5G Enhanced Service-based Core Design

5G is supposed to support not only explosive growth of mobile traffic but also massive number of connected devices. Simply evolving current 4G Long Term Evolution (LTE) networks can't meet the demand of 5G. 3rd Generation Partnership Project (3GPP) has proposed Service-Based Architecture (SBA) core network in release 15. But SBA also brings great complexity and big challenges to core network development and deployment. To solve challenging requirements related to SBA, 3GPP is working on enhancements to SBA design in release 16. We propose an enhanced SBA design called Not-Only-Stack (NoStack), including efficient inter-service communication mechanism and management plane for Network Functions (NFs) managing. The main idea of NoStack is to decouple business logic from inter-service communication to improve service agility. We also carry out some evaluations on performance of different inter-service communication mechanisms.