Research On LTE Handover Technology Based On OPNET

During the development of wireless mobile communication networks,the emergence of HetNet can solve the problems of partial coverage and deep coverage of the networks.These problems caused by the growth of data services and the unbalanced construction costs.In the LTE system,Small Cell technology can effectively solve problems such as edge local coverage and indoor depth coverage.However,the different deployment scenarios and coverage of base stations in HetNet,which cause the handover problems between the Macro Cell and the Small Cell.We research the handover problems in the single layer co-frequency networks and the bilayer HetNet fill blind scenario.First of all,we introduce the technology and analyze research status of Small Cell.Then,we describe the theoretical knowledge of network architecture and the handover technology of single-layer networks and bilayer HetNet.We mainly study the following two aspects by using OPNET.Firstly,in a seven-cell single-layer co-frequency network,we use S1 and X2 interface,make a handover decision by three events A3~A5 and then conclude a comprehensive assessment of the network performance combined relevant indicators.Secondly,in the case of a bilayer Het Net fill blind scenario,we use X2 interface and make a handover decision by A3 event.First of all,we analyze the influence of network when high-speed users of Macro station make a handover.Then,we analyze whether the network could meet the real-time voice service requirement when three different speed users to make a handover.Finally,we improve the handover decision strategy based on speed classification,service type,service quality and other factors of users.Similarly,we make a comprehensive assessment using the corresponding indicators.Simulation has showed follow results.In a single-layer co-frequency network scenario,the handover performance of the X2 interface is better than the S1 interface in terms of handover delay and throughput,and the A3 handover decision event is more applicable in the co-frequency handover.In the case of bilayer HetNet fill blind scenario,the improved handover strategy significantly promotes the overall system performance.