5g functional split
In 5G networks, the functional split refers to the distribution of network functions between the central or cloud-based infrastructure and the distributed edge nodes. This split is essential for achieving the high data rates, low latency, and massive device connectivity promised by 5G technology. The functional split is defined by the 3rd Generation Partnership Project (3GPP), the organization responsible for standardizing mobile communication technologies.
The 5G functional split is primarily categorized into two main parts: the Central Unit (CU) and the Distributed Unit (DU). Each of these units performs specific functions, and the split allows for more flexibility, scalability, and efficient use of resources.
- Central Unit (CU):
- The CU is responsible for higher-layer functions and centralized processing.
- It handles tasks such as radio resource management, connection establishment, mobility management, and user-plane functions related to traffic processing.
- The CU is typically located in a central cloud data center, allowing for centralized control and coordination of multiple DUs.
- Distributed Unit (DU):
- The DU is responsible for lower-layer functions and distributed processing.
- It manages the lower-layer functions of the radio access network (RAN) and handles tasks such as radio modulation/demodulation, beamforming, and error correction.
- The DU is distributed closer to the cell sites or radio access points, reducing latency and improving the efficiency of data transmission.
The functional split enables the network to efficiently handle both control plane (signaling) and user plane (data) traffic. By separating these functions, the network can scale more easily, allowing for the deployment of various services and applications with diverse requirements.
The functional split in 5G is further categorized into different options, each with its own set of advantages and use cases. These options define how much processing is performed in the CU and DU, and they include options like CU-DU split (Option 2), CU separated from DU (Option 3), and more.
It's important to note that the specific functional split used in a 5G network can vary depending on the network architecture chosen by the service provider or operator. The flexibility provided by these functional splits is crucial for accommodating different deployment scenarios and optimizing network performance for various use cases.