Can split bearer make a difference in 5G?

My friend: Hi Ibrahim, we have a problem here.

Me: What is the problem?

My friend: During the analysis of the 5G NR log we found that NR PDCP throughput is higher than the NR physical layer throughput which is not logic as always throughput is going higher when moving to lower layers as more headers are inserted at each layer.

Me: Yes, you are correct, this is usually the case, but could you please check if split bearer function is enabled from the gNB side? After a while….

My friend: Yes, it is enabled, but what does that mean?

Me: Split bearer is a function to allow the split of data going to gNB from the core side into two paths, the 1st path through the 5G air interface toward the UE and the 2nd one is toward X2 interface with the anchored eNB and then eNB will transfer this data through the 4G air interface to the UE.

Which means simply that UE is receiving the data from two paths simultaneously. So, if you checked the 4G throughput window, you’ll find it is showing some values which when added to the 5G NR throughput, you’ll get almost the 5G PDCP throughput you showed me.

My friend: Thanks a lot. I got it now.

Please share this information to spread it and make sure it is clear for everyone.

Source: Ibrahim Sayed

Linkedin Profile: https://www.linkedin.com/in/ibrahim-sayed-88a7747-5g/