Fast IP Handoff Support for VoIP and Multimedia Applications in 802.11 WLANs

Abstract

Wireless LANs (WLANs) have edged into numerous mobile and wireless users' daily experience worldwide as a mainstream connectivity solution for a broad range of applications. Even though WLANs offer very high channel bandwidth, they show long network-layer handoff latency. This is a restraining factor for mobile clients using interactive multimedia applications such as voice over IP (VoIP) or video streaming. This paper presents an 802.11-dependent fast IP handoff method which quickly restores IP connectivity for mobile clients running next generation WLAN applications such as Voice over WLANs (VoWLAN). This method outperforms other existing proposed IP mobility solutions in 802.11 WLANs as verified from real performance testing, while introduces insignificant compulsory additions to the existing 802.11 wireless LAN framework.

Minimum-Cost Data Delivery in Heterogeneous Wireless Networks

“…The exact handoff delay depends on the handoff strategy and the network-traffic condition. Typical handoff delays among the three different types of APs are listed below: The handoff delay between WiFi and 3G is around 400 ms [32]; the handoff delay between 3G cells is usually less than 100 ms [33]; and the handoff delay between WiFi cells is less than 100 ms [34]. Although without known experimental results, we assume that the handoff delay of WiMax is similar to that of WiFi, i.e., 100 ms between WiMax cells, 100 ms between WiMax cell and WiFi cell, and 300 ms between WiMax cell and 3G cell.…”

A seamless handoff scheme for IEEE 802.11 wireless networks

“…In Refs. [22,23], the authors extended IEEE 802.11f IAPP protocol too, and named it as IP-IAPP. They use BSs to serve as mobility agents.…”

“…In this section, our proposed new handoff scheme is evaluated using 'The Network Simulator ns-2.33' [26]. The number of packet losses, the channel probing latency, authentication and association latency and MIP handoff latency of our proposed handoff scheme are compared with traditional handoff method and IP-IAPP [22] method.…”

WiFi architecture for traffic control using MIPv6

“…This handover latency resulting from standard MIP procedures, namely movement detection, new Care of Address (CoA) configuration and Binding Update, is often unacceptable to real-time traffic such as Voice over IP (VoIP). Reducing the handover latency could be beneficial to non-real-time, throughput-sensitive applications as well [2].…”

“…During handover, there is a period during which the Mobile Node (MN) is unable to send or receive packets because of link switching delay and IP protocol operations. This handover latency resulting from standard MIP procedures, namely movement detection, new Care of Address (CoA) configuration, and Binding Update, is often unacceptable to real-time traffic such as Voice over IP (VoIP) [2].…”