The Research And Implementation Of Fast Cell Handover Technology Based On Special-using Small LTE Base Station

Long Term Evolution(LTE)mobile communication technology,as the main specification of the fourth-generation cellular mobile communication,has occupied a large share of commercial communication in recent years.The fourth-generation cellular mobile communication provides a wide range of services and high service quality in mobile broadband services.In addition,its application in the field of private network communications such as public safety has also been widely spread.Special-using small LTE base station is a small micro LTE base station system that appears with the advent of private network communications.This thesis is based on the research on the characteristics of visual service seamless handover in the communication system construction requirements in the field of public safety.By analyzing the source of delay caused by cell handover behavior,the signaling process level is improved.The fast cell handover method of communication is implemented in on a special-using small base station platform.In this paper,the research and implementation of fast cell handover technology based on special-using small LTE base stations includes the following:1.The previous generation of mobile communication systems and operators' LTE live networks to implement cell handover methods are summarized.It introduce the composition of the LTE system architecture and the introduction of the protocol stack of the LTE system.It focuses on the analysis of the functions of the RRC layer and the key processes of the RRC layer as the theoretical basis for the design,development,and implementation of the new method.2.The mobility management mechanism are summarized.For the S1 interface-based handover,based on the 3GPP common protocol,analyze each of the key steps involved in the handover process one by one,lead to the key issues to be solved in this article,discuss the reasons of handover delay via system-level simulation.Then the signaling flow and optimization scheme of the fast cell handover method based on the S1 interface are designed.3.Aiming at the problem to be solved,based on the special use scenario of the dedicated small base station,based on the BSC 9131 software and hardware development platform,the L3 layer overall framework design diagram and Low Layer Interface Manager module,UECC module,and S1 AP module are given.Based on the existing software architecture of the L3 layer,the function of cell handover is extended by writing function interface codes.In Chapter 4,the events and states of the finite state machine are used to explain that.Codes are compiled into an executable binary file and written into the BSC9131 platform,and it is made into a usable LTE base station by networking with the core network.4.A test plan is designed,and the setup of the double base station experimental environment is carried out and the core network networking process is performed.Through the capture of drive-test software and signaling analysis software during the movement of the user equipment between the coverage areas of two base stations,the completeness of the handover is reasonably analyzed,and the handover delay of the cell is counted according to the timestamp of the signaling,which is compared with the simulation result.The comparison is performed to verify the feasibility of the design ideas and implementation methods and the improvement of cell handover performance.5.Finally,the content of the full text is summarized,the deficiencies in the graduation design work are proposed,the follow-up work is prospected,and possible entry points and directions for further research are put forward.