IEEE 802.16e無線寬頻存取系統下的電源節省管理及QoS排程機制

Abstract

IEEE802.16e是最近熱門探討的技術，其標準定義了媒介存取控制層和實體層的協定，其中實體層的頻段是介於10~66GHz以及低於11GHz，而媒介存取控制層支援分時雙工和分頻雙工這兩種模式，並且定義了五種服務類別來支援服務品質，這五種等級分別是：UGS, rtPS, nrtPS, BE, and ertPS，但是802.16e並沒有定義針對不同服務類別的排程機制，此外IEEE 802.16e亦支援移動性，所以如何有效利用電源成為一重要研究議題。 本篇論文是在IEEE 802.16e上提出電源節省機制的架構，包括了電源控制的策略以及排程方法，整個機制是建構在分時雙工的模式上，在電源控制策略上是希望利用集中傳送時間的方式，以減少需要開啟電源的時間，達到省電的效果又能夠滿足其服務品質，並且提出一個公平的排程機制來合理的分配頻寬。 本篇論文透過模擬的方式來評估所提出演算法的效能。模擬的結果顯示提出之機制確實能夠達到省電的效果且公平分配頻寬。

The IEEE 802.16e standard for broadband wireless access is a recently popular technology which defines the medium access control (MAC) layer and the physical (PHY) layer with frequency bands between 10 and 66GHz and below 11 GHz. The MAC layer supports two duplexing, i.e., time division duplexing (TDD) and frequency division duplexing (FDD), and supports QoS by defining five service classes. However, how to do scheduling among these service classes is not defined in the standard. In addition, the IEEE 802.16e supports mobility, and thus how to utilize battery efficiently is an important issue for protocol design. In this thesis, we propose a novel power saving framework which includes a transmission merging mechanism and a scheduler for the IEEE 802.16e. This framework is designed for TDD mode. The transmission merging mechanism focuses on how to merge the transmission time to reduce the number of awake-frames. To still satisfy each connection’s quality of service (QoS) demand, and achieve fairness, we design a scheduler to allocate downlink (DL) and uplink (UL) subframes. In this thesis, we evaluate the proposed algorithm by simulations. The results show that the proposed method achieves both power efficiency and fair BW allocation.