Exploiting the power of multiplicity: a holistic survey of network-layer multipath

The Internet is inherently a multipath network: For an underlying network with only a single path, connecting various nodes would have been debilitatingly fragile. Unfortunately, traditional Internet technologies have been designed around the restrictive assumption of a single working path between a source and a destination. The lack of native multipath support constrains network performance even as the underlying network is richly connected and has redundant multiple paths. Computer networks can exploit the power of multiplicity, through which a diverse collection of paths is resource pooled as a single resource, to unlock the inherent redundancy of the Internet. This opens up a new vista of opportunities, promising increased throughput (through concurrent usage of multiple paths) and increased reliability and fault tolerance (through the use of multiple paths in backup/redundant arrangements). There are many emerging trends in networking that signify that the Internet's future will be multipath, including the use of multipath technology in data center computing; the ready availability of multiple heterogeneous radio interfaces in wireless (such as Wi-Fi and cellular) in wireless devices; ubiquity of mobile devices that are multihomed with heterogeneous access networks; and the development and standardization of multipath transport protocols such as multipath TCP. The aim of this paper is to provide a comprehensive survey of the literature on network-layer multipath solutions. We will present a detailed investigation of two important design issues, namely, the control plane problem of how to compute and select the routes and the data plane problem of how to split the flow on the computed paths. The main contribution of this paper is a systematic articulation of the main design issues in network-layer multipath routing along with a broad-ranging survey of the vast literature on network-layer multipathing. We also highlight open issues and identify directions for future work

Secure Large Scale Penetration of Electric Vehicles in the Power Grid

As part of the approaches used to meet climate goals set by international environmental agreements, policies are being applied worldwide for promoting the uptake of Electric Vehicles (EV)s. The resulting increase in EV sales and the accompanying expansion in the EV charging infrastructure carry along many challenges, mostly infrastructure-related. A pressing need arises to strengthen the power grid to handle and better manage the electricity demand by this mobile and geo-distributed load. Because the levels of penetration of EVs in the power grid have recently started increasing with the increase in EV sales, the real-time management of en-route EVs, before they connect to the grid, is quite recent and not many research works can be found in the literature covering this topic comprehensively. In this dissertation, advances and novel ideas are developed and presented, seizing the opportunities lying in this mobile load and addressing various challenges that arise in the application of public charging for EVs. A Bilateral Decision Support System (BDSS) is developed here for the management of en-route EVs. The BDSS is a middleware-based MAS that achieves a win-win situation for the EVs and the power grid. In this framework, the two are complementary in a way that the desired benefit of one cannot be achieved without attaining that of the other. A Fuzzy Logic based on-board module is developed for supporting the decision of the EV as to which charging station to charge at. GPU computing is used in the higher-end agents to handle the big amount of data resulting in such a large scale system with mobile and geo-distributed nodes. Cyber security risks that threaten the BDSS are assessed and measures are applied to revoke possible attacks. Furthermore, the Collective Distribution of Mobile Loads (CDML), a service with ancillary potential to the power system, is developed. It comprises a system-level optimization. In this service, the EVs requesting a public charging session are collectively redistributed onto charging stations with the objective of achieving the optimal and secure operation of the power system by reducing active power losses in normal conditions and mitigating line congestions in contingency conditions. The CDML uses the BDSS as an industrially viable tool to achieve the outcomes of the optimization in real time. By participating in this service, the EV is considered as an interacting node in the system-wide communication platform, providing both enhanced self-convenience in terms of access to public chargers, and contribution to the collective effort of providing benefit to the power system under the large scale uptake of EVs. On the EV charger level, several advantages have been reported favoring wireless charging of EVs over wired charging. Given that, new techniques are presented that facilitate the optimization of the magnetic link of wireless EV chargers while considering international EMC standards. The original techniques and developments presented in this dissertation were experimentally verified at the Energy Systems Research Laboratory at FIU

On Collaborative Intrusion Detection

Cyber-attacks have nowadays become more frightening than ever before. The growing dependency of our society on networked systems aggravates these threats; from interconnected corporate networks and Industrial Control Systems (ICSs) to smart households, the attack surface for the adversaries is increasing. At the same time, it is becoming evident that the utilization of classic fields of security research alone, e.g., cryptography, or the usage of isolated traditional defense mechanisms, e.g., firewalls and Intrusion Detection Systems ( IDSs ), is not enough to cope with the imminent security challenges. To move beyond monolithic approaches and concepts that follow a “cat and mouse” paradigm between the defender and the attacker, cyber-security research requires novel schemes. One such promis- ing approach is collaborative intrusion detection. Driven by the lessons learned from cyber-security research over the years, the aforesaid notion attempts to connect two instinctive questions: “if we acknowledge the fact that no security mechanism can detect all attacks, can we beneficially combine multiple approaches to operate together?” and “as the adversaries increasingly collaborate (e.g., Distributed Denial of Service (DDoS) attacks from whichever larger botnets) to achieve their goals, can the defenders beneficially collude too?”. Collabora- tive intrusion detection attempts to address the emerging security challenges by providing methods for IDSs and other security mech- anisms (e.g., firewalls and honeypots) to combine their knowledge towards generating a more holistic view of the monitored network. This thesis improves the state of the art in collaborative intrusion detection in several areas. In particular, the dissertation proposes methods for the detection of complex attacks and the generation of the corresponding intrusion detection signatures. Moreover, a novel approach for the generation of alert datasets is given, which can assist researchers in evaluating intrusion detection algorithms and systems. Furthermore, a method for the construction of communities of collab- orative monitoring sensors is given, along with a domain-awareness approach that incorporates an efficient data correlation mechanism. With regard to attacks and countermeasures, a detailed methodology is presented that is focusing on sensor-disclosure attacks in the con- text of collaborative intrusion detection. The scientific contributions can be structured into the following categories: Alert data generation: This thesis deals with the topic of alert data generation in a twofold manner: first it presents novel approaches for detecting complex attacks towards generating alert signatures for IDSs ; second a method for the synthetic generation of alert data is pro- posed. In particular, a novel security mechanism for mobile devices is proposed that is able to support users in assessing the security status of their networks. The system can detect sophisticated attacks and generate signatures to be utilized by IDSs . The dissertation also touches the topic of synthetic, yet realistic, dataset generation for the evaluation of intrusion detection algorithms and systems; it proposes a novel dynamic dataset generation concept that overcomes the short- comings of the related work. Collaborative intrusion detection: As a first step, the the- sis proposes a novel taxonomy for collaborative intrusion detection ac- companied with building blocks for Collaborative IDSs ( CIDSs ). More- over, the dissertation deals with the topics of (alert) data correlation and aggregation in the context of CIDSs . For this, a number of novel methods are proposed that aim at improving the clustering of mon- itoring sensors that exhibit similar traffic patterns. Furthermore, a novel alert correlation approach is presented that can minimize the messaging overhead of a CIDS. Attacks on CIDSs: It is common for research on cyber-defense to switch its perspective, taking on the viewpoint of attackers, trying to anticipate their remedies against novel defense approaches. The the- sis follows such an approach by focusing on a certain class of attacks on CIDSs that aim at identifying the network location of the monitor- ing sensors. In particular, the state of the art is advanced by proposing a novel scheme for the improvement of such attacks. Furthermore, the dissertation proposes novel mitigation techniques to overcome both the state of art and the proposed improved attacks. Evaluation: All the proposals and methods introduced in the dis- sertation were evaluated qualitatively, quantitatively and empirically. A comprehensive study of the state of the art in collaborative intru- sion detection was conducted via a qualitative approach, identifying research gaps and surveying the related work. To study the effective- ness of the proposed algorithms and systems extensive simulations were utilized. Moreover, the applicability and usability of some of the contributions in the area of alert data generation was additionally supported via Proof of Concepts (PoCs) and prototypes. The majority of the contributions were published in peer-reviewed journal articles, in book chapters, and in the proceedings of interna- tional conferences and workshops

Energy Efficiency in Green Internet of Things (IoT) Networks

Internet of Things (IoT) is having a major impact on the digital world and how we interact with the internet. The wireless sensor network (WSN) is a promising wireless communication system for enabling IoT networks. But these networks have limited energy (battery) resources and energy-saving has become a pressing need in such networks and there have been increasing efforts to minimise energy consumption via message scheduling, optimal routing, clustering formation, aggregation techniques, etc. However, significant improvement is still required and this study has produced algorithms which have been shown to reduce energy consumption and prolong network life. Increasing the number of neighbour nodes around a node has a negative impact on the network lifetime of WSNs. This is due to the adverse effects caused by overhearing and interference. This thesis presents a new routing technique that considers the transmission distances from one node to all neighbouring nodes within its transmission range. The interference measurement approach is adopted to select the next-hop node. The cluster head (CH) node selection is based on transmission distances to the base station (BS) with the nearest node to the BS in a sub-cluster elected as CH node for that sub-cluster. The thesis also introduces a novel scheduling algorithm called the “long hop” (LH) which assigns high priority to messages coming from sensor nodes that are located farthest away and have accessed a high number of hops, to be served first at CH nodes. This minimised energy consumption caused by the retransmission process. Redundant data increases the unnecessary/unwanted processing and transmission of data. Thus, the thesis introduces a new method that reduces redundant data transmission and lowers the communication costs related to sending unnecessary data. The study also provides a remote monitoring system for the end-user that can check and track the performance of the sensors/IoT devices during real-time communication. Extensive simulation tests on randomly situated WSNs show the potential of the solutions proposed in this thesis to reduce energy consumption and extend network lifetime

Electromechanical Dynamics of High Photovoltaic Power Grids

This dissertation study focuses on the impact of high PV penetration on power grid electromechanical dynamics. Several major aspects of power grid electromechanical dynamics are studied under high PV penetration, including frequency response and control, inter-area oscillations, transient rotor angle stability and electromechanical wave propagation.To obtain dynamic models that can reasonably represent future power systems, Chapter One studies the co-optimization of generation and transmission with large-scale wind and solar. The stochastic nature of renewables is considered in the formulation of mixed-integer programming model. Chapter Two presents the development procedures of high PV model and investigates the impact of high PV penetration on frequency responses. Chapter Three studies the impact of PV penetration on inter-area oscillations of the U.S. Eastern Interconnection system. Chapter Four presents the impacts of high PV on other electromechanical dynamic issues, including transient rotor angle stability and electromechanical wave propagation. Chapter Five investigates the frequency response enhancement by conventional resources. Chapter Six explores system frequency response improvement through real power control of wind and PV. For improving situation awareness and frequency control, Chapter Seven studies disturbance location determination based on electromechanical wave propagation. In addition, a new method is developed to generate the electromechanical wave propagation speed map, which is useful to detect system inertia distribution change. Chapter Eight provides a review on power grid data architectures for monitoring and controlling power grids. Challenges and essential elements of data architecture are analyzed to identify various requirements for operating high-renewable power grids and a conceptual data architecture is proposed. Conclusions of this dissertation study are given in Chapter Nine

Proceedings of the 9th Conference on Autonomous Robot Systems and Competitions

Welcome to ROBOTICA 2009. This is the 9th edition of the conference on Autonomous Robot Systems and Competitions, the third time with IEEE‐Robotics and Automation Society Technical Co‐Sponsorship. Previous editions were held since 2001 in Guimarães, Aveiro, Porto, Lisboa, Coimbra and Algarve. ROBOTICA 2009 is held on the 7th May, 2009, in Castelo Branco , Portugal. ROBOTICA has received 32 paper submissions, from 10 countries, in South America, Asia and Europe. To evaluate each submission, three reviews by paper were performed by the international program committee. 23 papers were published in the proceedings and presented at the conference. Of these, 14 papers were selected for oral presentation and 9 papers were selected for poster presentation. The global acceptance ratio was 72%. After the conference, eighth papers will be published in the Portuguese journal Robótica, and the best student paper will be published in IEEE Multidisciplinary Engineering Education Magazine. Three prizes will be awarded in the conference for: the best conference paper, the best student paper and the best presentation. The last two, sponsored by the IEEE Education Society ‐ Student Activities Committee. We would like to express our thanks to all participants. First of all to the authors, whose quality work is the essence of this conference. Next, to all the members of the international program committee and reviewers, who helped us with their expertise and valuable time. We would also like to deeply thank the invited speaker, Jean Paul Laumond, LAAS‐CNRS France, for their excellent contribution in the field of humanoid robots. Finally, a word of appreciation for the hard work of the secretariat and volunteers. Our deep gratitude goes to the Scientific Organisations that kindly agreed to sponsor the Conference, and made it come true. We look forward to seeing more results of R&D work on Robotics at ROBOTICA 2010, somewhere in Portugal

Energy-Sustainable IoT Connectivity: Vision, Technological Enablers, Challenges, and Future Directions

Technology solutions must effectively balance economic growth, social equity, and environmental integrity to achieve a sustainable society. Notably, although the Internet of Things (IoT) paradigm constitutes a key sustainability enabler, critical issues such as the increasing maintenance operations, energy consumption, and manufacturing/disposal of IoT devices have long-term negative economic, societal, and environmental impacts and must be efficiently addressed. This calls for self-sustainable IoT ecosystems requiring minimal external resources and intervention, effectively utilizing renewable energy sources, and recycling materials whenever possible, thus encompassing energy sustainability. In this work, we focus on energy-sustainable IoT during the operation phase, although our discussions sometimes extend to other sustainability aspects and IoT lifecycle phases. Specifically, we provide a fresh look at energy-sustainable IoT and identify energy provision, transfer, and energy efficiency as the three main energy-related processes whose harmonious coexistence pushes toward realizing self-sustainable IoT systems. Their main related technologies, recent advances, challenges, and research directions are also discussed. Moreover, we overview relevant performance metrics to assess the energy-sustainability potential of a certain technique, technology, device, or network and list some target values for the next generation of wireless systems. Overall, this paper offers insights that are valuable for advancing sustainability goals for present and future generations.Comment: 25 figures, 12 tables, submitted to IEEE Open Journal of the Communications Societ

Wireless Sensor Networks

The aim of this book is to present few important issues of WSNs, from the application, design and technology points of view. The book highlights power efficient design issues related to wireless sensor networks, the existing WSN applications, and discusses the research efforts being undertaken in this field which put the reader in good pace to be able to understand more advanced research and make a contribution in this field for themselves. It is believed that this book serves as a comprehensive reference for graduate and undergraduate senior students who seek to learn latest development in wireless sensor networks