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This thesis proposes new algorithms for restoration strategies that provision bandwidth guaranteed recovery for unicast and multicast connections. The primary focus is on online restoration strategies that sequentially do pre-planning of resource for each request using the current network resource state. Online restoration strategies do not require prior knowledge of all the requests like that of offline restoration strategies. Therefore, online restoration strategies are more suitable for on-demand and dynamic traffic engineering control. The proposed new algorithms are compared to known algorithms from literature. Most literature evaluates the performance of the algorithms with two metrics only: total bandwidth requirement and the number of requests accepted in the network. This thesis evaluates the algorithms in one additional dimension: the computational time. This is an important criterion when response times for establishing new connections are stringent. Each algorithm makes trade-off between computational complexity, bandwidth efficiency, and number of accepted requests. Results show that the proposed algorithms provide alternative trade-offs between the three performance metrics when compared to other existing algorithms. The alternatives provide more choice for the network providers and the best algorithm to use depends on the network's requirements. The restoration strategies used for unicast and multicast connections in this thesis are very compatible thus it is possible to integrate the restoration strategies into a single system where they share the same backup resources. Results from simulations show that using an integrated restoration model has significant benefits, which includes lower backup bandwidth requirement than the separate restoration model.

The need for information anywhere and at any time has been the driving force for the increasing growth in mobile networks and devices. The field of mobile computing is the merger of advances in computing and communications with the aim of providing seamless and ubiquitous computing environment for mobile users. Whereas notebook computers and personal digital assistants (PDAs) are self-contained, networked computing constitutes a new paradigm of computing that is revolutionizing the way computers are used. Mobile networking greatly enhances the utility of carrying a computing device. It provides mobile users with versatile communication to other people and expedient notification of important events, yet with much more flexibility than cellular telephones and pagers. It also permits continuous access to services and resources of the traditional land-based wired networks. This combination of networking and mobility will engender new applications and services, such as collaborative software to support impromptu meetings, electronic bulletin boards that adapt to the contents according to the participants present, self adjusting lighting and heating, and navigation software to guide users in unfamiliar places and tours. To support mobility in the Internet, the Internet Protocol (IP) has been extended to support mobility. Also at the same time, there is also a growing trend for these IP based networks to operate in an infrastructureless environment called mobile ad-hoc networks. However, the proliferation of such mobile networks depends on a multitude of factors, with trustworthiness being one of the primary challenges to be met. The objective of this dissertation is to address the issues involved in the design of security services for Mobile IP and ad-hoc networks. Extensions to IP based networks (both wired and infrastructureless networks) to facilitate mobility have not been designed keeping security in mind. However adequate security features are basic requirements for the continued functioning of mobile networks. Clearly the problem is so broad that there is no way to devise a general solution We aim to address most of these wide- ranging problems and in the process initiate a practical approach to the development of an integrated security infrastructure for mobile networks. The intention is to seamlessly integrate these security services and mechanisms at the IP level within the mobile IP and ad-hoc networks. The provision of security services at the higher and lower layers and their interoperability with our proposed framework is outside the scope of this thesis / Doctor of Philosophy (PhD)

This thesis proposes new algorithms for restoration strategies that provision bandwidth guaranteed recovery for unicast and multicast connections. The primary focus is on online restoration strategies that sequentially do pre-planning of resource for each request using the current network resource state. Online restoration strategies do not require prior knowledge of all the requests like that of offline restoration strategies. Therefore, online restoration strategies are more suitable for on-demand and dynamic traffic engineering control. The proposed new algorithms are compared to known algorithms from literature. Most literature evaluates the performance of the algorithms with two metrics only: total bandwidth requirement and the number of requests accepted in the network. This thesis evaluates the algorithms in one additional dimension: the computational time. This is an important criterion when response times for establishing new connections are stringent. Each algorithm makes trade-off between computational complexity, bandwidth efficiency, and number of accepted requests. Results show that the proposed algorithms provide alternative trade-offs between the three performance metrics when compared to other existing algorithms. The alternatives provide more choice for the network providers and the best algorithm to use depends on the network's requirements. The restoration strategies used for unicast and multicast connections in this thesis are very compatible thus it is possible to integrate the restoration strategies into a single system where they share the same backup resources. Results from simulations show that using an integrated restoration model has significant benefits, which includes lower backup bandwidth requirement than the separate restoration model.

This thesis proposes new algorithms for restoration strategies that provision bandwidth guaranteed recovery for unicast and multicast connections. The primary focus is on online restoration strategies that sequentially do pre-planning of resource for each request using the current network resource state. Online restoration strategies do not require prior knowledge of all the requests like that of offline restoration strategies. Therefore, online restoration strategies are more suitable for on-demand and dynamic traffic engineering control. The proposed new algorithms are compared to known algorithms from literature. Most literature evaluates the performance of the algorithms with two metrics only: total bandwidth requirement and the number of requests accepted in the network. This thesis evaluates the algorithms in one additional dimension: the computational time. This is an important criterion when response times for establishing new connections are stringent. Each algorithm makes trade-off between computational complexity, bandwidth efficiency, and number of accepted requests. Results show that the proposed algorithms provide alternative trade-offs between the three performance metrics when compared to other existing algorithms. The alternatives provide more choice for the network providers and the best algorithm to use depends on the network's requirements. The restoration strategies used for unicast and multicast connections in this thesis are very compatible thus it is possible to integrate the restoration strategies into a single system where they share the same backup resources. Results from simulations show that using an integrated restoration model has significant benefits, which includes lower backup bandwidth requirement than the separate restoration model.

Bibliography: leaves 112-115

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The safety of civil aviation has been endangered not only by terrorism, but also by many other unlawful acts committed by persons with varying motivation. The international community has worked to provide a secure and safe air transportation system for general people and thus has developed aviation security systems in the legal and technical fields to combat and prevent the man-made intentional harm against civil aviation. / The legal instruments are mainly based on several multilateral conventions, resolutions and declarations. They are all focused on how to eliminate safe heavens for unlawful actors against civil aviation, secure the safety of passenger and crew, and facilitate the resumption of affected aircraft. / The technical instruments, dealing with specific preventive security measures to suppress the unlawful acts against civil aviation on a practical basis, have been developed by ICAO as "Standards and Recommended Practices" (SARPs) in the form of Annexes. In addition, to promote global aviation security, ICAO launched its "Universal Security Audit Programme" immediately following the tragic events of September 11, 2001. / This thesis critically analyses the legal and technical aviation security systems under current international legal regimes and provides several recommendations to improve the remaining problems in the international aviation security system.