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Ítem Adaptive planning of 3G/4G systems using Q-analysis or polyhedral dynamics(IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC, 2004-01-01) Cardona, NarcisIn this paper we present a method for use Q-analysis in the initial planning process and later dynamic adaptation for 3G/4G cellular systems that intends to balance load in order to maximize capacity and reduce lost and dropped calls independently of the type of service. We support our proposal on dynamic simulations made with an own developed tool for dynamic simulations of CDMA systems, and show initial results that partially probe our proposed method.Ítem DVB Coverage Prediction Using Game Engine Based Ray-Tracing Techniques(IEEE, 2011-09-05) Gimenez, Jordi J.This paper presents the results of an evaluation of a propagation model based on ray-tracing techniques using a game engine and Graphics Processing Unit (GPU) in outdoor scenarios, as a gap-filler for a Digital Video Broadcasting Handheld (DVB-H) service. This model involves complete identification of the parameters of wave propagation, multipath components between the transmitter and the receiver as attenuation, time delay of arrival (TDA), full polarimetric transmission matrix, direction of arrival DoA and the direction of departure DoD. In the paper, we present the results of the simulation and compare them with measurements, obtaining a satisfactory fit. © 2011 IEEE.Ítem Applicability of Game Engine for Ray Tracing Techniques in a Complex Urban Environment(IEEE, 2010-09-10) Navarro Cadavid, AndresThis work presents results for a new method of ray tracing in urban environments using game engine and graphic processing unit (GPU). First advantage obtained with this method is the simplicity for 3D modeling from raster digital elevation model (DEM). Second advantage is the ability to precisely obtain ray parameters and the multiple paths interacting between transmitter and receiver in urban environment for high and low base station. A third advantage is the reduction in computing time by using the GPU capacity. In this paper, we show simulation results and compare them with measurements, obtaining a good fit. ©2010 IEEE.Ítem A statistical channel model for on body Area networks in Ultra Wide Band Communications(IEEE, 2009-09-10) Cardona, NarcisThis paper presents a novel statistical channel model for Ultra Wide Band Communications when On Body Area Networks Environments are considered. Results and Analysis of frequency measurements from 1GHz to 12GHz for body area networks are described. We propose a modified Saleh-Valenzuela statistical channel model considering different assumptions for small scale statistics in the model. Results show that the small scale amplitude follows a log normal distribution, the inter arrival times between multi path components are poisson process; the decay factor, the number of paths and clusters follow exponential distributions. The proposed model can be used for realistic simulations for on body communications in Ultra Wide Band systems. © 2009 IEEE.Ítem Performance analysis of scheduling algorithms in Next Generation Networks(IEEE, 2010-09-15) Cuellar Quiñones, Juan CarlosQoS in Convergent networks is widely discussed item in IP networks. But with the implementation of the Next Generation Networks by most operators around the world, QoS for different services and applications must fulfill. In order to deal with this problem, we simulate end to end QoS parameters, according to lTV Y.1540 and Y.1541 recommendations and different scheduling algorithms proposed by manufacturers and the literature. In this paper we show the results for such simulations for voice over IP service in different load conditions.Ítem Performance evaluation of Vertical Handoff Algorithms(IEEE, 2010-10-10) Navarro Cadavid, AndresDifferent Vertical Handoff Algorithms (VHA) have been proposed in the literature recently. However, there is no consensus on how to evaluate performance of different VHA at the research community. Although some models have been proposed for evaluation of the VHA, this issue is a challenge because the VHA have evolved to become more sophisticated, thus the evaluation models must consider a variety of parameters. In this paper, we propose a new evaluation model for VHA that has been designed based on specific concepts taken from the multi-criteria evaluation and operational reliability. The proposed evaluation model allows analyzing VHA using measured values of some defined parameters, which can be obtained from simulating VHA on a network simulation tool. We present as a case study an evaluation of two VHA that shows the new model functionality and results. © 2010 IEEE.Ítem Análisis y caracterización de frameworks para detección de aplicaciones maliciosas en android(ResearchGate, 2014-06-01) Londoño, Sebastiany caracterización de frameworks para detección de aplicaciones maliciosas en Android. XIV Jornada Internacional de Seguridad Informática ACIS 2014 1 Resumen—Android incorpora distintos sistemas de seguridad para solucionar los problemas generados por aplicaciones malware como el modelo de permisos para cada aplicación, su propia plataforma de distribución de aplicaciones móviles "Google Play", entre otras. Pero existen otras alternativas que tienen como función mejorar la protección contra el software malicioso. En este artículo se presenta la información más reciente sobre metodologías, frameworks y sistemas que permiten resolver algunos de los problemas generados por aplicaciones maliciosas (Malware) para dispositivos móviles con sistema operativo Android.Ítem Measurement-based ray-tracing models calibration in urban environments(IEEE, 2012-07-08) Cardona, NarcisThis paper investigates the effect produced on the accuracy of the estimate of path loss in an outdoor environment in order to adjust the permittivity values for building wall, building roof and street floor by using a full 3D ray-tracing system. Due to the complexity of a real situation, estimation of path loss using the ray-tracing method is generally assumed one or three large classes of homogeneous materials to represent the building walls, building roofs and street floors in order have a viable model of the 3D environment. However, in a real case, an outdoor environment consists of many buildings and streets made of heterogeneous materials. We analyze the behavior of the statistical variation of standard deviation, correlation coefficient and the average error between the values of estimated and measured path loss data when considering various values of permittivity of these three classes.Ítem Heuristic UTD coefficients applied for the channel characterization in an andean scenario(Institute of Electrical and Electronics Engineers Inc., 2015-07-19) Navarro Cadavid, AndresThis paper presents a comparison of three heuristic coefficients for the Uniform Theory of Diffraction (UTD), used to characterize the radiowave scattering in typical urban scenarios. The coefficients were implemented in a propagation model based on 3D ray-tracing techniques in an andean scenario. In order to evaluate each coefficient we analyze the statistical behavior of the mean and standard deviation of the absolute errors between the estimated values and the measured data of path loss in a large number of receptor points. Finally, we show the path loss prediction for each heuristic UTD coefficients proposed.Ítem Delay spread in mmwave bands for indoor using Game Engines 3D Ray based Tools(Institute of Electrical and Electronics Engineers Inc., 2016-04-10) Cruz, WilliamSimulation results of channel parameters using a Game Engine Ray Based Tool in different operating systems with different hardware architectures and using an open source 3D modeling tool for an indoor scenario are presented in this paper. We present simulation results and compare them with a set of measurements for an indoor scenario in the 5.4 GHz band, obtaining good matches between the rays traced by the tool and measurements for delay spread.
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