Beacon Scanning Optimization for Fast-Roaming over 802.11 Networks

Translated Titles



Joseph C. Mushi

Key Words

指示掃描 ; 認證 ; 重構 ; 快速漫遊 ; beacon scanning ; authentication ; re-association ; fast-roaming



Volume or Term/Year and Month of Publication

27卷5期(2005 / 10 / 01)

Page #

123 - 126

Content Language


Chinese Abstract

切換時延是由三種主要的移交過程造成的,即指示掃描,認證和重構。在這三種過程中,指示掃描造成的延時最為嚴重,這種時延為時間的定時製造了難度以至於出現快速漫遊。這個掃描的定時超前於移交,然而由於無線電信號不可預測的快速變化,802.11 station可能利用移交的時間使用過時的信息。另一方面手動掃描過程的定時需要延遲到一點,在這一點當前的接入點開始惡化,可是不能保證在適當的時間內完成移交。分析了不同作者對於減小掃描時間所作的貢獻,同時提出了802.11 NIC合適的定時時間來啟動掃描,可以解決以上難題。

English Abstract

Handoff latency is due to threemajor handover processes namely beacon scanning, authentication and re-association. Out of these three processes, beacon scanning has observed to impose a significant delay, which leads to a big challenge on how to schedule this event so as to favor fast-roaming. The scanning could be scheduled far in advance of handover, however there's a risk of 802.11 stations (STA) to use out-of-date information by the time of handover due to unpredictable rapid change in radio signals. On the other hand scanning process could be scheduled to delay tapoint where signals from current access point (oAP) start deteriorate, though there's no guarantee to complete handover processes in appropriate time. This paper analyzes different authors' contributions to minimize scanning delay and proposes when should 802.11 NIC be scheduled to initiate beacon scanning to resolve the above tradeoff.

Topic Category 基礎與應用科學 > 資訊科學
社會科學 > 管理學