§ 95.627   MedRadio transmitters in the 401-406 MHz band.

   The following provisions apply only to MedRadio transmitters operating in
   the 401-406 MHz band.

   (a) Frequency monitoring. Except as provided in (b) of this section, all
   MedRadio programmer/control transmitters operating in the 401-406 MHz band
   must operate under the control of a monitoring system that incorporates a
   mechanism for monitoring the channel or channels that the MedRadio 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 the monitoring system of a MedRadio programmer/control
   transmitter initiates a MedRadio 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 MedRadio programmer/control transmitter must monitor the
   channel or channels the 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 MedRadio communications
   session  transmitter  having the widest emission and G is the MedRadio
   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 MedRadio channel above the monitoring threshold power
   level is detected, the MedRadio programmer/control transmitter may initiate
   a MedRadio-communications session involving transmissions to and from a
   medical implant or medical body-worn device on that channel. The MedRadio
   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,
   MedRadio transmitters that are capable of operating on multiple channels may
   transmit on the alternate channel accessible by the device with the lowest
   monitored ambient power level. Except as provided in paragraph (b) of this
   section, MedRadio transmitters that operate on a single channel and thus do
   not have the capability of operating on alternate channels may not transmit
   unless no signal on the single channel of operation exceeds the monitoring
   threshold power level.

   (5) When a channel is selected prior to a MedRadio communications session,
   it is permissible to select an alternate channel for use if communications
   are 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 6dB 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
   MedRadio system or if the criteria in paragraphs (a)(5)(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.

   (ii) MedRadio channel—Any continuous segment of spectrum in the MedRadio
   band that is equal to the emission bandwidth of the device with the largest
   bandwidth that is to participate in a MedRadio communications session.

   Note to paragraph (a)(6)(ii): The rules do not specify a channeling scheme
   for use by MedRadio systems.

   (iii) MedRadio communications session—A collection of transmissions, that
   may or may not be continuous, between MedRadio system devices.

   (b)  Exceptions  to frequency monitoring criteria. MedRadio devices or
   communications sessions that meet any one of the following criteria are not
   required to use the access criteria set forth in paragraph (a) of this
   section:

   (1) MedRadio communications sessions initiated by a medical implant event.

   (2) MedRadio devices operating in either the 401-401.85 MHz or 405-406 MHz
   bands, provided that the transmit power is not greater than 250 nanowatts
   EIRP and the duty cycle for such transmissions does not exceed 0.1%, based
   on the total transmission time during a one-hour interval, and a maximum of
   100 transmissions per hour.

   (3) MedRadio devices operating in the 401.85-402 MHz band, provided that the
   transmit power is not greater than 25 microwatts EIRP and the duty cycle for
   such transmissions does not exceed 0.1%, based on the total transmission
   time during a one hour interval, and a maximum of 100 transmissions per
   hour.

   (4) MedRadio devices operating with a total emission bandwidth not exceeding
   300 kHz centered at 403.65 MHz, provided that the transmit power is not
   greater than 100 nanowatts EIRP and the duty cycle for such transmissions
   does  not  exceed 0.01%, based on the total transmission time during a
   one-hour interval, and a maximum of 10 transmissions per hour.

   (c) Operating frequency. MedRadio stations authorized under this part may
   operate on frequencies in the 401-406 MHz band as follows provided that the
   out-of-band emissions are attenuated in accordance with § 95.635:

   (1)  MedRadio  stations associated with medical implant devices, which
   incorporate a frequency monitoring system as set forth in paragraph (a) of
   this section, may operate on any of the frequencies in the 401-406 MHz band.

   (2) MedRadio stations associated with medical implant devices, which do not
   incorporate a frequency monitoring system as set forth in paragraph (a) of
   this section, may operate on any frequency in 401-402 MHz or 405-406 MHz
   bands, or at 403.65 MHz in the 402-405 MHz band.

   (3) MedRadio stations associated with medical body-worn devices, regardless
   of whether a frequency monitoring system as set forth in paragraph (a) of
   this section is employed, may operate on any of the frequencies in the
   401-402 MHz or 405-406 MHz bands.

   (4) MedRadio stations that are used externally to evaluate the efficacy of a
   more permanent medical implant device, regardless of whether a frequency
   monitoring system as set forth in paragraph (a) of this section is employed,
   may operate on any of the frequencies in the 402-405 MHz band, provided
   that:

   (i) Such external body-worn operation is limited solely to evaluating with a
   patient the efficacy of a fully implanted permanent medical device that is
   intended to replace the temporary body-worn device;

   (ii) RF transmissions from the external device must cease following the
   patient evaluation period, which may not exceed 30 days, except where a
   health care practitioner determines that additional time is necessary due to
   unforeseen circumstances;

   (iii) The maximum output power of the temporary body-worn device shall not
   exceed 200 nW EIRP; and

   (iv)  The  temporary body-worn device must comply fully with all other
   MedRadio rules applicable to medical implant device operation in the 402-405
   MHz band.

   (d) Authorized bandwidth. The authorized bandwidth of the emission from a
   MedRadio station operating between 402-405 MHz shall not exceed 300 kHz, and
   no communications session involving MedRadio stations shall use more than a
   total  of  300  kHz of bandwidth during such a session. The authorized
   bandwidth  of  the  emission from a MedRadio station operating between
   401-401.85  MHz  or  405-406  MHz  shall  not  exceed  100 kHz, and no
   communications session involving MedRadio stations shall use more than a
   total  of  100  kHz of bandwidth during such a session. The authorized
   bandwidth  of  the  emission from a MedRadio station operating between
   401.85-402 MHz shall not exceed 150 kHz, and no communications session
   involving  MedRadio stations shall use more than a total of 150 kHz of
   bandwidth during such a session.

   Note to paragraph (d): This provision does not preclude full duplex or half
   duplex communications provided that the total amount of bandwidth utilized
   by all of the MedRadio channels employed in such a MedRadio communications
   session does not exceed 300 kHz in the 402-405 MHz band, or 100 kHz in the
   401-402 MHz and 405-406 MHz bands.

   (e) Frequency stability. Each transmitter in the MedRadio service must
   maintain a frequency stability of ±100 ppm of the operating frequency over
   the range:

   (1) 25 °C to 45 °C in the case of medical implant transmitters; and

   (2) 0 °C to 55 °C in the case of MedRadio programmer/control transmitters
   and MedRadio body-worn transmitters.

   (f) Shared access. The provisions of this section shall not be used to
   extend the range of spectrum occupied over space or time for the purpose of
   denying fair access to spectrum for other MedRadio systems.

   (g) Measurement procedures. (1) MedRadio transmitters shall be tested for
   frequency  stability,  radiated emissions and EIRP limit compliance in
   accordance with paragraphs (g)(2) and (g)(3) of this section.

   (3) Radiated emissions and EIRP measurements may be determined by measuring
   the radiated field from the equipment under test at 3 meters and calculating
   the  EIRP.  The  equivalent radiated field strength at 3 meters for 25
   microwatts, 250 nanowatts, and 100 nanowatts EIRP is 18.2, 1.8, or 1.2
   mV/meter, respectively, when measured on an open area test site; or 9.1,
   0.9, or 0.6 mV/meter, respectively, when measured on a test site equivalent
   to free space such as a fully anechoic test chamber. Compliance with the
   maximum transmitter power requirements set forth in § 95.639(f) shall be
   based on measurements using a peak detector function and measured over an
   interval of time when transmission is continuous and at its maximum power
   level. In lieu of using a peak detector function, measurement procedures
   that have been found to be acceptable to the Commission in accordance with
   § 2.947 of this chapter may be used to demonstrate compliance.

   (2) Frequency stability testing shall be performed over the temperature
   range set forth in (e) of this section.

   (3) Radiated emissions and EIRP measurements may be determined by measuring
   the radiated field from the equipment under test at 3 meters and calculating
   the  EIRP.  The  equivalent radiated field strength at 3 meters for 25
   microwatts, 250 nanowatts, and 100 nanowatts EIRP is 18.2, 1.8, or 1.2
   mV/meter, respectively, when measured on an open area test site; or 9.1,
   0.9, or 0.6 mV/meter, respectively, when measured on a test site equivalent
   to free space such as a fully anechoic test chamber. Compliance with the
   maximum transmitter power requirements set forth in § 95.639(f) shall be
   based on measurements using a peak detector function and measured over an
   interval of time when transmission is continuous and at its maximum power
   level. In lieu of using a peak detector function, measurement procedures
   that have been found to be acceptable to the Commission in accordance with
   § 2.947 of this chapter may be used to demonstrate compliance.

   (i) For a transmitter intended to be implanted in a human body, radiated
   emissions and EIRP measurements for transmissions by stations authorized
   under this section may be made in accordance with a Commission-approved
   human body simulator and test technique. A formula for a suitable tissue
   substitute material is defined in OET Bulletin 65 Supplement C (01-01).

   [ 74 FR 22705 , May 14, 2009, as amended at  75 FR 52477 , Aug. 26, 2010.
   Redesignated and amended at  77 FR 4268 , Jan. 27, 2012]

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