# Is it possible IBLER should be 0%?

Hi 5G Experts,

I saw this in a presentation:

In peak test scenarios, DMRS SINR must be greater than 30 dB. This ensures that the MCS index is 27 and the IBLER is close to 0%.

Is it possible IBLER should be 0%?

IBLER is always 10%…
This is how MCS is decided based on cqi and BLER.

Only residual BLER is 0%
So phrases in powerpoints are hilarious.
There are up to 6 harq retransmissions for each packet so plenty of chances to get residual bler to 0%.
This is for 5G.

But that would be iBLER?

There are cases when SINR is 31 and IBLER is still over 10%.

I am quite confused about BLER calculation.
UE calculate it for a duration ( for eg: last 10ms,…) or how long?
SINR is measured immediately.

Sliding window.
We have in 5G codeblocks at layer 1 same like in 4G.
I think this is how bler is computed.

We know that: BLER = No of ACK Codeword / ( ACK + NACK) *100%.
But I mean, how long UE sum of CW?
UE and eNB/gNB both calculate BLER, their value may be different?