Wen Yonggang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references. / Abstracts in English and Chinese. / Chapter 1 --- Introduction / Chapter 1.1 --- Multi-Protocol Label Switching (MPLS) Technology --- p.1 / Chapter 1.2 --- Objective of this Thesis --- p.4 / Chapter 1.3 --- Reference --- p.5 / Chapter 2 --- Optical MPLS Network and Optical Label Schemes / Chapter 2.1 --- Optical MPLS Network --- p.7 / Chapter 2.2 --- Optical Label Schemes --- p.10 / Chapter 2.2.1 --- Time-division OMPLS scheme --- p.12 / Chapter 2.2.2 --- Wavelength-division OMPLS scheme --- p.16 / Chapter 2.2.3 --- Frequency-division OMPLS scheme --- p.22 / Chapter 2.2.3.1 --- UCSB Testbed --- p.23 / Chapter 2.2.3.2 --- UC-Davis Testbed --- p.26 / Chapter 2.2.3.3 --- NCTU-Telecordia Testbed --- p.28 / Chapter 2.2.4 --- Code-division OMPLS scheme --- p.30 / Chapter 2.2.4.1 --- Coherent Code-Division Label Scheme --- p.30 / Chapter 2.2.4.2 --- Noncoherent Code-Division Label Scheme --- p.32 / Chapter 2.3 --- Reference --- p.35 / Chapter 3 --- Architecture of OOC-based OMPLS network / Chapter 3.1 --- Infrastructure of OOC-label switch router (code converter) --- p.37 / Chapter 3.1.1 --- Architecture of the Proposed Code Converter --- p.38 / Chapter 3.1.2 --- Enhancement of the Code Converter --- p.41 / Chapter 3.2 --- Implementation of the OOC code converter --- p.43 / Chapter 3.2.1 --- Encoders/Decoders --- p.43 / Chapter 3.2.1.1 --- All-parallel encoders/decoders --- p.43 / Chapter 3.2.1.2 --- All-serial encoders/decoders --- p.45 / Chapter 3.2.1.3 --- Serial-to-parallel encoder/decoders --- p.47 / Chapter 3.2.1.4 --- Comparison of the three kinds of encoders/decoders --- p.49 / Chapter 3.2.2 --- Time-Gate-Intensity-Threshold (TGIT) Device --- p.50 / Chapter 3.2.3 --- Optical Space Switch Array --- p.54 / Chapter 3.2.3.1 --- All-optical Space Switch --- p.54 / Chapter 3.2.3.2 --- Optical switching technologies --- p.56 / Chapter 3.2.3.2.1 --- Scalability --- p.56 / Chapter 3.2.3.2.2 --- Switching Speed --- p.57 / Chapter 3.2.3.2.3 --- Reliability --- p.57 / Chapter 3.2.3.2.4 --- Losses --- p.58 / Chapter 3.2.3.2.5 --- Port-to-Port repeatability --- p.58 / Chapter 3.2.3.2.6 --- Cost --- p.59 / Chapter 3.2.3.2.7 --- Power Consumption --- p.60 / Chapter 3.3 --- Reference --- p.61 / Chapter 4 --- Scalability of OOC-based MPLS network / Chapter 4.1 --- Limitation on Label Switching Capacity --- p.63 / Chapter 4.1.1 --- Upper Bound --- p.65 / Chapter 4.1.2 --- Lower Bound --- p.66 / Chapter 4.2 --- Limitation on Switching Cascadability --- p.70 / Chapter 4.2.1. --- Limit Induced by the Inter-channel Crosstalk --- p.70 / Chapter 4.2.2 --- Limits Induced by the Residue Intensity of Sidelobes --- p.74 / Chapter 4.3 --- Appendix --- p.78 / Chapter 4.3.1 --- Derivation of Chip Intensity --- p.78 / Chapter 4.3.2 --- The 5% residue power criterion --- p.81 / Chapter 4.4 --- Reference --- p.83 / Chapter 5 --- Conclusion / Chapter 5.1 --- Summary of the Thesis --- p.85 / Chapter 5.2 --- Future work --- p.86

Reliable routing using alternate paths is investigated in this dissertation. We propose precalculated alternate paths as a method for fast recovery from link and node failures in IP networks. We demonstrate that path switching time, and thus failure recovery time are, as expected, considerably faster than the standard method of recalculating a new path on the fly. However, to be effective, the alternate paths should share a minimal set of links and nodes - preferably none - with the failed path. As shared links are considered in this work, we give a reliability model for this situation (non-disjoint alternate paths) and develop estimates of reliability as a function of the number of shared links. Alternate path finding algorithms to calculate suitable alternate paths subject to predefined constraints are also developed. Implementation of these techniques for improving routing reliability is shown to be straightforward for explicit routing protocols such as Multi-Protocol Label Switching (MPLS) with Explicit Routing mode. This mode is expected to be the protocol of choice for applications requiring guaranteed Quality of Service (QoS) carried on the coming generation of wavelength-switched networks (Internet II, CA Net III, etc.) We propose a Reliable MPLS (R-MPLS) protocol by applying alternate path routing to MPLS, using our new algorithms to precalculate appropriate alternate paths. Simulation results show that R-MPLS can achieve fast recovery from failures. We also address reliability issues for the problem of optimal Service Level Agreement (SLA) admission control. To achieve reliable admission control, we apply alternate path routing to an existing SLA-based admission controller called SLAOpt. In the existing Utility Model, SLA admission control is mapped to the Multiple-Choice Multi-Dimension Knapsack Problem (MMKP), where the aim is to maximize system utility (i.e., revenue). However, SLAOpt is static in terms of network topology and does not consider reliability. Motivated by this, we propose a Reliable SLAOpt (R-SLAOpt), in which utility optimization is subject to the additional constraint of reliability. A new algorithm was also developed to calculate multiple groups of alternate paths that meet the desired QoS demands and reliability requirement. After QoS adaptation, R-SLAOpt selects an appropriate path group containing two or three paths for each admitted session and performs resource reservation on all paths in the group. In the event of node or link failure, a session can be quickly switched to one of the alternate paths, maintaining the guaranteed QoS without having to run the full admission algorithm again. In this way, we have obtained a unified treatment of routing reliability and optimal SLA admission control. Finally, simulations are presented which investigate R-SLAOpt's impact on system performance and the gains made in reliability. / Graduate

No description available.

Thesis (M.Sc.) - Carleton University, 2005. / Includes bibliographical references (p. 76-81). Also available in electronic format on the Internet.

Thesis (Ph.D.)--Wichita State University, 2003. / Adviser: Ravi Pendse. Includes bibliographical references.

M. Tech. Electrical Engineering. / Discusses the study as limited to the formal specification/modelling and formal verification of protocols proposed and applicable to the initial network entry procedure in WiMAX networks. Secondly, formal specification of the existing protocols under consideration will be based on their informal specification available in the literature and not on proprietary protocols for which little or no information is available. Thirdly, this research work does not intend to wipe out the state space explosion problem but rather applies existing optimization techniques to supress it. Finally, the study does not assess the usability performance impact of the proposed security scheme and thus recommends that this analysis should be done as future work to evaluate the functionality and soundness of deploying the proposed security scheme.

There is currently much work focused on developing packet-switched optical networks to overcome the limitations of existing optical networks. Switch design for packet-switched optical networks is particularly challenging, in part due to the lack of a practical optical memory system. As a result, optical labels and all-optical label processing have attracted much attention. This thesis examines a crucial label processing component of an optical packet switch, namely the label swapper. / In this thesis, three different tabletop topologies for low-cost all-optical swapping of spectral amplitude code labels for packet-switched networks are examined in a proof-of-concept phase. The first uses cross-absorption modulation in an electro-absorption modulator within a semiconductor fiber ring laser (SFRL), the second uses cross-gain modulation (XGM) in a semiconductor optical amplifier (SOA) within an SFRL, and the third makes use of XGM in a SOA as well as injection locking in a Fabry-Perot laser diode for wavelength conversion. The benefits and limitations of each approach as well as future improvements are discussed. Building on these results, a high-performance integrated version of XGM swapper is designed, simulated, and masks are produced for fabrication using indium phosphide technology.

No description available.

No description available.

Thesis (MSc)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: lP networks offer scalability and flexibility for rapid deployment of value added lP services. However, with the increased demand and explosive growth of the Internet, carriers require a network infrastructure that is dependable, predictable, and offers consistent network performance. This thesis examines the functionality, performance and implementation aspects of the MPLS mechanisms to minimize the expected packet delay in MPLS networks. Optimal path selection and the assignment of bandwidth to those paths for minimizing the average packet delay are investigated. We present an efficient flow deviation algorithm (EFDA) which assigns a small amount of flow from a set of routes connecting each OD pair to the shortest path connecting the OD pair in the network. The flow is assigned in such a way that the network average packet delay is minimized. Bellman's algorithm is used to find the shortest routes between all OD pairs. The thesis studies the problem of determining the routes between an OD pair and assigning capacities to those routes. The EFDA algorithm iteratively determines the global minimum of the objective function. We also use the optimal flows to compute the optimal link capacities in both single and multirate networks. The algorithm has been applied to several examples and to different models of networks. The results are used to evaluate the performance of the EFDA algorithm and compare the optimal solutions obtained with different starting topologies and different techniques. They all fall within a close cost-performance range. They are all within the same range from the optimal solution as well. / AFRIKAANSE OPSOMMING: lP-netwerke voorsien die skaleerbaarheid en buigsaamheid vir die vinnige ontplooing van toegevoegde-waarde lP-dienste. Die vergrote aanvraag en eksplosiewe uitbreiding van die Internet benodig betroubare, voorspelbare en bestendige netwerkprestasie. Hierdie tesis ondersoek die funksionaliteit, prestasie en implementering van die MPLS(multiprotokoletiketskakel)- meganismes om die verwagte pakketvertraging te minimeer. Ons bespreek 'n doeltreffende algoritme vir vloei-afwyking (EFDA) wat 'n klein hoeveelheid vloei toewys uit die versameling van roetes wat elke OT(oorsprong-teiken)- paar verbind aan die kortste pad wat die OT-paar koppel. Die vloei word toegewys sodanig dat die netwerk se gemiddelde pakketvertraging geminimeer word. Bellman se algoritme word gebruik om die kortste roetes tussen alle OT-pare te bepaal. Die tesis bespreek die probleem van die bepaling van roetes tussen 'n OT-paar en die toewysing van kapasiteite aan sulke roetes. Die EFDA-algoritme bepaal die globale minimum iteratief. Ons gebruik ook optimale vloeie vir die berekening van die optimale skakelkapasiteite in beide enkel- en multikoers netwerke. Die algoritme is toegepas op verskeie voorbeelde en op verskillende netwerkmodelle. Die skakelkapasiteite word aangewend om die prestasie van die EFDAalgoritme te evalueer en dit te vergelyk met die optimale oplossings verkry met verskillende aanvangstopologieë en tegnieke. Die resultate val binne klein koste-prestasie perke wat ook na aan die optimale oplossing lê.