5G切片化网络中基于吞吐量最大化的用户切换机制

第五代无线通信系统(the fifth generation，5G)利用网络功能虚拟化(network function virtualization， NFV)和软件定义网络(software defined network， SDN)2项技术将网络进行了切片划分，让用户接入不同服务质量(quality of service，QoS)保障的虚拟网络切片以获得服务。为了解决切片化网络中由于用户移动性而导致的切片重新接入问题，提出了最大化网络吞吐量的用户切换机制来降低越区切换对已有网络切片的影响。该机制根据用户业务类型的QoS服务等级筛选备选接入站点的归属切片，运用贪心算法选择能为用户提供最大数据传输速率的切片接入服务，在网络切片代理的体系架构下完成切换过程的控制和管理。在与功率接入、负载接入和随机接入3种切换方案的性能对比中，相关仿真结果表明，随着越区用户数目和网络切片类型的增加，所提方案在保证较高网络吞吐量的同时，切换成功率始终维持在80%以上，远优于其他3种方案。

Throughput maximization-based user handover mechanism in sliced 5G network

The fifth generation mobile communication system (5G) enables physical network sliced by employing network function virtualization (NFV) and software defined network (SDN) technologies, and serves users through diverse QoS guaranteed virtual network slice. In order to deal with slice re-access caused by user mobility in sliced 5G network, a throughput maximization-based user handover mechanism was proposed to reduce the impact of handover on existing network slices. Firstly, the mechanism filtered the home slice of the candidate access points according to the QoS demand of user service type; Secondly, the greedy algorithm was utilized to select the slice which could provide the maximum data transmission rate for user; Finally, the proposed mechanism controlled and managed handover process under the new architecture that was applied to the network slice broker. In performance comparison to other three handover schemes such as power-based access, load-based access and random access, the simulation results validate the best efficiency of proposed mechanism on improvement of handover success ratio and throughput. Specifically, when the number of users and the number of network slice types increase separately, the handover success ratio of throughput maximization-based scheme remains above 80% while the throughput stays in high level, which is far better than the other three schemes.