An IEEE 802.11 Fast Reassociation and Pairwise Transient Key establishment Based on the Dynamic Cluster Method

Abstract

Wireless local area network (WLAN) based on the IEEE 802.11 technology becomes popular in recent years. However, the latency of the handoff process in WLAN is very large such that large handoff gap may bring excessive jitter in multimedia applications, e.g., voice over IP. Therefore, many researches have made efforts on how to fast handoff. In this paper, we propose an accelerated handoff mechanism in which two methods are involved: (1) Pairwise master key security association (PMKSA) distribution based on the dynamic cluster selection and transition and (2) fast reassociation with the pairwise transient key security association (PTKSA) establishment. Access points (APs) that are cluster members can cache PMKSA of client stations (STAs) in advance to reduce the 802.1X authentication delay. The former method is proposed to assure that STA stays within a cluster. In the latter, the fast reassociation with the PTKSA establishment process incorporates four-way-handshake into the IEEE 802.11 reassociation process to actively raise handoff process and to further accelerate handoff process.