無線都會型網路標準IEEE 802.16e在IEEE 802.16d固定式標準上加入了節點行動性處理的機制，其中一個處理機制為遞交機制。IEEE 802.16e之遞交機制中的掃描相鄰基地台程序，其中的關聯程序延用了固定式IEEE 802.16的初始測距程序，使得行動節點掃描相鄰基地台時的傳輸中斷時間成為遞交機制中傳輸延遲之瓶頸。在相關遞交程序的研究中，NFHO(Network-assisted Fast Handover)以 「快速關聯」程序縮短掃描時間：藉由服務基地台協調行動節點傳送初始測距碼之準確同步時間，使得行動節點在接收完相鄰基地台廣播訊息後，能繼續傳輸資料直到需再切換一次頻道以傳送初始測距碼為止；此外，NFHO以CSSC(Convergence Sublayer Switch Center)額外設備暫存及廣播交遞時中斷之資料封包，如此能加快行動節點交遞後繼續資料傳送的速度。本篇論文提出之RAPHO(Rapid Association and Prediction-assisted Handover)方法，旨在大幅縮短行動節點在掃描關聯程序時的中斷時間：利用服務基地台代替行動節點發送初始測距碼，並預測行動節點未來可能之交遞目標基地台清單。RAPHO由於不需行動站台參與關聯程序，更減少了掃描相鄰基地台的數量，所以改善的掃描延遲時間優於NFHO，雖然RAPHO從交遞到恢復資料傳輸之中斷時間不如NFHO，但實驗結果可知，整體延遲時間：掃描時間加上交遞延遲，RAPHO較NFHO為佳。

The standard of Wireless Metropolis Area Network, IEEE 802.16e, has mechanisms beyond the static standard, IEEE 802.16d, to cope with mobile nodes. One of the mechanisms is the handover procedure. Mobile node scanning of neighbor BSs in the IEEE 802.16e handover procedure has a procedure: Association. Association is an initial ranging procedure. The transmission is discontinued when a mobile node is scanning of neighbor BSs. Because initial ranging procedure is defined from the static standard, the delay time of association becomes a bottleneck of handover. One of the researches, NFHO (Network-assisted Fast Handover), proposes a method -”Fast Association” to shorten the scanning time. In the method, the serving BS coordinates neighbor stations the exactly synchronization time for mobile node transmission of the initial ranging code. Another method of NFHO is to add an equipment, CSSC (Convergence Sublayer Switch Center). CSSC stores and broadcasts the data packets which are discontinued between handover. The metric proposed in this thesis called RAPHO (Rapid Association and Prediction-assisted Handover) which can shorten much scanning discontinued time. In one part of RAPHO, the serving BS takes the role of the mobile node to send the initial ranging code; in another part, the serving BS predicts the possible target BSs list. Because the mobile node doesn’t participate in association and the number of scanning neighbor BSs is decreased, the improving scanning delay time of RAPHO is better than that of NFHO. According to the result of simulation, the total delay time (the scanning time plus the handover time) of RAPHO is better than that of NFHO.

第一章 導論 1
1.1 前言 1
1.2 研究動機 2
1.3 論文架構 2
第二章 相關背景與研究 3
2.1 IEEE 802.16相關名詞解釋 3
2.2 IEEE 802.16 無線媒體控制層介紹 5
2.3 媒體控制一般性子層 7
2.4 測距 11
2.5 網路進入與初始化 19
2.6 IEEE 802.16e 硬式交遞程序 22
2.6.1 獲得網路拓樸 22
2.6.2 交遞處理 28
2.7 改進目標 33
2.8 相關研究 34
第三章 提出的方法 38
3.1 架設環境 38
3.2 改善關聯程序 40
3.3 利用行動預測方法加快交遞 49
第四章 模擬結果與分析 53
4.1 模擬環境 53
4.2 模擬結果與分析 55
第五章 結論 60
參考文獻 61

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