寬頻分碼多工接取系統提供服務品質下之新封包排程演算法

Abstract

因應未來個人行動通訊系統在確保服務品質前提下提供包括語音，影像與數據資料等寬頻多媒體服務的趨勢，本論文針對寬頻分碼多工接取系統提供多重服務型態下無線資源管理之領域進行研究。首先，以系統提供單一服務型態為出發點，推演至當系統提供多重服務型態時，得以系統負載為估計系統資源的重要指標。以此為依據，設計封包排程演算法在提供服務品質下安排使用者可用的系統資源與傳輸時間，進而增加系統使用效率。在考慮實際系統規劃與其他無線資源管理演算法：功率控制、軟式換手轉換及允入控制的互動下，根據使用者對服務品質的要求、所欲傳輸的資料量與延遲狀況，我們提出兩個封包排程演算法，一為以最大負載為基礎的封包排程，二為以實際負載為基礎的封包排程。這兩個演算法處理了封包資料的脈衝性問題與提供系統資源分配的方法，並在低複雜度、系統負載與動態調整的考量下，得以提供使用者較佳的服務品質與增加系統運輸量。本論文進而從平均封包延遲、系統運輸量、訊框遺失率與使用者對服務品質的滿意度等數據結果顯示演算法的效能。

Future personal mobile communication systems are expected to provide multimedia services including voice, data, and video to mobile users with guaranteed quality of service (QoS). In the thesis, the issue of radio resource management (RRM) for packet-based multimedia services in the wideband code division multiple access (WCDMA) system is investigated. A system resource measure based on the concept of system loading is derived first for both the single- and multiple-service scenarios. Then, two new packet scheduling algorithms are proposed to schedule the system resource to packet-switched data users so as to achieve high system resource utilization (throughput) with guaranteed soft QoS provisioning. The first method is called maximum loading-based packet scheduling (MLBPS) in which the resource allocation is based on the maximum allowable system load that guarantees the planned coverage. The method is very simple but may not have the best resource utilization. The other is called real loading-based packet scheduling (RLBPS). As implies by its name, the resource allocation is based on the real system loading at the time of scheduling. With iterative updating the real load and presumed system load that is used for resource allocation, better resource utilization can be obtained at the expense of larger system complexity. Both the proposed methods outperform the existing ones in terms of throughput, averaged packet delay and frame loss rate.