Goto Section: 95.2557 | 95.2561 | Table of Contents
FCC 95.2559
Revised as of October 5, 2017
Goto Year:2016 |
2018
§ 95.2559 MedRadio channel access requirements.
To reduce interference and make the most effective use of the MedRadio
frequency bands, MedRadio transmitter types must be designed to operate
in accordance with the rules in this section.
(a) Frequency monitoring in the 401-406 MHz band. Except as provided in
paragraph (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 MedRadio
communications session. Before the monitoring system of a
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 MedRadio emission bandwidth of the
intended transmission.
(2) Within 5 seconds prior to initiating a MedRadio 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) The monitoring threshold power level, PMT, in dBm, is calculated
using the following formula.
PMT = 10 log B−150 (dBm/Hz) + G
Where:
(i) B is the MedRadio emission bandwidth in Hertz of the MedRadio
communications session transmitter having the widest emission; and,
(ii) G is the MedRadio programmer/control transmitter monitoring system
antenna gain, in decibels, relative to the gain of an isotropic antenna
(dBi).
(4) For the purposes of showing compliance with the above provisions,
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.
(5) If no signal above the monitoring threshold power level is detected
in a MedRadio channel, the MedRadio programmer/control transmitter may
initiate on that channel a MedRadio communications session involving
transmissions to and from a medical implant or medical body-worn
device. The MedRadio communications session may continue as long as any
silent period between consecutive data transmission bursts does not
exceed 5 seconds. If no channel meeting the requirements in paragraphs
(a)(3) and (4) of this section is available, 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.
(6) When a channel is selected prior to a MedRadio communications
session, it is permissible to select an alternate authorized 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 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 MedRadio system, or if the criteria in paragraphs (a)(6)(i) and
(ii) of this section are not met, any alternate authorized channel must
be selected using the access criteria specified in paragraphs (a)(1)
through (5) of this section.
(7) 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.
(b) Exceptions to frequency monitoring in the 401-406 MHz band.
MedRadio devices or communications sessions that meet any one of the
following criteria are not required to be operated in accordance with
the access rules set forth in paragraph (a) of this section:
(1) MedRadio communications sessions that are 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) 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.
(d) Frequency monitoring in the 413-419 MHz, 426-432 MHz, 438-444 MHz,
and 451-457 MHz bands. MedRadio programmer/control transmitters must
incorporate a mechanism for monitoring the authorized bandwidth of the
frequency band that the MedRadio transmitters intend to occupy. The
monitoring system antenna shall be the same antenna used by the
programmer/control transmitter for a communications session.
(1) The MedRadio programmer/control transmitter shall be capable of
monitoring any occupied frequency band at least once every second and
monitoring alternate frequency bands within two seconds prior to
executing a change to an alternate frequency band.
(2) The MedRadio programmer/control transmitter shall move to another
authorized frequency band within one second of detecting a persistent
(i.e., lasting more than 50 milliseconds) signal level greater than −60
dBm as received by a 0 dBi gain antenna in any 12.5 kHz bandwidth
within the authorized bandwidth.
(3) The MedRadio programmer/control transmitter shall be capable of
monitoring the authorized bandwidth of the occupied frequency band to
determine whether either direction of the communications link is
becoming degraded to the extent that communications is likely to be
lost for more than 45 milliseconds. Upon making such a determination
the MedRadio programmer/control transmitter shall move to another
authorized frequency band.
(e) System shutdown. MedRadio transmitters shall incorporate a
programmable means to implement a system shutdown process in the event
of communication failure, on command from the MedRadio
programmer/control transmitter, or when no authorized alternate
frequency band is available. The shutdown process shall commence within
45 milliseconds after loss of the communication link or receipt of the
shutdown command from the MedRadio programmer/control transmitter. This
requirement does not apply to MedRadio operations in the 401-406 MHz
band.
(f) Requirements for MBAN Networks. A MedRadio programmer/control
transmitter and its associated medical body-worn transmitters shall not
commence operating in, and shall automatically cease operating in, the
2360-2390 MHz band if the programmer/control transmitter does not
receive, in accordance with the protocols specified by the
manufacturer, a control message permitting such operation. Medical
body-worn transmitters shall cease operating in 2360-2390 MHz if they
lose communication with their associated programmer/control
transmitter. Additionally, a MedRadio programmer/control transmitter
and its associated medical body-worn transmitters operating in the
2360-2390 MHz band shall comply with a control message that notifies
the devices to limit transmissions to segments of the 2360-2390 MHz
band or to cease operation in the band.
return arrow Back to Top
Goto Section: 95.2557 | 95.2561
Goto Year: 2016 |
2018
CiteFind - See documents on FCC website that
cite this rule
Want to support this service?
Thanks!
Report errors in
this rule. Since these rules are converted to HTML by machine, it's possible errors have been made. Please
help us improve these rules by clicking the Report FCC Rule Errors link to report an error.
hallikainen.com
Helping make public information public