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5g split options

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5G (fifth-generation) mobile networks, the term "split options" refers to the distribution of functionality between different network components, specifically between the radio unit (RU) and the baseband unit (BBU) in the radio access network (RAN). These split options define how the processing tasks are divided between these two units in the network architecture. The split options are usually denoted by numbers, such as Option 2, Option 7-2, and so on.

Here is an explanation of some common split options:

  1. Option 2: Non-Standalone (NSA) Architecture:
    • Description: In this split option, the radio unit (RU) is responsible for the radio frequency (RF) functions, while the baseband unit (BBU) handles the digital baseband processing. The BBU is typically centralized, and multiple RUs can be connected to it.
    • Use Case: This split option is commonly used in the initial deployment of 5G alongside existing 4G infrastructure. The 5G deployment relies on the 4G core network for control functions.
  2. Option 7-2: Centralized Unit (CU) and Distributed Unit (DU) Split:
    • Description: This split option introduces a further division within the BBU, separating the centralized unit (CU) from the distributed unit (DU). The CU handles higher-layer functions, while the DU is responsible for lower-layer functions.
    • Use Case: Option 7-2 enables more flexibility in network deployment, allowing for a centralized control architecture with distributed radio units. It is part of the 5G Standalone (SA) architecture.
  3. Option 6: CU and DU Split with Fronthaul:
    • Description: Similar to Option 7-2, Option 6 splits the BBU into CU and DU, but it introduces a specific fronthaul interface connecting the CU and DU. The fronthaul is a high-capacity link that carries digitized and time-sensitive traffic between the CU and DU.
    • Use Case: This split option is designed to support higher capacity and lower latency requirements in the 5G network.
  4. Option 4: Distributed Unit (DU) and Remote Radio Head (RRH) Split:
    • Description: In Option 4, the BBU is further split into a distributed unit (DU) and a remote radio head (RRH). The DU handles central processing, while the RRH is responsible for radio frequency (RF) processing.
    • Use Case: Option 4 enables a more distributed architecture, allowing for greater flexibility in deploying radio units closer to the antennas.

These split options offer different trade-offs in terms of deployment flexibility, network latency, and resource utilization. The choice of a specific split option depends on factors such as network architecture, deployment scenarios, and performance requirements.