4 research outputs found

    A Study on UMTS Multimedia Broadcasting Multicasting Service

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    在網際網路上,群播技術已被廣泛運用來傳送多媒體內容。近年來,行動通訊網路已經和網際網路成功整合。為了將網際網路上的多媒體服務提供給行動裝置存取,第三代行動通訊網路組織(Third Generation Partnership Project;3GPP)提出了多媒體廣播群播服務(Multimedia Broadcast Multicast Service;MBMS)之相關規範,透過通用行動通訊服務(Universal Mobile Telecommunications System;UMTS)網路將多媒體內容群播給行動裝置。由於多媒體廣播群播服務之相關標準仍持續制定當中,為了提供更好的服務品質與效能之考量,標準所提出的機制仍舊有許多進步的空間。因此,本論文專注於提出更有智慧的機制使得多媒體廣播群播服務可以被更有效率的建置在UMTS網路上。我們考慮以下兩個非常重要的效能議題:題 1. 多媒體廣播群播服務之無線電資源管理機制:多媒體廣播群播服務中定義了點對點(Point-to-Point)傳輸以及點對多點(Point-to-Multipoint)的無線傳輸模式,其分別使用專用邏輯通道(Dedicated logical channel)和共用邏輯通道(Common logical channel)來傳輸多媒體廣播群播服務之資料給使用者。用共用邏輯通道時,雖可以同時服務多個使用者,但該通道必須使用足以傳送到整個涵蓋區域的傳送功率,因此會對專用邏輯通道造成嚴重干擾。所以,如何有效率地使用無線電資源來同時服務多媒體廣播群播服務以及使用專用邏輯通道之傳統電信服務使用者將是一個關鍵的議題。在此論文中,我們提出了兩種頻道分配的演算法,分別是群播資源預留(Reserved Resource for Multicasting; RRM)及群播資源不限(Unreserved Resource for Multicasting; URM)演算法。為了研究這兩個演算法的效能(包括通話未完成率以及用戶滿意度指標),我們推導其數學分析模型,並開發模擬程式。研究數據指出不管在傳統通話服務中的通話未完成率及用戶滿意度指標中,URM都較RRM優越,但URM會稍稍減少多媒體廣播群播服務之效能。題 2. 多媒體廣播群播服務之檔案修復機制:當多媒體檔案以群播方式傳送給使用者的時候,由於網路擁塞以及訊號品質不良的影響,在傳輸過程中會造成資料之遺失或錯誤。為了重傳遺失或錯誤的資料,3GPP 26.346制定了三種檔案修復機制(File Repair Mechanism)。但是,這三種修復機制明顯產生額外的信令及網路流量。為了減少資料的傳輸以及解決額外信令傳遞等問題,本論文提出了新的檔案修復機制稱為Reuse Bearer Service(RBS)。我們透過數學模型分析了四種檔案修復機制並且實作模擬模型來評估這些機制之效能。我們的研究顯示,以修復所有錯誤資料所耗費之網路資源為考量時,RBS修復機制優於3GPP所定義的三種檔案修復機制。The multicasting technique (one-source-many-destination) is widely utilized for multimedia content delivery in the Internet. In the recent years, mobile telecommunication networks have been integrated with the Internet. The Third Generation Partnership Project (3GPP) working group proposed the Multimedia Broadcast Multicast Service (MBMS) for multicasting multimedia content over the Universal Mobile Telecommunications System (UMTS). The standards for the UMTS MBMS service are currently under process. It is allowed rooms to enhance the current mechanisms proposed in the UMTS MBMS specifications so that better QoS and performance for the MBMS service can be achieved in the UMTS network. This dissertation focuses on proposing more intelligent mechanisms to make the MBMS service deployed more efficiently in UMTS. We consider the following two important issues for performance enhancement for the UMTS MBMS service.adio Resource Management. 3GPP 23.246 defines the MBMS to deliver multicasting content over the Universal Mobile Telecommunications System (UMTS), where the common logical channel may be enabled to serve multiple MBMS users at the same time. However, the usage of the common logical channel may cause interference to the dedicated logical channels serving the traditional calls. To more efficiently utilize the radio resource to serve both traditional and MBMS calls, this dissertation proposes two channel allocation algorithms: Reserved Resource for Multicasting (RRM) and Unreserved Resource for Multicasting (URM). We develop analytic and simulation models to investigate the performance for the two algorithms, including the call incompletion probability and customers'' satisfaction indication. Our study indicates that URM outperforms RRM in terms of the call incompletion probability for the traditional calls and satisfaction indication by slightly degrading the performance of MBMS calls.ile Repair Mechanism. During the MBMS content transmission, the data may be lost. Three file repair schemes were proposed in 3GPP 26.346 to retransmit the corrupted MBMS data. However, these schemes may introduce extra data traffic or signaling overheads. This dissertation proposes the Reuse Bearer Service (RBS) file repair scheme to resolve this issue. We analyze the four file repair schemes by analytical models and simulation experiments. Our study shows that the proposed RBS scheme may significantly outperform the previously proposed schemes.Acknowledgement . . . . . . . . . . . . . . . . . . . . . ihinese Abstract . . . . . . . . . . . . . . . . . . . iiinglish abstract . . . . . . . . . . . . . . . . . . . . vontents . . . . . . . . . . . . . . . . . . . . . . . viiist of Figures . . . . . . . . . . . . . . . . . . . . . xist of Tables . . . . . . . . . . .. . . . . . . . . . xiv Introduction . . . . . . . . . . . .. . . . . . . . . . 1 Radio Resource Management for MBMS . . . . . . . . . . 7.1 Channel Allocation Algorithms . . . . . . . . . . . . 9.2 Analytic Models . . . . . . . . . . . . . . . . . . 14.2.1 Analysis for Algorithm RRM . . . . . . . . . . . . 15.2.2 Analysis for Algorithm URM . . . . . . . . . . . . 20.2.3 Simulation Model . . . . . . . . . . . . . . . . . 23.2.4 Simulation Validation . . .. . . . . . . . . . . . 29.3 Performance Evaluation . . . . . . . . . . . . . . . 31 File Repair Mechanism for MBMS. . . . . . . . . . . . 41.1 Reuse Bearer Service (RBS) . . . . . . . . . . . . . 45.2 Analytic Models . . . . . . . . . . . . . . . . . . 48.2.1 Analysis for UFR . . . . . . . . . . . . . . . . . 51.2.2 Analysis for RMFR . . . . . . . . . . . . . . . . 53.2.3 Analysis for NBS . . . . . . . . . . . . . . . . . 55.2.4 Analysis for RBS . . . . . . . . . . . . . . . . . 56.3 Simulation Models . . . . . . . . . . . . . . . . . 57.4 Numerical Results . . . . . . . . . . . . . . . . . 66 Conclusions and Future Work . . . . . . . . . . . . . 73ibliography . . . . . . . . . . . . . . . . . . . . . . 77 The MBMS Multicast Service Activation Procedure . . . 85 The MBMS Session Start Procedure. . . . . . . . . . . .91 The RA Update Procedure . . . . . . . . . . . . . . .. 93 State Transition Rates for Algorithm URM . . . . . . . 99 The Derivation of Pf,t for Algorithm URM. . . . . . . 103 The Derivation of Pf,m for Algorithm URM . . . . . . .109urriculum Vita. . . . . . . . . . . . . .. . . . . . . 112ublication Lists and Awards. . . . . . . . . . . . . . 11

    Study on Light Extraction Efficiency of Deep UV-LEDs

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    本研究利用奈米壓印技術在藍寶石基板製作奈米圖形化結構(Nano-Pattern Sapphire Substrate, NPSS)應用於覆晶式深紫外光發光二極體(Deep Ultraviolet Light-Emitting Diode, DUV-LED),藉此改善元件光萃取效率(Light-Extraction Efficiency, LEE)。 使用TracePro模擬軟體進行光線追跡的模擬探討不同幾何圖形結構對於覆晶式DUV-LED的光提取效率。元件結構使用Ni/Au作為接觸層和Al作為反射鏡。奈米壓印圖形化結構有錐狀與孔洞兩種,在錐狀圖形中其尺寸分別為2.5 um、200 nm與400 nm,而孔洞狀圖形尺寸為350 nm、750 nm。 在350 mA電流注入下,與傳統具反射鏡覆晶式DUV-LED相比nano-imprint 2.5 μm-LED、nano-imprint 750 nm hole-LED、nano-imprint 200 nm-LED、nano-imprint 350 nm hole-LED、nano-imprint 400 nm-LED之光輸出功率分別提升9.9、17.2、25.7、41.3及50.2%。在光電轉換效率方面, nano-imprint 2.5 μm-LED、nano-imprint 750 nm hole-LED、nano-imprint 200 nm-LED、nano-imprint 350 nm hole-LED、nano-imprint 400 nm-LED的DUV-LED與傳統具反射鏡覆晶式DUV-LED相比分別提升16.7、25、36.1、52.8及69.4 %。而在光萃取效率方面, nano-imprint 2.5 μm-LED、nano-imprint 750 nm hole-LED、nano-imprint 200 nm-LED、nano-imprint 350 nm hole-LED、nano-imprint 400 nm-LED的DUV-LED與傳統具反射鏡覆晶式DUV-LED相比分別提升9.7、17.6、25.4、41.4及49.8 %。這些結果清楚地表明,在傳統式覆晶式元件,利用奈米壓印技術在藍寶石基板上製作幾何結構確實可以有效的提升覆晶式DUV-LEDs的光輸出功率、光萃取效率與光電轉換效率。致謝 i 摘要 ii Abstract iii 目錄 iv 表目錄 vii 圖目錄 viii 第一章 緒論 1 1-1前言 1 1-2研究動機 3 1-3 論文架構 4 第二章 理論基礎 5 2-1發光二極體發光理論 5 2-2金屬-半導體接面理論 5 2-2-1蕭特基接觸原理 6 2-2-2 歐姆接觸之原理 8 2-3光電特性 10 2-4發光二極體發光效率原理 11 2-4-1 內部量子效率Internal quantum efficiency(IQE) 11 2-4-2 光萃取效率(Extraction efficiency)及外部量子效率External Quantum Efficiency (EQE) 12 2-5 發光二極體的基本特性參數 14 2-5-1 順向電壓 (Forward Voltage,Vf) 14 2-5-2 漏電流 (Leakage Current,Ir) 15 2-5-3 光強度(Luminance Intensity, cd) 15 2-5-4 光輸出功率 (Light-Output Power) 15 2-5-5 光電轉換效率 (Wall Plug Efficiency, WPE) 15 第三章 實驗步驟 16 3-1前言 16 3-2深紫外光氮化鎵試片之磊晶結構 16 3-3 薄膜備製 17 3-3-1試片清洗 17 3-4 DUV -LED元件製作 17 3-4-1 試片清洗 17 3-4-2定義元件範圍 18 3-4-3 電極製作 18 3-4-4 元件切割及封裝 19 3-5 量測元件特性 20 3-5-1 光電特性量測 20 3-5-2 積分球量測系統 21 3-5-3 Alpha-Step量測系統 22 3-5-4 N&K光學量測系統 22 3-5-5 IR紅外熱像分析儀簡介 23 3-5-6掃描式顯微鏡原理簡介 23 3-5-7 CL分析技術原理 24 3-5-8原子力顯微鏡原理 25 3-5-9光致螢光光譜儀量測系統 26 3-6 TracePro 模擬軟體介紹 26 3-6-1 TracePro 軟體簡介 26 3-6-2 模擬參數設定方式 27 第四章結果與討論 28 4-1 TracePro模擬軟體參數設定與結果分析 28 4-2 反射鏡面與、透明導電層與幾何表面樣貌之探討 29 4-2-1 Al不同厚度對於深紫外光之反射率 29 4-2-2 Ni/Au(歐姆接觸層)對於深紫外光之穿透率 30 4-2-3 Ni/Au與p+GaN之歐姆接觸 32 4-2-4 不同結構的奈米壓印圖形於藍寶石基板之樣貌 33 4-2-5 金屬與n-AlGaN之歐姆接觸 39 4-3 深紫外光覆晶二極體(FC-LEDs)元件之光電特性 39 4-3-1 DUV-LED應用於FC-LEDs元件之電流-電壓特性 39 4-3-2 DUV-LED應用於FC-LEDs元件之光輸出功率分析 40 4-3-3 DUV-LED應用於FC-LEDs元件之光電轉換效率及外部量子效率 42 4-3-4 DUV-LED應用於FC-LEDs元件之光萃取效率 45 4-3-5 DUV-LED應用於FC-LEDs元件之電流對波長影響分析 47 4-3-6 DUV-LED應用於FC-LEDs元件之發光強度及發光角度量測分析 48 第五章 結論 50 第六章 未來展望 51 參考文獻 5

    A Study on GPRS-Based WLAN Authentication and Auto-Configuration

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    近幾年來,無線區域網路以及存取裝置迅速的發展,使用者的數目急速增加,普及性亦漸增。透過無線區域網路存取之技術,使用者能夠在其無線訊號涵貌漸籉饇炾鴗瑰H時隨地進行存取網際網路之服務,尤其是在Hot Spot地區。隨著802.11 WLAN逐漸普及化,WLAN服務涵遢d圍勢必擴大,甚至成為公眾系統。整合WLAN 與GPRS/UMTS衍然成為未來的趨勢。然而,欲將WLAN升為公眾系統,仍有幾個議題仍需解決。 當使用者在不同的無線區域網路中想要連上無線區域網路時,由於無線區域網路的建置並不像個人通訊系統一樣,必須遵照一套共同的標準,因此往往需要設定不同的無線區域網路組態,及利用不同的方式進行認證才能存取該無線區域網路(例如延伸服務集合(ESSID)、認證方式、不同的帳號及密碼格式等),方能使用此無線區域網路。對使用者而言是非常不方便的,所以如何能讓無線存取裝置自動設定該無線區域網路之組態並進行認證便成為一個重要的議題。 針對此議題,本論文提出了一個GPRS-Based(一般封包式)無線區域網路自動認證及組態機制,透過此機制,使用者不再需要記住各種繁雜的無線網路的相關組態及認證方法,便可以在不同無線網路服務範圍使用其無線網路。除此之外,本機制也可以解決需多原先在無線區域網路的安全問題。最後,我們也設計並實作一個自動認證及組態平台(WACAP),以驗證此機制在實際商業營運之可行性。With the huge number of deployment of 802.11 wireless LAN (WLAN), the coverage area of WLAN, known as hot-spot, is increasing rapidly. In these WLAN hot-spots, people enjoy wireless Internet access with high-speed data transmission rate anytime and anywhere. As a result, it becomes a trend that WLAN serves as a public system for wireless Internet services. In the existing business operations of WLAN, a WLAN user must be the customer of various WLAN operators before gaining wireless Internet services. In order to access WLAN networks of different operators, the user typically goes through various login or authentication procedures manually with different account/password format. Also, the user must remember WLAN card configuration setups for different WLAN networks. It is clear that such exercise is not user-friendly. Hence, how to provide a mechanism that automates the authentication and WLAN configuration setup procedure is a critical issue. In this thesis, we propose an authentication and auto-configuration mechanism for WLAN based on short message service of mobile telecommunications network. Through this mechanism, user can access WLAN services without tedious authentication and configuration setup procedure while roaming among different WLAN networks. Also this mechanism can avoid the several security attacks in the 802.11 WLAN. In addition to introducing the detail of mechanisms, we have designed and implemented a prototypical platform, Wireless Auto-configuration and Authentication Platform (WACAP) that realize the mechanism.Contents 1 Introduction 11 1.1 General Radio Packet Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.2 IEEE 802.11 Wireless LAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.3 The iSMS System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2 Authentication and Auto-configuration Mechanism 27 3 Implementation Issue ofWLR andWGW 35 4 Implementation of WACAP 41 4.1 The System Architecture of WACAP . . . . . . . . . . . . . . . . . . . . . . . . . 42 4.2 The Software Architecture of WACAP platform . . . . . . . . . . . . . . . . . . . 43 4.2.1 The Software Architecture of WACAP server . . . . . . . . . . . . . . . . 44 4.2.2 The Software Architecture of Wireless Gateway (WGW) . . . . . . . . . . 47 4.2.3 The Software Architecture of Mobile Terminal . . . . . . . . . . . . . . . 51 4.3 Authentication and Auto-Configuration Procedure in WACAP . . . . . . . . . . . 54 4.3.1 The Login Procedure on WACAP . . . . . . . . . . . . . . . . . . . . . . 55 4.3.2 The Logout Procedure on WACAP . . . . . . . . . . . . . . . . . . . . . . 59 5 Conclusion 65 List of Figures 1.1 The GPRS Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.2 The GPRS Interface between each nodes . . . . . . . . . . . . . . . . . . . . . . . 17 1.3 IEEE 802.11 Protocol Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.4 CSMA/CA mechanism(a)without RTC/CTS (B)with RTS/CTS . . . . . . . . . . . 21 1.5 The iSMS Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 1.6 The iSMS Software Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2.1 The Network Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2.2 The Message Flow of Authentication and Auto-configuration Mechanism . . . . . 29 2.3 The WLAN Configuration Profile in the Short Message . . . . . . . . . . . . . . . 30 2.4 The Round Trip Elapsed Time Distribution for Phase I . . . . . . . . . . . . . . . 31 2.5 The Message Flow of Logout Procedure . . . . . . . . . . . . . . . . . . . . . . . 33 2.6 The Message Flow of MT-Originated Detection . . . . . . . . . . . . . . . . . . . 33 2.7 The Message Flow of WGW-Originated Detection . . . . . . . . . . . . . . . . . 34 3.1 WLR, iSMS Gateway, HLR, and LSC . . . . . . . . . . . . . . . . . . . . . . . . 36 3.2 The ESS service area in WLAN . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 4.1 The System Architecture of WACAP . . . . . . . . . . . . . . . . . . . . . . . . . 42 4.2 The Software Architecture of WACAP Server . . . . . . . . . . . . . . . . . . . . 44 4.3 The class diagram of WACAP Server . . . . . . . . . . . . . . . . . . . . . . . . . 45 4.4 The Software Architecture of Wireless Gateway (WGW) . . . . . . . . . . . . . . 48 4.5 The class diagram of Wireless Gateway (WGW) . . . . . . . . . . . . . . . . . . . 50 4.6 The Software Architecture of User Device . . . . . . . . . . . . . . . . . . . . . . 52 4.7 The class diagram of User Device . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.8 The Login Procedure for authentication and auto-configuration in WACAP (Phase I) 56 4.9 The Login Procedure for authentication and auto-configuration in WACAP (Phase II) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.10 The Logout Procedure in WACAP . . . . . . . . . . . . . . . . . . . . . . . . . . 60 4.11 The Abnormal Logout Procedure in WACAP . . . . . . . . . . . . . . . . . . . . 62 List of Tables 1.1 IEEE 802.11 WLAN Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4.1 The member functions of classes in the WACAP server . . . . . . . . . . . . . . . 47 4.2 The member functions of classes in the Wireless Gateway (WGW) . . . . . . . . . 51 4.3 The member functions of classes in the WACAP Client . . . . . . . . . . . . . . . 5

    普通高速車床振動診斷之研究

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    [[abstract]]這份報告是量測普通高速車床的十種不同的齒輪配合,我 們將高轉速的四個不同轉速進行研究探討,並解釋所造成的頻 譜有何不同。 在這份報告中,會詳細敘述有關振動分析的相關文獻,並 且以車床量測四個不同轉速(370 rpm、700 rpm、1200 rpm、 1800 rpm),將分別做軸不平衡與齒輪振動的相關振動分析
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