A simulation study on the health concerns derived from GSM base station placement

In the last years a great concern has raised among population due to the placement of the base stations (BS) of cellular systems in urban areas. In some cases, it has been addressed with the (re)installation of BSs in far suburban areas. However, in these cases, mobile stations (MS) must raise transmission power. Thus, users may -potentially- suffer a higher radio exposure. In this paper we quantified the variation of the transmission power in this application scenario. The study has been done by means of the OPNET/GSM framework simulation tool. Suitable propagation models and the GSM power control algorithm have been added to the model, in order to compute the MS transmission power in a real environment. Results reveal a significative increment of the MS transmission power when the BS is relocated to suburban areas. Therefore, we conclude that it is necessary to introduce modifications in the GSM network architecture to solve this issue together with the BS placement problemThis work has been funded by the Spanish Economy, Industry and Innovation Council under the SOLIDMOVIL project (2I04SU044), by Fundación Séneca (Región de Murcia, Spain) ARENA project (00546/PI/04) and by the Spanish Research Council under the ARPaq project (TEC2004-05622- C04-02/TCM). The authors are also indebted to OPNET Technologies Inc. for granting licenses under the OPNET University program

Clasificación topoclimática de la sequía en la Península Ibérica de 1950 a 2007 a partir del SPI

Ponencia presentada en: VI Congreso Internacional de la Asociación Española de Climatología celebrado en Tarragona del 8 al 11 de octubre de 2008.[ES]Desde el punto de vista científico y social es interesante estudiar y clasificar los periodos de sequía que han ocurrido en la Península Ibérica en los últimos 50 años para poder identificar qué zonas tienen más susceptibilidad a padecer una escasez de agua. Mediante un estudio orográfico y una clasificación sinóptica podemos clasificar la Península en distintas zonas según la precipitación registrada en este periodo de tiempo y las situaciones meteorológicas que predominan en cada una de las zonas. Así podemos intentar analizar cuáles pueden ser las regiones con una tendencia más propensa a los periodos de sequía. Para establecer el criterio de sequía utilizamos el Índice Estandarizado de Precipitación (SPI) que nos proporciona una información directa y homogénea de la situación climática en cada momento. De esta forma clasificamos la Península Ibérica dividiéndola en 9 zonas características a partir de las cuales estudiamos la evolución del SPI utilizando el Índice para la escala temporal de 12 meses. Analizando los gráficos de la evolución anual del SPI localizamos y comprobamos episodios de sequía ocurridos a lo largo de nuestro periodo de estudio.[EN]From the scientific and social point of view it is interesting to study and to classify the drought's episode that the Iberian Peninsula has had in the last 50 years with this idea we are able to identify which areas are more susceptible to suffer a water shortage. By means of an orographical and synoptic study we can classify the Peninsula under different zones according to the rainfall registered in this period and the meteorological synoptic patterns in each of the zones. This way we can try to analyze which can be the regions with a high tendency to the periods of drought. To establish the criterion of drought we use the Standardized Precipitation Index (SPI) that provides us a direct and homogeneous information of the climatological situation in every moment. In this way we classify the Iberian Peninsula divided into 9 typical zones from which we study the evolution of the SPI using the Index for the time scale of 12 months. Analyzing the graphs of the annual evolution of the SPI we locate and verify episodes of drought happened along our period of study.Este trabajo está realizado dentro del proyecto CICYT: "DULCINEA. Desarrollo de Metodologías para caracterizar las cubiertas vegetales a partir de sensores de última generación. Cambio Climático y su incidencia en la vegetación de la Península Ibérica". Ref. CGL2005-0420

Regionalización de la sequía en la Península Ibérica desde 1950 hasta 2007 a partir del SPI y una modelización digital terreno

Ponencia presentada en: XXX Jornadas Científicas de la AME y el IX Encuentro Hispano Luso de Meteorología celebrado en Zaragoza, del 5 al 7 de mayo de 2008.Este trabajo está realizado dentro del proyecto CICYT: “DULCINEA. Desarrollo de Metodologías para caracterizar las cubiertas vegetales a partir de sensores de última generación. Cambio Climático y su incidencia en la vegetación de la Península Ibérica”. Ref. CGL2005-04202

Plataformas Middleware comerciales para la integración de flujos de vídeo bruto

El documento realiza un estudio sobre el uso de distintos componentes COTS (Comercial Off-The-Shelf) dirigido al desarrollo de aplicaciones que hagan posible la integración de flujos de vídeo. El objetivo es presentar tres plataformas de integración (CORBA, JavaRMI y .Net Remoting) que permitan construir aplicaciones y servicios distribuidos para transmitir y recibir flujos de vídeo sin compresión. CORBA y dentro de este, aquellos ORB’s que incorporen entre sus servicios el denominado A/V Stream, hace posible la implementación de este tipo de aplicaciones. JavaRMI y más recientemente .Net Remoting son dos plataformas que permiten el desarrollo de aplicaciones distribuidas multimedia, pero con limitaciones propias: en el caso de JavaRMI, el lenguaje de programación (Java) y en el caso de .Net Remoting, el sistema operativo (Windows).Escuela Técnica Superior de Ingeniería de Telecomunicació

Knockout packet loss probability analysis of SCWP optical packet switching wavelength distributed knockout architecture

The deployment of Optical Packet Switching (OPS) in Dense Wavelength Division Multiplexing (DWDM) backbone networks is perceived as a medium term promising alternative. Scalability restrictions imply that conventional switching architectures are unfeasible in this large-scale scenario. In a previous paper, the wavelength-distributed knockout architecture was proposed as a cost-effective scaling strategy for OPS switching fabrics. In this paper, this growable architecture is applied to OPS switching fabrics able to emulate output buffering. We also propose an scheduling algorithm which provides optimum performance if knockout packet losses are made negligible. The mathematical analysis to evaluate the knockout packet loss probability of this architecture is obtained, under uniform and non-uniform traffic patterns. To complement the switch dimensioning process, an upper bound assuring 0-knockout packet losses is compared with the exact analytical results.This research has been funded by Spanish MCyT grants TEC2004-05622-C04-01/TCM (CAPITAL) and TEC2004-05622-C04-02/TCM (ARPaq) and Xunta de Galicia grant PGIDIT04TIC322003PR

An IEEE 802.11 protocol test-bed in industrial environments using personal computing devices

IEEE 802.11 is being currently considered to develop telecommunications infrastructures in industrial environments. However, in such environments there may exist a high level of electromagnetic fields (EMF) contamination, due to the machinery in use. Wireless LANs are sensitive to this type of hazard, and therefore the performance of the protocols may be affected inside the industrial facilities. In this paper we conduct a study of the wireless link performance in these industrial scenarios, using personal computing devices. Such equipments will be likely used by employees rather than conventional computers. Since the results do not characterize the environment itself, but the set of environment and hardware, a proper measurement test-bed must include direct measurements with these devices. Besides, due to limitations in these equipments, a specific protocol to measure pairs of packet error probability and latency is also developed. Results reveal a significant linear dependency between both magnitudes, and a large correlation coefficient in the measurements under high EMF activity at mid-large ranges (distances greater than 5 meters)This work has been cofunded by the Economy,Industry and Innovation Council,with the SOLIDMOVIL project(2I04SU044),supported by Fundación Séneca,from the Región of Murcia with the ARENA Project(00546/PI/04),and by the Spanish Research Council with the ARPaq project(TEC2004-05622-C04-02/TCM)and the CSI-RHE Tproject(TEC2005-08068-C04-01/TCM)

Modelling rates of ecosystem recovery after fires by using Landsat TM data

The aim of this work consists of monitoring the recovery process after fire by means of satellite imagery. The objectives are to assess` the regrowth pathways followed by different species populations after a disturbance, to analyze the speed of recovery in the years following fire, and, finally, to estimate rates of regrowth. The test area is located in the north of the province of Alicante, on the Mediterranean coast of Spain. This area, especially prone to finest fires, shows a remarkable land-use history and human pressure. The test areas belong to different microclimatic zones, show diverse vegetation communities, and have different degrees of stoniness; so we attempted to discover their postfire behaviors according to their bioaeographical conditions. To accomplish these objectives, we used nine Landsat .5 thematic mapper images from 1984 to 1994 to which geometric and radioneetrie corrections were applied. Once the comparability between images was guaranteed, we generated a normalized difference vegetation index (NDVI) for each date. First, we demonstrated that the differences between (NDVI) images were suitable for mapping burned areas. Second, we undertook a nonlinear regression. analysis between NDVI values and the time elapsed since the fire to assess the recovery processes. The exponential adjustment between NDVI and three wa.s in. accord with the asymptotic behavior observed when the -recovery process is complete. The parameters supplied by the proposed method are helpful in quantifying the effects of fire on different ecosystein processes

OBIWAN: wireless sensor networks with OMNET++

Simulation is essential in WSN study. However, the nature of WSN makes it an unexpectedly complex task. The extremely large number of nodes, the need for an environment model, and the cross-layer dependencies of the models are some of the reasons for this complexity. Many of the existing simulation tools do not properly handle these issues. In this paper, OBIWAN, a new simulator for WSN is presented. In its design, critical issues like reusability, scalability and cross-layer dependencies have been addressed. The results on its capabilities and performance are provided through a case study involving several thousand nodes and an environment modelThis, work has been funded by the Economy,Industry and Innovation Council,with the SOLIDMOVIL project(2I04SU044),by Fundación Séneca both from the Region of Murcia with the ARENA Project(00546/PI/04)and by the Spanish Research Council with the ARPaq project(TEC2004-05622-C04-02/TCM)and CSI-RHET project(TEC2005-08068–C04-01/TCM)