N3 User plane interface betw. RAN and core network in 5G → NG U

The N3 User plane interface is an important communication interface between the Radio Access Network (RAN) and the Core Network in 5G. It is part of the Next-Generation (NG) Core Network architecture and plays a crucial role in the delivery of user data services in 5G. This interface is designed to enable the transfer of user data between the RAN and the Core Network in an efficient and reliable manner.

In this article, we will provide an in-depth explanation of the N3 User plane interface, its features, and its functions. We will discuss the NG Core Network architecture, the role of the N3 User plane interface within this architecture, and the protocols used in the interface.

NG Core Network Architecture

The Next-Generation (NG) Core Network architecture is a new network architecture that is designed to support the deployment of 5G networks. It is based on a service-based architecture that is highly flexible and scalable, and it is optimized for the delivery of high-bandwidth and low-latency services. The NG Core Network is divided into three main functional areas, namely, the Access and Mobility Management Function (AMF), the Session Management Function (SMF), and the User Plane Function (UPF).

The AMF is responsible for the management of access and mobility for the user equipment (UE) in the network. It handles functions such as authentication, authorization, and mobility management. The SMF, on the other hand, is responsible for the management of the user session. It is responsible for the establishment, maintenance, and release of user sessions. Finally, the UPF is responsible for the delivery of user data between the RAN and the Core Network. It performs functions such as traffic routing, forwarding, and packet inspection.

N3 User Plane Interface

The N3 User plane interface is the communication interface between the RAN and the Core Network. It is used to transport user data between the UPF and the RAN. The interface is designed to be highly efficient and reliable, with low latency and high throughput. It supports both IPv4 and IPv6 protocols and is designed to handle large amounts of user data traffic.

The N3 User plane interface is a point-to-point interface that connects the UPF and the gNB (Next-Generation NodeB) in the RAN. It is implemented using the GTP-U (GPRS Tunnelling Protocol-User) protocol, which is used for the encapsulation and transportation of user data packets between the RAN and the Core Network.

The N3 User plane interface supports various Quality of Service (QoS) parameters, which are used to ensure that user data traffic is delivered with the required level of performance. QoS parameters such as packet loss rate, packet delay, and packet jitter can be defined and managed by the UPF and the gNB to ensure that user data traffic is delivered with the required level of performance.

Functions of the N3 User Plane Interface

The N3 User plane interface performs several key functions in the NG Core Network architecture. These functions are essential for the efficient and reliable delivery of user data services in 5G networks. Some of the key functions of the N3 User plane interface are discussed below.

User Data Transport: The N3 User plane interface is responsible for the transport of user data packets between the RAN and the Core Network. It provides a reliable and efficient transport mechanism for the delivery of user data packets with low latency and high throughput.

QoS Management: The N3 User plane interface supports various QoS parameters, which are used to ensure that user data traffic is delivered with the required level of performance. These parameters can be defined and managed by the UPF and the gNB to ensure that user data traffic is delivered with the required level of performance.

Packet Inspection: The N3 User plane interface is responsible for the inspection of user data packets. It can inspect packets for security and policy enforcement purposes. The UPF can use packet inspection to enforce policies such as traffic shaping, filtering, and blocking.

Packet Routing: The N3 User plane interface is responsible for the routing of user data packets between the RAN and the Core Network. It can route packets based on various parameters, such as destination address, QoS parameters, and policy rules.

Packet Forwarding: The N3 User plane interface is responsible for the forwarding of user data packets from the RAN to the Core Network and vice versa. It ensures that user data packets are forwarded to the correct destination with minimal delay and without loss.

Protocol Translation: The N3 User plane interface can perform protocol translation between the RAN and the Core Network. It can translate protocols such as IPv4 to IPv6, and vice versa, to enable communication between devices that use different protocols.

Conclusion

The N3 User plane interface is a crucial component of the NG Core Network architecture in 5G networks. It is responsible for the efficient and reliable transport of user data between the RAN and the Core Network. It supports various QoS parameters, packet inspection, routing, forwarding, and protocol translation. These features ensure that user data traffic is delivered with the required level of performance, reliability, and security. Overall, the N3 User plane interface plays a key role in the delivery of user data services in 5G networks, and its efficient operation is essential for the success of 5G networks.