Goto Section: 22.653 | 22.659 | Table of Contents
FCC 22.657
Revised as of October 1, 2008
Goto Year:2007 |
2009
Sec. 22.657 Transmitter locations.
The purpose of the rules in paragraphs (a) and (b) of this section is to
define the areas in which the 470–512 MHz channels are allocated for public
mobile use. The purpose of the rules in paragraphs (c) through (f) of this
section is to reduce the likelihood that interference to television
reception from public mobile operations on these channels will occur. The
protected TV station locations specified in paragraphs (d), (e)(1) and (f)
of this section are the locations of record as of September 1974, and these
do not change even though the TV stations may have been subsequently
relocated.
(a) Base transmitter locations. Base transmitter locations must be within 80
kilometers (50 miles) of the designated locations in this paragraph. Mobile
transmitters must not be operated at locations more than 129 kilometers (80
miles) from the designated locations in this paragraph. Note: All
coordinates are referenced to North American Datum 1983 (NAD83).
Urban area N. latitude W. longitude
Houston, TX 29 °45'26.8" 95 °21'37.8"
New York, NY-NE NJ 40 °45'06.4" 73 °59'37.5"
(b) Mobile area of operation. Mobile transmitters must not be operated at
locations more than 48 kilometers (30 miles) from all associated base
stations.
(c) Protection from intermodulation interference. Base transmitter locations
must be at least 1.6 kilometers (1 mile) from the current main transmitter
locations of all TV stations transmitting on TV channels separated by 2, 3,
4, 5, 7, or 8 TV channels from the TV channel containing the frequencies on
which the base station will transmit. This requirement is intended to reduce
the likelihood of intermodulation interference.
(d) Adjacent channel protection from mobile transmitters. Base transmitter
locations must be at least 145 kilometers (90 miles) from the applicable
protected TV station locations specified in this paragraph. This requirement
is intended to provide a 0 dB minimum desired to undesired signal strength
ratio at the Grade B contour of an adjacent channel TV station. Note: All
coordinates are referenced to North American Datum 1983 (NAD83).
Control transmitter frequency range Protected TV station location TV channel
470–476 MHz Lancaster, PA, 40 °15'45.3" N. Lat. 76 °27'47.9" W. Long. (15)
476–482 MHz Scranton, PA, 41 °10'58.3" N. Lat. 75 °52'19.7" W. Long. (16)
(e) Co-channel protection from mobile transmitters. Base transmitter
locations must be at least the distance specified in paragraph (e)(2) of
this section from the applicable protected TV station locations specified in
paragraph (e)(1) of this section. This requirement is intended to provide a
40 dB minimum desired to undesired signal strength ratio at the Grade B
contour of a co-channel TV station.
(1) The protected TV station locations are as follows (all coordinates are
referenced to North American Datum 1983 (NAD83)):
Control transmitter frequency range Protected TV station location
470–476 MHz Washington, DC, 38 °57'17.4" N. Lat. 77 °00'15.9" W. Long.
476–482 MHz Lancaster, PA, 40 °15'45.3" N. Lat. 76 °27'47.9" W. Long.
(2) The required minimum distance depends upon the effective radiated power
(ERP) of the most powerful mobile transmitter(s) in the system:
Mobile unit ERP (watts) Minimum distance
Kilometers Miles
60 193 (120)
50 185 (115)
25 177 (110)
10 169 (105)
5 161 (100)
(f) Co-channel protection from base transmitters with high antennas. This
paragraph applies only to base transmitter locations in the New
York-Northeastern New Jersey urban area that utilize an antenna height of
more than 152 meters (500 feet) above average terrain. The distance between
the location of such a base transmitter and the applicable protected TV
station location specified in this paragraph must equal or exceed the sum of
the distance from the base transmitter location to the radio horizon in the
direction of the specified location and 89 kilometers (55 miles—representing
the distance from the main transmitter location of the TV station to its
Grade B contour in the direction of the base transmitter). The distance to
the radio horizon is calculated as follows:
[er14de98.026.gif]
Where d is the distance to the radio horizon in kilometers h is the height
of the antenna center of radiation above ground level in meters
Note: All coordinates are referenced to North American Datum 1983 (NAD83)):
Control transmitter frequency range Protected TV station location
470–476 MHz Washington, DC, 38 °57'17.4" N. Lat. 77 °00'15.9" W. Long.
476–482 MHz Lancaster, PA, 40 °15'45.3" N. Lat. 76 °27'47.9" W. Long.
(g) The FCC may waive specific distance separation requirements of
paragraphs (d) through (f) of this section if the applicant submits an
engineering analysis which demonstrates that terrain effects and/or
operation with less effective radiated power would satisfy the applicable
minimum desired to undesired signal strength ratios at the Grade B contours
of the protected TV stations. For this purpose, the Grade B contour of a TV
station is deemed to be a circle with a 89 kilometer (55 mile) radius,
centered on the protected TV station location, and along which the median TV
signal field strength is 64 dB µV/m. In any showing intended to demonstrate
compliance with the minimum desired to undesired signal ratio requirements
of this section, all predicted field strengths must have been determined
using the UHF TV propagation curves contained in part 73 of this chapter.
[ 59 FR 59507 , Nov. 17, 1994, as amended at 63 FR 68947 , Dec. 14, 1998]
Goto Section: 22.653 | 22.659
Goto Year: 2007 |
2009
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