Prevent-Scan: A Novel MAC Layer Scheme For The IEEE 802.11 Handoff

Wireless networks, specifically those based on the IEEE 802.11 standard (Wi-Fi), are experiencing rapid growth due to their low cost and high-speed connectivity. To cover larger areas, many AP's are required which need the use of handoff between different AP's. Therefore, handoff latency has become essential issue in wireless LANs. This delay affects the quality of real-time applications like VoIP. In this paper we evaluate the performances of the Prevent-Scan solution. This technique is an improved fast handoff mechanism developed to minimize the overall handoff latency and enhance the quality of service (QoS) for multimedia streams. The Prevent-Scan evaluation is performed by using our new WHand-Sim simulator. We prove that this technique decreases handoff latency significantly and achieves both fast and smooth handoff that multimedia applications entail.