ratio over this
45° sector must be at least 12.2 dB. (250 W forward power to 15 W rearward
power is a power ratio of 16.6 or 12.2 dB).
(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.
Paired Frequencies (MHz)
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]
return arrow Back to Top
Goto Section: 90.313 | 90.317
Goto Year: 2014 |
2016
CiteFind - See documents on FCC website that
cite this rule
Want to support this service?
Thanks!
Report errors in
this rule. Since these rules are converted to HTML by machine, it's possible errors have been made. Please
help us improve these rules by clicking the Report FCC Rule Errors link to report an error.
hallikainen.com
Helping make public information public