96 research outputs found

    Security-aware Cooperation in Dynamic Spectrum Access

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    We have witnessed a massive growth in wireless data, which almost doubles every year. The wireless data is expected to skyrocket further in the future due to the proliferation of devices and the emerging data-hungry applications. To accommodate the explosive growth in mobile traffic, a large amount of wireless spectrum is needed. With the limited spectrum resource, the current static spectrum allocation policy cannot serve well for future wireless systems. Moreover, it exacerbates the spectrum scarcity by resulting in severe spectrum underutilization. As a promising solution, dynamic spectrum access (DSA) is envisaged to increase spectrum efficiency by dynamic sharing all the spectrum. DSA can be enabled by cognitive radio technologies, which allow the unlicensed users (the secondary users, i.e., SUs) to dynamically access the unused spectrum (i.e., spectrum holes) owned by the licensed users (the primary users i.e., PUs). In order to identify the unused spectrum (spectrum holes), unlicensed users need to conduct spectrum sensing. While spectrum sensing might be inaccurate due to multipath fading and shadowing. To address this problem, user cooperation can be leveraged, with two main forms: cooperative spectrum sensing and cooperative cognitive radio networking (CCRN). For the former, SUs cooperate with each other in spectrum sensing to better detect the spectrum holes. For the latter, SUs cooperate with the PUs to gain access opportunities from the PUs by improving the transmission performance of the PUs. Whereas cooperation can also incur security issues, e.g., malicious users might participate into cooperation, corrupting or disrupting the communication of legitimate users, selfish users might refuse to contribute to cooperation for self-interests, etc. Those security issues are of great importance and need to be considered for cooperation in DSA. In this thesis, we study security-aware cooperation in DSA. First, we investigate cooperative spectrum sensing in multi-channel scenario such that a user can be scheduled for spectrum sensing and spectrum sharing. The cooperative framework can achieve a higher average throughput per user, which provides the incentive for selfish users to participate in cooperative spectrum sensing. Second, secure communication in CCRN is studied, where the SUs cooperate with the PU to enhance the latter’s communication security and then gain transmission opportunities. Partner selection, spectrum access time allocation, and power allocation are investigated. Third, we study risk aware cooperation based DSA for the multiple channel scenario, where multiple SUs cooperate with multiple PUs for spectrum access opportunities, considering the trustworthiness of SUs. Lastly, we propose an incentive mechanism to stimulate SUs to cooperate with PUs when they have no traffic. The cooperating SUs are motivated to cooperate with PUs to enhance the security of the PUs by accumulating credits and then consume the earned credits for spectrum trading when they have traffic in the future

    Cooperative Radio Communications for Green Smart Environments

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    The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin

    Cooperative Radio Communications for Green Smart Environments

    Get PDF
    The demand for mobile connectivity is continuously increasing, and by 2020 Mobile and Wireless Communications will serve not only very dense populations of mobile phones and nomadic computers, but also the expected multiplicity of devices and sensors located in machines, vehicles, health systems and city infrastructures. Future Mobile Networks are then faced with many new scenarios and use cases, which will load the networks with different data traffic patterns, in new or shared spectrum bands, creating new specific requirements. This book addresses both the techniques to model, analyse and optimise the radio links and transmission systems in such scenarios, together with the most advanced radio access, resource management and mobile networking technologies. This text summarises the work performed by more than 500 researchers from more than 120 institutions in Europe, America and Asia, from both academia and industries, within the framework of the COST IC1004 Action on "Cooperative Radio Communications for Green and Smart Environments". The book will have appeal to graduates and researchers in the Radio Communications area, and also to engineers working in the Wireless industry. Topics discussed in this book include: • Radio waves propagation phenomena in diverse urban, indoor, vehicular and body environments• Measurements, characterization, and modelling of radio channels beyond 4G networks• Key issues in Vehicle (V2X) communication• Wireless Body Area Networks, including specific Radio Channel Models for WBANs• Energy efficiency and resource management enhancements in Radio Access Networks• Definitions and models for the virtualised and cloud RAN architectures• Advances on feasible indoor localization and tracking techniques• Recent findings and innovations in antenna systems for communications• Physical Layer Network Coding for next generation wireless systems• Methods and techniques for MIMO Over the Air (OTA) testin

    A Dynamic Spectrum Access Framework (Bring Your Own Spectrum)

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    In this thesis, a unified and sustainable framework for spectrum allocation is presented. This multi-level operator-agnostic framework, Bring Your Own Spectrum (BYOS), is the result of a few thought experiments reflecting the ways in which spectrum could be bought and sold as an asset, similar to service models in cloud computing where every technical element can be traded via an "as-a-Service" model. BYOS architectural features form the major part of this thesis and cover four levels of abstraction as – contextual, conceptual, logical and physical. First, the contextual aspect of BYOS is covered, which addresses the question: "why is the framework needed?". To understand the reasons behind the need for a new framework an exhaustive survey of history of telecommunications policy development of 32 countries was conducted that included major economies in several key regions of the world. This research provided insight into the role of the government, mechanisms used for allocations, success/failure of allocations, and business models in the sector. Additionally, a review of existing and emerging technologies was done to understand various possible mechanisms of spectrum access. Next, the conceptual aspect of BYOS is presented, which addresses the question: "what does the framework look like?". For this, the information from the study above was converted into a skeleton framework, ensuring that it covers the requirements gathered. The framework has a three-level architecture with a quasi-static allocation scheme. The levels of architecture are designated based on periods of ownership and the thesis presents an original exponential-based-scale to determine the allocation periods (longest to shortest). The framework accommodates different types of operators, categorising in terms of their spectrum access privileges. Following this, the thesis focuses on the physical level of the framework, where the question: "with what?" i.e. the technical mechanisms are discussed. In this part, a novel analogy is presented where the wireless spectrum is compared to a multi-lane, multi-level highway. This analogy provides the basis for unit of information transport between two points, which in turn form the trading unit. In this thesis, "Interference (transmission power) spread over bandwidth" is chosen as the basic trading unit for the BYOS framework. Also included is a discussion on the required changes to the calculation of "population" – an inherent part of reserve price calculation – in view of the proliferation of device using different types of mobile technologies. A second part of the physical framework presents an original mechanism for competition management in view of the new framework and trading unit. Using the principles of network traffic management, a new tracking unit – token – is introduced, which helps the regulators keep track of the process of spectrum allocation, but in a hands-off manner. Multiple models of using tokens in the framework are presented. Tokens are intended only for the shortterm trades, though the initial number is determined by the total spectrum acquisitions and cumulative participation behaviour. Finally, the logical or system model of the framework is presented, which addresses the question: "how to structure and organise the architecture to achieve the desired requirements". This discussion is also divided into two parts. First, the discussion focuses on the multiple ways to use tokens and demonstrates the different use cases by way of competition games. Key novel points here are the discussion of competition management over multi-period allocation and addressing the needs of public safety services. Additionally, the discussion also focuses on unequal desirability of available spectrum lots based on spectrum characteristics, acquisition periods, and operator’s own requirements. The second part of the discussion focuses on various methods of implementation of this framework. A potential enterpriseblockchain based method is explored, though there may be other better solutions. Another focus of this thesis, which can be considered as a separate minor segment, came out of the initial policy research was to organize and analyse this information systematically. For this purpose, the theory of policy diffusion was explored, and the research provides evidence for the existence of, and analyses the mechanisms used for policy diffusion in different regions and countries.Thesis (Ph.D.) -- University of Adelaide, School of Electrical and Electronics, 202

    Active Learning in Cognitive Radio Networks

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    In this thesis, numerous Machine Learning (ML) applications for Cognitive Radios Networks (CRNs) are developed and presented which facilitate the e cient spectral coexistence of a legacy system, the Primary Users (PUs), and a CRN, the Secondary Users (SUs). One way to better exploit the capacity of the legacy system frequency band is to consider a coexistence scenario using underlay Cognitive Radio (CR) techniques, where SUs may transmit in the frequency band of the PU system as long as the induced to the PU interference is under a certain limit and thus does not harmfully a ect the legacy system operability

    Building the Future Internet through FIRE

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    The Internet as we know it today is the result of a continuous activity for improving network communications, end user services, computational processes and also information technology infrastructures. The Internet has become a critical infrastructure for the human-being by offering complex networking services and end-user applications that all together have transformed all aspects, mainly economical, of our lives. Recently, with the advent of new paradigms and the progress in wireless technology, sensor networks and information systems and also the inexorable shift towards everything connected paradigm, first as known as the Internet of Things and lately envisioning into the Internet of Everything, a data-driven society has been created. In a data-driven society, productivity, knowledge, and experience are dependent on increasingly open, dynamic, interdependent and complex Internet services. The challenge for the Internet of the Future design is to build robust enabling technologies, implement and deploy adaptive systems, to create business opportunities considering increasing uncertainties and emergent systemic behaviors where humans and machines seamlessly cooperate
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