Research On Optimal Algorithms Of Dual Connectivity In 5G Heterogeneous Networks

At the early stage of 5G deployment,the non-Standalone(NSA)networking solution is one of the main deployment solutions for operators due to the cost.NSA networking can utilize the existing 4G network for access,and tackle the problem of insufficient coverage at the initial stage of 5G deployment.Dual connectivity as an access technology in NSA allows users to simultaneously connect with two base stations and use spectrum resources at two different frequencies and is also lower in cost than the carrier aggregation technology for large-scale deployment.This paper studies the algorithm for dual connectivity optimization on top of the standardized NSA networking.This paper makes a brief analysis and introduction to the different architectures of dual connectivity in data link layer,and conducts in-depth research and analysis on the system architecture and access strategy of Option 3,which uses the 4G core network along with LTE master base stations.When exploring access strategy,we found an abnormal phenomenon in the performance of edge users with dual connection.Our analysis shows the data control algorithm between the base stations is poor,especially under the TCP protocol.In this paper,the flow control algorithm targets the abnormal performance of edge users,and optimizes its traffic-scheduling mechanism as well as data request volume.It mainly introduces the calculation and comparison of the transmission quality between the base stations,and also allows the master base station to have a more precise grasp of the data transmitted to the secondary base station.In order to meet the demand of data transmission under TCP protocol,this paper studies and designs a new flow control architecture as well as its corresponding algorithm,which can calculate the expected transmission rates of two transmission paths in advance and select the one with the shortest transmission time.The data distributed for master base station is no longer placed in the same buffer with the data for secondary base station,thereby alleviating the inconvenience caused by the congestion control algorithm of the TCP protocol.The simulation results show that the performance of optimized algorithm using the NSA configuration in which 4G base stations as the access for control plane data and the 5G base stations for user plane data.The average transmission rate of the users,especially the edge user's transmission rate,is significantly improved,and the improvement is also remarkable on the performance of the users under the TCP protocol.This paper studies the dual connectivity access strategy and optimizes the flow control algorithm in dual connectivity.Moreover,it introduces a new flow control architecture and scheduling mechanism to ensure its performance under the TCP protocol.