Multichannel Virtual Access Points for Seamless Handoffs in IEEE 802.11 Wireless Networks

Abstract

Abstract-Within IEEE 802.11 Wireless Local Area Networks (WLANs), client stations can move freely, but because of the short range of their Access Points (APs), they usually need to reassociate with different APs to continue to communicate. When changing APs, a client station starts a process known as a handoff that can take up to 2 seconds, which is too long for real-time applications such as Voice over IP (VoIP). Various solutions have been proposed to change or improve the client behaviour when doing a handoff. Previously, we proposed the idea of Virtual Access Points (VAP) implemented on APs in which a client station changes APs without disrupting its current communication. Based on this new concept, we have developed a solution called Multichannel Virtual Access Points (mVAP) to take advantage of APs operating on multiple channels. We have implemented mVAP using PACMAP, a tool for packet manipulation, and evaluated its performance. Our results show that mVAP is a new efficient technique for seamless handoffs without performance degradation.

ARNAB: Transparent Service Continuity Across Orchestrated Edge Networks

“…Later, a multichannel vAP handoff extension of [12] is proposed in [13]. In this solution, APs operate in different channels and communicate with each other to manage client mobility.…”

Mejora de la Calidad en Redes WLAN Coordinadas a través de SDWN

“…Para ello se plantea un segundo trabajo [4] en el que se define un protocolo distribuido entre los AP para informarse de la presencia de las diferentes STA. De nuevo está basado en el uso de LVAP y utiliza un único canal Wi-Fi.…”

The Design of an AP-Based Handoff Scheme for IEEE 802.11 WLANs

“…For passive scanning, a STA attempts to listen beacon frames which APs periodically transmit in each channel. For an active scanning, a STA broadcasts a Probe Request frame in each channel, and then waits a period time called MinChannelTime for Probe [7], [8] has been proposed recently. In their methods, they proposed to get rid of mobility management in mobile stations and put it entirely inside the network of interconnected access points.…”

“…To improve the scanning process is the most common strategy such as prescan [4], selective scan [5], and use RTS frame for scanning [6]. The concept of Virtual Access Points (VAPs) [7], [8] are also proposed. All these schemes can reduce the handoff latency, however, the interruption time of communication is still too long.…”