English  |  正體中文  |  简体中文  |  全文筆數/總筆數 : 64745/64745 (100%)
造訪人次 : 20457115      線上人數 : 289
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
搜尋範圍 查詢小技巧:
  • 您可在西文檢索詞彙前後加上"雙引號",以獲取較精準的檢索結果
  • 若欲以作者姓名搜尋,建議至進階搜尋限定作者欄位,可獲得較完整資料
  • 進階搜尋


    請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/8381


    題名: WiMAX網路群播輪詢群組競爭時槽適性調整機制之研究;Study of Adaptive Contention Slot Mechanism for Multicast Polling Group in WiMAX Network
    作者: 李尹琇;Yin-hsiu LEE
    貢獻者: 通訊工程研究所
    關鍵詞: WiMAX;群播輪詢;群組;競爭時槽;WiMAX;multicast polling;group;contention slot
    日期: 2009-07-09
    上傳時間: 2009-09-22 11:24:10 (UTC+8)
    出版者: 國立中央大學圖書館
    摘要: 在WiMAX網路上,SS在傳送資料前必須先向BS傳送頻寬需求,待分配到頻寬之後才可以上傳資料。傳送頻寬需求的方式又分單點輪詢(Unicast polling)、群播輪詢(Multicast polling)與廣播輪詢(Broadcast polling),本篇論文主要探討的是群播輪詢,並將非即時性服務之QoS(nrtPS、BE)分成數個群播輪詢群組。當SS數量增加的時候,相對傳送頻寬需求的次數也增加,若兩個SS同時在同一個競爭時槽中送出頻寬需求就會發生碰撞,使得BS無法接收到頻寬需求,換言之,BS無法得知SS在傳送頻寬需求當中發生了碰撞。本篇論文修改群播輪詢群組中SS傳送頻寬需求的MAC BR header來記錄碰撞訊息,根據不同的碰撞情形給予不同程度的量化加權,並藉此加權結果來計算該群組適當的競爭時槽長度。此外還提出一種有條件限制的競爭時槽比例計算方式,以提升優先權較高之群組成功傳送頻寬需求的次數。 論文的內容首先介紹WiMAX網路的標準—802.16規格,然後說明群播輪詢群組競爭機制,接著討論其他過去的競爭時槽分配方式,最後提出一個本篇的群播輪詢群組競爭時槽比例計算方式,並比較給予不同權重的QoS,其傳送頻寬需求的平均值,以及不同優先權的群播輪詢群組間競爭時槽比例的分配情況。 In WiMAX network, SS has to send bandwidth request to BS before transmitting data. After SS gets the allocated bandwidth from BS, SS is allowed to upload data. There are three methods to send bandwidth request, including unicast polling, multicast polling, and broadcast polling. In this paper, we focus on the multicast polling issue and divide different quality of services(nrtPS、BE) into several multicast polling group. When the numbers of SSs are increasing, the more collisions occur while at least two SSs send bandwidth request at the same time so that BS cannot receive bandwidth request. Therefore, BS is unable to know that whether SS has encountered collision during transmitting bandwidth request. Based on the reasons motioned before, this paper gives different weight to collision state for qualifying the degree of collision. The collision state is recorded by the SS's MAC BR header when SS sends bandwidth request to BS. Therefore, BS can calculate the length of contention window for the group. In addition, we also proposed a method that has joins a beta to count the length of contention window, The method promotes high priority group to send bandwidth request effectively. The paper provides a brief overview of WiMAX network standard at the beginning and presents the multicast polling group contention mechanism. Then the paper proposes a method to calculate the ratio of contention window of a multicast polling group, and compares the average value of bandwidth request and the allocation of contention window with different weight between different QoS and different priority for different group.
    顯示於類別:[通訊工程研究所] 博碩士論文

    文件中的檔案:

    檔案 大小格式瀏覽次數
    0KbUnknown755檢視/開啟


    在NCUIR中所有的資料項目都受到原著作權保護.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - 回饋  - 隱私權政策聲明