Signal Strength based Scanning Considering Free Capacity for Handover Execution in WiMAX Networks

In mobile networks handover is initiated when there is change in network Quality of Service (QoS) parameters such as signal strength, signal to interference noise ratio (SINR), bit error rate (BER) etc. 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 not necessary that selected target base station have enough capacity to handle the data of mobile station. In this paper we propose a multiple trigger initiated handover execution which considers the signal strength along with hysteresis and threshold during scanning phase and the estimation of free capacity during handover execution phase. We evaluate our proposed scheme in Opnet Modeler simulator and its performance is verified.