基于动态Cache 的无线局域网快速切换算法.pdf

35 2 2009 1 Vol.35 No.2 Computer Engineering January 2009 ·· 2009 A TP301.6 Cache 1,2 1,2 1,2 (1. 210096 2. 210096) BSS Cache Cache IEEE 802.11 Fast Handoff Algorithm for WLAN Based on Dynamic Cache NI Wei-guo1,2, DONG Yong-qiang1,2, ZHANG Cong1,2 (1. School of Computer Science and Engineering, Southeast University, Nanjing 210096; 2. Key Laboratory of Computer Network and Information Integration(Southeast University), Ministry of Education, Nanjing 210096) AbstractReal-time voice service is negatively influenced by the delay and jitter caused by Basic Service Set(BSS) handoff. This paper proposes a new handoff triggering mechanism with dynamic threshold, which is sensitive to signal variance while eliminating the Ping-Pong handoff effect. In order to achieve higher network performance, a fast handoff algorithm based on dynamic Cache is presented. Experimental result demonstrates that the algorithm effectively reduces handoff latency and outperforms other algorithms based on static Cache. Key wordsWLAN; IEEE 802.11 protocol; fast handoff IEEE 802.1 1b/g[1] (WALN) Cache WLAN SIP (active scan) (Station)AP BSS(passive scan) [4] [5-7] BSS(Basic Service Set) Cache BSS 1 BSS 2 1.1 Station AP