How know RSSI?

RE: How know RSSI?

Didrik Rokhaug — Fri, 26 Feb 2021 10:30:36 GMT

[quote user="tracking"]also I tried +CESQ AT=? command with follow results, but I don't know how to interpret these expression (0-34,255) and (0-97,255) [/quote]

The test command (=?) lists the ranges the values can have. I.e. the RSRQ can be between 0 and 34, or 255 (which indicates that it is unknown/no valid). The RSRP can be between 0 and 97, or 255.

https://infocenter.nordicsemi.com/topic/ref_at_commands/REF/at_commands/mob_termination_ctrl_status/cesq_test.html

[quote user="tracking"]I have proved +CESQ AT and get these values and used the equation, is result in dBm?[/quote]

Yes.

But, to the values you get from +CESQ are not the RSRQ and RSRP directly.

To get the RSRQ, you must subtract 19.5, and to get the RSRP you must subtract 140.

In your case, the result will be 10*log(6) + (48 - 140) - (24 - 19.5) = 10*log(6) + (-92) - 4.5 = -88.7dBm

RE: How know RSSI?

tracking — Wed, 24 Feb 2021 21:34:55 GMT

Hi Didrik

I have proved +CESQ AT and get these values and used the equation, is result in dBm?

10*LOG(6)+48-24 = 31.78

also I tried +CESQ AT=? command with follow results, but I don't know how to interpret these expression (0-34,255) and (0-97,255)

RE: How know RSSI?

Didrik Rokhaug — Wed, 24 Feb 2021 13:13:58 GMT

Hi,

[quote user=""]I need to know the RSSI[/quote]

LTE:

There are no way to get the RSSI directly when using the nRF9160. However, you can use the +CESQ AT command to get the RSRP and RSRQ.

You can then calculate the RSSI like this:

RSSI = 10log(N) + RSRP - RSRQ.

N is Resource Blocks and is 6 for LTE M1.

GPS:

Again, it is not possible to get the RSSI directly. Instead, you get the CN0, which is the carrier-to-noise-density ratio (or the ratio of the signal level to the (noise level in 1Hz BW)).

If you know the Noise Figure of the receiver, the RSSI = -174dBm + NF + CN0.

[quote user=""]I have another doubt, what is the period of time where I can do a question without be a necromancer?[/quote]

I assume you are talking about the Necromancer achievement?

In that case, it is 30 days:

Best regards,

Didrik