針對上行頻寬索取與傳輸機制在行動WiMAX系統

Abstract

在這篇論文中，我們介紹了行動WiMAX的物理層和媒介接取控制層。而行動WiMAX引用了IEEE 802.16d-2004和IEEE 802.16e-2005兩樣技術標準當參考。我們亦架構了Mobile WiMAX系統層級的模擬工具，且實現上行頻寬索取機制。 藉此模擬系統，我們完成了一套完整的上行傳輸機制效能分析，並實現了四種最通用的排程演算法。最後，我們更進一步的將不同的排程演算法在單一資料形式與混合資料形式的環境下模擬其效應，以探討不同演算法各自之間在傳輸速率、服務品質控制、以及系統容量等方面的優缺點，並觀察各自最適合的使用時機。這四種排程演算法包含了Early Deadline First (EDF)、Proportional Fair (PF)、Maximum CINR (MaxCINR)、和Round-Robin (RR)。另外，我們提出了一套時間延遲限制的概念，可應用於非即時傳輸服務(如FTP)的排程演算法。這個概念主要是將最小傳輸速度的限制，針對每一個封包，將其轉化為時間上的限制，不但提高了排程器的設計簡便性，也比單純用傳輸速率來當排程的指標的方法，有更好的效能表現。

In this thesis, we introduce the PHY and MAC of Mobile WiMAX, which applies the IEEE 802.16d-2004 and IEEE 802.16e-2005 standard as reference. Then, we build up a system-level simulator and a signaling control plane for the uplink bandwidth request Mechanism for the purpose of getting a complete uplink performance analysis and investigating the advantages and disadvantages of different scheduling algorithms, including Early Deadline First (EDF), Proportional Fair (PF), Maximum CINR (MaxCINR), and Round-Robin (RR). We further discuss the capacity and QoS issue in terms of different traffic type in both single traffic and mixed traffic environment. Through the simulation result, the uplink MAC throughput in Mobile WiMAX is clearly revealed, and several common scheduling algorithms are implemented to get a complete uplink performance analysis. In addition, a soft delay bound (SDB) method is used in order to properly schedule non-real-time service. It transforms the minimum rate into time domain delay bound. It facilitates the scheduler design and performs better QoS failure rate than just using data rate as the QoS indicator.