Your quick guide to Network Functions in 5G Core
Yes, 5G Core (5GC) is a new network architecture introduced in the 3GPP Release 15. Are you familiar with the new Network Functions in 5GC and how they compare to the Network Functions in Evolved Packet Core (EPC)? Read on for a quick guide and don’t miss the podcast with Lars Frid!
Why 5GC is different
3GPP has ended up in a potentially complex situation, where we now have two network architectures on the table. Consequently, depending on how communication service providers deploy their radio networks, which technology they use for coverage band, and which technology they use for capacity bands, they may end up with different core network solutions.
The major difference with 5GC compared to EPC is that 5GC’s control plane (CP) functions interact in a Service-Based Architecture (SBA). A key Network Function (NF) of SBA is the Network Repository Function (NRF), which provides NF service registration and discovery, enabling NFs to identify appropriate services in one another. SBA principles apply to interfaces between CP functions within 5GC only, so interfaces toward Radio Access Network (RAN), user equipment or user plane (UP) functions (N1, N2, N3, N4, N6 and N9) are excluded.
Another major difference in 5GC’s CP is the structure, because it has different functional separation of Access and Mobility Functions (AMF) and Session Management Functions (SMF). 5GC includes the separation of UP and CP functions of the gateway, which was an evolution of the gateway CP/UP separation (CUPS) introduced in EPC Release 14. Other changes include a separate Authentication Server (AUSF) and several new functions, such as the Network Slice Selection Function (NSSF) and the Network Exposure Function (NEF).
As we see it, service providers should only have to manage one core network, and any device should be able to access that network over any access technology. They should also have a common set of resources that can be used for serving the complete subscriber base. Finally, striving towards making operations as efficient as possible is key, while not forgetting the importance of flexibility to open up new business opportunities without bringing extensive or costly reconfigurations.
Taking a dual-mode approach to core evolution
Considering service providers’ concerns for protecting investments already made in the network, we have designed a solution, as described in Figure 1, that allows full integration of new cloud native NFs with Virtual or Physical NFs (VNFs and PNFs) in the same network, and offers different migration paths to bring all NFs into a full cloud native, dual-mode 5G Cloud Core over time. This makes deployment more flexible, allows for interworking with legacy networks and a smooth evolution to 5GC.
Our dual-mode 5G Cloud Core solution delivers cloud native applications that support both EPC and 5GC 3GPP architectures. It ensures capacity, elasticity and agnosticism to the underlying infrastructure, and high levels of orchestration and automation for operational efficiency.
Podcast with Lars Frid
A person who has been working with the 5G architecture for quite some time is Lars Frid, Director of 5G Core Strategic Product Management at Ericsson. Listen to this podcast on his experiences of introducing 2G, 3G, 4G and now also 5G. What is a ‘day in the life in 30 seconds’ for him when working with cloudification and preparing for zero touch networks? And what exactly is top of mind for service providers today, approaching commercial 5G?
For more info on our dual-mode 5G Cloud Core, download the solution description.