Hybrid predictive base station (HPBS) selection procedure in IEEE 802.16e-based WMAN

According to the mobility framework of IEEE 802.16e, a mobile station (MS) should scan the neighbouring base stations (BSs), for selecting the best BS for a potential handover activity. However, the standard does not specify the number of BSs to be scanned leaving room for unnecessary scanning. Moreover, prolonged scanning also interrupts data transmissions thus degrading the QoS of an ongoing connection. Reducing unnecessary scanning is an important issue. This paper proposes a scheme to reduce the number of BSs to scan (thus improving the overall handover performance). Simulation results have shown that this hybrid predictive BS selection scheme for potential scanning activities is more effective than the conventional IEEE 802.16e handover scheme in terms of handover delay and resource wastages.