210 research outputs found

    A Multi-Game Framework for Harmonized LTE-U and WiFi Coexistence over Unlicensed Bands

    Full text link
    The introduction of LTE over unlicensed bands (LTE-U) will enable LTE base stations (BSs) to boost their capacity and offload their traffic by exploiting the underused unlicensed bands. However, to reap the benefits of LTE-U, it is necessary to address various new challenges associated with LTE-U and WiFi coexistence. In particular, new resource management techniques must be developed to optimize the usage of the network resources while handling the interdependence between WiFi and LTE users and ensuring that WiFi users are not jeopardized. To this end, in this paper, a new game theoretic tool, dubbed as \emph{multi-game} framework is proposed as a promising approach for modeling resource allocation problems in LTE-U. In such a framework, multiple, co-existing and coupled games across heterogeneous channels can be formulated to capture the specific characteristics of LTE-U. Such games can be of different properties and types but their outcomes are largely interdependent. After introducing the basics of the multi-game framework, two classes of algorithms are outlined to achieve the new solution concepts of multi-games. Simulation results are then conducted to show how such a multi-game can effectively capture the specific properties of LTE-U and make of it a "friendly" neighbor to WiFi.Comment: Accepted for publication at IEEE Wireless Communications Magazine, Special Issue on LTE in Unlicensed Spectru

    DRS: Dynamic Resource Scheduling for Real-Time Analytics over Fast Streams

    Full text link
    In a data stream management system (DSMS), users register continuous queries, and receive result updates as data arrive and expire. We focus on applications with real-time constraints, in which the user must receive each result update within a given period after the update occurs. To handle fast data, the DSMS is commonly placed on top of a cloud infrastructure. Because stream properties such as arrival rates can fluctuate unpredictably, cloud resources must be dynamically provisioned and scheduled accordingly to ensure real-time response. It is quite essential, for the existing systems or future developments, to possess the ability of scheduling resources dynamically according to the current workload, in order to avoid wasting resources, or failing in delivering correct results on time. Motivated by this, we propose DRS, a novel dynamic resource scheduler for cloud-based DSMSs. DRS overcomes three fundamental challenges: (a) how to model the relationship between the provisioned resources and query response time (b) where to best place resources; and (c) how to measure system load with minimal overhead. In particular, DRS includes an accurate performance model based on the theory of \emph{Jackson open queueing networks} and is capable of handling \emph{arbitrary} operator topologies, possibly with loops, splits and joins. Extensive experiments with real data confirm that DRS achieves real-time response with close to optimal resource consumption.Comment: This is the our latest version with certain modificatio

    Cyberphysical network for crop monitoring and fertigation control

    Get PDF
    Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do ParanáFertigation is a cultivation technique that uses the precise application of nutrient solutions according to the requirements of the plant, environmental conditions and substrate. The use of this technique has become popular due to the advantages promoted, which include the reduction of fertilizers, phytopharmaceuticals and water consumption. However, this performance is achieved at the expense of rigorous monitoring and regulation of factors such as nutrient solutions, environmental conditions and the vegetative state of the crop. This work describes the architecture of a network based on agents and cyberphysical elements that will be implemented in a strawberry production unit by fertigation. The system must be responsible for the correct supply of water and agricultural inputs based on local information provided by sets of sensors. Each set of sensors, called a measurement node, is responsible for acquiring information around a given location. The communication of this information is carried out through a wireless network based on the LoRa protocol to a digital platform where the information from all nodes, together with meteorological data, is aggregated and processed. The result of processing this information will lead to the definition of the exact amount of nutrient solution as well as the optimization of the use of water leading to an increase in production efficiency.A fertirrigação é uma técnica de cultivo que recorre à aplicação precisa de soluções nutritivas de acordo com os requisitos da planta, condições ambientais e de substrato. A utilização desta técnica tem-se popularizado devido às vantagens promovidas onde se destacam a redução de fertilizantes, fitofármacos e consumo de água. No entanto, este desempenho é conseguido à custa de um rigoroso monitoramento e regulação de fatores tais como soluções nutritivas, condições ambientais e estado vegetativo da cultura. Este trabalho descreve a arquitetura de uma rede baseada em agentes e elementos ciberfísicos que serão implementados em uma unidade de produção de morango por fertirrigação. O sistema deve ser responsável pelo fornecimento correto de água e insumos agrícolas tendo por base informações locais fornecidas por conjuntos de sensores. Cada conjunto de sensores, chamado de nó de medida, é responsável pela aquisição da informação em torno de um determinado local. A comunicação destas informações é realizada através de uma rede sem fio baseada no protocolo LoRa até uma plataforma digital onde a informação provinda de todos os nós, juntamente com dados meteorológicos, é agregada e processada. O resultado do processamento desta informação levará à definição da quantidade exata de solução nutritiva bem como a otimização da utilização da água levando a um aumento da eficiência de produção

    How Physicality Enables Trust: A New Era of Trust-Centered Cyberphysical Systems

    Full text link
    Multi-agent cyberphysical systems enable new capabilities in efficiency, resilience, and security. The unique characteristics of these systems prompt a reevaluation of their security concepts, including their vulnerabilities, and mechanisms to mitigate these vulnerabilities. This survey paper examines how advancement in wireless networking, coupled with the sensing and computing in cyberphysical systems, can foster novel security capabilities. This study delves into three main themes related to securing multi-agent cyberphysical systems. First, we discuss the threats that are particularly relevant to multi-agent cyberphysical systems given the potential lack of trust between agents. Second, we present prospects for sensing, contextual awareness, and authentication, enabling the inference and measurement of ``inter-agent trust" for these systems. Third, we elaborate on the application of quantifiable trust notions to enable ``resilient coordination," where ``resilient" signifies sustained functionality amid attacks on multiagent cyberphysical systems. We refer to the capability of cyberphysical systems to self-organize, and coordinate to achieve a task as autonomy. This survey unveils the cyberphysical character of future interconnected systems as a pivotal catalyst for realizing robust, trust-centered autonomy in tomorrow's world

    Fundamentals of Large Sensor Networks: Connectivity, Capacity, Clocks and Computation

    Full text link
    Sensor networks potentially feature large numbers of nodes that can sense their environment over time, communicate with each other over a wireless network, and process information. They differ from data networks in that the network as a whole may be designed for a specific application. We study the theoretical foundations of such large scale sensor networks, addressing four fundamental issues- connectivity, capacity, clocks and function computation. To begin with, a sensor network must be connected so that information can indeed be exchanged between nodes. The connectivity graph of an ad-hoc network is modeled as a random graph and the critical range for asymptotic connectivity is determined, as well as the critical number of neighbors that a node needs to connect to. Next, given connectivity, we address the issue of how much data can be transported over the sensor network. We present fundamental bounds on capacity under several models, as well as architectural implications for how wireless communication should be organized. Temporal information is important both for the applications of sensor networks as well as their operation.We present fundamental bounds on the synchronizability of clocks in networks, and also present and analyze algorithms for clock synchronization. Finally we turn to the issue of gathering relevant information, that sensor networks are designed to do. One needs to study optimal strategies for in-network aggregation of data, in order to reliably compute a composite function of sensor measurements, as well as the complexity of doing so. We address the issue of how such computation can be performed efficiently in a sensor network and the algorithms for doing so, for some classes of functions.Comment: 10 pages, 3 figures, Submitted to the Proceedings of the IEE

    PDM: Privacy-Aware Deployment of Machine-Learning Applications for Industrial Cyber–Physical Cloud Systems

    Get PDF
    The cyber-physical cloud systems (CPCSs) release powerful capability in provisioning the complicated industrial services. Due to the advances of machine learning (ML) in attack detection, a wide range of ML applications are involved in industrial CPCSs. However, how to ensure the implementation efficiency of these applications, and meanwhile avoid the privacy disclosure of the datasets due to data acquisition by different operators, remain challenging for the design of the CPCSs. To fill this gap, in this article a privacy-aware deployment method (PDM), named PDM, is devised for hosting the ML applications in the industrial CPCSs. In PDM, the ML applications are partitioned as multiple computing tasks with certain execution order, like workflows. Specifically, the deployment problem is formulated as a multiobjective problem for improving the implementation performance and resource utility. Then, the most balanced and optimal strategy is selected by leveraging an improved differential evolution technique. Finally, through comprehensive experiments and comparison analysis, PDM is fully evaluated

    Scalable coexistence of eMBB, URLLC and mMTC enabled by non-orthogonal multiple access and network slicing

    Get PDF
    Abstract. The 5G systems feature three use cases: enhanced Mobile BroadBand (eMBB), massive Machine-Type Communications (mMTC) and Ultra-Reliable and Low-Latency Communications (URLLC). The diverse requirements of the corresponding services in terms of achievable data-rate, number of connected devices, latency and reliability can lead to sub-optimal use of the 5G resources, thus network slicing emerges as a promising alternative that customizes slices of the network specifically designed to meet specific requirements. By employing network slicing, the radio resources can be shared via orthogonal and non-orthogonal schemes. Motivated by the Industrial Internet of Things (IIoT) paradigm where a large number of sensors may require connectivity with stringent requirements of latency and reliability, we propose and evaluate the joint use of network slicing and Non-Orthogonal Multiple Access (NOMA) with Successive Interference Cancellation (SIC) in two different uplink scenarios. In the first scenario, eMBB coexists with URLLC in the same Radio Access Network (RAN) and, in order to improve the number of concurrent URLLC connections to the same base station (BS), they transmit simultaneously and across multiple frequency channels. In the second scenario, eMBB coexists with mMTC and, to provide connectivity to a massive number of devices, the BS has multiple receive antennas. In both cases, we set the reliability requirements for the services and compare the performance of both orthogonal and non-orthogonal network slicing schemes in terms of maximum achievable data rates and connected users. Our results show that, even with overlapping transmissions from multiple devices, network slicing, NOMA and SIC techniques allow us simultaneously satisfy all the heterogeneous requirements of the 5G services
    corecore