Sec.  90.672   Unacceptable interference to non-cellular 800 MHz licensees from
ESMR or Part 22 Cellular Radiotelephone systems.

   (a) Definition. Except as provided in 47 CFR 90.617(k), unacceptable
   interference to non-cellular licensees in the 800 MHz band will be deemed to
   occur when the below conditions are met:

   (1) A transceiver at a site at which interference is encountered:

   (i) Is in good repair and operating condition, and is receiving:

   (A) A median desired signal of −104 dBm or higher, as measured at the R.F.
   input of the receiver of a mobile unit; or

   (B) A median desired signal of −101 dBm or higher, as measured at the R.F.
   input of the receiver of a portable i.e. hand-held unit; and, either

   (ii) Is a voice transceiver:

   (A) With manufacturer published performance specifications for the receiver
   section of the transceiver equal to, or exceeding, the minimum standards set
   out in paragraph (b) of this section, and;

   (B) Receiving an undesired signal or signals which cause the measured
   Carrier to Noise plus Interference (C/(I+N)) ratio of the receiver section
   of said transceiver to be less than 20 dB, or;

   (iii) Is a non-voice transceiver receiving an undesired signal or signals
   which cause the measured bit error rate (BER) (or some comparable
   specification) of the receiver section of said transceiver to be more than
   the value reasonably designated by the manufacturer.

   (2) Provided, however, that if the receiver section of the mobile or
   portable voice transceiver does not conform to the standards set out in
   paragraph (b) of this section, then that transceiver shall be deemed subject
   to unacceptable interference only at sites where the median desired signal
   satisfies the applicable threshold measured signal power in paragraphs
   (a)(1)(i) of this section after an upward adjustment to account for the
   difference in receiver section performance. The upward adjustment shall be
   equal to the increase in the desired signal required to restore the receiver
   section of the subject transceiver to the 20 dB C/(I+N) ratio of paragraph
   (a)(1)(ii)(B) of this section. The adjusted threshold levels shall then
   define the minimum measured signal power(s) in lieu of paragraphs (a)(1)(i)
   of this section at which the licensee using such non-compliant transceiver
   is entitled to interference protection.

   (b) Minimum Receiver Requirements. Voice transceivers capable of operating
   in the 806–824 MHz portion of the 800 MHz band shall have the following
   minimum performance specifications in order for the system in which such
   transceivers are used to claim entitlement to full protection against
   unacceptable interference. (See paragraph (a)(2) of this section.)

   (1) Voice units intended for mobile use: 75 dB intermodulation rejection
   ratio; 75 dB adjacent channel rejection ratio; −116 dBm reference
   sensitivity.

   (2) Voice units intended for portable use: 70 dB intermodulation rejection
   ratio; 70 dB adjacent channel rejection ratio; −116 dBm reference
   sensitivity.