1,720,985 research outputs found
MOON: a New Overlay Network Architecture for Mobility and QoS Support
Full text linkThe continuously increasing diffusion of mobile devices
such as laptops, PDAs and smartphones, all equipped with
enhanced functionalities, has led to numerous studies about
mobility and to the definition of new network architectures
capable to support it.
Problems related to mobility have been addressed mostly
operating on the network or transport layers of the Internet
protocol stack. As a result, most of these solutions generally
require modifying the TCP and/or the IP protocol. Although this
approach is well suited to handle mobility, it lacks in
compatibility with the Internet Protocol Suite.
This consideration led us to study a fully TCP compatible and
flexible approach we dubbed MOON, for MObile Overlay
Network. This network architecture is currently under design at
LIPAR, the Internet, Protocols and Network Architecture Lab of
Politecnico di Torino
Fast Authentication in Heterogeneous Wireless Networks
Full text linkThe growing diffusion of wireless devices is
leading to an increasing demand for mobility and security.
At the same time, most applications can only tolerate short
breaks in the data flow, so that it is a challenge to find out
mobility and authentication methods able to cope with these
constraints. This paper aims to propose an authentication
scheme which significantly shortens the authentication
latency and that can be deployed in a variety of wireless
environments ranging from common Wireless LANs
(WLANs) to satellite-based access networks
Energy detection spectrum sensing with discontinuous primary user signal
No full textThis paper addresses the problem of spectrum sensing for cognitive radio, in the case of a primary signal characterized by a discontinuous channel occupation within the considered sensing window. Under such conditions, the performance of two different energy detectors is investigated. The first one (Energy Average Detector) decides whether the channel is free or busy on the basis of the energy sample average; the second one (Energy Threshold Detector) performs a soft estimation of the channel occupation probability by comparing the energy samples with a proper threshold. For both the detectors, an analytical model is derived and validated through simulation, and the optimal decision threshold is found as a function of the primary signal parameter
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Measurement-based Analysis of Spectrum Sensing in Adaptive WSNs under Wi-Fi and Bluetooth Interference
No full textAn Authentication and Key Establishment Scheme for the IP-Based Wireless Sensor Networks
Full text linkIntegration between wireless sensor networks and traditional IP networks using the IPv6 and 6LoWPAN standards is a very active research and application area. A combination of hybrid network significantly increases the complexity of addressing connectivity and fault tolerance problems in a highly heterogeneous environment, including for example different packet sizes in different networks. In such challenging conditions, securing the communication between nodes with very diverse computational, memory and energy storage resources is at the same time an essential requirement and a very complex issue. In this paper we present an efficient and secure mutual authentication and key establishment protocol based on Elliptic Curve Cryptography (ECC) by which different classes of nodes, with very different capabilities, can authenticate each other and establish a secret key for secure communication. The analysis of the proposed scheme shows that it provides good network connectivity and resilience against some well known attacks
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