Coverage enhancement - AT+CEINFO vs AT%CONEVAL

[trothamel]

I'm interested in determining the current coverage enhancement behavior of a device, and I'm noticing a discrepancy between the AT+CEINFO and AT%CONEVAL results. Specifically, I get: 

AT+CEINFO?

+CEINFO: 1,1,C,32,1,-97,8

OK

AT%CONEVAL

%CONEVAL: 0,1,8,44,18,33,"018CB702","311480",355,5230,13,0,0,6,1,1,119
OK

What's a bit confusing to me is that the CEINFO downlink repetition factor is 32, while CONEVAL reports rx repetitions to be 1. I'm curious as to why these differ, and which one I should use to understand the network state.  

[dejans]

Hi,

What's a bit confusing to me is that the CEINFO downlink repetition factor is 32, while CONEVAL reports rx repetitions to be 1. I'm curious as to why these differ, and which one I should use to understand the network state.  

It might be that the values are reported differently by these 2 commands. I will check this internally and get back to you by the end of the week.

Best regards,
Dejan

[dejans]

Hi,

What's a bit confusing to me is that the CEINFO downlink repetition factor is 32, while CONEVAL reports rx repetitions to be 1. I'm curious as to why these differ, and which one I should use to understand the network state.  

Repetition values reported by both CEINFO and CONEVAL are correct. CEINFO gives the worst-case repetition value which network can use while CONEVAL (when used in connected mode) shows the latest used Rx repetition value. In your case, Rx repetition value is 32 in CEINFO which means that Rx repetitions (configured by the network) can vary between 1 and 32. For some further context, information about CEINFO can be found in the 3GPP 36.331 specification

mpdcch-NumRepetition Maximum number of repetitions levels for UE-SS for MPDCCH, see TS 36.213 [23]

In connected mode, CONEVAL returns the latest used repetition value for Tx and Rx. In your case, the latest used repetition value was 1 which means that the signal was so good that repetitions were not needed. Energy estimate value in CONEVAL is 8 which indicates good signal and is in line with repetition value of 1.

Repetition value controlled by the network is dynamic and may vary during connection based on network conditions. As a general recommendation, you can rely on energy estimate from CONEVAL if you want to estimate expected current consumption. 

Best regards,
Dejan