5G Service Based Core Network Design

5G has put forward higher demand for networking and simply evolving current system cannot meet the demand. Along with the basic Service-Based Architecture(SBA) standardized by 3GPP, 5G core network architecture is undergoing an evolution. In this paper, we design and evaluate Not-Only Stack(NoStack), a mobile network controller which features Message Bus(MB) and Global Network View(GNV), to address the potential enhancement to SBA. NoStack MB decouples business logic from inter-service communication. It improves service availability and agility. NoStack GNV decouples storage from computing to enable the sharing of service context between different services or service instances at the cost of acceptable increase on latency. It improves reliability and flexibility, as well as reduces signalling cost. The performance of NoStack is evaluated with initial attach procedure on OpenairInterface(OAI). The impact of NoStack on current system procedure is analysed as well. Finally, the outlook of NoStack in beyond 5G stage is shown.