What are the gNB split options in 5G?

My friend: Hi Ibrahim, I have a question for you.

Me: Go ahead. My friend: What are the gNB split options available in 5G?

Me: Do you remember our last discussion? My friend: Yes, when you mentioned that CU is handling PDCP and above layers, while DU is handling RLC, MAC and physical layer (Check last post here )

Me: Great. Actually, this is only one option to split the CU and DU, while there are 8 options available as per 3GPP shown at the below snapshot, so you can split the gNB at different points in protocol stack. Option 2 was the one adapted by 3GPP in Rel-15. Moving from option 1 towards option 8 means high requirement for capacity and low latency and vice versa.

My Friend: But, why we have such a split?

Me: The split brings more flexibility and flexible hardware and software implementations allow scalable, cost-effective network deployments. Also, split architecture between CU and DU allows for coordination for performance features, load management and real-time performance optimization between all DUs via one CU.

My friend: Thanks a lot. Me: You are welcomed.

Source: Ibrahim Sayed

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