Seamless handover for high velocity mobile station in WiMAX

IEEE 802.16e [1] standard supports mobile wireless communication. Handover schemes are considered especially. Hard handover is defined to be mandatory and it is a Break-Before-Make (BBM) procedure. The hard handover process pauses during handover operation, and it causes degradation in system performance when implemented in real-time application such as Voice over IP (VoIP) and Internet protocol Television (IPTV). However, the standard considers only the received signal strength although the velocity of mobile station is also an important factor because it makes handover delay. This paper proposes an improvement handover scheme for mobile WIMAX. The scheme depends on the velocity factor of mobile station and aims to reduce handover delay time and enhance the network resource utilization. The simulation result shows that the proposed scheme provides handover latency better than standard hard handover about 90%.