4,512 research outputs found

    Denial of service attacks and challenges in broadband wireless networks

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    Broadband wireless networks are providing internet and related services to end users. The three most important broadband wireless technologies are IEEE 802.11, IEEE 802.16, and Wireless Mesh Network (WMN). Security attacks and vulnerabilities vary amongst these broadband wireless networks because of differences in topologies, network operations and physical setups. Amongst the various security risks, Denial of Service (DoS) attack is the most severe security threat, as DoS can compromise the availability and integrity of broadband wireless network. In this paper, we present DoS attack issues in broadband wireless networks, along with possible defenses and future directions

    A Simple Fiber Bragg Grating-Based Sensor Network Architecture with Self-Protecting and Monitoring Functions

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    A novel fiber Bragg grating (FBG)-based passive sensor architecture, which can be used to protect the fiber cut and monitor the multiple sensors simultaneously, is proposed and experimentally demonstrated. Here, we employ a wavelength-tunable erbium-doped fiber (EDF) laser scheme with 25 km cavity length acting as the detecting light source in central office (CO). Each FBG sensor, serving as a feedback element, is used in proposed sensor architecture. By tuning the tunable bandpass filter (TBF) placing inside cavity to match the corresponding Bragg wavelength of FBG over the amplification bandwidth, we can retrieve the related wavelength lasing for the FBG sensing and monitoring simultaneously. Moreover, the survivability and capacity of the passive FBG sensor architecture can be also enhanced

    Robust fiber-optic sensor networks

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    The ability to operate despite failure will become increasingly important as the use of optical sensor networks grows, and the amount of sensing information to be handled by a sensor network is increasing, especially for safety and security applications. In this review, the four categories of protection to allow service to be reestablished after a failure (dedicated/shared and line/path) are thoroughly discussed. This paper also presents an overview of the most representative robust fiber-optic sensor systems, discussing their schemes, pros and cons.The authors are grateful to the Spanish Government project TEC2010-20224-C02-01

    Internet of Things-aided Smart Grid: Technologies, Architectures, Applications, Prototypes, and Future Research Directions

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    Traditional power grids are being transformed into Smart Grids (SGs) to address the issues in existing power system due to uni-directional information flow, energy wastage, growing energy demand, reliability and security. SGs offer bi-directional energy flow between service providers and consumers, involving power generation, transmission, distribution and utilization systems. SGs employ various devices for the monitoring, analysis and control of the grid, deployed at power plants, distribution centers and in consumers' premises in a very large number. Hence, an SG requires connectivity, automation and the tracking of such devices. This is achieved with the help of Internet of Things (IoT). IoT helps SG systems to support various network functions throughout the generation, transmission, distribution and consumption of energy by incorporating IoT devices (such as sensors, actuators and smart meters), as well as by providing the connectivity, automation and tracking for such devices. In this paper, we provide a comprehensive survey on IoT-aided SG systems, which includes the existing architectures, applications and prototypes of IoT-aided SG systems. This survey also highlights the open issues, challenges and future research directions for IoT-aided SG systems

    Self-healing network architectures for multiwavelength optical metro/access networks.

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    Sun Xiaofeng.Thesis (M.Phil.)--Chinese University of Hong Kong, 2006.Includes bibliographical references (leaves 61-64).Abstracts in English and Chinese.Chapter CHAPTER 1 --- INTRODUCTION --- p.1Chapter 1.1 --- Optical network evolution --- p.2Chapter 1.1.1 --- Submarine and terrestrial long-haul fibre systems --- p.2Chapter 1.1.2 --- Metropolitan networks --- p.3Chapter 1.1.3 --- Access networks --- p.4Chapter 1.2 --- Motivation of this thesis --- p.6Chapter 1.3 --- Outline of this thesis --- p.7Chapter CHAPTER 2 --- PREVIOUS SELF-HEALING NETWORK ARCHITECTURES --- p.9Chapter 2.1 --- Introduction --- p.10Chapter 2.1.1 --- Previous protection architectures for access networks --- p.10Chapter 2.1.2 --- Previous protection architectures for metro access networks --- p.13Chapter 2.3 --- Previous protection architectures for metro backbone networks --- p.15Chapter 2.3.1 --- Unidirectional path-switched rings (UPSR) --- p.15Chapter 2.3.2 --- Bidirectional line-switched rings (BLSR) --- p.16Chapter 2.3.3 --- Ring interconnection and dual homing --- p.17Chapter 2.4 --- Summary --- p.19Chapter CHAPTER 3 --- SELF-HEALING NETWORK ARCHITECTURE FOR WDM OPTICAL ACCESS NETWORKS --- p.20Chapter 3.1 --- Introduction --- p.21Chapter 3.2 --- Star-Ring Protection Architecture (SRPA) --- p.21Chapter 3.2.1 --- Motivation --- p.21Chapter 3.2.2 --- Network topology of SRPA --- p.22Chapter 3.2.3 --- Wavelength assignment of SRPA --- p.22Chapter 3.2.4 --- Structure of ONU --- p.23Chapter 3.2.5 --- Protection mechanism --- p.25Chapter 3.2.6 --- Experimental demonstration --- p.26Chapter 3.2.7 --- Power budget --- p.28Chapter 3.2.8 --- Summary --- p.28Chapter 3.3 --- Duplicated-Tree Protection Architecture (DTPA) --- p.28Chapter 3.3.1 --- Motivation --- p.28Chapter 3.3.2 --- Network topology and wavelength assignment --- p.29Chapter 3.3.3 --- Structure of OLT --- p.30Chapter 3.3.4 --- Protection mechanism --- p.31Chapter 3.3.5 --- Experimental demonstration --- p.33Chapter 1.1.1 --- Summary --- p.34Chapter 1.4 --- Summary --- p.35Chapter CHAPTER 4 --- SINGLE-FIBER SELF-HEALING WDM RING NETWORK ARCHITECTURE FOR METRO ACCESS NETWORKS --- p.36Chapter 4.1 --- Introduction --- p.37Chapter 4.2 --- Network architecture and wavelength assignment --- p.37Chapter 4.3 --- Structure of access node --- p.39Chapter 4.4 --- Structure of hub node --- p.40Chapter 4.5 --- Protection mechanism --- p.42Chapter 4.6 --- Experimental demonstration --- p.43Chapter 4.7 --- Optimization of access node --- p.47Chapter 4.8 --- Scalability --- p.48Chapter 4.9 --- Summary --- p.49Chapter CHAPTER 5 --- SELF-HEALING WDM MESH NETWORK ARCHITECTURE FOR METRO BACKBONE NETWORKS… --- p.50Chapter 5.1 --- Introduction --- p.51Chapter 5.2 --- Network architecture and node structure --- p.51Chapter 5.3 --- Protection mechanism --- p.53Chapter 5.4 --- Experimental demonstration --- p.55Chapter 5.5 --- Summary --- p.57Chapter CHAPTER 6 --- SUMMARYAND FUTURE WORKS --- p.58Chapter 6.1 --- Summary of the Thesis --- p.59Chapter 6.2 --- Future Works --- p.59LIST OF PUBLICATIONS --- p.61REFERENCES --- p.6
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