Search results for "Telecommunication"

Implementation of a PLC Field Analyzer on a G3 Modem Platform

2021

Nowadays, power line communications (PLC) are a widely used technology in distribution grids, both for automatic meter reading and automation applications. PLC performances (in terms of capacity, coverage, robustness, and data transmission rate) can be significantly affected by electrical network topologies, connected loads and disturbances. Thus, utilities and modem manufacturers are increasing their interest in electrical network characterization. In this framework, a software tool is proposed in this paper to measure received signal and noise levels. As case study, it is implemented on a G3 PLC transceiver, widely used for smart metering purposes. In this way, a PLC channel characterizat…

ZigBee networks performance under WLAN 802.11b/g interference

2009

ZigBee is a standard protocol suite for low rate wireless personal area networks (LR-WPANs) and has been widely utilized in various fields. Since both ZigBee and WLAN (802.11b/g) operate in the 2.4GHz unlicensed industrial scientific medical (ISM) frequency band, mutual interference is likely to exist and cause signal degradation. In this paper, an interference analysis model is suggested to obtain an estimate of Packet Error Rate (PER) of a ZigBee network. A ZigBee evaluation kit, AVR RZ200, was implemented for measurement of Packet Loss Ratio (PLR). The measured PLR matches the estimated PER, with varied distances and different center frequency offsets of different channels.

Inference of Spatiotemporal Processes over Graphs via Kernel Kriged Kalman Filtering

2018

Inference of space-time signals evolving over graphs emerges naturally in a number of network science related applications. A frequently encountered challenge pertains to reconstructing such dynamic processes given their values over a subset of vertices and time instants. The present paper develops a graph-aware kernel-based kriged Kalman filtering approach that leverages the spatio-temporal dynamics to allow for efficient online reconstruction, while also coping with dynamically evolving network topologies. Laplacian kernels are employed to perform kriging over the graph when spatial second-order statistics are unknown, as is often the case. Numerical tests with synthetic and real data ill…

The dynamics over the next few years of the Spanish mobile telecommunications market share: a mathematical modelling approach

2013

Taking into account available data from 2002 to 2009 about the market share percentages of the Spanish mobile telecommunications service providers, a dynamic diffusion model to study the evolution of the clients’ change between the different companies during the period 2010–2016 is proposed. The constructed model provides a tool for forecasting short-term trends about the customers’ preferences with respect to mobile network operators taking into account both, autonomous decisions due to direct marketing and advertising strategies, and also decisions adopted through interaction via social influence. The model can provide insights to companies for designing strategies in order to gain market…

Discussion of “Free Overfall in Inverted Semicircular Channels” by Subhasih Dey

2004

Demo - Dynamic Adaptations of WiFi Channel Widths Without TX/RX Coordination

2017

Most modern standards for wireless communications support physical layer adaptations, in terms of dynamic selection of channel central frequency, transmission power, modulation format, etc., in order to increase link robustness under time-varying propagation and interference conditions. In this demo, we demonstrate that another powerful solution for extending physical layer flexibility in OFDM-based technologies is the dynamic adaptation of the channel width. Although some standards already define the possibility of utilizing multiple channel widths (e.g. 20MHz, 10MHz, 5MHz for IEEE 802.11a standards), such an utilization is limited to a static configuration of a value defined during the ne…

Basic Concepts of Power Distribution Network Design for High-Speed Transmission

2011

This paper tries to gather the Power Distribution Network (PDN) techniques used to preserve power integrity in PCB designs when transmitting data rates over 6 Gbps using the newest commercial optical modules. The PDN design described allows for proper impedance control of the power supply with the appropriate choice of the number, location and values of capacitors. This method needs the knowledge of the electrical RLC model of the regulators, copper planes, capacitors and vias used in the PCB. A particular case of PDN design will be presented for a module using one SNAP12 optical transmitter and one receiver connected to an Altera Stratix II GX FPGA. This board is designed to work with data…

Industrial Areas and the City. Equalization and Compensation in a Value-Oriented Allocation Pattern

2016

This study deals with the allocation of the firms in a large industrial area of Quarto, a town in the Naples’ district subject to a “Piano di Insediamenti Industriali” – PIP (Industrial Settlement Masterplan). The main concern of the Municipality is the fair integration between environmental issues, economic development and urban identity. Therefore a structured evaluation process, based on a survey about the company profiles and their geographical location, has been carried out in order to make the plan meet the needs of the firms, and to select the best companies to settle in the planned area. A “generative” MAVT pattern has been designed to outline several layout options and to select th…

The design of sum-of-cisoids rayleigh fading channel simulators assuming non-isotropic scattering conditions

2010

In this letter, we introduce the Riemann sum method (RSM) as an effective tool for the design of sum-of-cisoids (SOC) simulators for narrowband mobile Rayleigh fading channels under non-isotropic scattering conditions. We compare the performance of the RSM with that of the generalized method of equal areas (GMEA) and the Lp-norm method (LPNM), which were until now the only methods available for the design of SOC simulators for non-isotropic scattering channels. The obtained results indicate that the RSM is better suited than the GMEA and the LPNM to emulate the channel's autocorrelation function (ACF), whereas the latter two methods are more precise regarding the approximation of the envelo…

Security of information in IT systems

2005

The aim of the paper is to increase human awareness of the dangers connected with social engineering methods of obtaining information. The article demonstrates psychological and sociological methods of influencing people used in the attacks on IT systems. Little known techniques are presented about one of the greater threats that is electromagnetic emission or corona effect. Moreover, the work shows methods of protecting against this type of dangers. Also, in the paper one can find information on devices made according to the TEMPEST technology. The article not only discusses the methods of gathering information, but also instructs how to protect against its out-of-control loss.