Research And Realization Of LTE Femtocell Handover Algorithm

Abstract: As home base station (Femtocell) formally is integrated into the LTE net framework,Higher technique is required for LTE handover performance. Advanced self organization networkmeasurement mechanism, advanced handover decision algorithm and advanced handover accessalgorithm are proposed to solve the problem that difficult handover between Femtocells andMacrocells, high rate of Radio Link Failure(RLF), complex access into Femtocells and loss ofwireless resource allocation.In the procedure of Self Organization Network(SON) single step execution algorithm, anadvanced handover decision algorithm reasonablely statistics network feedback results, then todetermine how to adjust the handover decision parameters: Time to trigger (TTT), HandoverMargin (HM), Maximum allowable Speed of Femtocell(MSF). As measurement mechanismprovides data support to the advanced decision algorthim, advanced SON measurementmechanism is proposed in this thsis. It bases on the conventional one, is adaptive to the SONsingle-step execution algorithm. It also bases on the most extensively and practically LTE internalhandover judgment event (A3event), combined with the characteristics of the measurementsystem, the algorithm will complete the latest configuration parameter values, to realize adjust thehandover parameters dynamically. The advanced handover access algorithm mainly forFemtocell’s terminal capacity limited control, to prevent handover failed, due to the excessivenumber of users. It is important partial of radio resource control.Simulation which runs under three different scenarios of Femtocell handover, proves thatinnovations work well to decrease the failure rate of handover compared to the existing handovermechanism. Finally, it realized the Femtocell handover software system base on the existed LTEsoftware protocol stack architecture. Handover on software platform verifys the reliability andusefulness of mechanism.