§ 90.672   Unacceptable interference to non-cellular 800 MHz licensees from 800
MHz cellular systems or part 22 Cellular Radiotelephone systems, and within the
900 MHz Business/Industrial Land Transportation Pool.

   (a)  Definition.  Except as provided in 47 CFR 90.617(k), unacceptable
   interference to non-cellular licensees in the 800 MHz band from 800 MHz
   cellular systems or part 22 of this chapter, Cellular Radiotelephone systems
   and within the 900 MHz Business/Industrial Land Transportation (B/ILT) Pool
   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 strength of −104 dBm or higher if operating in
   the  800  MHz  band, or a median desired signal strength of −88 dBm if
   operating in the 900 MHz B/ILT Pool, as measured at the R.F. input of the
   receiver of a mobile unit; or

   (B) A median desired signal strength of −101 dBm or higher if operating in
   the  800  MHz  band, or a median desired signal strength of −85 dBm if
   operating in the 900 MHz B/ILT Pool, 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 if operating in the 800 MHz band,
   or less than 17 dB if operating in the 900 MHz B/ILT Pool, 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, or in the 900 MHz
   Business/Industrial Land Transportation Pool, 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.

   (3)  Voice  units  intended  for mobile or portable use in the 900 MHz
   Business/Industrial  Land  Transportation  Pool: 60 dB intermodulation
   rejection ratio; 60 dB adjacent channel rejection ratio; −116 dBm reference
   sensitivity.

   [ 73 FR 67800 , Nov. 17, 2008]

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