On the Integration of Grassmannian Constellations into LTE Networks: a Link-level Performance Study

This paper presents Grassmannian signaling as a transmission scheme that can be integrated in Long Term Evolution (LTE) to support higher user speeds and to increase the throughput achievable in the high Signal to Noise Ratio (SNR) regime. This signaling is compared, under realistic channel assumptions, with the diversity transmission modes standardized in LTE, in particular, Space-Frequency Block Coding and Frequency-Switched Transmit Diversity for two and four transmit antennas, respectively. In high-speed scenarios, and even with high antenna correlation, Grassmannian signaling outperforms the LTE diversity transmission modes starting from four transmit antennas. Furthermore, in the high SNR regime, Grassmannian signaling can increase the link data rate up to 10% and 15% for two and four antennas, respectively

Comparison of Optimization Methods for Aerial Base Station Placement with Users Mobility

Aerial base stations have been recently considered in the deployment of wireless networks. Finding the optimal position for one or multiple aerial base stations is a complex problem tackled by several works. However, just a few works consider the mobility of the users which makes necessary an online optimization to follow the changes in the scenario where the optimization is performed. This paper deals with the online optimization of an aerial base station placement considering different types of users mobility and three algorithms: a Q-learning technique, a Gradient-based solution and a Greedy-search solution. Our objective is to minimize in an urban environment the path loss of the user at street level with the highest path loss. Simulation results show that the performance of the three methods is similar when a high number of users move randomly and uniformly around the scenario under test. Nevertheless, in some situations when the number of users is reduced or when the users move together in a similar direction, both Gradient and Greedy algorithms present a significantly better performance than the Q-learning method.The work of Danaisy Prado was supported by the H2020 Marie Curie Program, with Project Grant No. 766231 WAVECOMBE - ITN - 2017Prado-Alvarez, D.; Inca-Sanchez, SA.; Martín-Sacristán, D.; Monserrat Del Río, JF. (2019). Comparison of Optimization Methods for Aerial Base Station Placement with Users Mobility. IEEE. 485-489. https://doi.org/10.1109/EuCNC.2019.8802053S48548

Millimeter-wave Human Blockage Model Enhancements for Directional Antennas and Multiple Blockers

[EN] The Third Generation Partnership Project (3GPP) has defined a blockage model as an add-on feature to the channel model used in its evaluations of the physical layer in the 0.5-100 GHz frequency range. This letter focuses on the human body blockage losses in the millimeter-wave band proposing: (i) a new criterion to place the diffraction points over the edges of the blockers that considers the precise position of the blocker with regard to the line-of-sight between the transmitter and the receiver, (ii) a specific criterion to determine which potential blockers, from a set of human bodies present in a certain scenario, should be considered effective blockers given the positions of a transmitter, a receiver, and those bodies, and (iii) a modification of the model to provide more accurate estimations in the case in which several blockers are closely located. The validity of our criteria and the accuracy improvement are confirmed by a set of measurements performed at 30 GHz with directional antennas and with multiple human blockers in different positions.The work of Danaisy Prado-Alvarez was supported by the H2020 Marie Curie Program, with Project Grant No. 766231 WAVECOMBE-ITN-2017. Part of this work has been performed in the framework of the H2020 project 5G-SMART co-funded by the EU. This was also supported by the Spanish Ministry of Science, Innovation and University under the project RTI2018-099880-B-C31. The associate editor coordinating the review of this letter and approving it for publication was J. Choi.Prado-Alvarez, D.; Inca-Sánchez, SA.; Martín-Sacristán, D.; Monserrat Del Río, JF. (2021). Millimeter-wave Human Blockage Model Enhancements for Directional Antennas and Multiple Blockers. IEEE Communications Letters. 25(9):2776-2780. https://doi.org/10.1109/LCOMM.2021.3095617S2776278025

Distribution of Road Hazard Warning Messages to Distant Vehicles in Intelligent Transport Systems

© 2018 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] The efficient distribution of intelligent transport system (ITS) messages is fundamental for the deployment and acceptance of ITS applications by mobile network operators and the automotive industry. In particular, the distribution of road hazard warning (RHW) messages to distant vehicles requires special mechanisms. In this case, the combination of direct communication between vehicles and the wide area coverage provided by cellular networks might be crucial not only for reducing the data transmission costs but also for improving the timeliness of ITS information. Moreover, the application of clustering and cluster head selection mechanisms among vehicles can increase the efficiency of hybrid vehicular and cellular communication networks. This paper introduces a novel cluster head selection technique for the distribution of RHW messages, and proposes an implementation of another legacy technique that was originally intended for mobile ad-hoc networks (MANETs). This paper evaluates the performance of these techniques by the means of computer simulations in two scenarios with distinct congestion and propagation conditions. The simulation results show the potential benefit of hybrid networks compared with pure cellular transmissions, especially, if the novel cluster head selection technique is used.Calabuig Soler, D.; Martín-Sacristán, D.; Monserrat Del Río, JF.; Botsov, M.; Gozálvez Serrano, D. (2018). Distribution of Road Hazard Warning Messages to Distant Vehicles in Intelligent Transport Systems. IEEE Transactions on Intelligent Transportation Systems. 19(4):1152-1165. https://doi.org/10.1109/TITS.2017.2718103S1152116519

Clinical pharmacology facing the real-world setting: Pharmacovigilance, pharmacoepidemiology and the economic evaluation of drugs

Adverse drug reaction; Effectiveness; PharmacoeconomicsReacció adversa als fàrmacs; Eficàcia; FarmacoeconomiaReacción adversa a medicamentos; Eficacia; FarmacoeconomíaTraditionally, clinical pharmacology has focused its activities on drug-organism interaction, from an individual or collective perspective. Drug efficacy assessment by performing randomized clinical trials and analysis of drug use in clinical practice by carrying out drug utilization studies have also been other areas of interest. From now on, Clinical pharmacology should move from the analysis of the drug-individual interaction to the analysis of the drug-individual-society interaction. It should also analyze the clinical and economic consequences of the use of drugs in the conditions of normal clinical practice, beyond clinical trials. The current exponential technological development that facilitates the analysis of real-life data offers us a golden opportunity to move to all these other areas of interest. This review describes the role that clinical pharmacology has played at the beginning and during the evolution of pharmacovigilance, pharmacoepidemiology and economic drug evaluations in Spain. In addition, the challenges that clinical pharmacology is going to face in the following years in these three areas are going to be outlined too

Reading virtual slide using web viewers: results of subjective experience with three different solutions

<p>Abstract</p> <p>Background</p> <p>Virtual slides are viewed using interactive software that enables the user to simulate the behaviour of a conventional optical microscope, like adjusting magnifications and navigating to any portion of the image. Nowadays, information about the performance and features of web-based solutions for reading slides in real environments is still scarce. The objective of this study is analyzing the subjective experience of pathologists with virtual slides, comparing the time needed to read slides using different web viewers and different network connections.</p> <p>Methods</p> <p>Eight slides were randomly selected (4 biopsies and 2 cytologies) from Hospital General de Ciudad Real (HGCR) archives. Three different virtual slide web-viewing solutions were analyzed: Aperio web server, Olympus NetImage Server, and Aurora mScope. Five pathologists studied to time needed to access images of each virtual slide, selecting a panoramic view, 10 low magnification fields, and 20 high magnification fields.</p> <p>Results</p> <p>Aperio viewer is very efficient in overview images. Aurora viewer is especially efficient in lower magnifications (10×). For larger magnifications (20× and 40×) no significant differences were found between different vendors. Olympus was found to be the most user-friendly interface. When comparing Internet with intranet connections, despite being slower, users also felt comfortable using virtual slides through Internet connection.</p> <p>Conclusion</p> <p>Available web solutions for virtual slides have different advantages, mainly in functionalities and optimization for different magnifications. Pathologist should select the solutions adapted to their needs.</p

Map-Based Channel Model for Urban Macrocell Propagation Scenarios

The evolution of LTE towards 5G has started and different research projects and institutions are in the process of verifying new technology components through simulations. Coordination between groups is strongly recommended and, in this sense, a common definition of test cases and simulation models is needed. The scope of this paper is to present a realistic channel model for urban macrocell scenarios. This model is map-based and takes into account the layout of buildings situated in the area under study. A detailed description of the model is given together with a comparison with other widely used channel models. The benchmark includes a measurement campaign in which the proposed model is shown to be much closer to the actual behavior of a cellular system. Particular attention is given to the outdoor component of the model, since it is here where the proposed approach is showing main difference with other previous models

Key Technologies for the Advent of the 6G

[EN] True, the scientific community still has a lot to investigate on how to get 5G to have a satisfactory journey in the development of standards. However, it is now that we must begin to glimpse the future of mobile technology, it is time to imagine what 6G will be. This paper offers a realistic view of what this technology might be. In this case, the experience of one of the most important groups in Europe dedicated to the mobile communication systems design, the iTEAM research institute, is combined with the one of the world's leading manufacturers of femtocells, Casa Systems. From the belief that the deployment of SG will come from homes, this paper analyzes the new use cases of the 6G, as well as the three technological pillars of this future technology.This work was supported by the Spanish Ministry of Science, Innovation and University under the project RTI2018-099880-B-C31.Monserrat Del Río, JF.; Martín-Sacristán, D.; Flores De Valgas, J.; Cardona Marcet, N.; Bouchmal, F.; Carrasco, Ó. (2020). Key Technologies for the Advent of the 6G. IEEE. 1-6. https://doi.org/10.1109/WCNCW48565.2020.9124725S1

Low-Latency Infrastructure-Based Cellular V2V Communications for Multi-Operator Environments With Regional Split

[EN] Mobile network operators are interested in providing Vehicle-to-Vehicle (V2V) communication services using their cellular infrastructure. Regional split of operators is one possible approach to support multi-operator infrastructure-based cellular V2V communication. In this approach, a geographical area is divided into non-overlapping regions, each one served by a unique operator. Its main drawback is the communication interruption motivated by the inter-operator handover in border areas, which prevents the fulfillment of the maximum end-to-end (E2E) latency requirements of fifth generation (5G) V2V services related to autonomous driving. In this work, we enable a fast inter-operator handover based on the pre-registration of the users on multiple operators, which substantially reduces the handover time to guarantee maximum E2E latency values of 100 ms in non-congested scenarios. To further reduce the latency of time-critical services to always less than 70 ms, even with the handover interruption time, while providing a latency around 20 ms in the majority of locations, we propose to complement the former technique with a mobile edge computing approach. Our proposal consists in the localization of application servers and broadcasting entities in all the base stations, to avoid the communication through the core network, together with the use of a new set of nodes in the base stations of cross-border areas called inter-operator relays, to minimize the communication latency between operators. Based on analytic and simulation results, it is demonstrated that the proposed techniques are effective to support low-latency infrastructure-based cellular V2V communications in multi-operator environments with regional split.The work of S. Roger was partially supported by the Spanish Ministry of Science, Innovation and Universities through grant number RYC-2017-22101.Martín-Sacristán, D.; Roger, S.; Garcia-Roger, D.; Monserrat Del Río, JF.; Spapis, P.; Zhou, C.; Kaloxylos, A. (2021). Low-Latency Infrastructure-Based Cellular V2V Communications for Multi-Operator Environments With Regional Split. IEEE Transactions on Intelligent Transportation Systems. 22(2):1052-1067. https://doi.org/10.1109/TITS.2019.29620971052106722

Análisis financiero farmacéuticos nacionales W.

La creación de empresas constituye una de las iniciativas más apasionantes para los emprendedores, es el primer paso hacia un camino lleno de retos, no obstante crecer y consolidarse en un mercado tan competido como lo es el sector farmacéutico, es el principal objetivo de cualquier compañía, por esta razón los modelos de gestión y dirección de las compañías evolucionan día a día ajustándose a los cambios que exigen el mundo actual. Una compañía que se adapta a los cambios, que constantemente se rediseña tiene como resultado, mayor productividad, mayor capacidad de competencia y mejores resultados operacionales y financieros en un mercado tan complicado como lo presenta la actual coyuntura. Por ello, se hace necesario estudiar e investigar los factores que determinan la administración financiera de las empresas y a partir de allí diseñar un plan estratégico de bienestar, el cual favorezca la promoción y ejecución de acciones destinadas a mejorar y optimización el desempeño productivo de las empresas; facilitando el desarrollo del potencial de las unidades de negocio de la compañía para lograr ser altamente productiva y competitiva en los mercados globales. En la compañía Farmacéuticos Nacionales W, la formulación de estrategias está orientada a fortalecer la administración financiera de la empresa, y de este modo, contribuir al mejoramiento de la productividad de la empresa. Por tanto, este trabajo busca analizar la situación financiera de la compañía y a partir de allí proponer estrategias orientadas a mejorar el desempeño de la compañía Farmacéuticos Nacionales W