Overview

 

Itron’s Milli Hardware Development Kit (HDK) provides IOT developers with all the necessary tools to develop battery and mains powered devices that extend Itron’s innovative industrial IOT networks in production at many of the world’s leading utilities and smart cities. One key component of this HDK is the IOT Router (IOTR), which serves as a WAN connection, Milli mesh network root node, and application development platform for IOT developers.  The IOTR can also be used as a diagnostics tool and automated test platform to assist developers in preparing their Milli-based solutions for production deployments, including FCC compliance.

The IOTR FCC tool includes a variety of configuration, diagnostics and testing capabilities to facilitate FCC compliance testing of Milli-based solutions for production deployments. This tool runs on the IOTR and is accessible via an SSH session into the IOTR. 

Iotr-fcc is a Snap application that exposes Milli configuration and diagnostics commands to aid in the FCC compliance testing of partner milli devices.

Access the iotr-fcc tool

To access this tool, first log in to the IOTR over an SSH session as the “dev” user.  The password for the ‘dev’ user is ‘starfish’. 

Any SSH client can be used to initiate an SSH session with the IOTR – Putty and Terraterm are two popular options that can be downloaded for free. To open an SSH session with the IOTR, you must know the IPv4 address of the IOTR on your local network:

To determine the IP address of your IoT Edge Router in WAN Mode, when DHCP assigned.

Step 1: Create a .txt file named “ipaddress.txt” on a USB flash drive

Step 2:Once the device is powered up place the USB drive into one of the ports

Step 3:After approximately 2 minutes remove the drive and place it into your PC and open ipaddress.txt and your DHCP assigned address will be in the file

Note: The character encoding used over the SSH session is UTF-8.  If the command line interface includes non-ASCII, or unreadable, characters, check your SSH client settings and make sure the character encoding is set correctly to UTF-8.

Using the tool

To run iotr-fcc, just enter iotr-fcc from the command prompt. This will replace the command line interface with a simple menu system as in Figure 3.  You can arrow up and down and select commands with the arrow keys or use linux keyboard mapping with the j key as “down” and k key as “up”.

Right mouse click will paste what is in the copy buffer.  You can use this to easily paste long arguments, such as your Milli device IPv6 address or MAC ID, or other commands that prompt for additional user input.

Figure 3

Figure 3: Iotr-fcc Startup Screen

The iotr-fcc tool has two main menus, which are the FCC Menu and Configuration Menu. The former contains commands to facilitate FCC compliance testing whereas the later contains commands to configure the IOTR.

 

Available commands in the iotr-fcc tool Configuration Menu

»   Check Network ID »   Set Network ID
»   Set Network ID »   Display Node Queue Milli
»   Check Pan ID »   Aggressive Milli Discovery
»   Set Pan ID »   Check Country Code
»   Check Mac State »   Set Mac State
»   Check Time »   Check RF Power Setting
»   Set Time »   Display Node Queue Zero
»   Restart NIC »   Direct Milli Discovery

 

 

Check Network ID and Check Pan ID are useful commands for verifying the IOTR’s configured network ID and PAN (personal area network) ID values respectively. These should be the default values in the HDKs that do not need to be changed. If changes are necessary, the Set Network ID and Set Pan ID are available to change the Network ID and PAN ID.  After changing either of these values, or after changing the MAC state of the IOTR, the IOTR must be reset with the Restart NIC command. The Check MAC State command should show a value of 1, indicating the IOTR’s Milli interface is enabled.

Figure 4: Check Network ID Output

Figure 4: Check Network ID Output

The Check Time command displays the current local time on the IoTR. If not set the time will default to the Unix epoch of 01/01/1970. The time must be set to successfully communicate with the milli. This is done using the Set Time command, but this is only required if the IoTR is in Edge mode as if it is operating in WAN mode its time will be set from the WAN network. The Get RF Power Setting command outputs the current power setting of the IOTR’s mesh radio and will vary by country. The current country the IoTR is set to can be retrieved using the Check Country Code command as in Figure 5.

Figure 5: Check Code Code Output

Figure 5: Check Code Code Output

The Display Node Queue (Milli) command lists the Milli devices that are seen by the IOTR.  The output of Display Node Queue (Milli) is shown below in Figure 6.  Note that the Milli is identified by its MAC address in this output.  Appearing in the IOTR’s Node Queue confirms RF connectivity to a Milli device but does not necessarily imply that the Milli has completed network registration and received an IPv6 address yet.  Make note of the last 4 hex characters in your Milli device’s MAC address (db:91 below).  This is the easiest way to identify a particular Milli.  On a Milli device, the MAC address appears on the printed label on the radio module. 

Figure 6: Display Node Queue (Milli) Output

Figure 6: Display Node Queue (Milli) Output

If the IoTR is operating in Edge mode it may be necessary to discover the milli, this is done using the Direct Milli Discovery command as in Figure 7. The user is required to enter the MAC address of the milli without colons.

Figure 7: Direct Milli Discovery Output

Figure 7: Direct Milli Discovery Output

FCC Menu

As discussed above, the commands to facilitate FCC compliance testing are contained in the FCC Menu, which is shown in Figure 8 below.

Figure 8: FCC Menu

Figure 8: FCC Menu

The Continuously Ping a Milli and Continuously List Certificates on a Milli are designed to support the following FCC Tests:

  • 20dB and 99% Bandwidth
  • Number of Channels 
  • Channel Spacing 
  • Dwell Time and Channel Occupancy

 

These tests require the milli to transmit in its normal operating mode (that is frequency hopping over all the available channels), but at a rate that would be more intensive than normal while a spectrum analyzer is used to perform the required measurements. Figure 9 contains a screen shot of the Continuously Ping a Milli command in operation.

Figure 9: Continuously Ping a Milli Output

Figure 9: Continuously Ping a Milli Output

The Continuously Ping a Milli command initiates a continuous ICMP IPv6 ping of a Milli’s link-local address. The user is requested to enter this address followed by a delay in seconds. The link-local address is fe80:: followed by the MAC address of the milli, with the first octet replaced with a 2. As an example, if the Milli’s MAC address is 00135050050047db91 the corresponding link-local address would be: fe80::213:5005:47:db91. The delay is the time between consecutive pings. This continuous pinging can be terminated at any time by pressing the Enter key. Figure 10 contains a screen shot of the Continuously List Certificates on a Milli command in operation.

Figure 10: Continuously List Certificates on a Milli Output

Figure 10: Continuously List Certificates on a Milli Output

The Continuously List Certificates on a Milli is a continuous request for the milli to respond with a list of its certificates owned. It is the only command that is available that does not require a secure association to be formed with the Milli. Once again, the user is required to enter the link-local IPv6 address of the Milli followed by a delay in seconds. However, in this case the delay is the time that the tool will wait between each successive request and response. If no response is received after 180 seconds another request will be sent. The command can be terminated at any time by pressing the Enter key.

 

The Select Milli Image/Mode to Run command is used to switch the Milli’s running firmware between the standard Production and Hardware (HW) Test modes. The Milli must be in the HW Test mode to perform the following tests:

  • Conducted Output Power
  • Conducted Spurious Emissions
  • Conducted Band Edge Emissions
  • Radiated Spurious Emissions
  • Radiated Band Edge Emissions
  • Radiated Emissions for Receivers

 

The first five of these above tests require the Milli to transmit modulated data but on a single fixed frequency. The last test requires the Milli to be in receive only mode. In order to switch between the different modes, the IOTR must be directly connected to the Milli’s debug port. This can be done using a USB to TTL RS232 cable, such as the FTDI Chip TTL-232R-RPi, connected between one of the IOTR’s USB ports and the Milli’s debug port. Figure 11 contains a screen shot of the user selecting the Select Milli Image/Mode to Run command.

Figure 11: Select Milli Image/Mode to Run Output Showing the Available Modes

Figure 11: Select Milli Image/Mode to Run Output Showing the Available Modes

The two relevant modes are HW Test Mode and Production Mode. The latter is the standard operating mode. Whereas the former contains the commands that allow the user to switch the Milli into continuous transmit mode or to disable the transmitter entirely. Selecting the HW Test Mode presents the user with the screen as in Figure 12.

Figure 12 Select Milli Image/Mode to Run Output Prompting the User to Short the Milli’s Reset Pins

Figure 12 Select Milli Image/Mode to Run Output Prompting the User to Short the Milli’s Reset Pins

Once the words “Reset mNIC now…” appear the user needs to short the reset pins on the Milli which will result in the Milli changing modes as in Figure 13.

Figure 13: Select Milli Image/Mode to Run Output Once the Milli has Changed to HW Test Mode

Figure 13: Select Milli Image/Mode to Run Output Once the Milli has Changed to HW Test Mode

Note that in Figure 13 the menu items have changed to reflect the commands that can be performed in the HW Test Mode. Once testing has been completed and to resume normal Milli operations the user must return the Milli back to the Production Mode.

 

The Set Continuous Transmission command allows the user to Enable or to Disable the Milli from continuously transmitting on a single channel. Figure 14 contains the output of the Set Continuous Transmission Enable command where the user has selected the Enable option.

Figure 14:  Set Continuous Transmission Enable Output

On Enable the default frequency is 902.2MHz. This frequency can be changed, within the range of 902-928MHz, using the Set Frequency command as shown in Figure 15. In the USA the Milli uses 186 equally spaced 200kHz channels.

Figure 15 Set Frequency Output

Figure 15 Set Frequency Output

Once testing has been completed the user must Disable continuous transmission as shown in Figure 16.

Figure 16 Set Continuous Transmission Disable Output

Figure 16: Set Continuous Transmission Disable Output

The Set Receive Only Mode command allows the user to Enable or to Disable receive only mode. In the receive only mode the transmitter is completely disabled. Figure 17 contains the output of the Set Receive Only Mode command where the user has selected the Enable option.

Figure 17: Set Continuous Transmission Enable Output

Figure 17: Set Continuous Transmission Enable Output

Once testing has been completed the user must Disable continuous reception as shown in Figure 18.

Figure 18: Set Receive Only Mode Disable Output

Figure 18: Set Receive Only Mode Disable Output

 

 

Steps to Manage the IOTR-FCC Snap

1.     To un-install a previous version prior to installing a new version:

sudo snap remove iotr-fcc

 

2.     To install a new version of iotr-tools:

scp snap to /home/dev directory (WinSCP is a free, downloadable, easy-to-use application for your laptop)

sudo snap install --dangerous --devmode iotr-fcc_1.0.0_armhf.snap

 

3.     To list available snaps on the IOTR:

snap list

 

Relevant FCC Requirements

To provide further details on the relevant FCC requirements, the following table provides additional guidance for partners:

 

No.

FCC Test

Test Configuration Type

Applicable FCC CFR (see table below)

Test Description

Milli Test Preparation instructions
1

20dB and 99% Bandwidth Measurement

Conducted RF Emission Testing

15.247(a)(1)(i)

Measure the 20dB and 99% bandwidth by connecting a spectrum analyzer the antenna port, while the EUT (Milli) is transmitting on the lowest, middle and highest channel.  

  1. Make sure the IOTR and EUT (Milli) are set up as described in "OTA Test Setup" below

  2. Power up and log in to the IOTR as "dev" user and then launch the iotr-fcc snap using the following command:
    iotr-fcc

  3. Power up the Milli (EUT) and wait a few minutes for it to finish establishing a wireless connection with the IOTR.

  4. Verify the connection between the EUT and the IOTR by going to the Configuration Menu in iotr-fcc snap and select this command:
    Display Node Queue (Milli)
    When the MAC ID of the EUT shows up on the mmesh nodeq of the IOTR and has a state of "4" the connection is fully established and read for communication

  5. Start capturing the frequency data on the test instrument while instructing the IOTR to communicate with the EUT, which can be done by going to the FCC Menu in the iotr-fcc snap and select this command:
    Continuously Ping a Milli
     Enter the link local IPv6 address of the EUT, e.g.:
    fe80::213:5005:47:abcd
    and follow the instruction to start pinging the Milli continuously.  Run this for as long as appropriate to complete the test.

  6. Alternately, use the "Continously List Certificates on a Milli" command from the FCC Menu to against the link local IPv6 address of the EUT repeatedly for as long as appropriate to complete the test.
2

Frequency Hopping:  Number of Hopping Channels 
15.247(a)(1)(i)

Conducted RF Emission Testing

15.247(a)(1)(i)

Measure the number of channels used by connecting a spectrum analyzer (set to observe the 902-928 MHz frequency bands) to the antenna port, while the EUT (Milli) is hopping through and transmitting on all channels used by the device.
The device should hop through all the channels in a reasonable amount of time.

See Test 1
3

Frequency Hopping:  Channel Spacing 

Conducted RF Emission Testing

15.247(a)(1)(i)

Measure channel spacing by connecting the spectrum analyzer (set to observe the 902-928 MHz frequency bands) to the antenna port, while the EUT (Milli) is hopping through and transmitting on all channels used by the device. 
The device should hop through all the channels in a reasonable amount of time.
This test is similar to the ‘Number of Channel’ test, with the difference being the spectrum analyzer span is changed to zoom in and allow for better measurement of channel spacing.

See Test 1
4

Frequency Hopping:  Dwell Time and Channel Occupancy 

Conducted RF Emission Testing

15.247(a)(1)(i)

Measure dwell time and channel occupancy by connecting a spectrum analyzer to the antenna port, while the EUT (Milli) is hopping through and trasnmitting on all the channels used by the device. Configure the spectrum analyzer to use zero span mode, set the spectrum analyzer frequency to the center frequency of the channel you need to measure and set the resolution bandwidth to 20dB.  Measure the time spent on the channel being monitored. 
The device should hop through and transmit on all the channels in a reasonable amount of time. 
The device should not occupy or dwell on a channel longer than it would do in normal operation.  

See Test 1
5

Conducted Output Power 

Conducted RF Emission Testing

15.247(b)(2), 15.247(b)(3)

Enable the Milli to continuously transmit modulated data on the lowest, middle and highest channels at 100% duty cycle.
Measure peak conducted output power by connecting a spectrum analyzer to the Milli antenna port, with the resolution bandwidth set to 1.5 x 20dB and the detector set to peak.  
Set the trace mode:

  • to average if the EUT is transmitting with 100% duty cycle, or 

  • to peak if the EUT is transmitting with a duty cycle less than 100%

  1. Make sure the IOTR and EUT (Milli) are set up as described in "Wired Setup" below

  2. From the iotr-fcc snap, use the "Set Continous Transmission" option and set the "Enable Continuous Transmission" operation to "Enable" to initiate continuous transmission of modulated data:
    rf cf use_cw 1
    rf cw on

  3. Use the "Set Frequency" option to instruct the Milli to transmit on the desired channel, e.g. 902.2 MHz:
    rf cf freq_hz 902200000

  4. At the end of the test, turn off continous transmission by setting "Enable Continuous Transmission" operation to "Disable":
    rf cw off
    rf tx on
6

Emissions:  Conducted Unwanted Spurious Emissions

Conducted RF Emission Testing

15.247(d)

Enable the Milli to continuously transmit modulated data on the lowest, middle and highest channels at 100% duty cycle.
Measure Conducted Emission by connecting a spectrum analyzer to the Milli antenna port, with the spectrum analyzer resolution bandwidth set to 100kHz.  Also set the spectrum analyzer span and center frequency according to the measurement performed and the channel on which the EUT is transmitting. 

See Test 5
7

Emissions:  Conducted Band Edge Emissions

Conducted RF Emission Testing

15.247(d)

Enable the Milli to continuously transmit modulated data on the lowest, middle and highest channels at 100% duty cycle.
Measure Conducted Emission by connecting a spectrum analyzer to the Milli antenna port, with the spectrum analyzer resolution bandwidth set to 100kHz.  Also set the spectrum analyzer span and center frequency according to the measurement performed and the channel on which the EUT is transmitting. 

See Test 5
8

Power Spectral Density

Conducted RF Emission Testing

15.247(e)

Calculate Power Spectral Density based on the results of Conducted Output Power Test (output power, antenna gain and duty cycle).

N/A
9

Emissions:  Radiated Spurious and Restricted Band Emissions 

Radiated Emission Testing

15.205, 15.209

Perform this test in a in an anechoic chamber with the receive antenna at 3 meter distance on every azimuth in both horizontal and vertical polarities.  
Enable the Milli to continuously transmit modulated data on the lowest, middle and highest channels at 100% duty cycle.

See Test 5
10

Emissions:  Radiated Digital Emissions for Receivers 

Digital Emission Testing

15.209

Perform this test in a in an anechoic chamber with the receive antenna at 3 meter distance on every azimuth in both horizontal and vertical polarities.  
Set the Milli to operate in receiver mode on the lowest, middle, and highest channel for this test.

  1. Make sure the IOTR and EUT (Milli) are set up as described in "Wired Setup" below

  2. From the iotr-fcc snap, use the "Set Receive Only Mode" option and set the "Enable Continuous Reception" operation to "Enable" to put Milli in constant receiver mode:
    rf tx off
    rf rx on

  3. Use the "Set Frequency" operation to instruct the Milli to receive on the desired channel, e.g. 902.2 MHz:
    rf cf freq_hz 902200000

  4. At the end of the test, turn off constant receiver mode by setting "Enable Continuous Reception" operation to "Disable":
    rf rx off
    rf tx o

 

Over the Air (OTA) Test Setup

 

 

  1. For Over The Air (OTA) tests, the general idea is to issue commands wirelessly and repeatedly from an IOTR to the Milli (EUT) to force the Milli to continuously transmit data while hopping through various frequency channels.
  2. In order for this to work the following prerequisites must be met:

     

     

     

    1. IOTR is provisioned and operational and must have the correct time
    2. The IOTR is preloaded with iotr-fcc snap tool.  Refer to the Milli FCC Compliance Tool page on Dev Portal for installation instructions.
    3. Both the Milli and the IOTR are configured with the same country code (e.g. 840 or USA), network ID (e.g. 1711) and PanID (e.g. 0).  Refer to the Milli personalization page on Dev Portal for instructions.
    4. Milli is personalized with "leaf node aggressive (dev kit)" profile and running production mode / image.   Refer to the Milli personalization page on Dev Portal for instructions.
  3. The IOTR can be accessed via two methods:

     

    1. Via hooking up a HDMI monitor and a USB keyboard to the IOTR.  The user can then log on locally using "dev" as the username and "starfish" as the password.
    2. Via connecting the IOTR to a Windows Laptop with an Ethernet cable.  The user can then ssh (e.g. using Putty as a client) to the IOTR and log in remotely using "dev" as username and "starfish" as password

Wired Test

  1. For wired tests, the general idea is to boot Milli (EUT) up in HW Test mode / image and issue commands to instruct the Milli to transmit at a particular modulated frequency channel or to enter listener mode.

  2. In order for this to work the following prerequisites must be met:

    1. IOTR is provisioned and operational and must have the correct time

    2. The IOTR is preloaded with iotr-fcc snap tool.  Refer to the Milli FCC Compliance Tool page on Dev Portal for installation instructions.

    3. Both the Milli and the IOTR are configured with the same country code (e.g. 840 or USA), network ID (e.g. 1711) and PanID (e.g. 0).  Refer to the Milli personalization page on Dev Portal for instructions.

    4. Milli is personalized with "leaf node aggressive (dev kit)" profile and running production image.   Refer to the Milli personalization page on Dev Portal for instructions.  

    5. The Milli (EUT) needs to have its test UART port exposed so that it can be connected to an IOTR via a USB-TTL cable

  3. The IOTR can be accessed via two methods:

    1. Via hooking up a HDMI monitor and a USB keyboard to the IOTR.  The user can then log on locally using "dev" as the username and "starfish" as the password.

    2. Via connecting the IOTR to a Windows Laptop with an Ethernet cable.  The user can then ssh (e.g. using Putty as a client) to the IOTR and log in remotely using "dev" as username and "starfish" as password.

  4. Connect the milli (EUT) via USB-TTL cable to a free USB port on the IOTR

  5. To boot the Milli up to run the HW Test image (mode), launch the iotr-fcc snap from the IOTR command prompt by using the following command:
    iotr-fcc "

  6. Select the FCC Menu and use the ""Select Image/Mode"" command to put the Milli in ""HW Test Mode""
    Short the reset pins on the Milli to reboot it when prompted"

  7. To interact with Milli in HW Test mode, select one of the following options as appropriate:

    • Set Continuous Transmission

    • Set Frequency

    • Set Receive Only Mode
      Please refer to the fcc-iotr user guide for more detailed description of each of these operations."

  8. Remember to return the Milli to production mode (image) after testing is completed by  using the ""Select Image/Mode"" command to select ""Production Mode""
      Short the reset pins on the Milli to reboot it when prompted"

Applicable FCC CFR

 

FCC CFR

Description

15.247(a)(1)(i)

§15.247   Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.

  1. Operation under the provisions of this Section is limited to frequency hopping and digitally modulated intentional radiators that comply with the following provisions:

    1. For frequency hopping systems operating in the 902-928 MHz band: if the 20 dB bandwidth of the hopping channel is less than 250 kHz, the system shall use at least 50 hopping frequencies and the average time of occupancy on any frequency shall not be greater than 0.4 seconds within a 20 second period; if the 20 dB bandwidth of the hopping channel is 250 kHz or greater, the system shall use at least 25 hopping frequencies and the average time of occupancy on any frequency shall not be greater than 0.4 seconds within a 10 second period. The maximum allowed 20 dB bandwidth of the hopping channel is 500 kHz.

15.247(b)(2),
15.247(b)(3)

§15.247   Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.

  1. The maximum peak conducted output power of the intentional radiator shall not exceed the following:

    1. For frequency hopping systems operating in the 902-928 MHz band: 1 watt for systems employing at least 50 hopping channels; and, 0.25 watts for systems employing less than 50 hopping channels, but at least 25 hopping channels, as permitted under paragraph (a)(1)(i) of this section.

    2. For systems using digital modulation in the 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz bands: 1 Watt. As an alternative to a peak power measurement, compliance with the one Watt limit can be based on a measurement of the maximum conducted output power. Maximum Conducted Output Power is defined as the total transmit power delivered to all antennas and antenna elements averaged across all symbols in the signaling alphabet when the transmitter is operating at its maximum power control level. Power must be summed across all antennas and antenna elements. The average must not include any time intervals during which the transmitter is off or is transmitting at a reduced power level. If multiple modes of operation are possible (e.g., alternative modulation methods), the maximum conducted output power is the highest total transmit power occurring in any mode.

15.247(d)

§15.247   Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.

  1. In any 100 kHz bandwidth outside the frequency band in which the spread spectrum or digitally modulated intentional radiator is operating, the radio frequency power that is produced by the intentional radiator shall be at least 20 dB below that in the 100 kHz bandwidth within the band that contains the highest level of the desired power, based on either an RF conducted or a radiated measurement, provided the transmitter demonstrates compliance with the peak conducted power limits. If the transmitter complies with the conducted power limits based on the use of RMS averaging over a time interval, as permitted under paragraph (b)(3) of this section, the attenuation required under this paragraph shall be 30 dB instead of 20 dB. Attenuation below the general limits specified in §15.209(a) is not required. In addition, radiated emissions which fall in the restricted bands, as defined in §15.205(a), must also comply with the radiated emission limits specified in §15.209(a) (see §15.205(c)). 

15.247(e)

§15.247   Operation within the bands 902-928 MHz, 2400-2483.5 MHz, and 5725-5850 MHz.

  1. For digitally modulated systems, the power spectral density conducted from the intentional radiator to the antenna shall not be greater than 8 dBm in any 3 kHz band during any time interval of continuous transmission. This power spectral density shall be determined in accordance with the provisions of paragraph (b) of this section. The same method of determining the conducted output power shall be used to determine the power spectral density.

15.205

§15.205   Restricted bands of operation.

  1. Except as shown in paragraph (d) of this section, only spurious emissions are permitted in any of the frequency bands listed below:

    MHz

    MHz

    MHz

    GHz

    0.090-0.110

    16.42-16.423

    399.9-410

    4.5-5.15

    0.495-0.505

    16.69475-16.69525

    608-614

    5.35-5.46

    2.1735-2.1905

    16.80425-16.80475

    960-1240

    7.25-7.75

    4.125-4.128

    25.5-25.67

    1300-1427

    8.025-8.5

    4.17725-4.17775

    37.5-38.25

    1435-1626.5

    9.0-9.2

    4.20725-4.20775

    73-74.6

    1645.5-1646.5

    9.3-9.5

    6.215-6.218

    74.8-75.2

    1660-1710

    10.6-12.7

    6.26775-6.26825

    108-121.94

    1718.8-1722.2

    13.25-13.4

    6.31175-6.31225

    123-138

    2200-2300

    14.47-14.5

    8.291-8.294

    149.9-150.05

    2310-2390

    15.35-16.2

    8.362-8.366

    156.52475-156.52525

    2483.5-2500

    17.7-21.4

    8.37625-8.38675

    156.7-156.9

    2690-2900

    22.01-23.12

    8.41425-8.41475

    162.0125-167.17

    3260-3267

    23.6-24.0

    12.29-12.293

    167.72-173.2

    3332-3339

    31.2-31.8

    12.51975-12.52025

    240-285

    3345.8-3358

    36.43-36.5

    12.57675-12.57725

    322-335.4

    3600-4400

    Above 38.6

    13.36-13.41

    		      

    1. Except as provided in paragraphs (d) and (e) of this section, the field strength of emissions appearing within these frequency bands shall not exceed the limits shown in §15.209. At frequencies equal to or less than 1000 MHz, compliance with the limits in §15.209 shall be demonstrated using measurement instrumentation employing a CISPR quasi-peak detector. Above 1000 MHz, compliance with the emission limits in §15.209 shall be demonstrated based on the average value of the measured emissions. The provisions in §15.35 apply to these measurements.

    2. Except as provided in paragraphs (d) and (e) of this section, regardless of the field strength limits specified elsewhere in this subpart, the provisions of this section apply to emissions from any intentional radiator.

    3. The following devices are exempt from the requirements of this section:

      1. Swept frequency field disturbance sensors operating between 1.705 and 37 MHz provided their emissions only sweep through the bands listed in paragraph (a) of this section, the sweep is never stopped with the fundamental emission within the bands listed in paragraph (a) of this section, and the fundamental emission is outside of the bands listed in paragraph (a) of this section more than 99% of the time the device is actively transmitting, without compensation for duty cycle.

      2. Transmitters used to detect buried electronic markers at 101.4 kHz which are employed by telephone companies.

      3. Cable locating equipment operated pursuant to §15.213.

      4. Any equipment operated under the provisions of §§15.255 and 15.256 in the frequency band 75-85 GHz, §15.257 in the 92-95 GHz band or §15.258.

      5. Biomedical telemetry devices operating under the provisions of §15.242 of this part are not subject to the restricted band 608-614 MHz but are subject to compliance within the other restricted bands

      6. Transmitters operating under the provisions of subparts D or F of this part.

      7. Devices operated pursuant to §15.225 are exempt from complying with this section for the 13.36-13.41 MHz band only.

      8. Devices operated in the 24.075-24.175 GHz band under §15.245 are exempt from complying with the requirements of this section for the 48.15-48.35 GHz and 72.225-72.525 GHz bands only, and shall not exceed the limits specified in §15.245(b).

      9. Devices operated in the 24.0-24.25 GHz band under §15.249 are exempt from complying with the requirements of this section for the 48.0-48.5 GHz and 72.0-72.75 GHz bands only, and shall not exceed the limits specified in §15.249(a).

      10. White space devices operating under subpart H of this part are exempt from complying with the requirements of this section for the 608-614 MHz band.

    4. Harmonic emissions appearing in the restricted bands above 17.7 GHz from field disturbance sensors operating under the provisions of §15.245 shall not exceed the limits specified in §15.245(b).

15.209

§15.209   Radiated emission limits; general requirements.

  1. Except as provided elsewhere in this subpart, the emissions from an intentional radiator shall not exceed the field strength levels specified in the following table:

    Frequency (MHz)

    Field strength (microvolts/meter)

    Measurement distance (meters)

    0.009-0.490

    2400/F(kHz)

    300

    0.490-1.705

    24000/F(kHz)

    30

    1.705-30.0

    30

    30

    30-88

    100 **

    3

    88-216

    150 **

    3

    216-960

    200 **

    3

    Above 960

    500

    3

    ** Except as provided in paragraph (g), fundamental emissions from intentional radiators operating under this section shall not be located in the frequency bands 54-72 MHz, 76-88 MHz, 174-216 MHz or 470-806 MHz. However, operation within these frequency bands is permitted under other sections of this part, e.g., §§ 15.231 and 15.241.

  2. In the emission table above, the tighter limit applies at the band edges.

  3. The level of any unwanted emissions from an intentional radiator operating under these general provisions shall not exceed the level of the fundamental emission. For intentional radiators which operate under the provisions of other sections within this part and which are required to reduce their unwanted emissions to the limits specified in this table, the limits in this table are based on the frequency of the unwanted emission and not the fundamental frequency. However, the level of any unwanted emissions shall not exceed the level of the fundamental frequency.

  4. The emission limits shown in the above table are based on measurements employing a CISPR quasi-peak detector except for the frequency bands 9-90 kHz, 110-490 kHz and above 1000 MHz. Radiated emission limits in these three bands are based on measurements employing an average detector.

  5. The provisions in §§15.31, 15.33, and 15.35 for measuring emissions at distances other than the distances specified in the above table, determining the frequency range over which radiated emissions are to be measured, and limiting peak emissions apply to all devices operated under this part.

  6. In accordance with §15.33(a), in some cases the emissions from an intentional radiator must be measured to beyond the tenth harmonic of the highest fundamental frequency designed to be emitted by the intentional radiator because of the incorporation of a digital device. If measurements above the tenth harmonic are so required, the radiated emissions above the tenth harmonic shall comply with the general radiated emission limits applicable to the incorporated digital device, as shown in §15.109 and as based on the frequency of the emission being measured, or, except for emissions contained in the restricted frequency bands shown in §15.205, the limit on spurious emissions specified for the intentional radiator, whichever is the higher limit. Emissions which must be measured above the tenth harmonic of the highest fundamental frequency designed to be emitted by the intentional radiator and which fall within the restricted bands shall comply with the general radiated emission limits in §15.109 that are applicable to the incorporated digital device.

  7. Perimeter protection systems may operate in the 54-72 MHz and 76-88 MHz bands under the provisions of this section. The use of such perimeter protection systems is limited to industrial, business and commercial applications.