Section 25.261 - [Effective until an indefinitely delayed date ] Sharing among NGSO FSS space stations(a)Scope. This section applies to NGSO FSS operation with earth stations with directional antennas anywhere in the world under a Commission license, or in the United States under a grant of U.S. market access.(b)Coordination. NGSO FSS licensees and market access recipients must coordinate in good faith the use of commonly authorized frequencies regardless of their processing round status.(c)Default procedure. Absent coordination between two or more satellite systems, whenever the increase in system noise temperature of an earth station receiver, or a space station receiver for a satellite with on-board processing, of either system, [DELTA]T/T, exceeds 6 percent due to interference from emissions originating in the other system in a commonly authorized frequency band, such frequency band will be divided among the affected satellite networks in accordance with the following procedure:(1) Each of n (number of) satellite networks involved that were licensed or granted market access through the same processing round, except as provided in paragraph (e) of this section, must select 1/n of the assigned spectrum available in each of these frequency bands. The selection order for each satellite network will be determined by the date that the first space station in each satellite system is launched and capable of operating in the frequency band under consideration;(2) The affected station(s) of the respective satellite systems may operate in only the selected (1/n) spectrum associated with its satellite system while the [DELTA]T/T of 6 percent threshold is exceeded;(3) All affected station(s) may resume operations throughout the assigned frequency bands once the threshold is no longer exceeded.(e)Sunsetting. Ten years after the first authorization or grant of market access in a processing round, the systems approved in that processing round will no longer be required to protect earlier-rounds systems, and instead will be required to share spectrum with earlier-round systems under paragraph (c) of this section. 82 FR 59986 , Dec. 18, 2017