Sec. 90.621  Selection and assignment of frequencies.

    (a) Applicants for frequencies in the Public Safety, Industrial/Land 
Transportation, and Business Categories must specify on the application 
the frequencies on which the proposed system will operate pursuant to a 
recommendation by the applicable frequency coordinator. Applicants for 
frequencies in the SMR Category must request specific frequencies by 
including in their applications the frequencies requested.
    (1) For trunked systems, the assignment of frequencies will be made 
in accordance with applicable loading criteria and in accordance with 
the following:
    (i) Channels will be chosen and assigned in accordance with 
Secs. 90.615, 90.617, or 90.619.
    (ii) A mobile station is authorized to transmit on any frequency 
assigned to its associated base station.
    (iii) There are no limitations on the number of frequencies that may 
be trunked. Authorizations for non-SMR stations may be granted for up to 
20 trunked frequency pairs at a time in accordance with the frequencies 
listed in Secs. 90.615, 90.617, and 90.619.
    (2) For conventional systems the assignment of frequencies will be 
made in accordance with applicable loading criteria. Accordingly, 
depending upon the number of mobile units to be served, an applicant may 
either be required to share a channel, or, if an applicant shows a 
sufficient number of mobile units to warrant the assignment of one or 
more channels for its exclusive use, it may be licensed to use such 
channel or channels on an unshared basis in the area of operation 
specified in its application.
    (i) Channels will be chosen and assigned in accordance with 
Secs. 90.615, 90.617, or 90.619.
    (ii) A mobile station is authorized to transmit on any frequency 
assigned to its associated base station.
    (b) Stations authorized on frequencies listed in this subpart, 
except for those stations authorized pursuant to paragraph (g) of this 
section and EA-based and MTA-based SMR systems, will be afforded 
protection solely on the basis of fixed distance separation criteria. 
For Channel Blocks A, through V, as set forth in Sec. 90.917(d), the 
separation between co-channel systems will be a minimum of 113 km (70 
mi) with one exception. For incumbent licensees in Channel Blocks D 
through V, that have received the consent of all affected parties to 
utilize an 18 dBV/m

[[Page 554]]

signal strength interference contour (see Sec. 90.693), the separation 
between co-channel systems will be a minimum of 173 km (107 mi). The 
following exceptions to these separations shall apply:
    (1) Except as indicated in paragraph (b)(4) of this section, no 
station in Channel Blocks A through V shall be less than 169 km (105 mi) 
distant from a co-channel station that has been granted channel 
exclusivity and authorized 1 kW ERP on any of the following mountaintop 
sites: Santiago Peak, Sierra Peak, Mount Lukens, Mount Wilson 
(California). Except as indicated in paragraph (b)(4) of this section, 
no incumbent licensee in Channel Blocks D through V that have received 
the consent of all affected parties to utilize an 18 dBV/m 
signal strength interference contour shall be less than 229 km (142 mi) 
distant from a co-channel station that has been granted channel 
exclusivity and authorized 1 kW ERP on any of the following mountaintop 
sites: Santiago Peak, Sierra Peak, Mount Lukens, Mount Wilson 
(California).
    (2) The separation between co-channel stations that have been 
granted exclusivity and that are located at high sites in California 
north of 35 deg. N Latitude and west of 118 deg. W Longitude shall be 
determined as follows:
    (i) Required co-channel separations between common antenna sites are 
given by table 1. A channel group assigned to a station on a site listed 
in the vertical column may not be re-assigned to a station on a site 
listed in the horizontal column if there is an ``X'' in the box created 
by the intersection of the vertical and horizontal lines. The geographic 
coordinates listed in the table represent an average for each particular 
site; all locations within 1.6 km (1 mi) of the coordinates will be 
considered to be at that site.
    (ii) Required co-channel separations involving antenna sites not 
listed in table 1 shall be determined by Commission staff on a case by 
case basis. The interference potential of proposed assignments will be 
evaluated considering parameters such as antenna height, effective 
radiated power, terrain irregularities, and market conditions.

  

[[Page 555]]

[GRAPHIC] [TIFF OMITTED] TC02AP91.013


    (3) Except as indicated in paragraph (b)(4) of this section, 
stations in Channel Blocks A through V that have been granted channel 
exclusivity and are located in the State of Washington at the locations 
listed below shall be separated from co-channel stations by a minimum of 
169 km (105 mi). Except as indicated in paragraph (b)(4) of this 
section, incumbent licensees in Channel Blocks D through V that have 
received the consent of all affected parties to utilize an 18 
dBV/m signal strength interference contour, have been granted 
channel exclusivity and are located in the State of Washington at the 
locations listed below shall be separated from co-channel stations by a 
minimum of 229 km (142 mi). Locations within one mile of the 
geographical coordinates listed in the table below will be considered to 
be at that site.

[[Page 556]]



                                                                        
------------------------------------------------------------------------
                                                    North        West   
                   Site name                      latitude    longitude 
------------------------------------------------------------------------
Mount Constitution.............................    48-40-48    122-50-24
Lyman Mountain.................................    48-35-42    122-09-35
Cultus Mountain................................    48-25-31    122-08-54
Gunsite Ridge..................................    48-03-23    121-51-37
Gold Mountain..................................    47-32-52    122-46-52
Buck Mountain..................................    47-47-06    122-59-30
Cougar Mountain................................    47-32-40    122-06-30
Squak Mountain.................................    47-30-15    122-03-30
Tiger Mountain.................................    47-30-14    121-58-28
Devils Mountain................................    48-21-53    122-16-02
McDonald Mountain..............................    47-20-12    122-51-26
Maynard Hill...................................    48-00-59    122-55-31
North Mountain.................................    47-19-08    123-20-44
Green Mountain.................................    47-33-41    122-48-27
Capitol Peak...................................    46-58-22    123-08-17
Rattlesnake Mountain...........................    47-28-10    121-49-13
Three Sisters Mountain.........................    47-07-20    121-53-30
Grass Mountain.................................    47-12-15    121-47-38
Spar Pole Hill.................................    47-02-52    122-08-35
------------------------------------------------------------------------

    (4) Upon an applicant's specific request to the Commission or a 
frequency coordinator, co-channel stations may be separated by less than 
113 km (70 mi) by meeting certain transmitter ERP and antenna height 
criteria. The following table indicates separations assignable to such 
co-channel stations for various transmitter power and antenna height 
combinations. The minimum separation permitted is 88 km (55 mi). 
Applicants will provide the Commission with a statement that the 
application is submitted for consideration under the table, a list of 
all co-channel stations within 113 km (70 mi), and the DHAATs and ERPs 
for these stations and the applicant's proposed station. Applicants 
seeking to be licensed for stations located at distances less than those 
prescribed in the table are required to secure a waiver and must submit 
with the application, in addition to the above, an interference 
analysis, based upon any of the generally-accepted terrain-based 
propagation models, that shows that co-channel stations would receive 
the same or greater interference protection than provided in the table. 
Requests for separations less than 88 km (55 mi) must also include an 
analysis of interference potential from mobile transmitters to existing 
co-channel base station receivers. Applicants seeking a waiver must 
submit with their application a certificate of service indicating that 
concurrent with the submission of the application to the Commission or a 
coordinator, all co-channel licensees within the applicable area were 
served with a copy of the application and all attachments thereto. 
Licensees thus served may file an opposition to the application within 
30 days from the date the application is filed with the Commission.
    (i) The directional height of the antenna above average terrain 
(DHAAT) is calculated from the average of the antenna heights above 
average terrain from 3 to 16 km (2 to 10 mi) from the proposed site 
along a radial extending in the direction of the existing station and 
the radials 15 degrees to either side of that radial.
    (ii) Except for the sites listed in paragraphs (b)(1), (b)(2), and 
(b)(3) of this section, additional co-channel distance separation must 
be afforded to an existing station from an applicant wishing to locate a 
station less than 113 km (70 mi) from a co-channel station, where either 
the applicant's or the existing station is located at sites with DHAATs 
of 458 m (1500 ft) and above. The separation between short-spaced co-
channel stations shall be determined as follows:
    (A) Calculate the DHAAT in each direction between every existing co-
channel station with 113 km (70 mi) and the proposed station.
    (B) In the table, locate the approximate ERP and DHAAT values for 
the proposed and existing stations.
    (C) When DHAAT values are greater than 458 m (1500 ft), use the 
required separation for 305 m (1000 ft) and add 1.6 km (1 mi) for every 
30.5 km (100 ft), or increment thereof, of DHAAT above 458 m (1500 ft) 
to the distance indicated in the table. If both the proposed existing 
stations have DHAATs of 458 m (1500 ft) or more, the additional distance 
is separately determined for each station and the combined distance is 
added to the distance obtained from the table. Protection to existing 
stations will be afforded only up to 113 km (70 mi).

[[Page 557]]



                                         Short-Spacing Separation Table                         
                
------------------------------------------------------------------------------------------------
----------------
                                                                 Distance between stations (km) 
1,2             
                                                  ----------------------------------------------
----------------
    Proposed station ERP (watts)/DHAAT(m) \3\                   Existing station DHAAT (meters) 
\3\             
                                                  ----------------------------------------------
----------------
                                                     305      215      150      108       75    
   54       37  
------------------------------------------------------------------------------------------------
----------------
1000/305.........................................      113      113      113      113      113  
    113      113
1000/215.........................................      113      113      113      113      113  
    113      110
1000/150.........................................      113      113      113      113      112  
    108      103
1000/108.........................................      113      113      113      110      107  
    103       98
1000/75..........................................      113      112      108      103      100  
     96       91
1000/54..........................................      113      109      105      100       97  
     93       88
1000/37..........................................      109      104      100       95       92  
     88       88
500/305..........................................      113      113      113      113      113  
    113      110
500/215..........................................      113      113      113      112      109  
    105      100
500/150..........................................      113      112      108      103      100  
     96       91
500/108..........................................      112      107      103       98       95  
     91       88
500/75...........................................      107      102       98       93       90  
     88       88
500/54...........................................      103       98       94       89       88  
     88       88
500/37...........................................       99       94       90       88       88  
     88       88
250/305..........................................      113      113      113      112      109  
    105      100
250/215..........................................      113      113      107      102       99  
     95       90
250/150..........................................      109      104      100       95       92  
     88       88
250/108..........................................      105      100       96       91       88  
     88       88
250/75...........................................       99       94       90       88       88  
     88       88
250/54...........................................       95       90       88       88       88  
     88       88
250/37...........................................       91       88       88       88       88  
     88       88
125/305..........................................      113      111      107      102       99  
     95       90
125/215..........................................      108      103       99       94       91  
     88       88
125/150..........................................      103       98       94       89       88  
     88       88
125/108..........................................       98       93       89       88       88  
     88       88
125/75...........................................       93       88       88       88       88  
     88       88
125/54...........................................       88       88       88       88       88  
     88       88
125/37...........................................       88       88       88       88       88  
     88       88
62/305...........................................      108      103       99       94       91  
     88       88
62/215...........................................      103       98       94       89       88  
     88       88
62/150...........................................       97       92       88       88       88  
     88       88
62/108...........................................       92       88       88       88       88  
     88       88
62/75............................................       88       88       88       88       88  
     88       88
62/54............................................       88       88       88       88       88  
     88       88
62/37............................................       88       88       88       88       88  
     88      88 
------------------------------------------------------------------------------------------------
----------------
\1\ Separations for stations on Santiago Peak, Sierra Peak, Mount Lukens, and Mount Wilson (CA) 
and the         
  locations in the State of Washington listed in paragraph (b)(3) of this section are 56 km (35 
mi) greater than
  those listed in the table above. In the event of conflict between this table and the table of 
additional      
  California high elevation sites shown in paragraph (b)(2) of this section, the latter will app
ly.             
\2\ Distances shown are derived from the R-6602 curves and are based upon a non-overlap of the 2
2 dBu (F50,10)  
  interference contour of the proposed station with the 40 dBu (F50,50) contour of the existing 
station(s). No  
  consideration is given to the 40 dBu service contour of the proposed station and the 22 dBu co
ntour of the    
  existing station(s). The minimum separation of stations will be 88 km (55 mi).                
                
\3\ All existing stations are assumed to operate with 1000 watts ERP. When the ERP and/or DHAAT 
of a proposed   
  station or the DHAAT of an existing station is not indicated in the table, the next higher val
ue(s) must be   
  used.                                                                                         
                

    (5) The separation between co-channel systems may be less than the 
separations defined above if an applicant submits with its application 
letters of concurrence indicating that the applicant and each co-channel 
licensee within the specified separation agree to accept any 
interference resulting from the reduced separation between their 
systems. Each letter from a co-channel licensee must certify that the 
system of the concurring licensee is constructed and fully operational. 
The applicant must also submit with its application a certificate of 
service indicating that all concurring co-channel licensees have been 
served with an actual copy of the application.
    (6) A station located closer than the distances provided in this 
section to a co-channel station that was authorized as short-spaced 
under paragraph (b)(4) of this section shall be permitted to modify its 
facilities as long as the station does not extend its 22 dBu contour 
beyond its maximum 22 dBu contour (i.e., the 22 dBu contour calculated 
using the station's maximum power and antenna height at its original 
location) in the direction of the short-spaced station.

[[Page 558]]

    (7) Offset frequencies in the 811-821/856-866 MHz band for use only 
within U.S./Mexico border area, as designated in Sec. 90.619(a), shall 
be considered co-channel with non-offset frequencies in this band as 
designated in Sec. 90.613. New applications for frequencies in this band 
for stations adjacent to the U.S./Mexico border area must comply with 
the co-channel separation provisions of this section.
    (c) Conventional systems authorized on frequencies in the Public 
Safety (except for those systems that have participated in a formal 
regional planning process as described in Sec. 90.16), Industrial/Land 
Transportation, Business, and Spectrum Block D frequencies in the 800 
MHz SMR service (formerly General) Categories which have not met the 
loading levels necessary for channel exclusivity will not be afforded 
co-channel protection.
    (d) UHF television translator stations using UHF output channels 
from Channels 70 through 83 operate on a secondary basis to land mobile 
stations using the UHF bands allocated under this subpart for land 
mobile use. Accordingly, such television translator stations will not be 
protected from interference from such authorized land mobile stations.
    (e) Frequencies in the 806-821/851-866 MHz bands listed as available 
for eligibles in the Public Safety, Industrial/Land Transportation, and 
Business Categories are available for inter-category sharing under the 
following conditions:
    (1) Channels in the Public Safety, Industrial/Land Transportation 
and Business categories will be available to eligible applicants in 
those categories only if there are no frequencies in their own category 
and no public safety systems are authorized on those channels under 
consideration to be shared.
    (2)-(4) [Reserved]
    (5) The applicant must submit a statement from its own category 
coordinator that frequencies are not available in that category, and 
coordination is required from the applicable out-of-category 
coordinator.
    (6) The out-of-category licensee must operate by the rules 
applicable to the category to which the frequency is allocated.
    (f) The 896-901/935-940 MHz channels listed as available for 
eligibles in the Industrial/Land Transportation and Business categories 
will be available for inter-category sharing to all persons eligible in 
those categories under the following conditions thirty-six (36) months 
from the date the first authorization in this spectrum is issued.
    (1) The applicant must submit a statement from its own category 
coordinator that frequencies are not available in that category, and 
coordination is required from the applicable out-of-category 
coordinator.
    (2) The out-of-category licensee must operate by the rules 
applicable to the category to which the frequency is allocated.
    (g) Applications for Public Safety systems (both trunked and 
conventional) in the 821-824/866-869 MHz bands will be assigned and 
protected based on the criteria established in the appropriate regional 
plan. See Sec. 90.16 and the Report and Order in General Docket 87-112.
    (h) Channel numbers 401-410, 441-450, 481-490, 521-530, and 561-570 
are available on co-primary basis to station in Basic Exchange 
Telecommunications Radio Service as described in part 22 of the 
Commission's Rules.
[ 47 FR 41032 , Sept. 16, 1982]

    Editorial Note: For Federal Register citations affecting 
Sec. 90.621, see the List of CFR Sections Affected in the Finding Aids 
section of this volume.