Achieving Low-latency Handoff through Two-Stage Authentication in WLAN

IEEE 802.11 WLANs are widely deployed nowadays. While a mobile device is moving around it may need to execute a handoff that usually requires authentication. This results in a long processing delay and leads to degradation of quality of service to the mobile device. Existing authentication methods such as AAA and IEEE 802.1x mechanisms are unable to accommodate low-latency handoff. In this article, we propose a two-stage authentication scheme that allows a mobile device to perform authentication through a fast handover protocol and obtain a temporary certificate from the targeted access point before roaming to the new domain, so that it can resume the authorized access quickly by using the temporary certificate. The mobile device must perform re-authentication to complete the normal authentication process within a short period; otherwise its authorized access will be terminated. Simulation results show that our two-stage authentication scheme significantly reduces the handoff latency and packet loss during the handoff process.