IEEE802.17彈性分封環乏晰公平控制機制之研究

Abstract

近幾年來，數據訊務的激增持續挑戰現存網際網路架構的負荷上限。為了支援日益增加的寬頻多媒體服務的需求以及傳輸服務品質(Quality of Service)的需要，IEEE在標準802.17中提出適用於都會區域網路(Metropolitan Area Network)的彈性分封環(Resilient Packet Ring)架構。不同於現存的同步光纖(SONET)環狀網路以及同步數位階(SDH)網路，彈性分封環並不使用分時多工(TDM)技術傳輸，而傾向於設計出環狀的高速封包傳輸網路。若是要妥善管理此一環狀網路，需要有效率而實用的公平控制機制，方能使得網路有效運用而不致於發生壅塞。在本篇論文中，我們提出一套適用於此一環狀網路的乏晰公平控制機制，此一機制運用模糊推論系統(Fuzzy Inference System)偵測可能發生的網路壅塞問題，並透過適應性的網路資源配置避免此一壅塞問題的發生。在模擬結果中可以發現，相較於原有的公平控制機制，此一乏晰公平控制機制具有較好的表現。因此乏晰公平控制機制對於彈性分封環而言，是一種有效且可行的公平控制方法。

In recent years, the highly increasing volume of data traffic is challenging the capacity limit of existing Internet infrastructures. To support the growing demands of the broadband multimedia services and the requirement of the quality of services, the Resilient Packet Ring (RPR) is defined for the Metropolitan Area Network (MAN) in the IEEE 802.17 Standard. To different from the existing synchronous optical network (SONET) or synchronous digital hierarchy (SDH) network, the RPR does not use time division multiplexing (TDM) transport technology, it is intended to enable the creation of high-speed networks optimized for packet transmission in ring topologies. To manage the network efficiently, an effective and feasible fairness control mechanism is indispensable. Thus the network can be operated effectively without congestion. In this thesis, we propose a fuzzy fairness control mechanism (FFCM). The FFCM uses the Fuzzy Inference System (FIS) to detect and prevent the congestion problem by allocating the network resources adaptively. In the simulation results, the performance of the FFCM is much better than the performance of the fairness control mechanism defined in the standard. Consequently, we can conclude that the FFCM is an effective and feasible fairness control mechanism.