A Location-Aware fast handover scheme for mobile WiMax networks

WiMax is the wireless metropolitan area network for broadband wireless communications. In IEEE 802.16e, the mobility support has been defined to handle the handovers for the continuity of the active services when the mobile stations move across the air interfaces of sectors. The overall handover process includes the scanning process to select the suitable neighbor base station as the target base station and the network re-entry process to establish the new connection with the selected target base station. Large delay to data transmission can be introduced based on the handover procedure specified in the IEEE 802.16e standard. In this paper, an improved handover scheme including the scanning and the network re-entry is proposed to reduce the interruption of the data transmission during the handover. The proposed scanning scheme is call location-aware scanning, which can reduce the scanning delay by reducing the number of the neighbor BSs to be scanned. The proposed network re-entry scheme is named as early transport CID update, which can reduce the latency incurred in the connection establishment by the earlier transport CID updating to allow the faster resuming of the ongoing applications. Simulation experiments have been conducted and the results show that the proposed handover scheme can significantly reduce the data transmission delay during the handover.