Using Chain of Mobile Access Gateway to Reduce Delay for PMIPv6 Protocol Applied in WLAN

Wireless LAN controller (WLC) is used to manage and control Access points (APs) in Wireless local area network (WLAN). Proxy mobile IPv6 (PMIPv6) protocol supports network-layer mobility in WLC based WLAN. However, it introduces extra delay in delivering packets from the APs to the WLC. We use Mobile access gateway (MAG) chain to reduce packet delay. The handoff delay and packet delivery delay under the proposed scheme are derived, based on which we formulate the delay minimization problem whose solution leads to the optimal MAG chain length. Numerical analysis results indicate that the proposed scheme outperforms the existing scheme in terms of delay in the case when the delay between Local mobility anchor (LMA) and WLC is relatively greater than the delay between two neighboring WLCs. The proposed scheme is able to reduce packet loss resulting from the traditional handoff procedure introduced in the PMIPv6 protocol and that due to delay limitation.