Research On Optimization Of Migration Process And Selection Of Migration Destination Of Carrier Migration In C-RAN

C-RAN,the new generation of radio access network,solves the shortcomings of the traditional radio access network,which are high costs for construction and operation,difficult upgrading and low resource utilization.The users' growing demand for communication traffic can be met by it.Carrier migration,an important technology for C-RAN,improves the performance of C-RAN by sharing the resources of different centralized baseband pools of the baseband pool system.Its essence is to migrate the virtual base station of the carrier.The research on carrier migration is of great significance to promote the wide application of C-RAN and to give full play to the advantages of C-RAN in practical application.Thus,the optimization of carrier migration process is firstly focused on this thesis to improve the migration performance.Secondly,the selection of migration destination is studied to optimize the multiple migration indictors at the same time.The major achievements and contributions are outlined as follows:(1)As a result of optimizing the carrier migration process,an improved carrier migration method based on the prediction of memory pages' rewriting probability is proposed.Based on the current carrier migration process,the improved method ameliorates carrier's memory migration that limits the migration performance by introducing a prediction process for memory pages' rewriting probability.In order to get the most accurate forecast result,the principle of time locality and spatial locality of carrier's memory calling are taken into account in the prediction process.Those memory pages of which the rewriting probability are greater than the threshold value are transferred in the later iterative migration phase.The migration performance is enhanced by reducing the repeated duplication of some memory pages.And the proposed method is verified by simulation to have better migration performance.(2)For the choice of baseband pool for carrier migration,a selection approach of multi-objective optimization based on conflict equilibrium is proposed.In order to make the carrier migration more meaningful,the simultaneous optimization of three conflicting targets,which are the service's quality of migrated carrier,the baseband pool system's power consumption and the energy consumption of the carrier migration,are considered by the selection approach.The incremental power consumption of baseband pool systems is proposed to measure the degree of optimization of the power consumption of the baseband pool system.And a selection model for migration destination of multi-objective optimization is established.Meanwhile,by transforming the traditional TOPSIS algorithm's configuration method of weight and calculation method of similarity,an upgraded TOPSIS algorithm based on dynamic objective weight and equalization value of conflict is put forward to solve the selection model.And the simulation results show that the proposed selection approach behaves better in balancing the conflict between different goals and simultaneously optimizing the multiple objectives.