NG C Control plane interface betw. RAN and core network in 5G → N2

The fifth generation (5G) of mobile communication is a revolutionary technology that offers higher data speeds, lower latency, and greater network capacity than its predecessors. One of the key components of 5G networks is the control plane interface between the Radio Access Network (RAN) and the core network, which is known as the N2 interface. In this essay, we will discuss the N2 interface in detail, including its purpose, architecture, and protocols.

Purpose of the N2 Interface

The N2 interface is responsible for providing a communication channel between the RAN and the core network in a 5G network. It is used to transfer control plane information, such as mobility management, session management, and QoS management, between the RAN and the core network. The N2 interface is also used to provide synchronization and timing information between the RAN and the core network.

The architecture of the N2 Interface

The N2 interface is a logical interface that is used to exchange control plane messages between the RAN and the core network. It is a point-to-point interface that connects the RAN and the core network. The N2 interface is divided into two parts: the control plane and the user plane.

The control plane is responsible for managing the signaling and control information between the RAN and the core network. It is used to establish and release sessions, transfer mobility management information, and manage QoS. The control plane is also responsible for providing synchronization and timing information between the RAN and the core network.

The user plane, on the other hand, is responsible for transporting user data between the RAN and the core network. It is used to transfer data packets between the RAN and the core network, and it is optimized for low latency and high throughput.

Protocols used in the N2 Interface

The N2 interface uses several protocols to ensure the smooth exchange of information between the RAN and the core network. These protocols include:

Session Management Protocol (SMP)

The SMP is used to establish and release sessions between the RAN and the core network. It is responsible for managing the session setup, session modification, and session release procedures. The SMP is also used to manage the state of the session between the RAN and the core network.

Mobility Management Protocol (MMP)

The MMP is used to manage the mobility of the UE (User Equipment) between different RAN nodes and the core network. It is responsible for managing the handover and roaming procedures, and it ensures that the UE maintains connectivity as it moves between different RAN nodes.

QoS Management Protocol (QMP)

The QMP is used to manage the QoS of the user data that is transported over the N2 interface. It is responsible for ensuring that the user data is transported with the required QoS parameters, such as delay, jitter, and packet loss.

Timing and Synchronization Protocol (TSP)

The TSP is used to provide synchronization and timing information between the RAN and the core network. It is responsible for ensuring that the RAN and the core network are synchronized in terms of timing, and it provides timing information to the RAN nodes to ensure that they can synchronize with each other.

User Plane Protocol (UPP)

The UPP is used to transport user data between the RAN and the core network. It is optimized for low latency and high throughput, and it ensures that the user data is transported with the required QoS parameters.

Conclusion

In conclusion, the N2 interface is a critical component of the 5G network architecture that provides a communication channel between the RAN and the core network. It is responsible for exchanging control plane information, managing sessions, managing mobility, managing QoS, and providing synchronization and timing information between the RAN and the core network. The N2 interface uses various protocols, such as the SMP, MMP, QMP, TSP, and UPP, to ensure the smooth exchange of information and the efficient transport of user data. The N2 interface plays a vital role in enabling the advanced features and capabilities of 5G networks, and it is essential for delivering high-performance and reliable 5G services to users.