§  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]