47 CFR 90.187 - Trunking in the bands between 150 and 512 MHz.

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§ 90.187 Trunking in the bands between 150 and 512 MHz.
(a) Applicants for trunked systems operating on frequencies between 150 and 512 MHz (except 220-222 MHz) must indicate on their applications (class of station code, instructions for FCC Form 601) that their system will be trunked. Licensees of stations that are not trunked, may trunk their systems only after modifying their license (see § 1.927 of this chapter).
(b) Trunked systems operating under this section must employ equipment that prevents transmission on a trunked frequency if a signal from another system is present on that frequency. The level of monitoring must be sufficient to avoid causing harmful interference to other systems. However, this monitoring requirement does not apply if the conditions in paragraph (b)(1) or (b)(2) of this section, are met:
(1) Where applicants for or licensees operating in the 470-512 MHz band meet the loading requirements of § 90.313 and have exclusive use of their frequencies in their service area.
(2) On frequencies where an applicant or licensee does not have an exclusive service area provided that all frequency coordination requirements are complied with and written consent is obtained from affected licensees using either the procedure set forth in paragraphs (b)(2)(i) and (b)(2)(ii) of this section (mileage separation) or the procedure set forth in paragraph (b)(2)(iii) of this section (protected contours).
(i) Affected licensees for the purposes of this section are licensees of stations that have assigned frequencies (base and mobile) that are 15 kHz or less removed from proposed stations that will operate with a 25 kHz channel bandwidth; stations that have assigned frequencies (base and mobile) that are 7.5 kHz or less removed from proposed stations that will operate with a 12.5 kHz bandwidth; or stations that have assigned frequencies (base and mobile) 3.75 kHz or less removed from proposed stations that will operate with a 6.25 kHz bandwidth.
(ii) Where such stations' service areas (37 dBu contour for stations in the 150-174 MHz band and 39 dBu contour for stations in the 421-512 MHz bands; see § 90.205) overlap a circle with radius 113 km (70 mi.) from the proposed base station.
(iii) In lieu of the mileage separation procedure set forth in paragraphs (b)(2)(i) and (b)(2)(ii) of this section, applicants for trunked facilities may obtain consent only from stations that would be subjected to objectionable interference from the trunked facilities. Objectionable interference will be considered to exist when the interference contour (19 dBu for VHF stations, 21 dBu for UHF stations) of a proposed trunked station would intersect the service contour (37 dBu for VHF stations, 39 dBu for UHF stations) of an existing station. The existing stations that must be considered in a contour overlap analysis are a function of the channel bandwidth of the proposed trunked station, as follows:
(A) For trunked stations proposing 25 kHz channel bandwidth: Existing co-channel stations and existing stations that have an operating frequency 15 kHz or less from the proposed trunked station.
(B) For trunked stations proposing 12.5 kHz channel bandwidth: Existing co-channel stations and existing stations that have an operating frequency 7.5 kHz or less from the proposed trunked station.
(C) For trunked stations proposing 6.25 kHz channel bandwidth: Existing co-channel stations and existing stations that have an operating frequency 3.75 kHz or less from the proposed trunked station.
(iv) The calculation of service and interference contours referenced in paragraph (b)(2)(iii) of this section shall be done using generally accepted engineering practices and standards which, for purposes of this section, shall presumptively be the practices and standards agreed to by a consensus of all certified frequency coordinators.
(v) The written consent from the licensees specified in paragraphs (b)(2)(i) and (b)(2)(ii) or (b)(2)(iii)(A), (b)(2)(iii)(B) and (b)(2)(iii)C of this section shall specifically state all terms agreed to by the parties and shall be signed by the parties. The written consent shall be maintained by the operator of the trunked station and be made available to the Commission upon request. The submission of a coordinated trunked application to the Commission shall include a certification from the applicant that written consent has been obtained from all licensees specified in paragraphs (b)(2)(i) and (b)(2)(ii) or (b)(2)(iii)(A), (b)(2)(iii)(B) and (b)(2)(iii)(C) of this section that the written consent documents encompass the complete understandings and agreements of the parties as to such consent; and that the terms and conditions thereof are consistent with the Commission's rules. Should a potential applicant disagree with a certified frequency coordinator's determination that objectionable interference exists with respect to a given channel or channels, that potential applicant may request the Commission to overturn the certified frequency coordinator's determination. In that event, the burden of proving by clear and convincing evidence that the certified frequency coordinator's determination is incorrect shall rest with the potential applicant. If a licensee has consented to the use of trunking, but later decides against the use of trunking, that licensee may request that the licensee(s) of the trunked system(s) cease the use of trunking. Should the trunked station(s) decline the licensee's request, the licensee may request a replacement channel from the Commission. A new applicant whose interference contour overlaps the service contour of a trunked licensee will be assigned the same channel as the trunked licensee only if the trunked licensee consents in writing and a copy of the written consent is submitted to the certified frequency coordinator responsible for coordination of the application.
(c) Trunking of systems licensed on paging-only channels or licensed in the Radiolocation Service (subpart F) is not permitted.
(d) Potential applicants proposing trunked operation may file written notice with any certified frequency coordinator for the pool (Public Safety or Industrial/Business) in which the applicant proposes to operate. The notice shall specify the channels on which the potential trunked applicant proposes to operate and the proposed effective radiated power, antenna pattern, height above ground, height above average terrain and proposed channel bandwidth. On receipt of such a notice, the certified frequency coordinator shall notify all other certified frequency coordinators in the relevant pool within one business day. For a period of sixty days thereafter, no application will be accepted for coordination which specifies parameters that would result in objectionable interference to the channels specified in the notice. Potential applicants shall not file another notice for the same channels within 10 km (6.2 miles) of the same location unless six months shall have elapsed since the filing of the last such notice. Certified frequency coordinators shall return without action, any coordination request which violates the terms of this paragraph (d).
(e) No more than 10 channels for trunked operation in the Industrial/Business Pool may be applied for in a single application. Subsequent applications, limited to an additional 10 channels or fewer, must be accompanied by a certification, submitted to the certified frequency coordinator coordinating the application, that all of the applicant's existing channels authorized for trunked operation have been constructed and placed in operation. Certified frequency coordinators are authorized to require documentation in support of the applicant's certification that existing channels have been constructed and placed in operation. Applicants in the Public Safety Pool may request more than 10 channels at a single location provided that any application for more than 10 Public Safety Pool channels must be accompanied by a showing of sufficient need. The requirement for such a showing may be satisfied by submission of loading studies demonstrating that requested channels in excess of 10 will be loaded with 50 mobiles per channel within a five year period commencing with grant of the application.
(f) If a licensee authorized for trunked operation discontinues trunked operation for a period of 30 consecutive days, the licensee, within 7 days of the expiration of said 30 day period, shall file a conforming application for modification of license with the Commission. Upon grant of that application, new applicants may file for the same channel or channels notwithstanding the interference contour of the new applicant's proposed channel or channels overlaps the service contour of the station that was previously engaged in trunked operation.
[65 FR 60875, Oct. 13, 2000]
Beta! The text on the eCFR tab represents the unofficial eCFR text at ecfr.gov.
§ 90.187 Trunking in the bands between 150 and 512 MHz.

(a) Applicants for centralized and decentralized trunked systems operating on frequencies between 150 and 512 MHz (except 220-222 MHz) must indicate on their applications (radio service and class of station code, instructions for FCC Form 601) that their system will be trunked. Licensees of stations that are not trunked may trunk their systems only after modifying their license (see § 1.927 of this chapter).

(b) Except as provided in paragraphs (c) and (d) of this section, trunked systems operating under this section must employ equipment that prevents transmission on a trunked frequency if a signal from another system is present on that frequency. The level of monitoring must be sufficient to avoid harmful interference to other systems.

(c) The monitoring requirement in paragraph (b) of this section does not apply to trunked systems operating in the 470-512 MHz band that meet the loading requirements of § 90.313 and have exclusive use of their frequencies in their service area.

(d) The monitoring requirement in paragraph (b) of this section does not apply if the application is accompanied by written consent from all affected licensees.

(1) Affected licensees for the purposes of this section are licensees (and previously filed pending applicants) meeting both a spectral and a contour overlap as defined:

(i) Spectral overlap. Licensees (and filers of previously filed pending applications) with an assigned (or proposed) frequency having a spectral separation from a frequency of the proposed centralized trunked station that does not exceed these values:

Proposed station Incumbent authorized bandwidth
25 kHz 12.5 kHz 6.25 kHz
25 kHz 15.0 kHz 15.0 kHz 15.0 kHz
12.5 kHz 15.0 kHz 7.5 kHz 7.5 kHz
6.25 kHz 15.0 kHz 7.5 kHz 5.0 kHz

The left column is the authorized bandwidth requested for the proposed trunked station. The second row is the authorized bandwidth of the incumbent. The other cells in the table show the frequency range above and below the frequency of the proposed centralized trunked station that must be considered.

(ii) Contour overlap.

(A) Licensees (and filers of previously filed pending applications) with a service contour (37 dBu for stations in the 150-174 MHz band, and 39 dBu for stations in the 421-512 MHz band) that is overlapped by the proposed centralized trunked station's interference contour (19 dBu for stations in the 150-174 MHz band, and 21 dBu for stations in the 421-512 MHz band). Contour calculations are required for base station facilities. Contour calculations are required for associated mobile stations only in the 150-174 MHz band, with the associated base station's service contour used as both the mobile station's service contour and its interference contour.

(B) The calculation of service and interference contours shall be performed using generally accepted engineering practices and standards, including appropriate derating factors, agreed to by a consensus of all certified frequency coordinators. Frequency coordinators shall make this information available to the Commission upon request.

(C) For purposes of this section, the authorized operating area of a station or proposed station with no associated base station shall be used as both the station's service contour and its interference contour.

(D) After January 1, 2013, licensees with an authorized bandwidth exceeding 12.5 kHz will not be deemed affected licensees, unless the licensee meets the efficiency standard set forth in § 90.203(j)(3) or the licensee was granted a waiver of § 90.209(b).

(2) The written consent from an affected licensee shall state all terms agreed to by the parties and shall be signed by the parties. The written consent shall be maintained by the operator of the centralized trunked station and be made available to the Commission upon request. An application for a centralized trunked station shall include either a certification from the applicant that written consent has been obtained from all affected licensees, or a certification from the frequency coordinator that there are no affected licensees.

(3) In addition, the service contour for proposed centralized trunked stations on Industrial/Business Pool frequencies shall not be overlapped by an incumbent licensee's interference contour. An application filed for Public Safety Pool frequencies, see § 90.20, for a proposed centralized trunked station in which the service contour of the proposed station is overlapped by the interference contour of the incumbent station(s) is allowed, but the applicant must accept any resultant interference.

(e) The exclusive service area of a station that has been authorized for centralized trunked operation will be protected from proposed centralized trunked, decentralized trunked or conventional operations in accordance with the standards of paragraph (d) of this section.

(f) Trunking of systems licensed on paging-only channels or licensed in the Radiolocation Service (subpart F) is not permitted.

(g) Channel limits.

(1) No more than 10 channels for new centralized trunked operation in the Industrial/Business Pool may be applied for at a single transmitter location or at locations with overlapping service contours as specified in paragraph (d) of this section. Subsequent applications for centralized trunked operation are limited to no more than an additional 10 channels, and must be accompanied by a certification, submitted to the certified frequency coordinator coordinating the application, that all of the applicant's existing channels authorized for centralized trunked operation at that location or at locations with overlapping service contours have been constructed and placed in operation. Certified frequency coordinators are authorized to require documentation in support of the applicant's certification that existing channels have been constructed and placed in operation.

(2) Applicants for Public Safety Pool channels may request more than 10 centralized trunked channels at a single location or at locations with overlapping service contours if accompanied by a showing of sufficient need. The requirement for such a showing may be satisfied by submission of loading studies demonstrating that requested channels in excess of 10 will be loaded with 50 mobiles per channel within a five year period commencing with the grant of the application.

(h) If a licensee authorized for centralized trunked operation discontinues trunked operation for a period of 30 consecutive days, the licensee, within 7 days thereafter, shall file a conforming application for modification of license with the Commission.

[78 FR 28754, May 16, 2013, as amended at 80 FR 18146, Apr. 3, 2015]

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    1. 80 FR 73696 - Public Safety and Homeland Security Bureau Seeks Comment on FirstNet's Incumbent Relocation Proposal
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