Sec. 24.237  Interference protection.

    (a) All licensees are required to coordinate their frequency usage 
with the co-channel or adjacent channel incumbent fixed microwave 
licensees in the 1850-1990 MHz band. Coordination must occur before 
initiating operations from any base station. Problems that arise during 
the coordination process are to be resolved by the parties to the 
coordination. Licensees are required to coordinate with all users 
possibly affected, as determined by Appendix I to this subpart E 
(Appendix E of the Memorandum Opinion and Order, GEN Docket No. 90-314, 
FCC 94-144; TIA Telecommunications Systems Bulletin 10-F, ``Interference 
Criteria for Microwave Systems,'' May 1994, (TSB10-F)); or an 
alternative method agreed to by the parties.
    (b) The results of the coordination process need to be reported to 
the Commission only if the parties fail to agree. Because broadband PCS 
licensees are required to protect fixed microwave licensees in the 1850-
1990 MHz band, the Commission will be involved in the coordination 
process only upon complaint of interference from a fixed microwave 
licensee. In such a case, the Commission will resolve the issues.
    (c) In all other respects, coordination procedures are to follow the 
requirements of Sec. 101.103(d) of this chapter to the extent that these 
requirements are

[[Page 248]]

not inconsistent with those specified in this part.
    (d) The licensee must perform an engineering analysis to assure that 
the proposed facilities will not cause interference to existing OFS 
stations within the coordination distance specified in Table 2 of a 
magnitude greater than that specified in the criteria set forth in 
paragraph (e) and (f) of this section, unless there is prior agreement 
with the affected OFS licensee. Interference calculations shall be based 
on the sum of the power received at the terminals of each microwave 
receiver from all of the applicant's current and proposed PCS 
operations.

                                                     Table 2.--Coordination Dis
tances In Kilometers                                                     
                                                        [PCS Base Station Anten
na HAAT in Meters]                                                       
-------------------------------------------------------------------------------
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                  e.i.r.p. (W)                       5      10      20      50 
     100     150     200     250     300     500    1000    1500    2000 
-------------------------------------------------------------------------------
-------------------------------------------------------------------------
0.1.............................................      90      93      99     11
0     122     131     139     146     152     173     210     239     263
0.5.............................................      96     100     105     11
6     128     137     145     152     158     179     216     245     269
1...............................................      99     103     108     11
9     131     140     148     155     161     182     219     248     272
2...............................................     120     122     126     13
3     142     148     154     159     164     184     222     250     274
5...............................................     154     157     161     16
8     177     183     189     194     198     213     241     263     282
10..............................................     180     183     187     19
4     203     210     215     220     225     240     268     291     310
20..............................................     206     209     213     22
1     229     236     242     247     251     267     296     318     337
50..............................................     241     244     248     25
5     264     271     277     282     287     302     331     354     374
100.............................................     267     270     274     28
2     291     297     303     308     313     329     358     382     401
200.............................................     293     296     300     30
8     317     324     330     335     340     356     386     409  ......
500.............................................     328     331     335     34
3     352     359     365     370     375     391     421  ......  ......
1000............................................     354     357     361     36
9     378     385     391     397     402     418  ......  ......  ......
1200............................................     361     364     368     37
6     385     392     398     404     409  ......  ......  ......  ......
1640............................................     372     375     379     33
8     397     404     410     416     421  ......  ......  ......  ......
-------------------------------------------------------------------------------
-------------------------------------------------------------------------
Note: If actual value does not match table values, round to the closest higher 
value on this table. See Section 24.53 for HAAT calculation method.      

    (e) For microwave paths of 25 kilometers or less, interference 
determinations  shall  be  based  on  the C/I criteria set forth in TIA 
Telecommunications Systems Bulletin 10-F, ``Interference Criteria for 
Microwave Systems,'' May 1994 (TSB10-F).
    (f) For microwave paths longer than 25 kilometers, the interference 
protection criterion shall be such that the interfering signal will not 
produce more than 1.0 dB degradation of the practical threshold of the 
microwave receiver for analog system, or such that the interfering 
signal will not cause an increase in the bit error rate (BER) from 10E-6 
to 10E-5 for digital systems.
    (g) The development of the C/I ratios and interference criteria 
specified in paragraphs (e) and (f) of this section and the methods 
employed to compute the interfering power at the microwave receivers 
shall follow generally acceptable good engineering practices. The 
procedures described for computing interfering signal levels in 
(Appendix I to this subpart E Appendix E of the Memorandum Opinion and 
Order, GEN Docket No. 90-314, FCC 94-144) shall be applied. 
Alternatively, procedures for determining interfering signal levels and 
other criteria as may be developed by the Electronics Industries 
Association (EIA), the Institute of Electrical and Electronics 
Engineers, Inc. (IEEE), the American National Standards Institute (ANSI) 
or any other recognized authority will be acceptable to the Commission.
[ 59 FR 32854 , June 24, 1994, as amended at  61 FR 29691 , June 21, 1996]