NRF9160 Zephyr ncs ZTE-M/NB-IOT Multiple Cell-Tower RSSI

[Thomas Li Fredriksen]

Good afternoon,

I have previously asked the following question ("NRF9160 Zephyr ncs ZTE-M/NB-IOT Cell-Tower RSSI"):

https://devzone.nordicsemi.com/f/nordic-q-a/42241/nrf9160-zephyr-ncs-zte-m-nb-iot-cell-tower-rssi

Unfortunately, I was a bit quick to accept the answer, as the suggested solution only seem to provide the RSSI for a single tower.

I am looking for some way of reading out the RSSI of multiple towers, preferably all towers within range.

Is this at all possible?

/Tom

[Thomas Li Fredriksen]

I did find the command "AT%NBRGRSRP", which seems promising, but I cannot seem to make sense of the provided Cell-Id, which appears to be only two or three digits?

[Håkon Alseth]

All commands that has a "AT%" are notification subscriber commands, so you should get a notification back if the subscribed command has a notification for you. Enabling it should not have a field for cell-id, but the returned data from the modem will. Could you post what you get back?

Cheers,

Håkon

[Thomas Li Fredriksen]

Hi Håkon,

This is what I get when running "AT%NBRGRSRP" in the LTE-monitor:

AT%NBRGRSRP
%NBRGRSRP: 157,6400,53,170,6400,46,168,6400,37,156,6400,33
OK

/Tom

[Håkon Alseth]

Hi Tom,

Thomas Li Fredriksen said:

%NBRGRSRP: 157,6400,53,170,6400,46,168,6400,37,156,6400,33

I see where you're confused (I was too). This provides the physical cell id (PCI), and not the cell identity.

157 = Physical Cell identity (http://lteuniversity.com/ask_the_expert/f/69/t/589.aspx)

6400 = EARFCN (https://www.cablefree.net/wirelesstechnology/4glte/lte-carrier-frequency-earfcn/)

53 = RSRP (-140 + 53 = -87 dbm)

 

Best regards,

Håkon

[Thomas Li Fredriksen]

Hi Håkon,

This appears to make more sense, however it does not resolve my problem.

I still need some way of reading the cell ID, not the PCI. I assumed this would be achieved by some AT-command, however some SDK-way of achieving this would be preferable.

/Tom