NRF9151 location tracking sample interval

RE: NRF9151 location tracking sample interval

Øyvind — Tue, 09 Sep 2025 08:14:01 GMT

Hi Jacky,

[quote user="Jacky1700"] I got the information that the only the LTE-M network support AS-RAI, the NB-iot network doesn't support the AS-RAI. So what we can do if the network here is the NB-iot network only? [/quote]

The nRF9151 supports both AS-RAI and CP-RAI, so RAI can be used also with NB-IoT. The application interface is the same for both. Do you mean that the network does not support RAI in NB-IoT?

[quote user="Jacky1700"]But he was suggested to refer to the nrf_socket.h....do you have a sample to show the details, based on the nRF_cloud_multi_service sample? [/quote]

Currently, there's no RAI support in the nrf_cloud_multi_service sample. The sample uses MQTT and CoAP stacks from Zephyr. RAI support needs to be implemented on the socket level, so RAI support would have to be in the Zephyr protocol stack implementation. This has been forwarded as a feature request.

That said, the UDP and modem_shell samples have RAI support. You can also test the AT command linked above in the AT Client.

[quote user="Jacky1700"]I remember that GNSS need to work on the LTE power saving time duration, so if we disable the PSM mode, it seems that GNSS module will have no opportunity to work normally. [/quote]

From the GPS receiver chapter in the nRF9151 Datasheet it states:

GPS receiver operation is time multiplexed with the LTE modem, and GPS and QZSS position can be received while the LTE modem is in RRC Idle mode, power saving mode (PSM), or completely deactivated.

This means that you do not need to be in PSM, RRC idle is sufficient. You can use Signaling connection status notification +CSCON to determine when the device is RRC Connected or RRC idle.

Kind regards,
Øyvind

RE: NRF9151 location tracking sample interval

Jacky1700 — Fri, 05 Sep 2025 15:54:56 GMT

Hi Øyvind,

I'd like to discuss some more details about the AS-RAI here.

On the nrf9151 AT spec, I have the same question as the person asked on the below link.
(+) LTE-M Release assistance indication (RAI): How to indicate? - Nordic Q&A - Nordic DevZone - Nordic DevZone

But he was suggested to refer to the nrf_socket.h....do you have a sample to show the details, based on the nRF_cloud_multi_service sample?

By the way, I got the information that the only the LTE-M network support AS-RAI, the NB-iot network doesn't support the AS-RAI. So what we can do if the network here is the NB-iot network only?

Thanks and regards,

Jacky

RE: NRF9151 location tracking sample interval

Jacky1700 — Wed, 03 Sep 2025 13:14:49 GMT

Hi Øyvind,

I set CONFIG_LTE_PSM_REQ=n this afternoon per your suggestion and I got the below feedback.

+CSCON: 0
[00:04:14.612,213] [0m<inf> location: Method specific timeout expired[0m
[00:04:14.612,243] [1;33m<wrn> location: GNSS timed out possibly due to too short GNSS time windows[0m
[00:04:14.612,731] [1;31m<err> location: Location acquisition failed and fallbacks are also done[0m

I remember that GNSS need to work on the LTE power saving time duration, so if we disable the PSM mode, it seems that GNSS module will have no opportunity to work normally.

RE: NRF9151 location tracking sample interval

Øyvind — Tue, 02 Sep 2025 13:16:07 GMT

Can you please test with

# Enable power savings mode

CONFIG_LTE_PSM_REQ=n

RE: NRF9151 location tracking sample interval

Jacky1700 — Tue, 02 Sep 2025 11:04:49 GMT

Hi Øyvind，

Current status already has the PMS enabled. Below is part of the prj.conf contents.

# Enable LTE Connectivity using Connection Manager

CONFIG_NET_IPV4=y

CONFIG_NET_IPV6=y

CONFIG_NET_IPV6_NBR_CACHE=n

CONFIG_NET_IPV6_MLD=n

CONFIG_NET_CONNECTION_MANAGER=y

CONFIG_NRF_MODEM_LIB_NET_IF=y

CONFIG_NRF_MODEM_LIB_NET_IF_AUTO_DOWN=y

CONFIG_NRF_MODEM_LIB_NET_IF_DOWN_DEFAULT_LTE_DISCONNECT=y

# Enable power savings mode

CONFIG_LTE_PSM_REQ=y

# Set the PSM Requested Active Time to 20 seconds

CONFIG_LTE_PSM_REQ_RAT="00000001"

# Modem library

CONFIG_NRF_MODEM_LIB=y

# AT commands interface

CONFIG_UART_INTERRUPT_DRIVEN=y

CONFIG_AT_HOST_LIBRARY=y

RE: NRF9151 location tracking sample interval

Øyvind — Tue, 02 Sep 2025 09:21:07 GMT

Hi Jacky, our experts provided the following feedback to your setup:

RAI (Release Assistance Indication) is currently the only mechanism available to expedite the release of the RRC (Radio Resource Control) connection, which is otherwise managed by the network. For GNSS tracking intervals in the range of 1–2 seconds, it is likely necessary to utilize an external GNSS solution to meet performance requirements.

It is also worth questioning the use of PSM (Power Saving Mode) in this context. If the device is transmitting location data to the network every few seconds, the benefits of PSM are significantly diminished. Furthermore, the configuration parameter CONFIG_LTE_PSM_REQ_RAT pertains to the requested PSM Active-Time—specifically, the duration during which the device remains available to receive paging messages from the network following RRC release, before entering PSM. There is no configurable parameter for the RRC Inactivity Timer, as this is entirely controlled by the network. Consequently, RAI remains the only viable method for reducing the RRC release delay.

With RAI enabled, a tracking interval of approximately 5 seconds may be achievable, depending on network conditions. However, due to the substantial signaling overhead this imposes on the network, a 10-second interval is generally recommended to maintain a balance between responsiveness and network efficiency.

Could you please test without PSM disabled on your side and provide feedback on the results?

Thanks!

Kind regards,
Øyvind

RE: NRF9151 location tracking sample interval

Jacky1700 — Tue, 02 Sep 2025 08:30:24 GMT

Hi Øyvind，

Thanks a lot for your answers!

We'd like to get the interval as small as possible. If 1s is NOT achievable, we may have to go back to consider about 5s or 10s per your suggestion.

Looking forward to getting your further solutions later!

Regards,
Jacky

RE: NRF9151 location tracking sample interval

Øyvind — Tue, 02 Sep 2025 08:21:50 GMT

Hello,

The general answer to this is that under optimal conditions, GNSS is capable of acquiring a position fix in approximately one second. The actual interval primarily depends on the speed at which the RRC (Radio Resource Control) connection can be established, data transmitted to the network, and the connection subsequently released. An update interval of a few seconds is likely feasible, subject to network performance. However, such frequent updates generate significant signaling traffic on the network side. Therefore, a recommended interval of around 10 seconds is generally advised to balance performance and network efficiency.

I've forwarded to our team for more information and will update you within 4 business days.

Kind regards,
Øyvind