[Code of Federal Regulations]
[Title 47, Volume 4]
[Revised as of October 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 47CFR78.108]

[Page 775-776]
 
                       TITLE 47--TELECOMMUNICATION
 
                         COMMISSION (CONTINUED)
 
PART 78_CABLE TELEVISION RELAY SERVICE--Table of Contents
 
                     Subpart D_Technical Regulations
 
Sec.  78.108  Minimum path lengths for fixed links.

    (a) The distance between end points of a fixed link must equal or 
exceed the value set forth in the table below or the EIRP must be 
reduced in accordance with the equation set forth below.

------------------------------------------------------------------------
           Frequency band (MHz)               Minimum path length (km)
------------------------------------------------------------------------
12,200 to 13,250..........................  5
Above 17,700..............................  N/A
------------------------------------------------------------------------


[[Page 776]]

    (b) For paths shorter than those specified in the Table, the EIRP 
shall not exceed the value derived from the following equation.


EIRP = MAXEIRP - 40 log(A/B) dBW
Where:

EIRP = The new maximum EIRP (equivalent isotropically radiated power) in 
dBW.
MAXEIRP = Maximum EIRP as set forth in the Table in Sec.  74.636 of this 
part.
A = Minimum path length from the Table above for the frequency band in 
kilometers.
B = The actual path length in kilometers.

    Note to paragraph (b): For transmitters using Automatic Transmitter 
Power Control, EIRP corresponds to the maximum transmitter power 
available, not the coordinated transmit power or the nominal transmit 
power.
    (c) Upon an appropriate technical showing, applicants and licensees 
unable to meet the minimum path length requirement may be granted an 
exception to these requirements.

    Note: Links authorized prior to April 1, 1987, are excluded from 
this requirement, except that, effective April 1, 1992, the Commission 
will require compliance with the criteria where an existing link would 
otherwise preclude establishment of a new link.

[52 FR 7145, Mar. 9, 1987, as amended at 68 FR 12776, Mar. 17, 2003]