Research On Online Wireless Resource Management Based On Network Slicing

Network slicing(NS)has attracted extensive attention and been researched in depth by scholars because it can customize logically independent end-to-end virtual networks on demand on a shared underlying physical network,and better support the coexistence of vertical industries with differentiated performance requirements.The characteristics of NS itself,which are customization on demand,flexible scalability and the ability of providing specific service performance,put forward relatively high requirements on the flexibility of wireless resource management.Therefore,online wireless resource management technique plays an important role,which can optimize network resource configuration so that the differentiated quality of service(Qo S)requirements among different applications can be well satisfied simultaneously.Combining the NS with online wireless resource management technique may derive potential performance benefits.This dissertation focuses on the problem of NS-based online wireless resource management and the main research work is summarized as follows:1.For the problem of efficient and dynamic resource allocation for NS in cloud radio access network(C-RAN),a virtual resource allocation algorithm for NS in virtualized C-RAN is proposed in this thesis.Firstly,a stochastic optimization model in virtualized C-RAN is established based on the constrained Markov decision process(CMDP)theory,which maximizes the average sum rate of all slices as its objective,and is subject to the average delay constraint for each slice as well as the average network backhaul link bandwidth consumption constraint in the meantime.Secondly,in order to overcome the issue of having difficulties in acquiring the accurate transition probabilities of the system states in the proposed CMDP optimization problem,this thesis introduces the post-decision state(PDS),and it incorporates all of the known information about the system state transition.Finally,a PDS-based online virtual resource allocation algorithm is proposed for network slices in virtualized C-RAN,and it will allocate appropriate resource blocks(RBs)and caching resource for each network slice according to the observed current system state.The simulation results reveal that the proposed algorithm could effectively satisfy the Qo S demand of each individual network slice,reduce the pressure of backhaul link on bandwidth consumption and improve the system throughput.2.For dynamic resource scheduling problem for network slices in heterogeneous cloud radio access network(H-CRAN)where diverse application scenarios coexist,by jointly considering traffic admission control,congestion control,resource allocation and reuse,this thesis formulates the problem as a stochastic optimization programming which maximizes network average total throughput as its objective and is subject to constraints like base station(BS)transmit power,system stability,Qo S requirements of different slices as well as resource allocation and reuse.Furthermore,this thesis leverages the Lyapunov optimization theory to convert the established mathematical model with time-averaged objective and constraints into a single-slot optimization problem.Then an online resource allocation algorithm for network slices based on system stability and Qo S guarantee is proposed.Specifically,the proposed algorithm further decomposes the single-slot optimization problem into two independent sub-problems,namely the traffic admission control and sub-carrier allocation,reuse and power allocation sub-problems,and then solves them separately.The theoretical analysis and simulation results show that the proposed algorithm could improve network overall throughput while satisfying the different Qo S requirements of slice users and maintaining network stability.Besides,it could also flexibly strike a dynamic balance between delay and throughput by simply tuning an introduced control parameter.