以集中式協調為基礎的合作網路中選取合作夥伴之機制

A Partner Choosing Algorithm in Polling-based Cooperative Networks

陳瀅心(Ying-Shin Chen)

指導教授 ： 陳志成

國立清華大學/電機資訊學院/資訊工程學系/碩士(2007年)

https://doi.org/10.6843/NTHU.2007.00355

摘要

近年來，隨著無線網路的廣泛使用，各種應用程式日新月異，對無線網路的需求更是與日遽增。但相對於有線網路，由於無線訊號的不穩定性，在無線網路中提供穩定的服務是很重要的議題。以最被廣泛使用的無線區域網路技術IEEE802.11為基礎，此篇論文針對無線訊號的不穩定性提出可增進效能的方法。

目前已有一些不同形式的多元性的使用來對抗無線網路訊號無法預測的波動。其中，空間上的多元性是最多人使用的。此論文主要利用空間多元性的優點提出新的增進802.11集中式網路效能的方法。網路協調者利用位置資訊來分配幫手給各使用者，如此一來即使遭遇訊號不良的情形也可以經由幫手完成資料的傳遞，所提出的方法不僅提高資料的傳送量，並可平均分配幫忙其他使用者的工作量到所有使用者。模擬的結果亦支持所提出的方法可以達到更高的效能。

關鍵字

合作網路 ； 選取合作夥伴 ； 空間多元性 ； 集中式協調系統

並列摘要

Quality of service (QoS) in multimedia applications has become an important issue. Due to the lack of radio link stability, QoS in wireless networks is more challenging than that in wired networks. This thesis provides an enhancement for the most widely deployed wireless
LAN technology, IEEE 802.11. Because of the suffering from severe variation in channel condition, some forms of diversity have been proposed to combat the effects of fading. Spatial diversity is one of the well-known forms of diversity. In this thesis, a solution to improve the performance of the polling-based Point Coordination Function (PCF) in 802.11 via user spatial cooperation diversity is proposed. Wireless stations are assigned partners so that they can overcome the fluctuant channel conditions. The proposed method not only increases users’ throughput, but also balance the load of help among all wireless stations. The use of spatial diversity has critical influence on the performance of PCF. The simulation
results show that the proposed method outperforms the original polling-based system no matter in throughput, delay, or packet loss ratio. The solutions proposed in this thesis are fully complied with IEEE 802.11. By extensive simulation, it has been shown that the proposed solutions are both efficient and practical.

並列關鍵字

Cooperative Networks ； partner choosing ； spatial diversity ； IEEE 802.11 PCF

參考文獻

[1] J. Laneman, D. Tse, and G. Wornell, “Cooperative diversity in wireless networks: Efficient

[3] A. Sendonaris, E. Erkip, and B. Aazhang, “User Cooperation Diversity–Part I: System

Description” and “User Cooperation Diversity–Part II: Implementation Aspects and

[4] A. Sendonaris, E. Erkip, and B. Aazhang, “Increasing uplink capacity via user cooperation

[5] A. Ganz, A. Phonphoem, and Z. Ganz, “Robust superpoll protocol for ieee 802.11