Search results for "TELECOMMUNICATION"

An over-the-distance wireless battery charger based on RF energy harvesting

2017

An RF powered receiver silicon IC (integrated circuit) for RF energy harvesting is presented as wireless battery charger. This includes an RF-to-DC energy converter specifically designed with a sensitivity of -18.8 dBm and an energy conversion efficiency of ∼45% at 900 MHz with a transmitting power of 0.5 W in free space. Experimental results concerned with remotely battery charging using a complete prototype working in realistic scenarios will be shown.

Episodes of second-degree ventriculo-atrial block during ventricular tachycardia

2017

A limited feedback scheme based on spatially correlated channels for coordinated multipoint systems

2012

High spectral efficiency can be achieved in the downlink of multi-antenna coordinated multi-point systems provided that the multiuser interference is appropriately managed at the transmitter side. For this sake, downlink channel information needs to be sent back by the users, thus reducing the rate available at the uplink channel. The amount and type of feedback information required has been extensively studied and many limited feedback schemes have been proposed lately. A common pattern to all of them is that achieving low rates of feedback information is possible at the cost of increasing complexity at the user side and, sometimes, assuming that some statistics of the channel are known. I…

Is IS Online Chatter Just Noise?: An Analysis of the Islamic State Strategic Communications

2020

The objective of this research is to analyze the potential use of strategic communication, and specifically, strategic brand management and online communications directed to a foreign target by the...

A privacy enhanced device access protocol for an IoT context

2013

In this paper, we present the case for a device authentication protocol that authenticates a device/service class rather than an individual device. The devices in question are providing services available to the public. The proposed protocol is an online protocol, and it uses a pseudo-random temporary identity scheme to provide user privacy. This allows the Internet-of-Things device to have full assurance of the user, with respect to the request service, while permitting the user to remain anonymous with respect to the device. The user can then enjoy identity and location privacy in addition to untraceability with respect to device access. Copyright © 2013 John Wiley & Sons, Ltd.

Experimental Assessment of the Backoff Behavior of Commercial IEEE 802.11b Network Cards

2007

It has been observed that different IEEE 802.11 commercial cards produced by different vendors experience different performance, either when accessing alone the channel, as well as when competing against each other. These differences persist also when thorough measurement methodologies (such as RF shielding, laptop rotation, etc) are applied, and alignment of the environmental factors (same laptop models, traffic generators, etc) is carried out. This paper provides an extensive experimental characterization of the backoff operation of six commercial NIC cards. It suggests a relevant methodological approach, namely a repeatable, well defined, set of experiments, for such a characterization. …

Unlocking behaviors of long-term service consumers : the role of action inertia

2017

Purpose The purpose of this paper is to examine the antecedents of word-of-mouth (WOM) in long-term service settings. Specifically, the authors examine the moderating role of action inertia in the relationships between satisfaction and repatronage intention, satisfaction and WOM, and repatronage intention and WOM. Design/methodology/approach The proposed model was empirically tested using survey data from 1,385 telecommunications service subscribers. The data were analyzed using partial least squares path modeling. Findings Results suggest that a positive link between repatronage intention and WOM, hereto a neglected relationship in the marketing literature, in contrast to previous literat…

Learning from Errors: Detecting ZigBee Interference in WiFi Networks

2014

In this work we show how to detect ZigBee interference on commodity WiFi cards by monitoring the reception errors, such as synchronization errors, invalid header formats, too long frames, etc., caused by ZigBee transmissions. Indeed, in presence of non-WiFi modulated signals, the occurrence of these types of errors follows statistics that can be easily recognized. Moreover, the duration of the error bursts depends on the transmission interval of the interference source, while the error spacing depends on the receiver implementation. On the basis of these considerations, we propose the adoption of hidden Markov chains for characterizing the behavior of WiFi receivers in presence of controlle…

Time-domain-induced polarization: Full-decay forward modeling and 1D laterally constrained inversion of Cole-Cole parameters

2012

Time-domain-induced polarization has significantly broadenedits field of reference during the last decade, from mineralexploration to environmental geophysics, e.g., for clay and peatidentification and landfill characterization. Though, insufficientmodeling tools have hitherto limited the use of time-domaininducedpolarization for wider purposes. For these reasons, anew forward code and inversion algorithm have been developedusing the full-time decay of the induced polarization response,together with an accurate description of the transmitter waveformand of the receiver transfer function, to reconstruct thedistribution of the Cole-Cole parameters of the earth. The accuratemodeling of the tra…

Digital information receiver based on stochastic resonance

2003

International audience; An electronic receiver based on stochastic resonance is presented to rescue subthreshold modulated digital data. In real experiment, it is shown that a complete data restoration is achieved for both uniform and Gaussian white noise.