On 03/08/2021 15:28, Denis Kenzior wrote:
> Hi Alex,
>
>> I have been chasing this up with Quectel and they tell me this the 
>> correct implementation.
>>
>> "QCOPS and QENG command show the RSSI、RSRP and SINR value of the 
>> network, this is in accordance with the 3GPP TS regulations, so it is 
>> normal for negative numbers to be displayed.image"
>
>
> So the image shows the value for <rsrp>
>
> '0' if -140 dbm
> ...
> '95' if dbm is -46 to -45
> etc.
>
> <rsrp> (what is actually sent over AT commands) is never negative. 
> Isn't the image supporting my earlier assertion:  'AT commands do not 
> have a concept of negative numbers'?
>
> oFono exposes the <rsrp> value from 3GPP:
>
> "byte ReferenceSignalReceivedPower [optional, lte]
>
>         Contains the Reference Signal Received Power.  Valid range of 
> values
>         is 0-97. Refer to <rsrp> in 27.007, Section 8.69 for more 
> details.
> "
>
> Regards,
> -Denis


Denis - I am being directed to the ITU 36.133 spec here

https://portal.3gpp.org/desktopmodules/Specifications/SpecificationDetails.aspx?specificationId=2420

This document defines this in 9.1.4

I can't see where RSRP_-17 is defined anywhere but the strong 
implication to me is that this number should be -17

Can you confirm where it states that these numbers cannot be negative 
numbers as I cannot find that requirement.

Thanks,

Alex

------------------------------------------------------------------------

A colleague has just pointed me to a UBlox document which specifies for 
negative values too

Regards,

Alex