Pre-coordination mechanism for fast handover in WiMAX networks

The most challenging research issue of investigating broadband wireless access (BWA) technologies is how to support mobility in WiMAX networks smoothly and seamlessly. It is essential that providing continuous services of multimedia streaming data when a mobile subscriber station (MSS) is across a boundary of a serving area to another one. Although the IEEE 802.16e standard is proposed to tackle this difficult problem, the disruption time (DT) of handover is still too long to overcome the maximum delay time of real-time services. To deal with this problem, this paper proposes a pre-coordination mechanism (PCM) for supporting fast handover in WiMAX networks. This goal is achieved by measuring the distance between the BS and the MSS and predicting the time of handover occurs, and thus pre-allocating available resources for handover usages. Simulation results show that the enhanced DT of handover can achieve approximately to 11 milliseconds. The proposed mechanism is fully compatible with the IEEE 802.16e standard.