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NORDIC nRF9151-SMA DK Satellite NTN Network

This guide covers AT commands for the Nordic nRF9151 module, which now includes support for NB-IoT over Non-Terrestrial Networks (NTN) via the Skylo network.

Quick Navigation

Set up the EVK Kit

  • Connect the UBC Cable to the EVK kit.

  • Connect the LTE antenna

  • Connect the GPS

  • Insert the Monogoto SIM

Connect your PC to the EVK Kit

Use the USB to connect your computer to the AT CMD port of the EVK Kit

Connect to the EVK kit using a terminal program. You can use PuTTY for Windows, or Screen, minicom, or Miniterm for Mac or Linux.

Set the baud rate to 115200 Enter AT, if the connection with the nRF9151-SMA DK modem has been established, the board will answer with OK.

Connect the nRF9151-SMA DK to Skylo

Check the status of the SIM card. The correct response should be: +CPIN: READY

AT+CPIN?

+CPIN: READY means that the SIM is ready for use and does not require any PIN entry.

Executing Commands by Version

Execute various commands based on the software version you are using. Make sure to execute the commands that correspond to your version.

Query device information

Request the firmware version:

AT+CGMR

Example response:

mfw_nrf9151-ntn_0.4.1-prealpha

Request the Hardware version:

AT%HWVERSION

Expected response: %HWVERSION:nRF9151 LACA APA

Request the IMSI (International Mobile Subscriber Identity):

AT+CIMI

Request the ICCID (Integrated Circuit Card ID), which is the identification number of the iSIM 

AT%XICCID

Disable radio

AT+CFUN=0

Set the NTN mode, and attempt to connect over satellite NB-IoT only

AT%XSYSTEMMODE=0,0,0,0,1

Lock the modem to a specific region/band

AT%XBANDLOCK=2,,"23,255,256"

Although the modem may support many different NTN bands,

23 = Canada

255 = L band Global (United States, Taiwan, Australia, New Zealand, Japan)

256 = S band Europe

Set GPS location

AT%LOCATION=<mode>,"<latitude>","<longitude>","<altitude>",<uncertainty>,<status>

example

AT%LOCATION=2,"37.37065","-122.12406","109.6",0,0

You can use the following tool to obtain accurate GPS coordinates and elevation for your location: https://www.freemaptools.com/elevation-finder.htm

Simply enter your address or point on the map to retrieve the latitude, longitude, and altitude values required for the AT%LOCATION command.

Set the APN to data.mono:

AT+CGDCONT=0,"ip","data.mono"

Network status indications

AT+CEREG=5

Send the reporting of error codes sent by the network status indications

AT+CNEC=24

Ubscribe to connection state indications

AT+CSCON=3

subscribe sending of modem domain events

AT%MDMEV=2

Enable radio

AT+CFUN=1

Example response:

%%MDMEV: SEARCH STATUS 1
+CEREG: 2,"3AAE","0021CC6E",14
%MDMEV: PRACH CE-LEVEL 0
+CSCON: 1,7,4
%MDMEV: SEARCH STATUS 2
+CEREG: 5,"3AAE","0021CC6E",14,,,"11100000","00111000"

CEREG State Change Report Codes

The table below provides an overview of the possible values for CEREG state change reports, indicating the module's network registration status.

Value
Description

0

Not registered, and the module is not searching for a network.

1

Registered to the home network.

2

Not registered, but the module is attempting to attach or searching for a network.

3

Registration denied by the network.

4

Unknown (for example, out of coverage)

5

Registered and roaming.

Check the radio signal strength and signal quality:

AT+CESQ

Example response: +CESQ: 99,99,255,255,15,53

+CESQ returns 6 values separated by commas. The last 2 values indicate the RSRQ (Reference Signal Received Quality) and RSRP (Reference Signal Received Power) respectively. RSRQ is indicated with a value between 0 and 34, RSRP is with a value between 0 and 97. Higher values represent better signal quality.

Query the signal measurement

Request a specific network measurement, such as signal strength, noise levels, or other metrics:

AT%XMONITOR

Example response: 5,"","","90198","3A9D",14,255,"0007DBBD",5,228841,9,19,"","11100000","00111000","11100000"

Test the connection by sending a UDP payload

In order to send data using UDP, 3 AT Commands needs to be sent:

  1. Create UDP socket

  2. Send UDP data

  3. Close UDP Socket

1. Create a UDP socket 

AT#XSOCKET=1,2,0

Example message: #XSOCKET:0,2,17

2. Activate Socket 

AT#XCONNECT="18.199.15.247",1055

Example response: #XCONNECT:1

3. Send UDP data 

AT#XSEND="Hello Nordic"

Example message: #XSEND:12

4. Close the UDP socket

End your UDP session by closing the UDP socket.

AT#XSOCKET=0

Expected response: #XSOCET:0,"closed"

Great work on connecting the NORDIC nRF9151-SMA DK to Monogoto! Have a look at the Things logs in the Monogoto Console to find more details about the established connection.

Transition Between Satellite Network and Public Network

When transitioning between satellite and public networks using the nRF9151-SMA DK Kit, use the following commands:

Disable radio

AT+CFUN=0

Command for Switching to Public Network: 

AT%XSYSTEMMODE=1,0,0,0,0

Enable radio

AT+CFUN=1

This command activates the CAT-M mode for public networks, allowing the device to switch from satellite connectivity to a cellular public network.

Disable radio

AT+CFUN=0

Command for Switching Back to Satellite Network 

AT%XSYSTEMMODE=0,0,0,0,1

Enable radio

AT+CFUN=1

This command activates the NBNTN mode, returning the device to satellite network connectivity.

Useful Links

PreviousSierra Wireless HL7810/HL7812 Satellite NTN NetworkNextNTN Certified Chipsets

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