5G Throughput Optimization Basics #2 - BLER Target: Fixed Or Variable?

[@OurTechPlanet]

For 5G Concepts & Basics, check out the complete playlist below :) 🌐5G Throughput Optimization 💡kzbin.info/aero/PL4OXTttOk9WggxSQfJT7HvCKzqukpqgWf

[@AliMiro-x3l]

Bro God bless you. Next week I have interview you helped me a lot. Thank you!

[@OurTechPlanet]

Thanks. Best of luck!

[@singlaswati]

Am I missing anything? My understanding is that lower the BLER target is, more strict the target is and more restransmissions will happen. So for large size traffic type, lower bler target should result in more retransmissions and more resource consumption.

[@OurTechPlanet]

The BLER Target refers to the Initial BLER Target. So, for Initial BLER target to be lower, it means that the first transmission should be successfully received. This means that to ensure that the first transmission is successfully received, it has to be very robust and thus, the MCS is reduced to make it that robust.

[@akshaybaghmar254]

Hi, Thank you for the video and explanation. I had a small query regarding BLER in PDSCH or throughput. If in case my RBLER is more than the target (IBLER is also more) during throughput. Will/can condition this lead to RLF ?

[@OurTechPlanet]

RLF happens on RLC BLER so if RLC fails all retransmissions then it will cause an RLF. So, very high RBLER can trigger this issue.

[@coolmunzir]

Acknowledgments at Application Layer (higher RTT), you were referring to Negative Acknowledgements (NACK) right?

[@OurTechPlanet]

I was referring to DUP ACK scenario in application layer (if TCP is being used)

[@coolmunzir]

With lower IBLER Target in case of Large Packets will decrease the MCS (will increase segmentation by reducing TB Size) impacting Throughput so there is a compromise over Throughput by reducing Re-Transmissions of Large Packets because of Large Overhead Size, although the compromise can be of lower magnitude in some cases in good RF Conditions. Similarly with higher IBLER Target in case of Small Packets will increase the MCS (reduce segmentation by increasing TB Size) which will increase Throughput in comparison to lower IBLER Target (Small Packets) but here compromising over Re-Transmissions since Overhead size is Small. Is this what you explained, correct? And will the roles be reversed in case of Large Packets in poor RF Conditions and Small Packets in good RF Conditions? So in conclusion Variable IBLER is better than fixed IBLER?

[@OurTechPlanet]

Yeah I think you summarized is well. For role reversal, it might not work because usually there is a TBS limit applied here.

[@munzirkhalil4213]

@@OurTechPlanet i think in case of large packet in weak coverage having ibler target less than 10% would be more feasible and similarly small packets in good rf conditions having ibler target > 10%

[@ramportland]

Request that you please cover the topic of Carrier Aggregation

[@OurTechPlanet]

Sure, will add that soon!

[@ankurtomar]

Love it

[@OurTechPlanet]

Thanks Ankur!

[@giacomocroce5905]

Thanks

[@OurTechPlanet]

Welcome :)

[@yap9660]

What is the definition of overhead?

[@OurTechPlanet]

Anything that is not data or that is redundant is overhead.

[@swarnban8634]

@@OurTechPlanet But retransmission is also a data to be sent in DL, why you are telling it as redundant (no data)?

[@OurTechPlanet]

@@swarnban8634 I meant that Retransmission is overhead