270 research outputs found

    Optical Wireless Data Center Networks

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    Bandwidth and computation-intensive Big Data applications in disciplines like social media, bio- and nano-informatics, Internet-of-Things (IoT), and real-time analytics, are pushing existing access and core (backbone) networks as well as Data Center Networks (DCNs) to their limits. Next generation DCNs must support continuously increasing network traffic while satisfying minimum performance requirements of latency, reliability, flexibility and scalability. Therefore, a larger number of cables (i.e., copper-cables and fiber optics) may be required in conventional wired DCNs. In addition to limiting the possible topologies, large number of cables may result into design and development problems related to wire ducting and maintenance, heat dissipation, and power consumption. To address the cabling complexity in wired DCNs, we propose OWCells, a class of optical wireless cellular data center network architectures in which fixed line of sight (LOS) optical wireless communication (OWC) links are used to connect the racks arranged in regular polygonal topologies. We present the OWCell DCN architecture, develop its theoretical underpinnings, and investigate routing protocols and OWC transceiver design. To realize a fully wireless DCN, servers in racks must also be connected using OWC links. There is, however, a difficulty of connecting multiple adjacent network components, such as servers in a rack, using point-to-point LOS links. To overcome this problem, we propose and validate the feasibility of an FSO-Bus to connect multiple adjacent network components using NLOS point-to-point OWC links. Finally, to complete the design of the OWC transceiver, we develop a new class of strictly and rearrangeably non-blocking multicast optical switches in which multicast is performed efficiently at the physical optical (lower) layer rather than upper layers (e.g., application layer). Advisors: Jitender S. Deogun and Dennis R. Alexande

    Exploration and Design of Power-Efficient Networked Many-Core Systems

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    Multiprocessing is a promising solution to meet the requirements of near future applications. To get full benefit from parallel processing, a manycore system needs efficient, on-chip communication architecture. Networkon- Chip (NoC) is a general purpose communication concept that offers highthroughput, reduced power consumption, and keeps complexity in check by a regular composition of basic building blocks. This thesis presents power efficient communication approaches for networked many-core systems. We address a range of issues being important for designing power-efficient manycore systems at two different levels: the network-level and the router-level. From the network-level point of view, exploiting state-of-the-art concepts such as Globally Asynchronous Locally Synchronous (GALS), Voltage/ Frequency Island (VFI), and 3D Networks-on-Chip approaches may be a solution to the excessive power consumption demanded by today’s and future many-core systems. To this end, a low-cost 3D NoC architecture, based on high-speed GALS-based vertical channels, is proposed to mitigate high peak temperatures, power densities, and area footprints of vertical interconnects in 3D ICs. To further exploit the beneficial feature of a negligible inter-layer distance of 3D ICs, we propose a novel hybridization scheme for inter-layer communication. In addition, an efficient adaptive routing algorithm is presented which enables congestion-aware and reliable communication for the hybridized NoC architecture. An integrated monitoring and management platform on top of this architecture is also developed in order to implement more scalable power optimization techniques. From the router-level perspective, four design styles for implementing power-efficient reconfigurable interfaces in VFI-based NoC systems are proposed. To enhance the utilization of virtual channel buffers and to manage their power consumption, a partial virtual channel sharing method for NoC routers is devised and implemented. Extensive experiments with synthetic and real benchmarks show significant power savings and mitigated hotspots with similar performance compared to latest NoC architectures. The thesis concludes that careful codesigned elements from different network levels enable considerable power savings for many-core systems.Siirretty Doriast

    Active Fault-Tolerance in Wireless Networked Control Systems

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    In a Wireless Networked Control System (WNCS), several nodes or components of the system may communicate over the common network that connects them together. Thus, there may be communication taking place between the sensors and the controller nodes, among the controllers themselves, among the sensors themselves, among the actuator themselves, and between the controller and the actuator nodes. The purpose of this communication is to improve the performance of the control system. The performance may be a measurable quantity defined in terms of a performance criterion, as in the case of optimal control or estimation, or it may be a qualitative measure described as a desired behaviour. Each node of the WNCS may act as a decision maker, making control as well as communication decisions. The presence of a network brings in constraints in the design of the control system, as information between the various decision makers must be exchanged according to the rules and dynamics of the network. Our goal is to quantify some of these constraints, and design the control system together with the communication system so as both do their best given the constraints. This work in no way attempts to suggest the best way to design a communication network that suits the needs of a particular control system, but some of the results obtained here may be used in conjunction with other results in forming an understanding as to how to proceed in the design of such systems in the future. The work proposes a novel real-time communication protocol based on the Time Division Multiple Access (TDMA) strategy, which has built-in tolerance against the network-induced effects like lost packets, assuring a highly deterministic and reliable behaviour of the overall networked control system, thus allowing the use of classical control design methods with WNCS. Determinism in the transmission times, for sending and for receiving, is assured by a communication schedule that is dynamically updated based on the conditions of the network and the propagation environment. An advanced experimentation platform has been developed, called WiNC, which demonstrates the efficiency of the protocol with two well-known laboratory benchmarks that have very different dynamics, namely the three-tank system and the inverted pendulum system. Wireless nodes belonging to both systems are coordinated and synchronized by a master node, namely the controller node. The WiNC platform uses only open source software and general-purpose (commercial, off-the shelf) hardware, thus making it with a minimal investment (low cost) a flexible and easily extendable research platform for WNCS. And considering the general trend towards the adoption of Linux as a real-time operating system for embedded system in automation, the developed concepts and algorithms can be ported with minimum effort to the industrial embedded devices which already run Linux

    Internet of things: Vision, applications and research challenges

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    The term “Internet-of-Things” is used as an umbrella keyword for covering various aspects related to the extension of the Internet and the Web into the physical realm, by means of the widespread deployment of spatially distributed devices with embedded identification, sensing and/or actuation capabilities. Internet-of-Things envisions a future in which digital and physical entities can be linked, by means of appropriate information and communication technologies, to enable a whole new class of applications and services. In this article, we present a survey of technologies, applications and research challenges for Internet-of-Things

    Final report on dissemination, regulation, standardization, exploitation & training : D6.3

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    In D6.1 deliverable project dissemination, exploitation and training plans, as well as standardization & regulatory approach strategy was presented. The D6.2 reported on the necessary updates of these strategies and the actions taken by the partners in line with them, as well as the obtained results. In this D6.3 deliverable, a full set of project dissemination activities, standardization & regulatory contributions as well as an operator’s “cook book” outlining steps necessary for full deployment of ON functionality and services, are presented.Deliverable D6.3 del projecte OneFITPostprint (author’s final draft

    A novel approach to emergency management of wireless telecommunication system

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    The survivability concerns the service continuity when the components of a system are damaged. This concept is especially useful in the emergency management of the system, as often emergencies involve accidents or incident disasters which more or less damage the system. The overall objective of this thesis study is to develop a quantitative management approach to the emergency management of a wireless cellular telecommunication system in light of its service continuity in emergency situations – namely the survivability of the system. A particular wireless cellular telecommunication system, WCDMA, is taken as an example to ground this research.The thesis proposes an ontology-based paradigm for service management such that the management system contains three models: (1) the work domain model, (2) the dynamic model, and (3) the reconfiguration model. A powerful work domain modeling tool called Function-Behavior-Structure (FBS) is employed for developing the work domain model of the WCDMA system. Petri-Net theory, as well as its formalization, is applied to develop the dynamic model of the WCDMA system. A concept in engineering design called the general and specific function concept is applied to develop a new approach to system reconfiguration for the high survivability of the system. These models are implemented along with a user-interface which can be used by emergency management personnel. A demonstration of the effectiveness of this study approach is included.There are a couple of contributions with this thesis study. First, the proposed approach can be added to contemporary telecommunication management systems. Second, the Petri Net model of the WCDMA system is more comprehensive than any dynamic model of the telecommunication systems in literature. Furthermore, this model can be extended to any other telecommunication system. Third, the proposed system reconfiguration approach, based on the general and specific function concept, offers a unique way for the survivability of any service provider system.In conclusion, the ontology-based paradigm for a service system management provides a total solution to service continuity as well as its emergency management. This paradigm makes the complex mathematical modeling of the system transparent to the manager or managerial personnel and provides a feasible scenario of the human-in-the-loop management

    Internet of Things. Information Processing in an Increasingly Connected World

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    This open access book constitutes the refereed post-conference proceedings of the First IFIP International Cross-Domain Conference on Internet of Things, IFIPIoT 2018, held at the 24th IFIP World Computer Congress, WCC 2018, in Poznan, Poland, in September 2018. The 12 full papers presented were carefully reviewed and selected from 24 submissions. Also included in this volume are 4 WCC 2018 plenary contributions, an invited talk and a position paper from the IFIP domain committee on IoT. The papers cover a wide range of topics from a technology to a business perspective and include among others hardware, software and management aspects, process innovation, privacy, power consumption, architecture, applications
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