Abstract— Handoff mechanism is an important issue in wireless networks since the incurring interrupts may be unsatisfactory to support fast real-time services with stringent Quality of Service (QoS) requirements such as Voice over IP (VoIP). In this paper, we propose a novel seamless handoff scheme for IEEE 802.11 networks by equipping Access Points (APs) with multiple Wireless Network Interface Cards (WNICs), one of which is set to operate for normal transmission and the others listen or receive STAtion(STA) packets for signal measurements. We place the handoff decision in the AP and transmit management frames between APs using Inter Access Point Protocol (IAPP). The proposed scheme is compatible with the existing STAs without any hardware modifications. The NS-2 simulation results demonstrate that our proposed scheme can reduce layer-2 handoff interrupt time effectively.

Index Terms— IEEE 802.11, Layer 2 handoff, seamless handoff.

Y.-C. Chan and D.-J. Lin are with the Department of Computer Science and Information Engineering, National Changhua University of Education, Changhua 500, Taiwan (e-mail: ycchan@cc.ncue.edu.tw, achin178@gmail.com).

Cite: Yi-Cheng Chan and Dai-Jiong Lin, " The Design of an AP-Based Handoff Scheme for IEEE 802.11 WLANs," International Journal of e-Education, e-Business, e-Management and e-Learning vol. 4, no. 1, pp. 72-76, 2014.