Abstract：Dynamic Spectrum Sharing(DSS) is emerging as an important technology for the smooth evolution to 5G, which can effectively improve the spectrum utilization efficiency of low frequency bands. One of the key points for the design and operation of DSS is to solve the problem of 4G LTE and 5G NR uplink physical layer conflicts. In this paper, the format selection and resource allocation for uplink(UL) physical channel and reference signal are studied in multiple dimensions. And a load-based uplink resource allocation method is proposed to provide configurations for DSS deployment.

Abstract：December 2019, 3GPP determined more than 20 study and work items for 5G R17 version, of which RAN slicing enhancement technology is one of the key technologies enabling vertical industries. This article analyzes the key technical achievements of RAN slicing in the 3GPP R15 version, and combines the progress and existing problems of the existing technology. From the perspective of solving actual network problems and enabling richer applications, the latest study directions of R17 RAN slicing enhancement technology are discussed.

Abstract：With large scale commercializing of 5G network in 2020, operators in the whole world have accelerated 5G deployment. In this paper, the network architecture and evolution scheme of NSA and SA are introduced, the 5G NSA to SA , SA to NSA handover technology are studied, and SA to NSA optimized handover strategy in R16 is analyzed , which are under NSA/SA hybrid networking.

Abstract：SA is the final network architecture of 5G network evolution and development, which adopts a brand new network deployment. But it will coexist with current LTE networks for quite a long time. In order to ensure that UEs enjoy uninterrupted service in the mobile process, the network needs to provide efficient mobility management. Mobility management can be divided into cell reselection, handover, and redirection based on UE state. And it can be divided into intra-system mobility management and inter-system mobility management according to whether the service cells cross the system. To achieve the 0 ms interruption delay of handover, R16 had proposed several mobility management enhancement solutions. The paper mainly introduced the mobility management between NR cells, the interoperability between 4G/5G cells and the mobility management enhancement solutions in R16, which provided a reference for the mobility management optimization of 5G SA network.

Abstract：Dynamic spectrum sharing(DSS) technology allocates spectrum resources dynamically and flexibly for different communication technologies in the same frequency band. This technology is of great significance in the rapid deployment of 5G network to realize the smooth evolution from 4G to 5G, and the realization of 5G network wide coverage by using low frequency band. Although DSS can improve the utilization of spectrum resources by flexibly allocating spectrum resources in most cases, the introduction of DSS technology also brings additional spectrum cost. This paper will introduce the current mainstream DSS technology scheme and the corresponding cost calculation method, and analyze the advantages and disadvantages of various DSS technology schemes by comparing the cost loss before and after the introduction of DSS technology.