Mobility Management For SDN-Based Heterogeneous Networks

In recent years,the mobile communication technology is rapidly increasing and it is foreseeable that the trend will continue in the future.The exponentially increasing data traffic,addition in types of terminals,and enhancing diverse service scenarios are the big challenges for future mobile networks.According to several studies,the demand for data traffic will likely increase 10,000 fold by 2025.In order to achieve high capacity and data rate,the current cellular network is unable to support this situation.With the increase of data traffic demand,communication industries are planning to deploy heterogeneous networks(HetNets)with high number of small cells in mobile network to provide high capacity and data rate,throughput,and low latency which are the basic requirements for next generation network.It will be an increasingly dense and complex network system.This problem generally arises due to management of the system.In this research,the issues of mobility management are addressed in HetNets.In this thesis we introduced the concept of software defined networking(SDN)in HetNets to reduce the problems related to handover management and improve the user mobility.In SDN,the control plan is decoupled from data plan to achieve high flexibility and performance,therefore it will be easy to manage the whole system from centralized controller.The proposed SDN-based cell selection scheme improves the user's dynamic mobility and is designed to detect the optimal cell for user equipment(UE)handover.The centralized controller collects all the statistic information about the cells and user location from UE.The controller saves the user location and cells information to select the most optimal cell for UE handover based on the movement direction of the user's,RSS value,cell load,and sojourn time.Linear programing(LP)is used to reduce the calculation during cell selection.Additionally,the proposed algorithm for cell selection is compared with traditional cell selection scheme used in long term evolution(LTE).The results show that the proposed algorithm in software defined heterogeneous network(SDHN)reduces the problems related to handover management such as frequent handovers,unnecessary handovers and overhead signaling among UE and cells.The overall system delay can be decreased which is the main requirement of next generation network,and the performance of the system can be enhanced.,while maintaining an easily manageable structure of the whole system.Moreover,the simulation results show that the performance of the system is enhanced in terms of handover management and cell load.The problems related to heterogeneous network management,such as,unnecessary handover,frequent handover and signaling overhead are reduced to improve the quality of service.