Extended coverage without roaming for beyond 5G non-public networks

With the accelerating development and deployment of 5G Non-Public Networks (NPNs), many customized and private networks, providing services to local users and devices, are being installed across the world. To fully use the capacity of these networks, their services should also be reachable from other locations outside their limited coverage area. The only solution provided by 5G and beyond-5G 3GPP standardization at the current moment is based on roaming interfaces, which presumes that the NPN operator makes costly and complex peering roaming agreements with many different large scale and NPN operators. This article proposes an alternative to the roaming mechanism based on an Over-The-Top (OTT) peering approach. Similar to the non-3GPP integration, the connectivity in the visited network is transparently used to establish a binding with the home domain. Furthermore, the proposed architecture is implemented and evaluated in a basic form using Fraunhofer 5G Playground, a comprehensive 5G testbed network using commercial base stations and the Fraunhofer Open5GCore in conjunction with standard Android OS devices. Showing that such a solution represents a cost-effective, reduced functionality and relatively easy to implement solution outperforming the roaming approach in both dynamicity and ease of management.