Mobility Management Based On NFV And Its Performance Optimization

To support the typical application scenarios defined in the fifth generation mobile communication technology,such as the enhanced mobile broadband,massive machine type of communication,ultra-reliable and low-latency communication,virtual Mobility Management Entity(vMME)is proposed as a promising solution.vMME runs on universal servers based on network functions virtualization(NFV),which replaces conventional hardware-dedicated mobility management entity.Among different vMME mapping solutions,the decomposing of MME into multiple components is a prospective approach to implementing customized mobility management.In this thesis,the optimization of mobility management is addressed by using NFV and service function chain(SFC),and the research work mainly includes:Firstly,a control framework of mobility management based on NFV is proposed,and the mobile management orchestration framework based on MANO is presented.A general signaling processing flow of vMME based on SFC is analyzed.Secondly,the performance of vMME is formulated as an optimization problem aiming at minimizing the total signaling communication over-head cost,the total signaling communication overhead cost on backhauls as well as the migration overhead cost of state data under different function component placement of vMME.Since this optimization problem is NP-hard,three heuristic approach is presented including Min-TSCOC,Min-TSCOCB and Min-MOCSD.The simulation results show that it is beneficial to decompose the function of mobility management,and the performance gains from vMME for different network function composition strictly depend on four mobility events.The simulation results also show that the proposed algorithm can effectively reduce the computational complexity of the mobility management optimization problems.