NTN Support and Application Feasibility on nRF9151

[Priyesh Shahi]

Inquiry: NTN Support and Application Feasibility on nRF9151

I would like to seek clarification regarding Non-Terrestrial Network (NTN) support on the nRF9151.

There have been discussions and references suggesting NTN capability on the nRF9151, and I would like to better understand the current level of support and practical limitations.

Specifically, I am interested in the following:

1. Resource Availability

• Which nRF Connect SDK versions include sample applications or support for NTN on nRF9151?

• Are there example projects, reference code, or documentation demonstrating NTN connectivity in practice?

• If official samples are not yet available, is there a roadmap or expected timeline for when they might be provided?

• What type of antenna is required or recommended for NTN operation on the nRF9151?

2. Application Feasibility

We are currently using the nRF9151 with a Hologram eSIM in India, and our solution is working reliably:

• connectivity

• Cellular IoT stack

• Data transmission to a CoAP server

Given this setup:

• Is a similar application architecture feasible over NTN?

• Can CoAP-based data transmission be supported over NTN in a comparable manner?

3. SDK Support and Examples

• I could not find any nRF Connect SDK samples, documentation, or application notes specifically related to NTN on nRF9151

• Are there any example applications, experimental features, or recommended references available?

• If not, could you please advise on the current status and roadmap for NTN support on nRF9151?

Any guidance, documentation links, or clarification would be greatly appreciated.

Thank you for your support.

[Achim Kraus]

Though I'm an other user, that's just my experience:

AFAIK, there is still no NCS support, but to add that (extend some link control function with new values), was on my side a work of two afternoons. The new AT-cmds and/or parameter and/or  parameter-values are documented.

You will need a SIM card, that supports some NTN provider, and considering that, you may also check and consider the (much) higher costs.

I use CoAP/DTLS 1.2 CID over NTN (own device DTLS stack (Eclipse/tinydtls) to relax the timing (timeout to 30s), Eclipse/Californium (also with relaxed timing). Depending on antenna, boards and what ever, it works, but sometimes the modem requires a couple of retransmissions (not sure, if the messages are lost before they billed or after ;-) ). The overhead of IP/UDP/DTLS 1.2 CID/CoAP is about 100 extra bytes. If you want to use an ACK or CoAP response, you will need a second 100 bytes for that message. Using tinydtls allows you also to offload the dtls session from the socket, so that works pretty well to have an "handshake on TN" and the switch to "NTN". If that's a good idea depends on your usage. Statically located without TN requires to do some handshakes over NTN, with DTLS 1.2 CID, they are rare.

I run that now since September. with an send interval of 9h.

Alternatively you may use a VPN from your provider to your server or maybe OSCORE, if you have a implementation for that.

Hope that gives you a first impression.

[Achim Kraus]

I checked NCS 3.2.1 for NTN support and it's now there, see xsystemmode. 

[Benjamin]

Hi Priyesh,
To fill out some more information not already answered by Achim:

Which nRF Connect SDK versions include sample applications or support for NTN on nRF9151?

The NCS version you need is v3.2.0. 

We recommend starting with either of this two options:

• The Serial Modem Application (modem only apporach, AT commands)
• Asset Tracker Template configured for satellite connectivity.

Note: To ensure NTN support is correctly implemented, please refer to our dedicated NTN use case doc and NTN and TN use case doc, as the standard template is not configured for NTN by default.

If official samples are not yet available, is there a roadmap or expected timeline for when they might be provided?

Please reach out to the regional sales manager for your area as we cannot talk about roadmap on DevZone.

What type of antenna is required or recommended for NTN operation on the nRF9151?

We recommend reaching out to our antenna solution partners. They are equipped to provide detailed guidance on the most suitable antenna for your specific application.

NTN NB-IoT require optimal link conditions, and the choice of antenna depends on multiple factors, including whether the application supports both LTE and NTN or NTN alone, as well as the physical constraints of the product.

For applications targeting both LTE and NTN, it is essential to select a wideband antenna that can meet the performance and form factor requirements of both technologies. The antenna must support a broad frequency range to satisfy the performance criteria of LTE networks and the relevant satellite operators.

The nRF9151 SMA DK includes Taoglas (LTE/NTN/NR+) and Kyocera (GNSS) antennas.

If not, could you please advise on the current status and roadmap for NTN support on nRF9151?

The alpha version of the NTN modem FW is now public and can be downloaded here. This firmware is only for nRF9151 LACA A1 SiP.

Regards,
Benjamin

[Priyesh Shahi]

Hi Benjamin,

Thanks for the info.

Quick question:

Can we connect to a CoAP server over NTN like we do on cellular, or is NTN only for location updates?
Is custom payload upload supported beyond basic asset tracking?

Regards ,
Priyesh

[Benjamin]

Yes, CoAP or other custom payloads are supported.

This is NB-IoT over satellite rather than terrestrial cell towers. You can now access several satellite-based cellular networks in much the same way as traditional LTE-M or NB-IoT networks. Also see the answer from Achim Kraus.

Regards,
Benjamin