Bibliography: pages 77-80. / This is a study of the simulated performance of two local area networks, Ethernet and the MAP network, respectively based on the IEEE standards 802.3 and 802.4. The simulation language chosen is of the discrete event type rather than the more usual analytical model. This is done in order to observe the interaction between the various entities of a network in order to gain a better understanding of the method of operation of such a system. The performance demanded of a node entity by the networks is determined. The performance of some commercially available hardware is derived from manufacturer's specifications and compared with that required by the network. It is found that there is a significant disparity, with the network requirements far exceeding that of the hardware capabilities. The simulation models developed are used to determine the performance of the networks both with and without the limitations imposed by currently available hardware. While the inclusion of the hardware performance causes little ·loss in performance for the Ethernet network, it has a highly detrimental effect on that of the MAP network. A possible solution is found to this limitation which requires minimal change to the existing protocol. The conclusions reached are that with currently available hardware a group of nodes are able to fully utilise the performance of the Ethernet LAN although a single pair of nodes is unable to do so. With regard to the MAP network, the network performance is limited by that of the node performance although this can be offset to a certain extent by careful choice of one of the protocol parameters, or modification of the hardware design.

No description available.

No / Recently there has been an exponential rise in the use of Wireless Sensor Networks (WSNs) in various applications. While WSNs have been primarily used as independent networks, researchers are now looking into ways of integrating them with other existing networks. One such network is the satellite network which provides a reliable communication backbone to remote areas that lack appropriate terrestrial infrastructure. However, due to the integration of the two networks with different transmission and operational characteristics interoperability and security become major concerns. This paper presents an ns-2 based simulation framework of a WSN-satellite integrated network that is used to evaluate the effects of data aggregation and security mechanisms on overall network performance. The average end-to-end packet delay, overall energy consumption and aggregation efficiency are considered for this analysis. This paper also looks into the effects of implementing hop-by-hop security and end-to-end security and justifies the need for end-to-end security in the WSN-satellite integrated networks.

No description available.

Enhancement of network data-plane functionality is an open problem that has recently gained momentum. Addition and programmability of new functions inside the network data-plane to enable high speed, complex network functions with minimum resource utilization, is main focus of this thesis. In this work, we look at different levels of the network data-plane design and using network virtualization and software defined networking we propose data-plane enhancements to achieve these goals. This thesis is divided into two parts, in first part we take a ground up approach where we focus our attention at the fast path packet processing. Using hardware and software based network virtualization we show how hardware and software based network switches can be designed to achieve above mentioned goals. We then present a switch design to quickly add these custom fast path packet processors to the network data-plane using software defined networking. In second part of this thesis we take a top to bottom approach where we present a programming abstraction for network operators and a network function deployment system for this programming abstraction. We use network virtualization and software defined networking to introduce new functions inside the network data-plane while alleviating the network operators of the deployment details and minimizing the network resource utilization.

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

published_or_final_version / abstract / Electrical and Electronic Engineering / Master / Master of Philosophy

The motivation behind this thesis is to develop a procedure for internetworking the Defense Data Network (DDN) with an Integrated Services Digital Network (ISDN). To accomplish this internetworking problem an integrated gateway must be designed to compensate for incompatibilities between the two networks. This thesis approaches this problem by giving a description of the two networks, DDN and ISDN, and also presenting a general approach to gateway design. This information is then combined into a detailed procedure for implementing a gateway to internetwork the DDN and ISDN. This is followed by a discussion of the practical aspects of the DDN/ISDN internetworking problem.

Zhang Jialiang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 51-52). / Abstracts in English and Chinese. / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation and Related Work --- p.1 / Chapter 1.2 --- Organization of the Thesis --- p.3 / Chapter Chapter 2 --- Interference Modeling for Directional Antennas --- p.5 / Chapter 2.1 --- Pair-wise Physical Link Interference Model of Generic Directional Antenna --- p.6 / Chapter 2.2 --- Potential Interference Region --- p.8 / Chapter 2.3 --- Antenna Pattern and Phased Array Antenna --- p.9 / Chapter Chapter 3 --- Null Width of Directional Antennas --- p.12 / Chapter 3.1 --- Concept of Null Width --- p.12 / Chapter 3.2 --- Effective Null Width and Interference --- p.14 / Chapter 3.2.1 --- Probability of Interference --- p.14 / Chapter 3.2.2 --- Scenario of Directional Transmission and Omni-directional Reception --- p.15 / Chapter 3.2.3 --- Scenario of Directional Transmission and Directional Reception --- p.17 / Chapter 3.3 --- Properties of General Effective Beam Width --- p.18 / Chapter 3.4 --- Numerical Scaling Law of Effective Beam Width of Some Particular Antenna Patterns --- p.23 / Chapter 3.5 --- Summary --- p.26 / Chapter Chapter 4 --- Scaling Law of Network Capacity of Wireless Random Networks with Directional Antennas --- p.27 / Chapter 4.1 --- Random Network Model and Network Capacity --- p.27 / Chapter 4.2 --- Node distribution and MAC Protocol --- p.29 / Chapter 4.3 --- Scenario of Directional Transmission and Omni-directional Reception --- p.30 / Chapter 4.3.1 --- Probability of Transmission to be Success and Per-Link (Transport) Throughput --- p.30 / Chapter 4.3.2 --- Scaling Law of Network Capacity --- p.32 / Chapter 4.3.3 --- Concluding Remark --- p.37 / Chapter 4.4 --- Scenario of Directional Transmission and Directional Reception --- p.38 / Chapter 4.4.1 --- Antenna Steering Protocol --- p.39 / Chapter 4.4.2 --- Probability of Transmission to be Success --- p.40 / Chapter 4.4.3 --- Scaling Law of Network Capacity --- p.41 / Chapter 4.4.4 --- Scaling Law of Phased Array Antennas --- p.42 / Chapter Chapter 5 --- Conclusion --- p.44 / Appendix A: Proof of equation (22) --- p.47 / Appendix B: Proof of equation (28) --- p.49 / Appendix C: Constraint on Region of Optimality for pt and r --- p.50 / References --- p.51

Lau Ka Ming. / Thesis submitted in: August 2005. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 69-72). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.iii / Table of Contents --- p.iv / List of Figures --- p.vi / List of Tables --- p.viii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Wireless Ad Hoc Networks --- p.2 / Chapter 1.2.1 --- Wireless Sensor Network --- p.3 / Chapter 1.2.2 --- IEEE802.11 Ad Hoc Network --- p.3 / Chapter 1.2.3 --- Bluetooth Personal Area Network --- p.4 / Chapter 1.3 --- Power Saving in Wireless Ad Hoc Networks --- p.4 / Chapter 1.4 --- Contributions of the Thesis --- p.8 / Chapter 1.5 --- Outline of the Thesis --- p.9 / Chapter 2 --- Power Saving Mechanisms in Wireless Ad hoc Networks --- p.10 / Chapter 2.1 --- Recent Research Proposals --- p.10 / Chapter 2.1.1 --- Synchronous Power Saving Schemes --- p.11 / Chapter 2.1.2 --- Asynchronous Power Saving Schemes --- p.12 / Chapter 2.2 --- Existing Standards --- p.17 / Chapter 2.2.1 --- IEEE802.1l Ad Hoc Power Saving Mode --- p.17 / Chapter 2.2.2 --- Bluetooth Low Power Modes --- p.20 / Chapter 3 --- Analytical Framework for Designing Synchronous Wakeup Patterns --- p.22 / Chapter 3.1 --- System Model --- p.23 / Chapter 3.1.1 --- Vacation Model --- p.23 / Chapter 3.1.2 --- Optimal Wakeup Pattern --- p.25 / Chapter 3.2 --- Analytical analysis of different wakeup patterns --- p.27 / Chapter 3.2.1 --- Exhaustive Wakeup Pattern --- p.27 / Chapter 3.2.2 --- Gated Wakeup Pattern --- p.31 / Chapter 3.2.3 --- Gated Wakeup With Constant Cycle Time --- p.34 / Chapter 3.3 --- Discussion of results --- p.43 / Chapter 3.3.1 --- Performances impacts of various system parameters --- p.43 / Chapter 3.3.2 --- Performances comparison of different wakeup patterns --- p.47 / Chapter 3.4 --- Chapter Summary --- p.48 / Chapter 4 --- An improved IEEE802.1l Power Saving Mode --- p.49 / Chapter 4.1 --- Related Proposals --- p.50 / Chapter 4.2 --- Proposed Scheme --- p.52 / Chapter 4.2.1 --- Overview --- p.52 / Chapter 4.2.2 --- Beacon Sending Station --- p.53 / Chapter 4.2.3 --- Beacon Receiving Station --- p.55 / Chapter 4.2.4 --- Computing the Transmission Schedule --- p.55 / Chapter 4.2.5 --- Data Transmission Specifications --- p.56 / Chapter 4.2.6 --- Failure Conditions --- p.58 / Chapter 4.3 --- Performances Evaluation --- p.58 / Chapter 4.3.1 --- Simulation Model --- p.60 / Chapter 4.3.2 --- Simulation Results --- p.60 / Chapter 4.4 --- Chapter Summary --- p.64 / Chapter 5 --- Conclusion --- p.66