5G NSA Option 4, 4a

Option 4 series

Now let's introduce Option 4.

For this series, 5G is completely in the spotlight. The core network has already been switched to the 5G core, and the 5G base station has also become the anchor point of the control plane.

Option 4

Option 4a

Option 4 Series is divided into Option 4 and 4a. As can be seen from the two figures above, the only difference between them is whether the data split anchor is in the 5G base station or the 5G core network. Both of these are new network elements and do not involve the upgrading and transformation of legacy equipment, so both options are acceptable.

The application scenario for Option 4 series is in the middle and late stages of 5G deployment. 5G has achieved continuous coverage, completely leaving 4G behind as a complement to 5G.

Terms Explanation

Control plane: the channel to send the signaling required to manage and schedule resources.

User plane: the channel to send the user data. The user plane and the control plane are completely separate.

Dual connection: As the name suggests, the mobile phone can communicate with both 4G and 5G networks and download data at the same time. Typically, there will be a master connection and a slave connection.

Control plane anchor: the base station responsible for the control plane in the dual connection is called control plane anchor.

Data split anchor: the user's data needs to be split for transmission in the two paths of dual connection, but where should it be split? This location is called data split anchor.