Caracterización experimental de las pérdidas de propagación en comunicaciones vehiculares a 700 MHz y 5,9 GHz

En esta Tesis Doctoral se realiza una caracterización experimental de las pérdidas de propagación del canal radio vehicular basada en una extensa campaña de medidas realizada en diferentes escenarios de propagación, todos ellos potenciales entornos de comunicaciones vehiculares. Se han realizado medidas en escenarios urbanos, suburbanos, rurales y de autovía, con condiciones reales de tráfico rodado, diferentes densidades de vehículos y condiciones de propagación. La sonda de canal empleada en las medidas ha sido diseñada e implementada con el propósito de realizar una caracterización en banda estrecha permitiendo analizar el efecto de las pérdidas de propagación y desvanecimiento multicamino. Las medidas se han realizado en la banda DSRC (Dedicated Short-Range Communications) a 5,9 GHz, adoptada en EEUU y Europa para comunicaciones vehiculares, y en la banda de 700 MHz propuesta por Japón para este tipo de comunicaciones. En este sentido, los resultados mostrados en esta Tesis Doctoral a 700 MHz son los primeros realizados en esta banda de frecuencia. Se han propuesto diferentes métodos de análisis de las medidas realizadas, permitiendo un extenso estudio de los parámetros que caracterizan las pérdidas de propagación. Se ha analizado el canal radio vehículo a vehículo (V2V, Vehicular-to-Vehicular) y el canal vehículo a infraestructura (V2I, Vehicular-to-Infrastructure), estableciendo un modelo lineal entre las pérdidas de propagación y el logaritmo de la distancia entre el transmisor y receptor. Se trata de un modelo sencillo, pero bastante exacto, que permite una fácil implementación en simuladores de redes vehiculares. A diferencia de otros trabajos previos, que solamente analizan valores medios de los parámetros del modelo de pérdidas, en esta tesis se presentan resultados que permiten conocer el rango de variación de dichos parámetros En la investigación realizada se ha analizado el impacto que las condiciones de propagación, en lo que respecta a línea de visión directa y obstrucción de la misma, tienen sobre el comportamiento de la atenuación introducida por el canal radio. Los resultados derivados de esta Tesis Doctoral pueden ser utilizados el diseño y evaluación de protocolos de comunicación bajo condiciones de propagación próximas a la realidad, así como en el diseño y planificación de las futuras redes vehiculares.Fernández González, HA. (2014). Caracterización experimental de las pérdidas de propagación en comunicaciones vehiculares a 700 MHz y 5,9 GHz [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/40370TESI

Path loss characterization for vehicular communications at 700 MHz and 5.9 GHz under LOS and NLOS conditions

In this letter, we present a path loss characterization of the vehicular-to-vehicular (V2V) propagation channel. We have assumed a path loss model suitable for vehicular ad hoc networks (VANETs) simulators. We have investigated the value of the model parameters, categorizing in line-of-sight (LOS) and non-LOS (NLOS) paths. The model parameters have been derived from extensive narrowband channel measurements at 700 MHz and 5.9 GHz. The measurements have been collected in typical expected V2V communications scenarios, i.e., urban, suburban, rural, and highway, for different road traffic densities, speeds, and driven conditions. The results reported here can be used to simulate and design the future vehicular networks.Fernández González, HA.; Rubio Arjona, L.; Rodrigo Peñarrocha, VM.; Reig, J. (2014). Path loss characterization for vehicular communications at 700 MHz and 5.9 GHz under LOS and NLOS conditions. IEEE Antennas and Wireless Propagation Letters. 13:931-934. doi:10.1109/LAWP.2014.2322261S9319341

Analysis of Small-Scale Fading Distributions in Vehicle-to-Vehicle Communications

[EN] This work analyzes the characteristics of the small-scale fading distribution in vehicle-to-vehicle (V2V) channels. The analysis is based on a narrowband channelmeasurements campaign at 5.9GHz designed specifically for that purpose.Themeasurements were carried out in highway and urban environments around the city of Valencia, Spain.Theexperimental distribution of the small-scale fading is compared to several analytical distributions traditionally used to model the fast fading in wireless communications, such as Rayleigh, Nakagami-𝑚,Weibull, Rice, and 𝛼-𝜇 distributions. The parameters of the distributions are derived through statistical inference techniques and their goodness-of-fit is evaluated using the Kolmogorov-Smirnov (K-S) test. Our results show that the 𝛼-𝜇 distribution exhibits a better fit compared to the other distributions, making its use interesting to model the small-scale fading in V2V channels.This work has been funded in part by the Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia del Ministerio de Economia y Competitividad, Spain, TEC2013-47360-C3-3-P, and the Departamento Administrativo de Ciencia, Tecnologia e Innovacion COLCIENCIAS en Colombia.Rodrigo Peñarrocha, VM.; Reig, J.; Rubio Arjona, L.; Fernández González, HA.; Loredo, S. (2016). Analysis of Small-Scale Fading Distributions in Vehicle-to-Vehicle Communications. Mobile Information Systems. 2016:1-7. https://doi.org/10.1155/2016/9584815S17201

CIUDADES INTELIGENTES, MARCO REGULATORIO EN COLOMBIA

This paper presents a literature review of the regulatory and normative aspects that have been developed under the concept of smart cities in Colombia. Through the Ministry of Information and Communication Technologies (MinTIC, Ministerio de Tecnologías de la Información y las Comunicaciones) has been proposed to develop a public policy in order to standardize the implementation of technology in several sectors of Colombian society over the next five years. In this sense, it has been synthesized the aspects to regulate in accordance with the seven components proposed by MinTIC: competitiveness, coexistence, culture, habitat, Infrastructure, resources and services, making a brief description of the regulatory framework that could apply to each of these components.En este trabajo se presenta una revisión de literatura de los aspectos regulatorios y normativos que se han venido desarrollando bajo el concepto de ciudades inteligentes, smart Cities, en Colombia. A través del Ministerio de Tecnologías de la Información y las Comunicaciones (MinTIC) se ha propuesto elaborar una política pública con el objeto de estandarizar la implementación de tecnología en los diversos sectores de la sociedad colombiana durante los próximos cinco años. En este sentido, se han sintetizado los aspectos a regular de acuerdo con los siete componentes propuestos por MinTIC: competitividad, convivencia, cultura, hábitat, infraestructura, recursos y servicios, haciendo una breve descripción del marco normativo que podría aplicarse a cada uno de los componentes en particular

Caracterización de las pérdidas de propagación a 700 MHz y 5.9 GHz para comunicaciones vehiculares

[EN] This paper presents a path loss characterization of the vehicular-to-vehicular (V2V) propagation channel. We have proposed a linear relationship between the path loss and the logarithm of the transmitter-receiver separation distance. The parameters of the path loss model have been derived from extensive narrowband channel measurements at 700 MHz and 5.9 GHz. The measurements have been collected in typical expected V2V communications scenarios, i.e., urban, suburban, rural and highway, for different road traffic densities, speed and driven conditions. Values of the path loss exponent for a 95 % confidence interval are reported.Fernández González, HA.; Rodrigo Peñarrocha, VM.; Reig, J.; Rubio Arjona, L. (2014). Caracterización de las pérdidas de propagación a 700 MHz y 5.9 GHz para comunicaciones vehiculares. http://hdl.handle.net/10251/54433

Experimental UWB propagation channel path loss and time-dispersion characterization in a laboratory environment

The knowledge of the propagation channel properties is an important issue for a successful design of ultrawideband (UWB) communication systems enabling high data rates in short-range applications. From an indoor measurement campaign carried out in a typical laboratory environment, this paper analyzes the path loss and time-dispersion properties of the UWB channel. Values of the path loss exponent are derived for the direct path and for a Rake receiver structure, examining the maximum multipath diversity gain when an all Rake (ARake) receiver is used. Also, the relationship between time-dispersion parameters and path loss is investigated. The UWB channel transfer function (CTF) was measured in the frequency domain over a channel bandwidth of 7.5GHz in accordance with the UWB frequency range (3.1 10.6GHz).The authors would like to thank the anonymous reviewer for his constructive suggestions and useful comments which have improved the final quality of the paper. This work has been funded in part by the Spanish Ministerio de Ciencia e Innovacion (TEC-2010-20841-C04-1).Rubio Arjona, L.; Reig, J.; Fernández González, HA.; Rodrigo Peñarrocha, VM. (2013). Experimental UWB propagation channel path loss and time-dispersion characterization in a laboratory environment. International Journal of Antennas and Propagation. 2013:1-7. https://doi.org/10.1155/2013/350167S17201

Caracterización de las pérdidas de propagación en el canal de radio V2V para un escenario suburbano

El diseño de los futuros sistemas de comunicaciones vehiculares ha centrado la atención de la comunidad científica, los organismos de estandarización y fabricantes de vehículos durante estos últimos años como consecuenciade la introducción de los denominados sistemas de transporte inteligente y el gran potencial que tienen para mejorar las condiciones de seguridad en las carreteras, teniendo como propósito reducir el número de accidentes de tráfico y facilitar el flujo vehicular. Para diseñar, evaluar y optimizar las aplicaciones de los sistemas de transporte inteligente orientadas a la seguridad vehicular y basadas en sistemas de comunicaciones inalámbricos, es de vital importancia el conocimiento de las características del canal de propagación, en particular las pérdidas básicas de propagación. En este sentido, en el presente artículo se analizan las pérdidas de propagación en función de la distancia de separación entre los vehículos transmisor (Tx) y receptor (Rx). Con base en una campaña de medidas realizada a 700 MHz y 5,9 GHz en un entorno suburbano, de elevada densidad de tráfico rodado, se presentan resultados sobre el rango de variación del exponente de pérdidas y las características de desvanecimiento o variabilidad temporal de la señal recibida. Los resultados son comparados con otros estudios publicados en la literatura

Millimeter-wave channel measurements and path loss characterization in a typical indoor office environment

In this paper, a path loss characterization at millimeter-wave (mmWave) frequencies is performed in a typical indoor office environment. Path loss results were derived from propagation channel measurements collected in the 25–40 GHz frequency band, in both line-of-sight (LOS) and obstructed-LOS (OLOS) propagation conditions. The channel measurements were performed using a frequency-domain channel sounder, which integrates an amplified radio over fiber (RoF) link to avoid the high losses at mmWave. The path loss was analyzed in the 26 GHz, 28 GHz, 33 GHz and 38 GHz frequency bands through the close-in free space reference distance (CI) and the floating-intercept (FI) models. These models take into account the distance dependence of the path loss for a single frequency. Nevertheless, to jointly study the distance and frequency dependence of the path loss, multi-frequency models were considered. The parameters of the ABG (A-alpha, B-beta and G-gamma) and the close-in free space reference distance with frequency path loss exponent (CIF) models were derived from the channel measurements in the whole 25–40 GHz band under the minimum mean square error (MMSE) approach. The results show that, in general, there is some relationship between the model parameters and the frequency. Path loss exponent (PLE) values smaller than the theoretical free space propagation were obtained, showing that there are a waveguide effect and a constructive interference of multipath components (MPCs). Since the measurements were obtained in the same environment and with the same configuration and measurement setup, it is possible to establish realistic comparisons between the model parameters and the propagation behavior at the different frequencies considered. The results provided here allow us to have a better knowledge of the propagation at mmWave frequencies and may be of interest to other researchers in the simulation and performance evaluation of future wireless communication systems in indoor hotspot environments.This work has been funded in part by the MCIN/AEI/10.13039/501100011033/ through the I+D+i Project under Grant PID2020-119173RB-C21 and Grant PID2020-119173RB-C22, and by COLCIENCIAS in Colombia

On the applicability of ray-tracing propagation models to V2V-intersection environments

In this work, we analyze the applicability of a geometric-based stochastic (GBS) model based on ray-tracing techniques to vehicular-to-vehicular (V2V) intersections. The accuracy and usefulness of the proposed model is analyzed using simulated results and narrowband channel measurements at 5.9 GHz. The results show that these type of models can be a good choice to evaluate communications protocols and system performance of future vehicular networks

Vehicular-to-vehicular channel characterization and measurement results

[EN] Vehicular-to-Vehicular (V2V) communications are receiving considerable attention due to the introduction of the intelligent transportation system (ITS) concept. To design, evaluate and optimize ITS applications oriented to vehicular safety based on wireless systems, the knowledge of the propagation channel is vital, in particular the path loss. From a narrowband V2V channel measurements campaign carried out in a suburban area of the city of Valencia (Spain), this paper analyzes the path loss in terms of the transmitter (Tx) and receiver (Rx) separation distance. Based on a linear slope model, values for the path loss exponent and the standard deviation of shadowing are reported. Also, the Doppler Power Spectral Density (PSD) due to the time-selective behavior is examined.This work has been funded in part by the Programa de Apoyo a la Investigación y Desarrollo de la Universitat Politècnica de València (PAID-05-10) and the Departamento Administrativo de Ciencia, Tecnología e Innovación COLCIENCIAS de Colombia.Campuzano Candel, AJ.; Fernández González, HA.; Balaguer Andrés, D.; Vila Jiménez, A.; Bernardo Clemente, B.; Rodrigo Peñarrocha, VM.; Reig, J.... (2012). Vehicular-to-vehicular channel characterization and measurement results. Waves. 4:15-24. http://hdl.handle.net/10251/54869S1524