IEEE 802.16e 服務品質保證之 省電機制排程演算法

Abstract

本篇論文即根據此睡眠機制，針對非請求的頻寬分配(UGS)的服務、固定位元率(CBR)，提出一種排程演算法，目的既要達到服務品質保證(QoS)，即不違反延遲界限(delay bound)，又要達到省電，以及頻寬使用最大化。 此排程演算法根據比率單調排程(Rate Monotonic Scheduling)而設計，每個系統內的工作站都具有靜態優先權(static priority)，當工作站達到可以接受服務的條件，才可以進行服務，萬一超過一個工作站符合服務條件，則基地台會挑選優先權最高的工作站進行服務。另外，針對這個排程演算法，我們討論其允入控制(admission control)，先探討系統內多個工作站的可排性(schedulability)，再推導下一個系統可以允許進入服務的新工作站，其最小的封包抵達時間間隔(inter-arrival time)為多少。最後並將此演算法與其他方法做省電效能與系統吞吐量的比較。

This thesis focuses on the scheduling problem for CBR traffic with delay constraint in IEEE 802.16e broadband access networks. Multiple MSSs are considered in our work. In order not to violate the delay constraint, and maximize both the energy efficiency and bandwidth utilization, we propose a scheduling algorithm based on rate monotonic scheduling for CBR traffic. In this scheduling algorithm, any connection would be served when it becomes eligible. The highest priority would be selected for service when there is more than one eligible connection. Moreover, we discuss the admission control for this algorithm which aims to obtain the minimum inter-arrival time of next acceptable connection. The numerical results show that our scheduling algorithm performs well on energy efficiency and bandwidth utilization.