Multiple trigger initiated handover execution in WiMAX networks

Handover in mobile networks considers Quality of Service (QoS) parameters such as signal strength, signal to interference noise ratio (SINR), bit error rate (BER) etc. for its initiation. Handover considering signal strength is a basic scheme in mobile networks. Considering only signal strength is not ideal for WiMAX networks, which has stringent QoS requirements. Signal strength along with hysteresis and threshold serves as an accurate handover mechanism in WiMAX network. But it is necessary that selected target base station have enough capacity to handle the data of mobile station. Moreover considering the mobility of the users in vehicular environments, user velocity must also be considered before handover execution to avoid unnecessary handovers. In this paper we propose a multiple trigger initiated handover execution which considers the signal strength along with hysteresis and threshold, the estimation of free capacity and dependence on mobile velocity during the handover process. We evaluate our proposed scheme in Opnet Modeler simulator and its performance is verified.