Simulating electromagnetic field inside small aircraft from wireless camera equipment

This work forms part of the project HIRF SE which is financially supported under the European Union 7th Framework Programme (FP7). The authors are solely responsible for the contents of the paper which does not represent the opinion of the European Commission.The proliferation of wireless systems has urged the aviation industry to consider the exploitation of such a technology to introduce new services and to curtail its cabling weight requirements. Nevertheless, prior to implementing such communication systems, manufactures must ensure that the paramount criterion of aircraft safety is unaffected and thus the potential electromagnetic (EM) field posed on aircraft equipment must be carefully assessed and respective countermeasures taken. To this end, this paper adopts a frequency-domain based three-dimensional ray tracing algorithm, based on geometrical optics to compute the EM field generated from the use of wireless camera equipment transmitting at 2.4 GHz inside the cabin of a typical business jet. The model comprehensively considers the various propagation methodologies utilized by multipath signals to provide a holistic understanding of the resultant average field strength incident at each location inside the fuselage.peer-reviewe

Modeling electromagnetic interference generated by a WLAN system onboard commercial aircraft

This work forms part of the project HIRF SE which is financially supported under the European Union 7th Framework Programme (FP7). The authors are solely responsible for the contents of the paper which does not represent the opinion of the European Commission.The growing demand for the utilization of personal electronic communication devices onboard commercial aircraft necessitates the assurance of safety by airline operators and regulators. This implies that the potential risks posed by the deployment of wireless communication systems on critical aircraft equipment must be carefully assessed and countermeasures taken when required. In this paper, a model based on a ray-tracing algorithm is developed to calculate the electromagnetic interference incident on the fuselage structure of a commercial airline. The source of interference is a 2.4 GHz data communications network. Two scenarios are considered; the first assumes a base station in the centre of the cabin while the second considers four base stations, transmitting at a lower power, distributed along the cabin. The model first determines the propagation map generated by the base stations. These results are used to establish the transmission power required by the personal mobile devices which is then employed to determine the propagation map of each device. The overall electromagnetic interference map incident on the fuselage resulting from the onboard wireless network is generated by vectorially combining the resulting propagation maps. Results for the two scenarios are presented.peer-reviewe

Modelado de canal inalámbrico empleando técnicas de trazado de rayos: Una revisión sistemática

This paper presents an analysis of the research conducted by the scientific community who report similar characteristics in their evaluation. Predictions based on the use of computational tools that improve response times with acceptable accuracy. These calculations are corroborated by extensive measurement campaigns at specific sites in order to demonstrate the hypothesis. Finally the results were analyzed for each situation presented.Este trabajo presenta un análisis de las investigaciones realizadas por la comunidad científica que reportan características similares en su evaluación. Predicciones basadas en el uso de herramientas computacionales que mejoran cada vez los tiempos de respuesta con precisiones aceptables. Estos cálculos han sido corroborados a través de extensas campañas de medición en sitios específicos con el fin de evidenciar las hipótesis. Finalmente se exponen los resultados para cada situación analizada

An efficient ray validation technique for ray-tracing in urban microcellular environments

Ray-tracing propagation models for urban microcellular environments become time consuming as the validation of higher order of ray interactions presents a significant computational overhead. This letter presents a time efficient ray validation algorithm for ray-tracing models. The model presented in this letter uses a pre-computed database of building faces that are completely or partially visible to each face and vertical edge of all the buildings in the radio environment. This database is used to readily validate the ray-segments between the transmitter and receiver. The validation results show considerable time saving over previous models

Algoritmo de trazado de rayos para modelado de canales inalámbricos en entornos interiores.

This work proposes a simulation algorithm for modelling a wireless channel in indoor environments, based on dimensional‘image-based’ ray tracing method that considers the effects of channel dispersion. The algorithm implemented in Matlab, allows to simulatescenarios of different dimensions and with different types of walls into a building. The proposed algorithm was validated with analytical modelsand commercial software (Wireless Insite). To carry out the modelling, the dispersers, the dielectric characteristics of the materials, the frequencyand the distance, among others, are considered; The effects of reflection, refraction and diffraction phenomena are also included to increase theaccuracy of the prediction. The presented work proposes an algorithm to estimate the power received in a wireless channel for interiors thatseek to perform the channel estimation. A simulation of a real scenario is obtained with results that, according to the recommendation ITU-RP.1238-7, are accurate, with an average relative error of 3.85% and a difference of less than 3 dB.En este trabajo es propuesto un algoritmo para modelar un canal inalámbrico en un entorno de interiores, usando el métodode trazado de rayos conocido como ¨método de imágenes¨ que considera el efecto dispersivo. Este algoritmo fue implementado en Matlab,permitiendo simular escenarios de diferentes dimensiones y con diferentes materiales en sus paredes. El algoritmo propuesto fue validado conun modelo analítico y un software comercial (Wireless Insite). Los dispersores se modelaron con las características dieléctricas de los materialesque le componen, la frecuencia y la distancia, entre otras. Los efectos de reflexión, refracción y difracción también son considerados paraaumentar la precisión de la estimación. Con el trabajo propuesto se obtiene un algoritmo para estimar la potencia recibida en un canal inalámbricode interior que estima el comportamiento del canal. Una simulación de un escenario real es realizada con los resultados obtenidos dentro de losparámetros de la recomendación ITU-R P.1238-7, asegurando su precisión, con un error relativo promedio de 3.85% y una diferencia inferior a3 d

The characterisation and modelling of the wireless propagation channel in small cells scenarios

“A thesis submitted to the University of Bedfordshire, in partial fulfilment of the requirements for the degree of Doctor of Philosophy”.The rapid growth in wireless data traffic in recent years has placed a great strain on the wireless spectrum and the capacity of current wireless networks. In addition, the makeup of the typical wireless propagation environment is rapidly changing as a greater percentage of data traffic moves indoors, where the coverage of radio signals is poor. This dual fronted assault on coverage and capacity has meant that the tradition cellular model is no longer sustainable, as the gains from constructing new macrocells falls short of the increasing cost. The key emerging concept that can solve the aforementioned challenges is smaller base stations such as micro-, pico- and femto-cells collectively known as small cells. However with this solution come new challenges: while small cells are efficient at improving the indoor coverage and capacity; they compound the lack of spectrum even more and cause high levels of interference. Current channel models are not suited to characterise this interference as the small cells propagation environment is vast different. The result is that overall efficiency of the networks suffers. This thesis presents an investigation into the characteristics of the wireless propagation channel in small cell environments, including measurement, analysis, modelling, validation and extraction of channel data. Two comprehensive data collection campaigns were carried out, one of them employed a RUSK channel sounder and featured dual-polarised MIMO antennas. From the first dataset an empirical path loss model, adapted to typical indoor and outdoor scenarios found in small cell environments, was constructed using regression analysis and was validated using the second dataset. The model shows good accuracy for small cell environments and can be implemented in system level simulations quickly without much requirements