Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references (leaves 47-48). Also available in electronic version. Access restricted to campus users.

The development of pulse code modulation systems and electronic exchanges, together with the increase in volume of data traffic, have made it desirable to establish a means for handling both voice and data trarfic in the telephone network. A technique is required whereby integrated voice and data switching may be accomplished in an electronic exchange. It is proposed that a data adaptor unit be incorporated in electronic exchanges for the ourpose of concentrating data traffic onto PCM highways. A conceptual design for the architecture of such a unit is presented and its performance evaluated. The protocols for connecting data adaptors into a network, and the use of flow control procedures for regulating data traffic within the network, are described. The hardware implementation of the unit is not considered. The proposed data adaptor operates on the packet switching principle. It is comprised of three types of modules each dedicated to carrying out a particular communication function. The modules are the interface processor that interacts with data transmitting devices, the network processor for sending data over PCM channels between adaptors, and the supervisory processor for regulating activities within the adaptor unit.

published_or_final_version / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

在如同全IP網路(ALL-IP Network)這類的分封交換網路(packet-switching network)中提供具時效性的服務(time-sensitive services)必須嚴格的控制時間。路由規劃是網路管理中重要的一環，所以這類網路的路由規劃必須考慮網路延遲。然而就我們目前所知，多數的傳統路由演算法並不以傳輸延遲(path delay)為主要考量因素；例外少數有考量延遲時間的演算法也僅限於鍊結延遲(link delay)，而未考慮節點延遲(node delay)。此乃肇因於以往頻寬的成本極為昂貴，因而造成演算法設計者在設計時會儘可能有效利用頻寬，如此免不了會犧牲傳遞速度。在過去幾年間，由於光通訊技術的提升，網路頻寬的成長速度遠遠已超過路由器(router)處理能力的成長。在這樣不對等的成長比例驅使下，節點延遲，亦即路由器處理封包時所耗時間，在傳輸延遲中所佔的比例亦隨之快速增長。也因此我們認為，在為高速封包交換網路設計路由演算法時，必須同時考量鍊結延遲和節點延遲。在本論文中，我們設計了一個訊務流為基礎的路由演算法(flow-based routing algorithm)，KLONE，來驗證我們的論點。在規劃路由時，KLONE會把發生在鍊結和節點上的延遲時間一併列入計算，並以全體延遲時間為主要考量。透過我們反覆的測試實驗，我們發現其較之於常用的OSPF演算法，可以在效能上有30%的勝出。藉此，我們的論點得到初步的證實。 / Providing time sensitive services becomes an essential task for some packet-switching networks such as All-IP networks, which will carry all the traffics supported by both circuit-switching and packet-switching networks. To fulfill this demand, such networks require a delay sensitive routing mechanism to provide time-related QoS for delay sensitive services. However, most of traditional routing algorithms do not take delay time as a major concern. Only a few are designed for time sensitive services. These time sensitive routing algorithms are designed at the time when the link bandwidth is the only scarce resource. As the bandwidth of communication links grows rapidly in recent years due to the advance of optical communication technologies, link bandwidth is no longer the only scarce resource. The processing speed of nodes, for example, routers, becomes another critical source of delay time. In this thesis, we designed a new flow-based routing algorithm, the KLONE algorithm, which takes average delay time as its minimization objective and takes both nodes and links as delay components. Through an intensive evaluation using simulation method, we demonstrate that a routing algorithm that considers both link and node delay might outperform the traditional OSPF algorithm.

The object of interest in this research is the evaluation of the combined routing and flow control scheme proposed by Muralidhar and Sundareshan. A slightly modified design using results from positive system theory is proposed as an attempt to improve the performance. Then a detailed performance evaluation of Muralidhar and Sundareshan's scheme and its modified version proposed here is conducted using discrete-event simulation. The application of positive system theory to the combined routing and flow control algorithm proposed by Muralidhar and Sundareshan proved to be quite effective in improving the overall performance only in the initial transient period. The fact that the improvement is restricted to a particular time period appears to be attributable to poor buffer management and certain other fundamental problems with Muralidhar and Sundareshan's scheme. These problems are identified and are described in detail.

No description available.

No description available.

by Ngai Tin Yee. / Bibliography: leaves [28]-[29] / Thesis (M.Ph.)--Chinese University of Hong Kong, 1984

Yang Yi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 51-55). / Abstracts in English and Chinese. / ACKNOWLEDGEMENTS --- p.II / ABSTRACT --- p.III / 摘要 --- p.IV / CONTENTS --- p.V / Chapter CHAPTER 1: --- INTRODUCTION --- p.1 / Chapter 1.1. --- Modulation Formats in Optical Communication SYSTEMS --- p.2 / Chapter 1.1.1 --- Optical ASK Format --- p.3 / Chapter 1.1.2 --- Optical FSK Format --- p.4 / Chapter 1.1.3 --- Optical PSK Format --- p.5 / Chapter 1.1.4 --- Optical Orthogonal Modulation --- p.7 / Chapter 1.2. --- All-Optical Packet Switching --- p.8 / Chapter 1.2.1 --- AOLS Using Subcarrier Labels --- p.9 / Chapter 1.2.2 --- Serial Labels --- p.10 / Chapter 1.2.3 --- Orthogonal Modulated Labels --- p.12 / Chapter 1.3. --- Optical Supervisory Control --- p.13 / Chapter 1.3.1 --- OXC Supervisory Schemes --- p.13 / Chapter 1.3.2 --- Optical A mplifier Supervisory Schemes --- p.14 / Chapter 1.3.3 --- Optical Supervisory Schemes for Transmission Networks --- p.15 / Chapter 1.4. --- Thesis Organization --- p.16 / Chapter CHAPTER 2: --- PREVIOUS STUDIES ON OPTICAL ORTHOGONAL MODULATION….… --- p.17 / Chapter 2.1. --- Orthogonal Modulation Used in STARNET --- p.17 / Chapter 2.2. --- AOLS in IP-over-WDM Networks Employing Orthogonal Modulation --- p.18 / Chapter 2.2.1 --- DPSK Labels on ASK Payload --- p.18 / Chapter 2.2.2 --- FSK Labels on ASK Payload --- p.20 / Chapter 2.2.3 --- Experimental Result of ASK/DPSK Label Swapping --- p.21 / Chapter 2.3. --- Quaternary Optical ASK-DPSK Modulation --- p.22 / Chapter 2.4. --- Conclusion --- p.23 / Chapter CHAPTER 3: --- OPTICAL DPSK/ASK ORTHOGONAL MODULATION SCHEME --- p.24 / Chapter 3.1. --- motivation --- p.24 / Chapter 3.2. --- Proposed Optical DPSK/ASK Orthogonal Modulation Scheme --- p.25 / Chapter 3.3. --- DPSK/ASK orthogonal modulation modules --- p.26 / Chapter 3.4. --- Numerical Simulations --- p.27 / Chapter 3.4.1 --- Mathematical Model of DPSK/ASK Signal --- p.28 / Chapter 3.4.2 --- Simulation Model --- p.31 / Chapter 3.4.3 --- Simulation Results --- p.32 / Chapter 3.5. --- Experimental Demonstration --- p.34 / Chapter 3.5.1 --- Experimental Setup --- p.34 / Chapter 3.5.2 --- Experimental Results --- p.36 / Chapter 3.6. --- transmission experiment --- p.38 / Chapter 3.7. --- Supervisory Information Dissemination Using DPSK/ASK Orthogonal Modulation --- p.41 / Chapter 3.8. --- Label Swapping Experiment and Results --- p.42 / Chapter 3.8.1 --- Experiment Setup --- p.42 / Chapter 3.8.2 --- Experiment Results --- p.45 / Chapter CHAPTER 4: --- CONCLUSION --- p.48 / Chapter 4.1. --- Thesis Summary --- p.48 / Chapter 4.2. --- Future Work --- p.49 / LIST OF PUBLICATIONS --- p.50 / REFERENCES --- p.51

Deng Yun. / Thesis submitted in: July 2003. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 54-56). / Abstracts in English and Chinese. / Acknowledgments --- p.ii / 摘要 --- p.iii / Abstract --- p.v / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Optical Switching --- p.1 / Chapter 1.1.1 --- Optical Circuit Switching --- p.2 / Chapter 1.1.2 --- Optical Packet Switching --- p.3 / Chapter 1.1.3 --- Optical Burst Switching --- p.4 / Chapter 1.2 --- Design of Optical Burst Switching Node --- p.8 / Chapter 1.2.1 --- Burst Switched Network Architecture --- p.8 / Chapter 1.2.2 --- Design of Optical Burst Switching Node --- p.10 / Chapter 1.2.3 --- Scalable Architecture With Multi-plane Fabric --- p.12 / Chapter 1.3 --- Organization --- p.13 / Chapter Chapter 2 --- Proposed OBS Node and Blocking probability due to Output Contention --- p.14 / Chapter 2.1 --- OBS Node Architecture --- p.14 / Chapter 2.2 --- Burst Traffic Model --- p.16 / Chapter 2.3 --- Blocking Probability due to Output Contention --- p.17 / Chapter 2.4 --- Poisson Approximation of Burst Traffic --- p.19 / Chapter 2.5 --- Simulation Results --- p.21 / Chapter Chapter 3 --- Deflection Routed Switch Based on Shuffle-exchange network and Burst Loss Rate due to Insufficient Number of Stages --- p.22 / Chapter 3.1 --- Architecture of Shuffle-exchange Network --- p.22 / Chapter 3.2 --- The traffic loading entering into the second stage --- p.23 / Chapter 3.3 --- The Deflection Probability in a 2x2 Switching Module of SN --- p.26 / Chapter 3.4 --- Analysis of Burst Loss Rate due to Insufficient Number of Stages in SN --- p.27 / Chapter 3.5 --- Total Burst Loss Probability --- p.30 / Chapter 3.6 --- Multi-plane Architecture --- p.32 / Chapter 3.6.1 --- Relationship between k and loading of SN --- p.33 / Chapter 3.6.2 --- Relationship between k and n: Log2(Number of input-output ports) --- p.36 / Chapter 3.6.3 --- The result of appropriate number of planes k --- p.38 / Chapter Chapter 4 --- Switch Based on Dual Shuffle-exchange network and Comparison with Shuffle-exchange network --- p.40 / Chapter 4.1 --- Architecture of Dual Shuffle-exchange Network --- p.40 / Chapter 4.2 --- The deflection Probability in a 4x4 Switching Module of DSN --- p.41 / Chapter 4.3 --- Burst Loss Rate due to Insufficient Number of Stages of DSN --- p.43 / Chapter 4.4 --- Comparison of SN and DSN --- p.45 / Chapter 4.4.1 --- Comparison with different n --- p.47 / Chapter 4.4.2 --- Comparison with different loading --- p.48 / Chapter 4.4.3 --- The result of comparison --- p.49 / Chapter Chapter 5 --- Conclusions --- p.50 / Chapter 5.1 --- The Burst Loss Probability of Proposed OBS Based on SN --- p.51 / Chapter 5.2 --- The multi-plane Fabric with appropriate number of planes k --- p.51 / Chapter 5.3 --- Performance of OBS Design Based on DSN and Comparison of SN and DSN --- p.52 / Bibliography --- p.54