Connectivity Requirements for 5G Core and RAN

This section describes core and edge connectivity requirements to support different deployment models of 5G RAN.

• Core and Edge connectivity: Core and Edge connectivity can have a significant impact on the 5G core deployment and it provides application-specific SLA. The type of radio spectrum, connectivity, and the available bandwidth can have a great influence on the placement of CNFs.

• WAN connectivity: In the centralized deployment model, the WAN connectivity must be reliable between the sites. Any unexpected WAN outage prevents 5G user sessions from being established as all 5G control travels from the edge to core.

• Components deployment in Cell Site: Due to the physical constraints of remote Cell Site locations, place only the required function at the Cell Site and deploy the remaining components centrally. For example, the platform monitoring and logging are often deployed centrally to provide universal visibility and control without replicating the core data center at the remote edge Cell Site locations. Non- latency-sensitive user metrics are often forwarded centrally for processing.

• Available WAN bandwidth: The available WAN bandwidth between Cell Site and Central Core sites must be sized to meet the worst-case bandwidth demand. Also, when multiple classes of an application share a WAN, proper network QoS is critical.

• Fully distributed 5G core stack: A fully distributed 5G core stack is ideal for private 5G use cases, where the edge data center must be self-contained. It survives extended outages that impact connectivity to the core data center. The Enterprise edge can be the aggregation point for 5G Core control plane, UPF, distributed radio sites, and selective mobile edge applications. A fully distributed 5GC reduces the dependency on WAN, but it increases the compute and storage requirements.

• Network Routing in Cell Site: Each Cell Site can locally route the user plane traffic and all the Internet traffic through the local Internet gateways, while the management and non-real time sensitive applications leverage the core for device communication.