Satellite- Terrestrial Integrated Network Architecture Towards 6G with User Plane Function Trimming.

Both the academic and industry begin the early research on the network architectures of the 6th generation (6G) mobile communication system, which integrates the satellite networks for ubiquitous access. However, the 5th generation non-terrestrial network (5G NTN) architecture and the existing integrated network architectures do not consider the specific trimming schemes of network element functions placed on-orbit, which may cause the waste of resources. Therefore, we propose a microservice-based satellite-terrestrial integrated network architecture, where the access network (AN) and the user plane function (UPF) are servized, to achieve deeper integration between the AN and the core network (CN). Based on the new network architecture, a basic principle of network element function trimming is proposed, and two examples of UPF function trimming are given in the typical scenarios with satellite networks. The function trimming results have exhibited that the UPF effectively reduces the number of functions equipped on the satellite by probably 42 % and 63 % in two typical scenarios, respectively, which saves the satellite resources.