English  |  正體中文  |  简体中文  |  Items with full text/Total items : 49641/84944 (58%)
Visitors : 7698662      Online Users : 59
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library & TKU Library IR team.
Scope Tips:
  • please add "double quotation mark" for query phrases to get precise results
  • please goto advance search for comprehansive author search
  • Adv. Search
    HomeLoginUploadHelpAboutAdminister Goto mobile version
    Please use this identifier to cite or link to this item: http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/35641


    Title: Study of efficient data forwarding in heterogeneous and multihop wireless metropolitan area networks
    Other Titles: 異質與多跳躍之無線都會網路高效能資料傳送之研究
    Authors: 尹華強;Yin, Hua-chiang
    Contributors: 淡江大學電機工程學系博士班
    許獻聰;詹益光
    Keywords: 資料轉送;通用封包無線服務;換手;異質網路;多節點跳躍中繼台;全球互通微波存取;無線區域網路;無線都會網路;Data Forwarding;GPRS;Handover;heterogeneous;Multihop Relay;WiMAX;WLAN;WMAN
    Date: 2008
    Issue Date: 2010-01-11 06:55:59 (UTC+8)
    Abstract: 隨著無線接取網路技術的蓬勃發展,行動網際網路的時代已正式在日常生活中逐漸成形,多樣的資訊與通信服務開創電子商務的新契機,亦大幅改變現代人們的生活型態。綜觀網際網路由有線到無線的技術歷程,其發展趨勢的主要重點在於為行動用戶端提供高速率的資料傳輸,通用封包無線服務(General Packet Radio Service, GPRS) 和第三代行動通訊(Third Generation , 3G) 雖有其高涵蓋範圍特性,但其傳輸速率與系統可傳輸資料量卻遠不如小涵蓋範圍用於無線區域網路的IEEE 802.11 系統(Wireless Fidelity, WiFi) 和近似高涵蓋範圍用於無線都會網路的IEEE 802.16系統(Worldwide Interoperability for Microwave Access, WiMAX);為擷取上述不同技術的優點以完成行動用戶端可使用高傳輸資料量的要求,本論文分成三項策略來增進無線網路服務效能。
    首先,在目前已在使用中之GPRS和WiFi系統上,提出異質網路換手機制。此機制考量服務範圍和傳輸速率的差異性,提出的迴路探測策略(Circular Probe Strategy, CPS)可提供4種用於異質網路的認證與快速無間隙換手之方法;並以在淡江大學架設之IEEE 802.11無線區域網路與台灣大哥大行動電信公司的GPRS系統實測,藉傳輸訊號強度、訊號傳輸距離、封包延遲、封包延遲差異等以數值分析方式驗證所提方法之效能,證實行動用戶端可以獲得較大的傳輸頻寬。
    由WiMAX所選定的IEEE 802.16為基礎之無線大都會區域網路於2006年5月成立802.16j任務群(Task Group),以中繼台(Relay Station, RS) 佈建多節點跳躍中繼網路來增加訊號涵蓋範圍與提升資料傳輸速率。在此,本論文分析正交分頻多重存取(Orthogonal Frequency Division Multiple Access, OFDMA)技術的配置方式,提出無線資源使用索引機制(Radio Resource Utilization Index, RRUI)計算在媒介擷取控制層(Medium Access Control, MAC)所產生之成本,並進而用以作為資料傳送給行動用戶端的路徑選擇依據。
    本論文最後考量提出3種有效且快速資料傳送的方法,以減少目前IEEE 802.16j 草案中資料轉送的額外成本。其主要的功能在提供需廣播的管理訊息可以不需加掛訊框表頭直接以單播轉送,或先分類需廣播的管理訊息再以群播方式轉送共同部分,繼再以單播轉送其餘部分。再者,對於需更換資料路徑的行動中繼台或行動用戶端提供不需加掛訊框表頭、不需維護路由表、不需分析訊框與不需交換動態服務的快速資料轉送機制。
    Recent wireless access technology has been about to launch various services for mobile users. The main development consideration of the trend is to provide broadband services for mobile users. Although the coverage of the general packet radio service (GPRS) or third generation (3G) is larger than the wireless fidelity (WiFi) system adopting IEEE 802.11 specification as the wireless local area network (WLAN) solution, the system throughput and the data transmission rate are significantly lower than the WLAN. Comparing GPRS/3G with the worldwide interoperability for microwave access (WiMAX) system, which uses IEEE 802.16 specification to deploy the wireless metropolitan area network (WMAN), the system throughput of GPRS/3G is lower than that of WiMAX which also can provide wide coverage cell. This dissertation mainly focuses on the strategies of providing high throughput for every mobile user and proposes three efficient strategies to increase the system performance of wireless network services.
    First, this dissertation proposes a heterogeneous handover solution for the existing wireless service environment between GPRS and WiFi. Considering the system coverage and the data transmission rate, four mechanisms are implemented for the authorization and fast seamless handover via the proposed circular probe strategy (CPS). By using the received signal strength indication (RSSI), delay time, and jitter as the system performance criteria, it verifies that the performance of the proposed handover strategy can provide higher throughput for mobile users.
    Secondly, the IEEE 802.16j task group has designed a multihop relay network for amending the existing 802.16e network to have better coverage and higher system throughput. This dissertation analyzes the orthogonal frequency division multiple access (OFDMA) permutations used in the 802.16j frame and then proposes a metric named radio resource utilization index (RRUI) for evaluating the useful radio resource as well as selecting a path with mimial cost in a multihop relay network.
    Finally, this dissertation proposes three fast forwarding schemes in order to reduce the overheads existed in the IEEE 802.16j draft. The proposed CID-translated forwarding scheme can relay broadcast messages without appending any relay medium access control (MAC) header. The proposed enhanced CID-translated forwarding scheme classifies the content of the relayed broadcast messages and then uses efficient relaying method to relay the messages. For a moving station that may change the data path frequently, the proposed burst-based forwarding scheme can relay data directly without negotiating any dynamic service flow, updating a forwarding table, appending any relay MAC header, and parsing every relayed MAC protocol data unit (PDU).
    Appears in Collections:[電機工程學系暨研究所] 學位論文

    Files in This Item:

    File SizeFormat
    0KbUnknown189View/Open

    All items in 機構典藏 are protected by copyright, with all rights reserved.


    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library & TKU Library IR teams. Copyright ©   - Feedback