Sec. 95.628  MICS transmitter.

    (a) Frequency monitoring. Medical implant programmer/control 
transmitters must incorporate a mechanism for monitoring the channel or 
channels that the MICS system devices intend to occupy. The monitoring 
system antenna shall be the antenna normally used by the programmer/
control transmitter for a communications session. Before a medical 
implant programmer/control transmitter initiates a MICS communications 
session, the following access criteria must be met:
    (1) The monitoring system bandwidth measured at its 20 dB down 
points must be equal to or greater than the emission bandwidth of the 
intended transmission.
    (2) Within 5 seconds prior to initiating a communications session, 
circuitry associated with a medical implant programmer/control 
transmitter must monitor the channel or channels the MICS system devices 
intend to occupy for a minimum of 10 milliseconds per channel.
    (3) Based on use of an isotropic monitoring system antenna, the 
monitoring threshold power level must not be more than 10logB(Hz) - 150 
(dBm/Hz) + G(dBi) where B is the emission bandwidth of the MICS 
communication session transmitter having the widest emission and G is 
the medical implant programmer/control transmitter monitoring system 
antenna gain relative to an isotropic antenna. For purposes of showing 
compliance with the above provision, the above calculated threshold 
power level must be increased or decreased by an amount equal to the 
monitoring system antenna gain above or below the gain of an isotropic 
antenna, respectively.
    (4) If no signal in a MICS channel above the monitoring threshold 
power level is detected, the medical implant programmer/control 
transmitter may initiate a MICS communications session involving 
transmissions to and from a medical implant device on that channel. The 
MICS communications session may continue as long as any silent period 
between consecutive data transmission bursts does not exceed 5 seconds. 
If a channel meeting the criteria in paragraph (a)(3) of this section is 
unavailable, the channel with the lowest ambient power level may be 
accessed.
    (5) When a channel is selected prior to a MICS communications 
session, it is permissible to select an alternate channel for use if 
communications is interrupted, provided that the alternate channel 
selected is the next best choice using the above criteria. The alternate 
channel may be accessed in the event a communications session is 
interrupted by interference. The following criteria must be met:
    (i) Before transmitting on the alternate channel, the channel must 
be monitored for a period of at least 10 milliseconds.
    (ii) The detected power level during this 10 millisecond or greater 
monitoring period must be no higher than 6 dB above the power level 
detected when the channel was chosen as the alternate channel.
    (iii) In the event that this alternate channel provision is not used 
by the MICS system or if the criteria in (i) and (ii) are not met, a 
channel must be selected using the access criteria specified in 
paragraphs (a)(1) through (a)(4) of this section.
    (6) As used in this section, the following definitions apply:
    (i) Emission bandwidth--Measured as the width of the signal between 
the points on either side of carrier center frequency that are 20 dB 
down relative to the maximum level of the modulated carrier. Compliance 
will be determined using instrumentation employing a peak detector 
function and a resolution bandwidth approximately equal to 1% of the 
emission bandwidth of the device under test.

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    (ii) MICS channel--Any continuous segment of spectrum that is equal 
to the emission bandwidth of the device with the largest bandwidth that 
is to participate in a MICS communications session. (Note: The rules do 
not specify a channeling scheme for use by MICS systems.)
    (iii) MICS communications session--A collection of transmissions, 
that may or may not be continuous, between MICS system devices.
    (b) MICS communications sessions initiated by a medical implant 
event are not required to use the access criteria set forth in paragraph 
(a) of this section.
    (c) Stations may operate on any of the frequencies in the band 402-
405 MHz, provided that the out-of-band emissions are attenuated in 
accordance with Sec. 95.635.
    (d) The authorized bandwidth of the emission from a MICS station 
shall not exceed 300 kHz, and no communications session involving MICS 
stations shall use more than a total of 300 kHz of bandwidth during such 
a session. Note: This provision does not preclude full duplex or half 
duplex communications provided that the total amount of bandwidth 
utilized by all of the MICS channels employed in such a MICS 
communications session does not exceed 300 kHz.
    (e) Each transmitter in the MICS service must maintain a frequency 
stability of +/-100 ppm of the operating frequency over the range:
    (1) 25[deg]C to 45[deg]C in the case of medical implant 
transmitters; and
    (2) 0[deg]C to 55[deg]C in the case of medical implant programmer/
control transmitters.
    (f) The provisions of this section shall not be used to extend the 
range of spectrum occupied over space or time for the purpose denying 
fair access to spectrum for other MICS systems.

[ 64 FR 69930 , Dec. 15, 1999]