3,499 research outputs found

    A Framework of Cooperating Agents Hierarchies for Local-Area Mobility Support

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    Host mobility creates a routing problem in the Internet, where an IP address reflects the network\u27s point of attachment. Mobile IP, relying on a mapping between a home address and a care-of address, and a home registration process, is widely accepted as a solution for the host mobility problem in wide-area mobility scenarios. However, its home registration requirement, upon each change of point of attachment, makes it unsuitable to handle local-area mobility, resulting in large handoff latencies, increased packet loss, and disrupted services. In this dissertation, we introduce a local-area mobility support framework for IPv4 based on the deployment of multiple cooperating mobility agents hierarchies in the foreign domain. First, we introduce a hierarchy model offering a backward compatible mode to service legacy mobile hosts, unaware of local-area mobility extensions. Second, for intra-hierarchy handoffs, we identify several design deficiencies within the current Mobile IP hierarchy extension proposal, and present an enhanced regional registration framework for local handoffs that encompasses a replay protection identification value dissemination mechanism. In addition, we present two novel registration frameworks for home registrations involving local handoffs, in which we identify the dual nature of such registrations, and attempt to emphasize the local handoff aspect. One technique, maintains tunneling of data packets to the MH (Mobile Host) through an old path until a home registration reply is received to set up the new path. In contrast, the other technique adopts a more proactive bold approach in switching immediately to the new path resulting in a reduction of the handoff latency. Third, for inter-hierarchy handoffs, we present a scalable, configurable, and cooperation based framework between mobility agents hierarchies to reduce the handoffs latencies. An attempt is made to exploit the expected network proximity between hierarchies within the foreign domain, and maintain a mobile host\u27s home-registered care-of address unchanged while within the same foreign domain. In addition, the involved registration signaling design requires a reduced number of security associations between mobility agents belonging to different hierarchies, and copes with the fact that the mobile host\u27s home-registered care-of address might not be reachable

    Context Aware Computing for The Internet of Things: A Survey

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    As we are moving towards the Internet of Things (IoT), the number of sensors deployed around the world is growing at a rapid pace. Market research has shown a significant growth of sensor deployments over the past decade and has predicted a significant increment of the growth rate in the future. These sensors continuously generate enormous amounts of data. However, in order to add value to raw sensor data we need to understand it. Collection, modelling, reasoning, and distribution of context in relation to sensor data plays critical role in this challenge. Context-aware computing has proven to be successful in understanding sensor data. In this paper, we survey context awareness from an IoT perspective. We present the necessary background by introducing the IoT paradigm and context-aware fundamentals at the beginning. Then we provide an in-depth analysis of context life cycle. We evaluate a subset of projects (50) which represent the majority of research and commercial solutions proposed in the field of context-aware computing conducted over the last decade (2001-2011) based on our own taxonomy. Finally, based on our evaluation, we highlight the lessons to be learnt from the past and some possible directions for future research. The survey addresses a broad range of techniques, methods, models, functionalities, systems, applications, and middleware solutions related to context awareness and IoT. Our goal is not only to analyse, compare and consolidate past research work but also to appreciate their findings and discuss their applicability towards the IoT.Comment: IEEE Communications Surveys & Tutorials Journal, 201

    Security and management policy specification

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    Training of Crisis Mappers and Map Production from Multi-sensor Data: Vernazza Case Study (Cinque Terre National Park, Italy)

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    This aim of paper is to presents the development of a multidisciplinary project carried out by the cooperation between Politecnico di Torino and ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action). The goal of the project was the training in geospatial data acquiring and processing for students attending Architecture and Engineering Courses, in order to start up a team of "volunteer mappers". Indeed, the project is aimed to document the environmental and built heritage subject to disaster; the purpose is to improve the capabilities of the actors involved in the activities connected in geospatial data collection, integration and sharing. The proposed area for testing the training activities is the Cinque Terre National Park, registered in the World Heritage List since 1997. The area was affected by flood on the 25th of October 2011. According to other international experiences, the group is expected to be active after emergencies in order to upgrade maps, using data acquired by typical geomatic methods and techniques such as terrestrial and aerial Lidar, close-range and aerial photogrammetry, topographic and GNSS instruments etc.; or by non conventional systems and instruments such us UAV, mobile mapping etc. The ultimate goal is to implement a WebGIS platform to share all the data collected with local authorities and the Civil Protectio

    Rewriting Citizenship in Displacement: Displaced People’s Struggles for Rights

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    For displaced people , citizenship(or the lack of it) is a crucial issue . Displaced people are denied formal citizenship and rights but are now claiming them , subjectively seeing their de facto experience as live d citizenship. Protests, claim assertions and transnational alliances are ways in which their struggle for rights is manifested. Much of the existing literature tends to focus on a top- down understanding of displaced people as citizens/non- citizens and the formal processes available (or not available ) to them, ignoring the importance of informal processes as well as local agency and practice, which this article explores through case study examples. The article also examines displacement in the light of differing theoretical meanings of citizenship, and asks to what extent the forced migrant is a global or transnational citizen

    Exploring Blockchain Governance

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    Blockchain systems continue to attract significant interest from both practitioners and researchers. What is more, blockchain systems come in various types, such as cryptocurrencies or as inter-organizational systems in business networks. As an example of a cryptocurrency, Bitcoin, one of the most prominent blockchain systems to date and born at the time of a major financial crisis, spearheaded the promise of relying on code and computation instead of a central governing entity. Proponents would argue that Bitcoin stood the test of time, as Bitcoin continues to operate to date for over a decade. However, these proponents overlook the never-ending, heated debates “behind the scenes” caused by diverging goals of central actors, which led to numerous alternative systems (forks) of Bitcoin. To accommodate these actors’ interests in the pursuit of their common goal is a tightrope act, and this is where this dissertation commences: blockchain governance. Based on the empirical examples of various types and application domains of blockchain systems, it is the goal of this dissertation to 1) uncover governance patterns by showing, how blockchain systems are governed, 2) derive governance challenges faced or caused by blockchain systems, and, consequently, to 3) contribute to a better understanding to what blockchain governance is. This dissertation includes four parts, each of these covering different thematical areas: In the first part, this dissertation focuses on obtaining a better understanding of blockchain governance’s context of reference by studying blockchain systems from various application domains and system types, for example, led by inter-organizational networks, states, or an independent group of actors. The second part, then, focuses on a blockchain as an inter-organizational system called “cardossier”, a project I was involved in, and its governance as a frame of reference. Hereupon, for one, I report on learnings from my project involvement in the form of managerial guidelines, and, for two, I report on structural problems within cardossier, and problems caused by membership growth and how they can be resolved. The third part focuses on a wider study of blockchains as inter-organizational systems, where I summarize findings of an analysis of 19 blockchain consortia. The findings, for one, answer the question of why blockchain consortia adopt blockchain technology, and, for two, show internal and external challenges these systems faced to derive managerial recommendations. The fourth and last part studies blockchain governance’s evolution and contributes an analysis of blockchain’s governance features and its contrast to established modes of governance. These four parts, altogether, have scientific value as they increase our understanding on blockchain governance. Consequently, this dissertation contributes to the body of knowledge on modes of governance, distributed system governance, and blockchain governance in general. I do so, by grounding the concept of blockchain governance in empirical detail, showing how these systems are governed on various application domains and system types, and by studying empirical challenges faced or caused by these systems. This approach is relevant and necessary, as blockchain systems in general, but particularly outside of cryptocurrencies, mostly still are in pursuit of a sustainable blockchain governance. As blockchains can be expected to continue to mature, the upcoming years offer very fruitful ground for empirical research along the empirical insights and theoretical lines shown in this dissertation

    Contributions to Edge Computing

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    Efforts related to Internet of Things (IoT), Cyber-Physical Systems (CPS), Machine to Machine (M2M) technologies, Industrial Internet, and Smart Cities aim to improve society through the coordination of distributed devices and analysis of resulting data. By the year 2020 there will be an estimated 50 billion network connected devices globally and 43 trillion gigabytes of electronic data. Current practices of moving data directly from end-devices to remote and potentially distant cloud computing services will not be sufficient to manage future device and data growth. Edge Computing is the migration of computational functionality to sources of data generation. The importance of edge computing increases with the size and complexity of devices and resulting data. In addition, the coordination of global edge-to-edge communications, shared resources, high-level application scheduling, monitoring, measurement, and Quality of Service (QoS) enforcement will be critical to address the rapid growth of connected devices and associated data. We present a new distributed agent-based framework designed to address the challenges of edge computing. This actor-model framework implementation is designed to manage large numbers of geographically distributed services, comprised from heterogeneous resources and communication protocols, in support of low-latency real-time streaming applications. As part of this framework, an application description language was developed and implemented. Using the application description language a number of high-order management modules were implemented including solutions for resource and workload comparison, performance observation, scheduling, and provisioning. A number of hypothetical and real-world use cases are described to support the framework implementation

    A web services based framework for efficient monitoring and event reporting.

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    Network and Service Management (NSM) is a research discipline with significant research contributions the last 25 years. Despite the numerous standardised solutions that have been proposed for NSM, the quest for an "all encompassing technology" still continues. A new technology introduced lately to address NSM problems is Web Services (WS). Despite the research effort put into WS and their potential for addressing NSM objectives, there are efficiency, interoperability, etc issues that need to be solved before using WS for NSM. This thesis looks at two techniques to increase the efficiency of WS management applications so that the latter can be used for efficient monitoring and event reporting. The first is a query tool we built that can be used for efficient retrieval of management state data close to the devices where they are hosted. The second technique is policies used to delegate a number of tasks from a manager to an agent to make WS-based event reporting systems more efficient. We tested the performance of these mechanisms by incorporating them in a custom monitoring and event reporting framework and supporting systems we have built, against other similar mechanisms (XPath) that have been proposed for the same tasks, as well as previous technologies such as SNMP. Through these tests we have shown that these mechanisms are capable of allowing us to use WS efficiently in various monitoring and event reporting scenarios. Having shown the potential of our techniques we also present the design and implementation challenges for building a GUI tool to support and enhance the above systems with extra capabilities. In summary, we expect that other problems WS face will be solved in the near future, making WS a capable platform for it to be used for NSM
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