DEVELOPMENT OF A MODIFIED HANDOVER DECISION ALGORITHM FOR INTER-FEMTOCELL HANDOVER IN LONG TERM EVOLUTION NETWORK

DEVELOPMENT OF A MODIFIED HANDOVER DECISION ALGORITHM FOR INTER-FEMTOCELL HANDOVER IN LONG TERM EVOLUTION NETWORK

Abstract:

The present day cellular network faces an increasing problem of providing capacity and coverage for users. The Long Term Evolution (LTE) system provides a number of ways in vi mitigating these problems among one of which is the deployment of femtocell technology. The femtocell is an example of a heterogeneous network which comprises of different layers of different cell sizes ranging from microcell, picocell and radio relay nodes.The femtocell is the least in size of network densification and is deployed at indoor environments. Deployment of femtocells is not without its challenges, among which is frequent handover. The problem of frequent handover arises from the nature of the femtocell owing to its unplanned deployment, small cell size and access control techniques. Thefrequent handovers in femtocells reduces the user‟s call quality. This research work addressed thefrequent handover problem by considering the users motion as it changes, using the Link Expiration Time (LET) method and theinter-femtocell handover scheme of Rajabizadeh and Abouei in order to accommodate mobile users whose speeds are varying.This scheme was designed to establish a communication link with the nearest femtocell when the users speed undergoes an abrupt change. The developed handover scheme was implemented using a developed Graphical User Interface (GUI) in MATLAB and its performance was evaluated with the traditional handover scheme based on the number of handovers and the time interval between handovers as performance metrics. It was observed from the results obtained that the developed handover scheme performed fewer handovers in comparison to the 3GPP handover schemewhich was better by 24.17%.

DEVELOPMENT OF A MODIFIED HANDOVER DECISION ALGORITHM FOR INTER-FEMTOCELL HANDOVER IN LONG TERM EVOLUTION NETWORK