2,095,650 research outputs found

    Communication models with distributed transmission rates and buffer sizes

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    The paper is concerned with the interplay between network structure and traffic dynamics in a communications network, from the viewpoint of end-to-end performance of packet transfer. We use a model of network generation that allows the transition from random to scale-free networks. Specifically, we are able to consider three different topologycal types of networks: (a) random; (b) scale-free with \gamma=3; (c) scale free with \gamma=2. We also use an LRD traffic generator in order to reproduce the fractal behavior that is observed in real world data communication. The issue is addressed of how the traffic behavior on the network is influenced by the variable factors of the transmission rates and queue length restrictions at the network vertices. We show that these factors can induce drastic changes in the throughput and delivery time of network performance and are able to counter-balance some undesirable effects due to the topology.Comment: 4 pages, 5 figures, IEEE Symposium on Circuits and Systems, Island of Kos, Greece, 200

    Conceptual Model for Communication

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    A variety of idealized models of communication systems exist, and all may have something in common. Starting with Shannons communication model and ending with the OSI model, this paper presents progressively more advanced forms of modeling of communication systems by tying communication models together based on the notion of flow. The basic communication process is divided into different spheres (sources, channels, and destinations), each with its own five interior stages, receiving, processing, creating, releasing, and transferring of information. The flow of information is ontologically distinguished from the flow of physical signals, accordingly, Shannons model, network based OSI models, and TCP IP are redesigned.Comment: 13 pages IEEE format, International Journal of Computer Science and Information Security, IJCSIS November 2009, ISSN 1947 5500, http://sites.google.com/site/ijcsis

    Communication, cultural form and theology

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    This essay explores some relationships between the areas of communication science and theology, beginning with a brief examination of what is called the \u27cultural studies\u27 model of communication and the institutional roles of communication in contemporary society. The second section presents a look at some models of communication interacting with theology in an earlier historical era, while the third reviews some contemporary models of communication within theology. The last section also examines the contemporary period but focusses on more specific projects

    Towards an analytical framework of science communication models

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    This chapter reviews the discussion in science communication circles of models for public communication of science and technology (PCST). It questions the claim that there has been a large-scale shift from a ‘deficit model’ of communication to a ‘dialogue model’, and it demonstrates the survival of the deficit model along with the ambiguities of that model. Similar discussions in related fields of communication, including the critique of dialogue, are briefly sketched. Outlining the complex circumstances governing approaches to PCST, the author argues that communications models often perceived to be opposed can, in fact, coexist when the choices are made explicit. To aid this process, the author proposes an analytical framework of communication models based on deficit, dialogue and participation, including variations on each

    Bell scenarios with communication

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    Classical and quantum physics provide fundamentally different predictions about experiments with separate observers that do not communicate, a phenomenon known as quantum nonlocality. This insight is a key element of our present understanding of quantum physics, and also enables a number of information processing protocols with security beyond what is classically attainable. Relaxing the pivotal assumption of no communication leads to new insights into the nature quantum correlations, and may enable new applications where security can be established under less strict assumptions. Here, we study such relaxations where different forms of communication are allowed. We consider communication of inputs, outputs, and of a message between the parties. Using several measures, we study how much communication is required for classical models to reproduce quantum or general no-signalling correlations, as well as how quantum models can be augmented with classical communication to reproduce no-signalling correlations.Comment: 12 pages, 3 figures. Includes a more detailed explanation of results appearing in the appendix of arXiv:1411.4648 [quant-ph

    On the Public Communication Needed to Achieve SK Capacity in the Multiterminal Source Model

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    The focus of this paper is on the public communication required for generating a maximal-rate secret key (SK) within the multiterminal source model of Csisz{\'a}r and Narayan. Building on the prior work of Tyagi for the two-terminal scenario, we derive a lower bound on the communication complexity, RSKR_{\text{SK}}, defined to be the minimum rate of public communication needed to generate a maximal-rate SK. It is well known that the minimum rate of communication for omniscience, denoted by RCOR_{\text{CO}}, is an upper bound on RSKR_{\text{SK}}. For the class of pairwise independent network (PIN) models defined on uniform hypergraphs, we show that a certain "Type S\mathcal{S}" condition, which is verifiable in polynomial time, guarantees that our lower bound on RSKR_{\text{SK}} meets the RCOR_{\text{CO}} upper bound. Thus, PIN models satisfying our condition are RSKR_{\text{SK}}-maximal, meaning that the upper bound RSKRCOR_{\text{SK}} \le R_{\text{CO}} holds with equality. This allows us to explicitly evaluate RSKR_{\text{SK}} for such PIN models. We also give several examples of PIN models that satisfy our Type S\mathcal S condition. Finally, we prove that for an arbitrary multiterminal source model, a stricter version of our Type S\mathcal S condition implies that communication from \emph{all} terminals ("omnivocality") is needed for establishing a SK of maximum rate. For three-terminal source models, the converse is also true: omnivocality is needed for generating a maximal-rate SK only if the strict Type S\mathcal S condition is satisfied. Counterexamples exist that show that the converse is not true in general for source models with four or more terminals.Comment: Submitted to the IEEE Transactions on Information Theory. arXiv admin note: text overlap with arXiv:1504.0062
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