§ 21.938 - BTA and PSA technical and interference provisions.

(a) BTA or PSA authorization holders are expected to cooperate with one another by designing their stations in a manner that protects service in adjoining BTAs and PSAs including consideration of interference abatement techniques such as cross polarization, frequency offset, directional antennas, antenna beam tilt, EIRP decrease, reduction of antenna height, and terrain shielding.

(b) Unless the affected parties have executed a written interference agreement in accordance with § 21.937, and subject to the provisions of §§ 21.909, 21.913, 21.949, 74.939 of this chapter, 74.949 of this chapter and 74.985 of this chapter regarding the protection of response station hubs, booster service areas and 125 kHz channels from harmful electromagnetic interference, stations licensed to a BTA or PSA authorization holder must not cause harmful electromagnetic interference to the following:

(1) The protected service area of other authorization holders in adjoining BTAs or PSAs.

(2) The 56.33 km (35 mile) protected service areas of authorized or previously proposed MDS stations (incumbents).

(3) Registered receive sites and protected service areas of authorized or previously proposed stations in the Instructional Television Fixed Service pursuant to the manner in which interference is defined in § 74.903(a).

(c)(1) ITFS applicants may locate a new station in an unused portion of a BTA or PSA where interference to a previously-proposed or authorized MDS station of a BTA or PSA authorization holder would not be predicted.

(2) With respect to ITFS applications only and for purposes of determining the existence of harmful electromagnetic interference as caused to MDS stations licensed to BTA or PSA authorization holders by subsequently proposed ITFS stations within that BTA, MDS stations licensed to BTA and PSA authorization holders and will have a protected service area of 56.33 km (35 miles), centered on the antenna site of the MDS stations.

(3) The 56.33 km (35 mile) protected service area afforded to a previously-proposed or authorized MDS station of a BTA or PSA authorization holder with respect to a subsequently proposed ITFS station is entitled to the interference protection standards of § 21.902.

(4) An ITFS station authorized before September 15, 1995 may be modified, provided the power flux density of that station does not exceed −73 dBW/m2 (or the appropriate value for bandwidth other than 6 MHz) at locations along the 56.33 km (35 mile) circle centered on the then-existing transmitting antenna site or service area of a collocated incumbent MDS station, as applicable.

(d) Unless the affected parties have executed a written interference agreement in accordance with § 21.937, it shall be the responsibility of a BTA or PSA authorization holder to correct at its expense any condition of harmful electromagnetic interference caused to authorized MDS service at locations within other BTAs or PSAs or within the 56.33 km (35 mile) protected service areas of authorized or previously proposed ITFS and MDS stations (incumbents), or at authorized or previously proposed ITFS receive sites.

(e) Unless specifically excepted, BTA or PSA authorization holders are governed by the interference protection and other technical provisions applicable to MDS.

(f) The calculated free space power flux density from an MDS station, other than an incumbent MDS station, may not exceed −73 dBW/m2 (or the appropriate value for bandwidth other than 6 MHz) at locations on BTA or PSA boundaries for which there is an unobstructed signal path from the transmitting antenna to the boundary, unless the applicant has obtained the written consent of the authorization holder for the affected BTA or PSA.

(g)(1) Authorization holders for BTAs or PSAs must notify authorization holders of adjoining areas of their application filings for new or modified stations; provided the proposed facility would produce an unobstructed signal path anywhere within the adjoining BTA or PSA.

(2) This service of written notification must include a copy of the FCC application and occur on or before the date the application is filed with the Commission.

(3) With regard to incumbent MDS stations, authorization holders for BTAs or PSAs must comply with the requirements of § 21.902.

(h) Where a PSA adjoins a BTA and both authorizations are held by the same individual or entity, the PSA shall be considered an extension of the protected service area of the BTA regarding the interference protection, limiting signal strength, and notification provisions of this section.