The convergence of multiservice heterogeneous networks and ever increasing Internet applications, like peer to peer networking and the increased number of users and services, demand a more efficient bandwidth allocation in optical networks. In this context, new architectures and protocols are needed in conjuction with cost effective quantitative methodologies in order to provide an insight into the performance aspects of the next and future generation Internets. This thesis reports an investigation, based on efficient simulation methodologies, in order to assess existing high performance algorithms and to propose new ones. The analysis of the traffic characteristics of an OC-192 link (9953.28 Mbps) is initially conducted, a requirement due to the discovery of self-similar long-range dependent properties in network traffic, and the suitability of the GE distribution for modelling interarrival times of bursty traffic in short time scales is presented. Consequently, using a heuristic approach, the self-similar properties of the GE/G/∞ are being presented, providing a method to generate self-similar traffic that takes into consideration burstiness in small time scales. A description of the state of the art in optical networking providing a deeper insight into the current technologies, protocols and architectures in the field, which creates the motivation for more research into the promising switching technique of 'Optical Burst Switching' (OBS). An investigation into the performance impact of various burst assembly strategies on an OBS edge node's mean buffer length is conducted. Realistic traffic characteristics are considered based on the analysis of the OC-192 backbone traffic traces. In addition the effect of burstiness in the small time scales on mean assembly time and burst size distribution is investigated. A new Dynamic OBS Offset Allocation Protocol is devised and favourable comparisons are carried out between the proposed OBS protocol and the Just Enough Time (JET) protocol, in terms of mean queue length, blocking and throughput. Finally the research focuses on simulation methodologies employed throughout the thesis using the Graphics Processing Unit (GPU) on a commercial NVidia GeForce 8800 GTX, which was initially designed for gaming computers. Parallel generators of Optical Bursts are implemented and simulated in 'Compute Unified Device Architecture' (CUDA) and compared with simulations run on general-purpose CPU proving the GPU to be a cost-effective platform which can significantly speed-up calculations in order to make simulations of more complex and demanding networks easier to develop.

This thesis is concerned with the design of a high-speed backbone network which provides a high bandwidth interconnection for various Personal Computer Networks (PC-Networks) with an integrated service of voice and data. With the advanced technology of optical fiber as the transmission medium, several different existing topologies and protocols are discussed for the backbone network design. The token ring protocol is simulated and evaluated to find out a suitable buffer size and the length of voice and data packet for backbone network. The Network II.5 simulation tool is applied to simulate the token ring simulation model with different parameters. The Network Interface Unit (NIU) is designed from the simulation results with a cost-effective consideration.

The use of permutations in data compression is an aspect that is worthy of further exploration. The work that has been done in video compression based on permutations was primarily oriented towards lossless algorithms. The study of previous algorithms has led to a new algorithm that could be either lossless or lossy, for which the amount of compression and the quality of the output can be controlled. The lossless version of our algorithm performs close to lossy versions of H.264 and it improves on them for the majority of the videos that we analyzed. Our algorithm could be used in situations where there is a need for lossless compression and the video sequences are part of a single scene, e.g., medical videos, where loss of information could be risky or expensive. Some results on permutations, which may be of independent interest, arose in developing this algorithm. We report on these as well. / by Amalya Mihnea. / Thesis (Ph.D.)--Florida Atlantic University, 2011. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2011. Mode of access: World Wide Web.

Cloud Computing is a new computing model consists of a large pool of hardware and software resources on remote datacenters that are accessed through the Internet. Cloud Computing faces significant obstacles to its acceptance, such as security, virtualization, and lack of standardization. For Cloud standards, there is a long debate about their role, and more demands for Cloud standards are put on the table. The Cloud standardization landscape is so ambiguous. To model and analyze security standards for Cloud Computing and web services, we have surveyed Cloud standards focusing more on the standards for security, and we classified them by groups of interests. Cloud Computing leverages a number of technologies such as: Web 2.0, virtualization, and Service Oriented Architecture (SOA). SOA uses web services to facilitate the creation of SOA systems by adopting different technologies despite their differences in formats and protocols. Several committees such as W3C and OASIS are developing standards for web services; their standards are rather complex and verbose. We have expressed web services security standards as patterns to make it easy for designers and users to understand their key points. We have written two patterns for two web services standards; WS-Secure Conversation, and WS-Federation. This completed an earlier work we have done on web services standards. We showed relationships between web services security standards and used them to solve major Cloud security issues, such as, authorization and access control, trust, and identity management. Close to web services, we investigated Business Process Execution Language (BPEL), and we addressed security considerations in BPEL and how to enforce them. To see how Cloud vendors look at web services standards, we took Amazon Web Services (AWS) as a case-study. By reviewing AWS documentations, web services security standards are barely mentioned. We highlighted some areas where web services security standards could solve some AWS limitations, and improve AWS security process. Finally, we studied the security guidance of two major Cloud-developing organizations, CSA and NIST. Both missed the quality of attributes offered by web services security standards. We expanded their work and added benefits of adopting web services security standards in securing the Cloud. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2013.

A social network is a structure of individuals and organizations, which are connected by one or more types of interdependency, such as friendship, affinity, common interests or knowledge. Social networks use Web 2.0 technology, which is mostly based on a service-oriented architecture. We are studying patterns for social networks in this environment. A pattern is an encapsulated solution to a software problem in a given context, secure threats are possible in this context. We present a collection of patterns associated with the most important aspects of social networks, with emphasis on controlling the actions of the users of these networks. / by Carolina Marina. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.

Nowadays, broadband applications, such as interactive video and multimedia services, have further increased the demand of bandwidth, and thus make high speed multi-wavelength optical access network highly desirable. Wavelength division multiplexing passive optical network (WDM-PON) is a promising candidate to realize the next generation optical access networks due to its dedicated bandwidth for each subscriber and more flexible bandwidth management. As the network traffic is becoming more data-centric, more networking capabilities are required to provide the data service in a more flexible and reliable way. In this thesis, we have proposed and investigated several interesting optical multicast overlay schemes and network protection architectures for WDM-PONs. Optical multicast overlay technique can support the additional multicast transmission on the existing point-to-point data services, while network protection architectures can assure network availability with short traffic restoration time. We will briefly discuss our work in the following sub-topics. / Optical multicast overlay in WDM-PON: Traditional WDM-PONs support only two-way point-to-point data transmission between the optical line terminal (OLT) and the individual subscribers, via the respective designated set of wavelengths. To enhance the network flexibility, it is more desirable to support various different modes of data or video delivery such as broadcast and multicast, in addition to point-to-point transmissions. In this thesis, we systematically investigate the problems and propose our several feasible schemes to overlay multicast transmission onto the existing point-to-point traffic in a WDM-PON. In the first approach, the control of the multicast transmission is achieved by a simple polarization-assisted scheme at the OLT. By the cross-use of wavelengths, a separate path is provided for the multicast differential phase shift keying (DPSK) data from downstream point-to-point amplitude shift keying (ASK) data without additional light sources, which guarantees the transmission performances in both directions, since the upstream ASK signal is imposed on the multicast DPSK signal. We have also demonstrated its variant, in which an optical switch replaces the polarization-assisted control for multicast transmission. The second approach is based on the optical carrier suppression (OCS) technique at the OLT so as to generate the optical subcarriers or sidebands for multicast ASK data modulation. The downstream unicast data is modulated in DPSK format, which will be re-modulated with the upstream ASK data at the respective optical network unit (ONU). As the downstream unicast signal and the upstream signal are calTied on different fiber feeders, while the upstream signal and the multicast signal are carried on different subcarriers, though on the same fiber feeder, the possible Rayleigh backscattering effect is much alleviated. In the third scheme, by using subcarrier modulation technique, we have first successfully overlaid two independent multicast data streams simultaneously onto a WDM-PON, which is believed to further enhance the network capability for multiple destination traffic and improve the cost effectiveness for the future network. Finally, we will provide a comprehensive comparison on all the proposed schemes in this topic. / Survivable network architectures for WDM-PONs: A survivable WDM-PON architecture which can provide self-protection is attractive to avoid enormous loss in data and business due to fiber cuts. To facilitate the network management, the protection switching is realized at the OLT. In this thesis, a simple centrally controlled survivable WDM-PON architecture employing OCS technique is proposed. Protection switching at the OLT employs electrical switches to control the clock signal for the protection sub-carrier generation, via optical carrier suppression. Both distribution and feeder fibers are protected simultaneously. By employing inverse-RZ (IRZ) format for the downstream transmission and non-retum-to-zero (NRZ) for the upstream re-modulated signal, the optical network units are kept colorless and simple. On the other hand, wavelength division multiplexing/time division multiplexing (WDM/TDM) hybrid network, which combines TDM technology and WDM technology, can further increase the network reach, transmission capacity, and reduces the cost per subscriber. Although the bandwidth per subscriber in a WDM/TDM PON is less than that in a WDM-PON, it is still considered as a smooth migration from TDM-PON to WDM-PON. In this thesis, we have proposed a novel WDM/TDM PON architecture which can provide self-protection using a ring topology to connect the subscribers. Finally, we will provide a comprehensive comparison on all the proposed schemes in this topic. / Qiu, Yang. / Adviser: Chun-Kit Chan. / Source: Dissertation Abstracts International, Volume: 73-06, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 130-140). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

"Resource sharing between applications can significantly improve the resources required for all, which can reduce cost, and improve performance. Isolating resources on the other hand can also be beneficial as the failure or significant load on one application does not affect another. There is a delicate balance between resource sharing and resource isolation. Virtual machines may be a solution to this problem with the added benefit of being able to perform more dynamic load balancing, but this solution may be at a significant cost in performance. This thesis compares three different configurations for machines running application servers. It looks at speed at which a new application server can be started up, resource sharing and resource isolation between applications in an attempt to quantify the tradeoffs for each type of configuration."

by Lee Chi Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 63-65). / Abstracts in English and Chinese. / Chapter CHAPTER 1 --- INTRODUCTION --- p.5 / Chapter 1.1 --- Background --- p.5 / Chapter 1.1.1 --- Backbone network - Long haul mesh network problem --- p.5 / Chapter 1.1.2 --- Access network ´ؤ Last mile problems --- p.8 / Chapter 1.1.3 --- Network integration --- p.9 / Chapter 1.2 --- SUMMARY OF INSIGHTS --- p.10 / Chapter 1.3 --- Contribution of this thesis --- p.11 / Chapter 1.4 --- Structure of the thesis --- p.11 / Chapter CHAPTER 2 --- PREVIOUS PROTECTION ARCHITECTURES --- p.12 / Chapter 2.1 --- Introduction --- p.12 / Chapter 2.2 --- Traditional physical protection architectures in metro area --- p.13 / Chapter 2.2.1 --- Self healing ring --- p.17 / Chapter 2.2.2 --- Some terminology in ring protection --- p.13 / Chapter 2.2.3 --- Unidirectional path-switched rings (UPSR) [17] --- p.13 / Chapter 2.2.4 --- Bidirectional line-switched rings (BLSR) [17] --- p.14 / Chapter 2.2.5 --- Ring interconnection and dual homing [17] --- p.16 / Chapter 2.3 --- Traditional physical protection architectures in access networks --- p.17 / Chapter 2.3.1 --- Basic architecture in passive optical networks --- p.17 / Chapter 2.3.2 --- Fault management issue in access networks --- p.18 / Chapter 2.3.3 --- Some protection architectures --- p.18 / Chapter 2.4 --- Recent protection architectures on a ccess networks --- p.21 / Chapter 2.4.1 --- Star-Ring-Bus architecture --- p.21 / Chapter 2.5 --- Concluding remarks --- p.22 / Chapter CHAPTER 3 --- GROUP PROTECTION ARCHITECTURE (GPA) FOR TRAFFIC RESTORATION IN MULTI- WAVELENGTH PASSIVE OPTICAL NETWORKS --- p.23 / Chapter 3.1 --- Background --- p.23 / Chapter 3.2 --- Organization of Chapter 3 --- p.24 / Chapter 3.3 --- Overview of Group Protection Architecture --- p.24 / Chapter 3.3.1 --- Network architecture --- p.24 / Chapter 3.3.2 --- Wavelength assignment --- p.25 / Chapter 3.3.3 --- Normal operation of the scheme --- p.25 / Chapter 3.3.4 --- Protection mechanism --- p.26 / Chapter 3.4 --- Enhanced GPA architecture --- p.27 / Chapter 3.4.1 --- Network architecture --- p.27 / Chapter 3.4.2 --- Wavelength assignment --- p.28 / Chapter 3.4.3 --- Realization of network elements --- p.28 / Chapter 3.4.3.1 --- Optical line terminal (OLT) --- p.28 / Chapter 3.4.3.2 --- Remote node (RN) --- p.29 / Chapter 3.4.3.3 --- Realization of optical network unit (ONU) --- p.30 / Chapter 3.4.4 --- Protection switching and restoration --- p.31 / Chapter 3.4.5 --- Experimental demonstration --- p.31 / Chapter 3.5 --- Conclusion --- p.33 / Chapter CHAPTER 4 --- A NOVEL CONE PROTECTION ARCHITECTURE (CPA) SCHEME FOR WDM PASSIVE OPTICAL ACCESS NETWORKS --- p.35 / Chapter 4.1 --- Introduction --- p.35 / Chapter 4.2 --- Single-side Cone Protection Architecture (SS-CPA) --- p.36 / Chapter 4.2.1 --- Network topology of SS-CPA --- p.36 / Chapter 4.2.2 --- Wavelength assignment of SS-CPA --- p.36 / Chapter 4.2.3 --- Realization of remote node --- p.37 / Chapter 4.2.4 --- Realization of optical network unit --- p.39 / Chapter 4.2.5 --- Two types of failures --- p.40 / Chapter 4.2.6 --- Protection mechanism against failure --- p.40 / Chapter 4.2.6.1 --- Multi-failures of type I failure --- p.40 / Chapter 4.2.6.2 --- Type II failure --- p.40 / Chapter 4.2.7 --- Experimental demonstration --- p.41 / Chapter 4.2.8 --- Power budget --- p.42 / Chapter 4.2.9 --- Protection capability analysis --- p.42 / Chapter 4.2.10 --- Non-fully-connected case and its extensibility for addition --- p.42 / Chapter 4.2.11 --- Scalability --- p.43 / Chapter 4.2.12 --- Summary --- p.43 / Chapter 4.3 --- Comparison between GPA and SS-CPA scheme --- p.43 / Chapter 4.1 --- Resources comparison --- p.43 / Chapter 4.2 --- Protection capability comparison --- p.44 / Chapter 4.4 --- Concluding remarks --- p.45 / Chapter CHAPTER 5 --- MUL 77- WA VELENGTH MUL TICAST NETWORK IN PASSIVE OPTICAL NETWORK --- p.46 / Chapter 5.1 --- Introduction --- p.46 / Chapter 5.2 --- Organization of this chapter --- p.47 / Chapter 5.3 --- Simple Group Multicast Network (SGMN) scheme --- p.47 / Chapter 5.3.1 --- Network design principle --- p.47 / Chapter 5.3.2 --- Wavelength assignment of SGMN --- p.48 / Chapter 5.3.3 --- Realization of remote node --- p.49 / Chapter 5.3.3 --- Realization of optical network unit --- p.50 / Chapter 5.3.4 --- Power budget --- p.51 / Chapter 5.4 --- A mulTI- wa velength a ccess network with reconfigurable multicast …… --- p.51 / Chapter 5.4.1 --- Motivation --- p.51 / Chapter 5.4.2 --- Background --- p.51 / Chapter 5.4.3 --- Network design principle --- p.52 / Chapter 5.4.4 --- Wavelength assignment --- p.52 / Chapter 5.4.5 --- Remote Node design --- p.53 / Chapter 5.4.6 --- Optical network unit design --- p.54 / Chapter 5.4.7 --- Multicast connection pattern --- p.55 / Chapter 5.4.8 --- Multicast group selection in OLT --- p.57 / Chapter 5.4.9 --- Scalability --- p.57 / Chapter 5.4.10 --- Experimental configuration --- p.58 / Chapter 5.4.11 --- Concluding remarks --- p.59 / Chapter CHAPTER 6 --- CONCLUSIONS --- p.60 / LIST OF PUBLICATIONS: --- p.62 / REFERENCES: --- p.63

During the last few years, Service-Oriented Architecture (SOA) has been considered to be the new phase in the evolution of distributed enterprise applications. Even though there is a common acceptance of this concept, a real problem hinders the widespread use of SOA : A methodology to design and build secure service-oriented applications is needed. In this dissertation, we design a novel process to secure service-oriented applications. Our contribution is original not only because it applies the MDA approach to the design of service-oriented applications but also because it allows their securing by dynamically applying security patterns throughout the whole process. Security patterns capture security knowledge and describe security mechanisms. In our process, we present a structured map of security patterns for SOA and web services and its corresponding catalog. At the different steps of a software lifecycle, the architect or designer needs to make some security decisions. / An approach using a decision tree made of security pattern nodes is proposed to help making these choices. We show how to extract a decision tree from our map of security patterns. Model-Driven Architecture (MDA) is an approach which promotes the systematic use of models during a system's development lifecycle. In the dissertation we describe a chain of transformations necessary to obtain secure models of the service-oriented application. A main benefit of this process is that it decouples the application domain expertise from the security expertise that are both needed to build a secure application. Security knowledge is captured by pre-defined security patterns, their selection is rendered easier by using the decision trees and their application can be automated. A consequence is that the inclusion of security during the software development process becomes more convenient for the architects/designers. / A second benefit is that the insertion of security is semi-automated and traceable. Thus, the process is flexible and can easily adapt to changing requirements. Given that SOA was developed in order to provide enterprises with modular, reusable and adaptable architectures, but that security was the principal factor that hindered its use, we believe that our process can act as an enabler for service-oriented applications. / by Nelly A. Delessy. / Thesis (Ph.D.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, FL : 2008 Mode of access: World Wide Web.

Currently, optical communications plays an important role in the transmission aspect of backbone fiber networks. However, there still remain two challenges in this field: one is the bottleneck between high-capacity local area networks (LANs) and the backbone network, where the answer is the broadband optical fiber access networks; the other is the bottleneck of low-speed electrical signal processing in high capacity optical networks, where one possible solution is all-optical nonlinear signal processing. This thesis will cover both of the two topics. In the first topic, the emphasis will be put on the novel optical access network infrastructure design to improve the access network reliability and functionality as well as the reduction of system complexity. In the second topic, the focus is how to utilize the newly-emerging photonic devices or newly-designed configurations to improve the performance of current optical signal processing subsystems for applications in lightwave transmission systems. / In summary, this thesis introduces a series of novel optical access network architecture designs and transmission system technologies for optical fiber communications and discusses their feasibilities in practice from the research perspective. We hope that these proposed technologies can contribute to the further developments in this field. / In the area of broadband optical fiber access networks, two aspects are considered: survivability and monitoring function. For the first part, several new network protection schemes among various access network topologies (i.e. tree and ring) are proposed and experimentally demonstrated, which could reduce the access network cost and simplifying the operation of the access network. For the second part, an interesting in-service fault surveillance scheme in the current TDM-PON is proposed via analyzing the composite radio-frequency (RF) spectrum of the common supervisory channel at the central office (CO). Experiment proves its effectiveness with negligible influence on the signal channels. In addition, a system demonstration of the WDM-based optical broadband access network with automatic optical protection function is presented, showing the potential of WDM technologies in the broadband optical access networks. / In the area of nonlinear optical signal processing, the technology innovation is in two areas: new architecture design and the new photonic devices. For the issue of architecture design, the focus is on the Nonlinear Optical Loop Mirror (NOLM) structure. A new polarization-independent OTDM demultiplexing scheme is proposed and demonstrated by incorporating a polarization-diversity loop into a conventional NOLM, which offers stable operation using the conventional components without sacrificing the operation speed or structural simplicity. In another study the design of a novel OFSK transmitter based on phase-modulator-embedded NOLM is conceived and implemented, which features data-rate transparent, continuous tuning of the wavelength spacing and stable operation. For the aspect of new photonic devices, this thesis focuses on the applications of photonic crystal fibers (PCF). In one work, a relatively short-length of dispersion-flattened high-nonlinearity PCF (gamma=11.2 (W-km)-1, D<-1 ps/nm/km 1500-1600 nm, S<1 x 10-3 ps/km/nm2) is integrated into a dispersion-imbalanced loop mirror (DILM) to form a nonlinear intensity discriminator and its application in the nonlinear suppression of the incoherent interferometric crosstalk has been successfully demonstrated. The special characteristics of the PCF ensure a broadband signal quality improvement and make the DILM more compact and stable. In the other work, the small birefringence of this PCF helps to simply achieve the polarization-insensitive wide-band wavelength converter based on four-wave-mixing in PCF. / Wang Zhaoxin. / "September 2006." / Advisers: Chinlon Lin; Chun-Kit Chan. / Source: Dissertation Abstracts International, Volume: 68-03, Section: B, page: 1846. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 93-101). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.