Question Regarding BLE Channel Sounding Ranging Failure Beyond ~1 Meter

RE: Question Regarding BLE Channel Sounding Ranging Failure Beyond ~1 Meter

Asbjørn — Mon, 05 Jan 2026 09:55:54 GMT

Hello Mike,

I'm surprised that you are seeing this with the DKs you have. Can't really explain why and it makes me a bit concerned. May I ask which version of NCS and toolchain you have used to build the example? Sample used: `samples/bluetooth/channel_sounding_ras_initiator` I'd like to try and recreate the build here and see what it does.

Best regards

Asbjørn

RE: Question Regarding BLE Channel Sounding Ranging Failure Beyond ~1 Meter

Mike Lyu — Fri, 02 Jan 2026 07:52:53 GMT

Hello Asbjørn,

As a further update, we would like to share additional test observations.

We currently have four nRF54L15 DKs available and have conducted multiple ranging tests using different DK combinations (Initiator/Reflector pairings). Based on these repeated measurements, we observed that the maximum achievable ranging distance varies between individual DKs.

However, across all tested combinations, the Channel Sounding ranging functionality generally degrades and becomes unreliable beyond approximately 2 meters, after which distance estimation consistently fails due to insufficient valid Channel Sounding tone data.

This behavior appears to be reproducible across multiple test runs and DK pairings.

We would appreciate your insight on whether this level of unit-to-unit variation and the observed distance limitation are expected characteristics of the DK hardware or the default Channel Sounding configuration.

Best regards,
Mike

RE: Question Regarding BLE Channel Sounding Ranging Failure Beyond ~1 Meter

Mike Lyu — Fri, 02 Jan 2026 01:56:05 GMT

Hello Asbjørn,

Thank you for your clarification and suggestions.

To confirm, our current measurements are performed using nRF54L15 DKs on both the Initiator and Reflector sides, not a custom board. The observations previously described are based on DK-to-DK testing with default sample configuration and on-board antennas.

nRF54L15 DK ↓

Configuration ↓

Regarding your suggestion of using a different development board as the Initiator for comparison, we will proceed with this test setup and evaluate the ranging performance accordingly. Once we have the results, we will share our observations with you for further discussion.

If there are any specific test conditions, configurations, or metrics you would recommend focusing on during this comparison (e.g., PHY selection, TX power, antenna path, or logging details), please let us know.

Thank you again for your support.

Best regards,
Mike

RE: Question Regarding BLE Channel Sounding Ranging Failure Beyond ~1 Meter

Asbjørn — Wed, 31 Dec 2025 10:52:27 GMT

Hello Mike,

No, the range isn't limited to within a meter. My initial question will be to ask what sort of HW you are using.

Q1: Have you developed your own custom board or are the range testing done with the nRF54L15 DK?

Based on your observations I suspect that you are using a custom board. Would you be able to share with us the details of the boards as I suspect that the performance you are getting is a result of the HW.

Do you have two nRF54L15 DK available? What performance do you see when using those to for a comparisson test?

Best regards

Asbjørn