The interface in 5G Non-Standalone (NSA) architecture plays a crucial role in enabling communication and coordination between different network elements. NSA is a deployment scenario in 5G where the 5G radio access network (New Radio or NR) is deployed alongside the existing 4G LTE infrastructure. The interface in 5G NSA involves interactions between the evolved NodeB (eNB) from LTE and the new 5G elements, including the 5G Next-Generation NodeB (gNB) and the 5G Core (5GC).
One of the key interfaces in 5G NSA is the Xn interface. This interface facilitates communication between two gNBs, allowing for inter-gNB mobility and handovers. It is essential for seamless connectivity as users move across different cells served by different gNBs.
Another important interface in 5G NSA is the E1 interface, which connects the gNB to the EPC (Evolved Packet Core) of the LTE network. This interface is crucial for the exchange of signaling messages and user data between the 5G RAN (Radio Access Network) and the LTE core network. It enables the coexistence of 4G and 5G technologies, ensuring a smooth transition for services and applications.
In addition to the Xn and E1 interfaces, the NG interface connects the 5G Core (5GC) with the gNB. The 5GC is a fundamental component of the 5G architecture, responsible for managing the core network functions and services. The NG interface allows communication between the 5GC and the gNB for tasks such as session management, mobility management, and the establishment of user connections.
The interaction between the gNB and the LTE eNB is supported by the X2 interface, which enables coordination for mobility and handovers between the 5G and LTE networks. This is particularly important in 5G NSA deployments, where both technologies work together to provide enhanced connectivity and performance.
In summary, the interfaces in 5G NSA, including Xn, E1, NG, and X2, are essential for the integration of 5G with existing LTE networks. They enable communication, coordination, and data exchange between the new 5G RAN and the LTE core network, ensuring a smooth and efficient deployment of 5G services in a non-standalone architecture.