Abstract：In 3GPP release 15, service-based architecture work item mainly finished the mechanism of service discovery. However, communication between network functions is still in a direct way which adopts point-to-point pattern and is hard for operations in future complicated network environment. At the same time, there is no mature protecting measure for the reliability of network functions. This paper mainly studies on the evolution of service-based architecture in 5G Core. More specifically, it analyzes the indirect communication method based on service communication proxy and gives the advantages and implementation suggestions. Also, it analyzes the high reliability mechanism of the network function set as well as the network function service set and gives the evolution of network functions as focusing on computing and removing the functionalities of storage and switching.

Abstract：3GPP R15 does not support handoff cross SMF service area and home routing. To solve this problem, ETSUN which is the one of new features of 3GPP Release 16 is introduced. In this paper ，the application scenes, technical solutions and communication flows are introduced，and recommendating about applying ESTUN and requirement of enhancing present R15 5G network are also proposed. This will be helpful to study ETSUN technical solutions and technical requirements of network equipment.

Abstract：In this paper, emergence background and intention of NPN are introduced, with the characteristic of two kind of NPN networks and their key technologic content. The relation between NPN and PLMN and technical requirement of NPN network entities are analysed. On the view of network deployment, comparison among Slicing, SNPN and PNI-NPN are presented, then selection of technology for private network is suggested.

Abstract：With the advancement of 5G network construction and service development, especially the development of network slicing towards convergence, diversification and intelligence in vertical industry-oriented application scenarios, new requirements are placed on the service functions of 5G network slicing. In order to adapt to the business needs of the 5G era, create 5G differentiated SLA advantages, and fully leverage the value of operators in the 5G era, this paper presents technical research and capability validation on 5G network slicing, service level guarantees and application practices. At the same time, based on the progress of 5G Stand Alone(SA) standards, key network slicing technologies were discussed, 5G business forms were refined, and new business models were simultaneously explored, providing technical optimization and support for the full-scale commercial implementation of 5G SA.

Abstract：Since 2020，most of global main telecommunication operators have turned to 5G standalone architecture, and roll out the the commercial deployment of 5G standalone architecture. In the meantime，3GPP R16 standard which supports all 5G service scenarios was frozen. The 5G Core network needs to be upgraded and make a evolution again soon. In line with the 3GPP standard schedule and product roadmap, 3GPP R17 and R18 standard version will miss the peak period of 5G SA construction, so 3GPP R16 maybe the most nominated commerical standard version in the next 3～5 years. As a result, it is very essential to make a systematic study about 3GPP R16, especially focusing on function architecture, application scenarios and impact on network.