§ 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  § 101.103(d) of this chapter to the extent that these
   requirements are 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 3 of a magnitude greater
   than that specified in the criteria set forth in paragraphs (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 3—Coordination Distances in Kilometers
   PCS Base Station Antenna HAAT in Meters
   EIRP(W) 5 10 20 50 100 150 200 250 300 500 1000 1500 2000
   0.1 90 93 99 110 122 131 139 146 152 173 210 239 263
   0.5 96 100 105 116 128 137 145 152 158 179 216 245 269
   1 99 103 108 119 131 140 148 155 161 182 219 248 272
   2 120 122 126 133 142 148 154 159 164 184 222 250 274
   5 154 157 161 168 177 183 189 194 198 213 241 263 282
   10 180 183 187 194 203 210 215 220 225 240 268 291 310
   20 206 209 213 221 229 236 242 247 251 267 296 318 337
   50 241 244 248 255 264 271 277 282 287 302 331 354 374
   100 267 270 274 282 291 297 303 308 313 329 358 382 401
   200 293 296 300 308 317 324 330 335 340 356 386 409 436
   500 328 331 335 343 352 359 365 370 375 391 421 440
   1000 354 357 361 369 378 385 391 397 402 418
   1200 361 364 368 376 385 392 398 404 409 425
   1640 372 375 379 388 397 404 410 416 421 437
   2400 384 387 391 399 408 415 423 427 431
   3280 396 399 403 412 419 427 435 439 446

   (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;  69 FR 75171 , Dec. 15, 2004]

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