47 CFR § 22.972 - Interference resolution procedures.
(a) Initial notification.
(1) Cellular Radiotelephone licensees may receive initial notification of interference from non-cellular part 90 of this chapter licensees in the 800 MHz band pursuant to § 90.674(a) of this chapter.
(2) Cellular Radiotelephone licensees, in conjunction with part 90 ESMR licensees, shall establish an electronic means of receiving the initial notification described in § 90.674(a) of this chapter. The electronic system must be designed so that all appropriate Cellular Radiotelephone licensees and part 90 ESMR licensees can be contacted about the interference incident with a single notification. The electronic system for receipt of initial notification of interference complaints must be operating no later than February 22, 2005.
(3) Cellular Radiotelephone licensees must respond to the initial notification described in § 90.674(a) of this chapter, as soon as possible and no later than 24 hours after receipt of notification from a part 90 public safety/CII licensee. This response time may be extended to 48 hours after receipt from other part 90 non-cellular licensees provided affected communications on these systems are not safety related.
(b) Interference analysis. Cellular Radiotelephone licensees—who receive an initial notification described in § 90.674(a) of this chapter—shall perform a timely analysis of the interference to identify the possible source. Immediate on-site visits may be conducted when necessary to complete timely analysis. Interference analysis must be completed and corrective action initiated within 48 hours of the initial complaint from a part 90 of this chapter public safety/CII licensee. This response time may be extended to 96 hours after the initial complaint from other part 90 of this chapter non-cellular licensees provided affected communications on these systems are not safety related. Corrective action may be delayed if the affected licensee agrees in writing (which may be, but is not required to be, recorded via e-mail or other electronic means) to a longer period.
(c) Mitigation steps.
(1) All Cellular Radiotelephone and part 90 of this chapter—800 MHz cellular system licensees who are responsible for causing unacceptable interference shall take all affirmative measures to resolve such interference. Cellular Radiotelephone licensees found to contribute to unacceptable interference, as defined in § 22.970, shall resolve such interference in the shortest time practicable. Cellular Radiotelephone licensees and part 90 of this chapter—800 MHz cellular system licensees must provide all necessary test apparatus and technical personnel skilled in the operation of such equipment as may be necessary to determine the most appropriate means of timely eliminating the interference. However, the means whereby interference is abated or the cell parameters that may need to be adjusted is left to the discretion of the Cellular Radiotelephone and/or part 90 of this chapter—800 MHz cellular system licensees, whose affirmative measures may include, but not be limited to, the following techniques:
(i) Increasing the desired power of the public safety/CII signal;
(ii) Decreasing the power of the part 90 ESMR and/or Cellular Radiotelephone system signal;
(iii) Modifying the part 90 ESMR and/or Cellular Radiotelephone system antenna height;
(iv) Modifying the part 90 ESMR and/or Cellular Radiotelephone system antenna characteristics;
(v) Incorporating filters into part 90 ESMR and/or Cellular Radiotelephone transmission equipment;
(vi) Permanently changing part 90 ESMR and/or Cellular Radiotelephone frequencies; and
(vii) Supplying interference-resistant receivers to the affected public safety/CII licensee(s). If this technique is used, in all circumstances, Cellular Radiotelephone and/or part 90 of this chapter ESMR licensees shall be responsible for all costs thereof.
(2) Whenever short-term interference abatement measures prove inadequate, the affected part 90 of this chapter non-cellular licensee shall, consistent with but not compromising safety, make all necessary concessions to accepting interference until a longer-term remedy can be implemented.
(3) Discontinuing operations when clear imminent danger exists. When a part 90 of this chapter public safety licensee determines that a continuing presence of interference constitutes a clear and imminent danger to life or property, the licensee causing the interference must discontinue the associated operation immediately, until a remedy can be identified and applied. The determination that a continuing presence exists that constitutes a clear and imminent danger to life or property, must be made by written statement that:
(i) Is in the form of a declaration, notarized affidavit, or statement under penalty or perjury, from an officer or executive of the affected public safety licensee;
(ii) Thoroughly describes the basis of the claim of clear and imminent danger;
(iii) Was formulated on the basis of either personal knowledge or belief after due diligence;
(iv) Is not proffered by a contractor or other third party; and
(v) Has been approved by the Chief of the Public Safety and Homeland Security Bureau or other designated Commission official. Prior to the authorized official making a determination that a clear and imminent danger exists, the associated written statement must be served by hand-delivery or receipted fax on the applicable offending licensee, with a copy transmitted by the fastest available means to the Washington, DC office of the Commission's Public Safety and Homeland Security Bureau.