Hello,
I'm currently using the nRF9151-DK hardware to develop our product based on the nRF9151 SiP. We selected the ncs-serial-modem firmware, and the modem is controlled via AT commands by our main MCU.
We are evaluating the nRF Cloud Location feature to determine device position using cellular or Wi-Fi data. I have implemented and tested this functionality in multiple areas around Uberlândia, Brazil.
However, I’ve observed that Single Cell Location does not provide the accuracy we need, so I tried using the Multi-Cell Location service. According to the documentation (https://docs.nordicsemi.com/bundle/addon-serial_modem-latest/page/app/NRFCLOUD_AT_commands.html), the NCELLMEAS command should perform a neighboring cell scan.
During my field tests at over 15 different locations across the city, every NCELLMEAS scan returned only one cell after a few hundred milliseconds — as shown in the AT command output below. On the nRF Cloud Location web interface, my results always appear as Single Cell, never Multi-Cell.
[SER] 2023-01-01T00:00:15 TX Modem 14 bytes: AT%NCELLMEAS [SER] 2023-01-01T00:00:15 RX Modem 6 bytes: OK [SER] 2023-01-01T00:00:15 RX Modem 71 bytes: %NCELLMEAS: 0,"05314208","72405","9CC6",48,9610,411,71,26,7060,6733 [SER] 2023-01-01T00:00:15 TX Modem 21 bytes: AT#XNRFCLOUDPOS=2,0 [SER] 2023-01-01T00:00:15 RX Modem 6 bytes: OK [SER] 2023-01-01T00:00:16 RX Modem 46 bytes: #XNRFCLOUDPOS: 0,-18.905003,-48.241289,546
In the coverage area of my residence, I have already observed the nRF9151 connecting to three different Cells, so I believe there is neighboring cell coverage available.
I also rebuilt and flashed the ncs-serial-modem firmware with trace logging enabled to analyze the behavior. The same issue persisted — only a single cell is reported in each scan. I’ve attached the trace log file for reference.
Could you please clarify if there are:
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Any specific commands or configuration parameters required to enable multi-cell scanning?
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Any known hardware limitations on the nRF9151 that prevent multi-cell measurements?
Thank you for your support.
