§  27.1184   Triggering a reimbursement obligation.

   (a) The clearinghouse will apply the following test to determine when
   an AWS entity has triggered a cost-sharing obligation and therefore
   must pay an AWS relocator of a BRS system in accordance with the
   formula detailed in § 27.1180:

   (1) All or part of the relocated BRS system was initially co-channel
   with the licensed AWS band(s) of the AWS entity;

   (2) An AWS relocator has paid the relocation costs of the BRS
   incumbent; and

   (3) The other AWS entity has turned on or is preparing to turn on a
   fixed base station at commercial power and the incumbent BRS system
   would have been within the line of sight of the AWS entity's fixed base
   station, defined as follows.

   (i) For a BRS system using the 2150-2160/62 MHz band exclusively to
   provide one-way transmissions to subscribers, the clearinghouse will
   determine whether there is an unobstructed signal path (line of sight)
   to the incumbent licensee's geographic service area (GSA), based on the
   following criteria: use of 9.1 meters (30 feet) for the receiving
   antenna height, use of the actual transmitting antenna height and
   terrain elevation, and assumption of 4/3 Earth radius propagation
   conditions. Terrain elevation data must be obtained from the U.S.
   Geological Survey (USGS) 3-second database. All coordinates used in
   carrying out the required analysis shall be based upon use of NAD-83.

   (ii) For all other BRS systems using the 2150-2160/62 MHz band, the
   clearinghouse will determine whether there is an unobstructed signal
   path (line of sight) to the incumbent licensee's receive station hub
   using the method prescribed in "Methods for Predicting Interference
   from Response Station Transmitters and to Response Station Hubs and for
   Supplying Data on Response Station Systems. MM Docket 97-217," in
   Amendment of 47 CFR parts 1, 21 and 74 to Enable Multipoint
   Distribution Service and Instructional Television Fixed Service
   Licensees to Engage in Fixed Two-Way Transmissions, MM Docket No.
   97-217, Report and Order on Further Reconsideration and Further Notice
   of Proposed Rulemaking, 15 FCC Rcd 14566 at 14610, Appendix D.

   (b) If the application of the trigger test described in paragraphs
   (a)(3)(i) and (ii) of this section, indicates that a reimbursement
   obligation exists, the clearinghouse will calculate the reimbursement
   amount in accordance with the cost-sharing formula and notify the
   subsequent AWS entity of the total amount of its reimbursement
   obligation.

   (c) Once a reimbursement obligation is triggered, the AWS entity may
   not avoid paying its cost-sharing obligation by deconstructing or
   modifying its facilities.