What is Option 7.2?
Option 7.2 specifies a split between the Central Unit (CU) and the Distributed Unit (DU) within the RAN. Specifically, this option divides the functionalities at a point in the protocol stack between the Lower PHY (Physical) layer – the bit that interfaces between the hardware and the software – and the Upper PHY layer. Here’s how it works:
Central Unit (CU): The CU retains control functionalities and some parts of the packet processing functions. It is responsible for higher-layer protocols and non-real-time functions.
Distributed Unit (DU): The DU handles real-time processing tasks. Under Option 7.2, the DU processes the upper part of the PHY layer, including functions such as HARQ (Hybrid Automatic Repeat Request) processing and part of the forward error correction.
Advantages of Option 7.2
Performance: By handling the upper PHY functions close to the radio (at the DU), Option 7.2 can better manage high-throughput and low-latency requirements, crucial for many 5G applications.
Flexibility and Scalability: This split allows for flexible deployment scenarios and scalability, as DUs can be densely deployed in areas requiring intense computation and fast response times, while CUs can be centralized and shared among multiple DUs.
