Zephyr (or other RTOS) and nRF9151 and Skylo certification

RE: Zephyr (or other RTOS) and nRF9151 and Skylo certification

Øyvind — Tue, 01 Apr 2025 09:43:02 GMT

[quote user="Aclassifier"]Is PSM Phase-shift keying?[/quote]

PSM stands for Power Saving Mode, which is part of the power optimization for nRF91 Series. It is part of 3GPP Release 12 to improve battery life of IoT (Internet of Things) devices by minimizing energy consumption. See 3GPP 27.007 Ch. 7.38 for more information.

[quote user="Aclassifier"]With 2.7µA, what is the power (I guess the average voltage applies)? Is there a reference to this test?[/quote]

What test are you referring to? The 2,7µA measurement?

[quote user="Aclassifier"] Also, how many Zephyr tasks, and what do they do? Kind of, what is the "task model"?[/quote]

Please note that the nRF91-series consists of two cores, an application core and a "modem core". The modem is a "black box" which is communicated with using modem library in non-secure.

[quote user="Aclassifier"]Event driven from embedded HW modules or busy polling or whatever?[/quote]

This is an event driven system. Have a look at the nRF Connect SDK Intermediate course in our Developer Academy:

"...thread management and data passing in the nRF Connect SDK/Zephyr. We have two execution contexts: Thread context and Interrupt context. Each context has its own usage and timing implications."

I would recommend to look at our white paper on Best practices for cellular IoT development, and the developer academy course on both nRF Connect SDK and Cellular IoT fundamentals.

Kind regards,
Øyvind

RE: Zephyr (or other RTOS) and nRF9151 and Skylo certification

Achim Kraus — Sat, 29 Mar 2025 18:11:38 GMT

In my experience from last year with NTN (not the nRF9151), it's easy, just multiply everything with at least 10:

- 10x more power consumption compared to NB-IoT

- 10x longer RTT (and you need to throttle the responses as well, though last year it was only 1 message with 200 bytes every 30s allowed).

- 10x times the costs

Maybe that has changed, we will see, how that develops.

I guess the main pattern will be something as "1 alive message per weak and notifications for important events on demand".

RE: Zephyr (or other RTOS) and nRF9151 and Skylo certification

Aclassifier — Fri, 28 Mar 2025 18:04:54 GMT

Thanks a lot, Øyvind ! Looks like Zephyr certainly is used also for this.

Is PSM Phase-shift keying? With 2.7µA, what is the power (I guess the average voltage applies)? Is there a reference to this test? Also, how many Zephyr tasks, and what do they do? Kind of, what is the "task model"? Event driven from embedded HW modules or busy polling or whatever? I assume more than one task; how do they communicate?

I did follow your suggestions and landed on these urls out of coincidental curiosity. On some I left DevZone or GitHub searches and used Google instead:

https://docs.nordicsemi.com/bundle/comp_matrix_nrf9151/page/COMP/nrf9151/nrf9151_comp_matrix.html
https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/app_dev.html
https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/develop/application/index.html#application
https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/samples/synchronization/README.html#synchronization
https://github.com/zephyrproject-rtos/zephyr/blob/main/samples/synchronization/README.rst?plain=1
https://github.com/zephyrproject-rtos/zephyr/blob/main/samples/synchronization/src/main.c
https://docs.zephyrproject.org/apidoc/latest/group__thread__apis.html
https://docs.zephyrproject.org/apidoc/latest/group__thread__apis.html#ga550b642e071480323e589866abb99c22
https://docs.zephyrproject.org/apidoc/latest/group__thread__apis.html#ga51307cdfe153ab3e918b18755d97c5d9
https://github.com/zephyrproject-rtos/zephyr/blob/main/samples/synchronization/src/main.c

Øyvind

RE: Zephyr (or other RTOS) and nRF9151 and Skylo certification

Øyvind — Fri, 28 Mar 2025 15:10:00 GMT

Hello,

There is not much information out on NTN power consumption yet as we have no official solution out yet. What has been said so far is that the power numbers are close to NB-IoT, these are shown here: nRF9151 Hardware Design Guidelines - VDD current consumption

[quote user=""]Like, is Zephyr or other RTOS combinable with the Skylo certified nRF9151?[/quote]

Yes, the nRF91-series is controlled by libraries design for nRF Connect SDK which is based on Zephyr OS. And based on this we are able to achieve current consumption down to 2.7µA in PSM.

If you are interested in testing the NTN solution, have a look at our product page for Cellular solutions

Our sales team can provide more information on the timeline of the NTN solution.

Kind regards,
Øyvind

RE: Zephyr (or other RTOS) and nRF9151 and Skylo certification

Aclassifier — Fri, 28 Mar 2025 09:35:37 GMT

I found something at Power consumption nRF9151. However, that's kind of into the code. I'd like to learn about the genarel matters, kind of.