The technical details of the Radio Unit (RU) and Distributed Unit (DU) in 5G architecture.
Radio Unit (RU)
The Radio Unit (RU) is a critical component in the 5G Radio Access Network (RAN). It is responsible for the following functions:
- Digital Front End (DFE): The RU handles the digital front end, which includes tasks like digital signal processing and conversion between digital and analog signals.
- Lower PHY Layer: It processes parts of the physical layer (PHY), including functions like modulation, coding, and digital beamforming.
- Radio Frequency (RF) Functions: The RU transmits, receives, amplifies, and digitizes RF signals. It is typically located near or integrated with the antenna to minimize signal loss and latency.
Distributed Unit (DU)
The Distributed Unit (DU) is another essential component in the 5G RAN, responsible for real-time processing and lower-layer functions:
- Layer 1 (L1) and Layer 2 (L2) Functions: The DU handles real-time processing tasks, including the physical layer (L1) and parts of the data link layer (L2). This includes functions like scheduling, MAC (Medium Access Control), and RLC (Radio Link Control).
- Deployment: The DU is usually deployed on-site or close to the RU to ensure low latency and efficient processing. It can be hosted on commercial off-the-shelf (COTS) servers.
- Fronthaul Interface: The DU connects to the RU via the fronthaul interface, which is a high-bandwidth, low-latency link. This interface is crucial for maintaining the performance and reliability of the 5G network.
Interaction Between RU and DU
The RU and DU work together to ensure efficient and high-performance 5G network operations. The RU handles the RF and lower PHY functions, while the DU manages real-time processing and scheduling. This split architecture allows for greater flexibility, scalability, and cost-effectiveness in network deployment.