Sec.  22.859   Incumbent commercial aviation air-ground systems.

   This section contains rules concerning continued operation of commercial
   aviation air-ground systems that were originally authorized prior to January
   1, 2004 to provide radiotelephone service using narrowband (6 kHz) channels,
   and that have been providing service continuously since the original
   commencement of service (hereinafter “incumbent systems”).

   (a) An incumbent system may continue to operate under its authorization, for
   the remaining term of such authorization, subject to the terms and
   conditions attached thereto. Wherever such technical and operational
   conditions differ from technical and operational rules in this subpart,
   those conditions shall govern its operations.

   (b) Notwithstanding any other provision in this chapter, the licensee of an
   incumbent system shall not be entitled to an expectation of renewal of said
   authorization.

   (c) During the period that an incumbent system continues to operate and
   provide service pursuant to paragraph (a) of this section, air-ground
   systems of licensees holding a new authorization for the spectrum within
   which the incumbent system operates must not cause interference to the
   incumbent system. Protection from interference requires that the signals of
   the new systems must not exceed a ground station received power of −130 dBm
   within a 6 kHz receive bandwidth, calculated assuming a 0 dBi vertically
   polarized receive antenna.

   [ 70 FR 19310 , Apr. 13, 2005]