IEEE 802.11無線區域網路(Wireless Local Area Networks, WLAN)是目前國內通訊領域極具份量的一項產業。隨著個人手持裝置（PDA、Smart phone）、筆記型電腦…等消費性電子商品愈益輕薄化，以及近年來提供無線上網之公共場所驟速增長，如：捷運站、辦公大樓、學校，使得802.11無線網路之使用普及率大幅上升。不過，802.11系統因使用頻帶（2.4G或5.2G頻段）、通訊環境（通常為室內）及傳送功率等限制，導致實際網路通信量並不如規格內容所預期。整體效能評估上最令人詬病的仍是基地台（Access Point, AP）與其用戶（Station, STA）之間的通訊距離、傳輸可靠性、傳送速率…等問題。
本論文的目的即針對 IEEE 802.11 a/b/g系統，研究開發可延伸基地台服務範圍及縮短單躍（Single Hop）的傳輸距離，進而提高通訊品質、傳輸速率的技術及系統設計。本論文研究構想為引進無線橋接器（Wireless Bridge , WB）作為AP及STA間之中繼站（Repeater），其功效不祇延伸AP之涵蓋範圍，並可因STA與WR或WR與AP間的傳輸距離縮短而提高單躍（Single Hop）接收訊號品質與傳送速率（Data Rate），獲致整體通信效益並提升系統傳輸通信量。

Nowadays, IEEE 802.11 wireless local area networks (WLAN) related product plays an important role in the domestic communication industry. The huge utilization was accomplished with thin and light designs of consuming electronic products sold popularly and wide distributions of 802.11 hot spot. However, WLAN systems usually offer a low throughput due to several constraints on license band usage（only 2.4GHz and 5 GHZ）、communication environment （indoor） and transmission power. The mayjor cause, long transmission distance, can also lead to signal fading drastically and poor communication reliability.
The purpose of this thesis is to study and develop a way to extend the communication range of AP and improve the system throughput. The conceptual idea is to induce a novel device, called Wireless Bridge (WB), WB plays as a normal STA associated with Access Point（AP） and also a repeater placed between AP and all other STAs. From shortening the communication distance of single hop will enhance transmission rate and the quality of signal. The benefits we can get against such design are extending AP’s coverage, improving the system throughput, etc

[1]. IEEE, ”Wireless LAN Medium Access Medium Access Control(MAC) and Physical Layer (PHY) specifications.” IEEE Standard 802.11, June, 1999.
[2]. O’REILLY, ‘802.11 Wireless Networks: The Definitive Guide, Second Edition’, April 2005.
[3]. IEEE Standard for Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications Amendment 4: Further Higher Data Rate Extension in the 2.4 GHz Band, (802.11g), June. 2003
[4]. The CMU Monarch Projects Wireless and Mobility Extensions to ns. URL: http://www.monarch.cs.cmu.edu/, 2000-04-25, work in progress.
[5]. Network Simulator—NS2, Univ. California, Berkeley, CA, 2004.
[6]. J. Yee and H. Pezeshki-Esfahani, “Understanding wireless lan performance trade-offs.” in CommsDesign.com, Nov. 2002.
[7]. S.-C. Wang, Y.-M. Chen, Tsern-Huei Lee ,and A. Helmy, “Performance evaluations for hybrid IEEE 802.11b and 802.11g wireless networks.” in IPCCC, April 2005.
[8]. T. Rapppaport, Wireless Communication: Principles and Practice. Prentice-Hall, 2002.
[9]. Jui-Chi Hsu, Design of Non-transparent Wireless Bridge for IEEE 802.11 WLAN, 2005.
[10]. Huazhi Gong; Nahm, K.; Jong Won Kim, “Distributed Fair Access Point Selection for Multi-Rate IEEE 802.11 WLANs” in CCNC 2008.
[11]. Arunesh Mishra; Eric Rozner, “Exploiting Partially Overlapping Channels in Wireless Networks: Truing a Peril into an Advantage” in IMC 2005.