Selective Channel Scanning for Fast Handoff in Wireless LAN Using Neighbor Graph

摘要

Handoff at the link layer 2 (L2) consists of three phases: scanning, authentication, and reassociation. Among the three phases, scanning is dominant in terms of time delay. Thus, in this paper, we propose an improved scanning mechanism to minimize the disconnected time while the wireless station (STA) changes the associated access points (APs). According to IEEE 802.11 standard, the STA has to scan all channels in the scanning phase. In this paper, based on the neighbor graph (NG), we introduce a selective channel scanning method for fast handoff in which the STA scans only channels selected by the NG. Experimental results show that the proposed method reduces the scanning delay drastically.