End-to-end communications in low-rate wireless networks: Problems and solutions in satellite scenarios

Satellite communication links are susceptible to present numerous discontinuities in the transmission. Specific solutions are necessary to be developed to cope this problem. In this sense Delay and Disruptive Tolerant Networks are envisaged as solutions trying to optimize in some sense the communication link. In this TFG the problem of disruptive networks will be studied and possible solutions will be analyzed having in mind satellites scenarios. The work will require the definition of a scenario and the implementation of some state-of-the art solutions in a simulator.Since the Sputnik 1 was first launched in 1957, satellites have taken over the world with their multiple applications in our day-to-day life, specially in the telecommunications field, from television broadcast to mobile communications. One of the main issues they present, is that a single satellite can't provide an end-to-end communication between two spots widely separated. This issue implies that a continuous network between these two spots can never be implemented, and that's why so many public and private companies have been working for a long time in clusters of satellites to provide global coverage of the earth. In the last decade, the M2M (machine-to-machine) communications have become one of the most advanced fields in the engineering world, as they are changing it in order to create a more sophisticated and automatized future. These type of low-rate wireless communications can be supported in a satellite network but they sometimes require a low latency in its channel. In this project, several satellite network scenarios are simulated in order to study the different delays in them and to find the way to optimize the latency in the M2M communication between two fixed spots in the globe, while creating a continuous network made out of GEO and LEO satellites. The project is focused on the idea of finding the best satellite architecture to obtain a fluid communication without any relevant delay along the way, as well as discussing the trade-off between the delay of the signal and the energy consumption of the satellite, specially in the nanosatellite case.Desde que el Sputnik 1 fue lanzado por primera vez en 1957, los satélites han tomado el mundo con sus múltiples aplicaciones en nuestro, especialmente en el campo de las telecomunicaciones, desde la emisión de televisión a las comunicaciones móviles. Uno de los principales problemas que presentan, es que un solo satélite no puede proporcionar una comunicación de extremo a extremo entre dos puntos muy distantes entre sí. Este problema implica que una red contínua entre estos dos puntos no se puede implementar, y es por eso por lo que muchas empresas públicas y privadas han estado trabajando durante mucho tiempo en grupos de satélites para proporcionar una cobertura global de la Tierra. En la última década, las comunicaciones M2M (machine-to-machine) se han convertido en uno de los campos más avanzados en el mundo de la ingeniería, y lo están cambiando con el fin de crear un futuro más sofisticado y automatizado. Este tipo de comunicaciones sin hilos de bajo ritmo de bit puede ser apoyado en una red de satélites, pero que a veces requiere una latencia baja en su canal. En este proyecto, varios escenarios de redes de satélite son simulados con el fin de estudiar los diferentes retardos en todos ellos y en encontrar la manera de optimizar la latencia en la comunicación M2M entre dos puntos fijos en el mundo, usando la creación de una red continua hecha de satélites GEO y LEO. El proyecto se centra en la idea de encontrar la mejor arquitectura de satélites para obtener una comunicación fluida y sin ningún retraso relevante en el camino, así como en discutir el equilibrio entre el retardo de la señal y el consumo de energía del satélite, especialmente en el caso de nanosatélites.Des de que l'Sputnik 1 es llançava per primer cop el 1957, els satèl·lits han dominat el món amb les seves múltiples aplicacions en la nostra vida quotidiana, especialment en el camp de les telecomunicacions, des de difusió de televisió a les comunicacions mòbils. Una de les principals qüestions que presenten, és que un únic satèl·lit no pot proporcionar una comunicació extrem a extrem entre dos punts molt distants. Això implica que mai no es pugui implementar una xarxa contínua entre aquests dos punts, i és per això que moltes empreses públiques i privades han estat treballant durant molt temps en agrupacions de satèl·lits per donar cobertura global de la terra. En la darrera dècada, les comunicacions de M2M (machine-to-machine) han esdevingut un dels camps més avançats del món de l'enginyeria, ja que estan canviant-lo per tal de crear un més sofisticat i automatitzat futur. Aquests tipus de comunicacions sense fils de baix ritme de bit poden ser recolzades en una xarxa de satèl·lits però de vegades requereixen una latència baixa al seu canal. En aquest projecte, diversos escenaris de xarxes de satèl·lits són simulats per tal d'estudiar els diferents retards en tots ells i en trobar la manera d'optimitzar la latència en la comunicació M2M entre dos punts fixos en el món, utilitzant la creació d'una xarxa contínua de satèl·lits GEO i LEO. El projecte es centra en la idea de trobar la millor arquitectura de satèl·lits per obtenir una comunicació fluida sense demora pertinent en el camí, així com en discutir la solució de compromís que existeix entre el retard del senyal i el consum energètic del satèl·lit, especialment en el cas dels nanosatèl·lits

Never retreat, never surrender: The bargaining power of commitment in the Hawk-Dove game

This paper studies experimentally the conditions that improve bargaining power using threats in a negotiation process. Following Schelling’s (1960) ideas we choose the hawk-dove game because is the simplest negotiation environment with inequity distribution in equilibrium. The analysis is focused on three essential elements of commitment: the possibility of a player to announce his own actions, the credibility of these messages and the experience acquired in the negotiation process. The empirical evidence shows that, in the first period, subjects do not realize the bargaining power of commitment. When the game is repeated and experience increases, subjects gradually understand the advantages of a threat, turning the payoffs into their favor. Credibility is also relevant for the relation, if subjects can choose their message, it is common to find strategic liars, and their rivals punish this behavior.Credible threats, negotiation, experiments

OFAR-CM: Efficient Dragonfly networks with simple congestion management

Dragonfly networks are appealing topologies for large-scale Data center and HPC networks, that provide high throughput with low diameter and moderate cost. However, they are prone to congestion under certain frequent traffic patterns that saturate specific network links. Adaptive non-minimal routing can be used to avoid such congestion. That kind of routing employs longer paths to circumvent local or global congested links. However, if a distance-based deadlock avoidance mechanism is employed, more Virtual Channels (VCs) are required, what increases design complexity and cost. OFAR (On-the-Fly Adaptive Routing) is a previously proposed routing that decouples VCs from deadlock avoidance, making local and global misrouting affordable. However, the severity of congestion with OFAR is higher, as it relies on an escape sub network with low bisection bandwidth. Additionally, OFAR allows for unlimited misroutings on the escape sub network, leading to unbounded paths in the network and long latencies. In this paper we propose and evaluate OFAR-CM, a variant of OFAR combined with a simple congestion management (CM) mechanism which only relies on local information, specifically the credit count of the output ports in the local router. With simple escape sub networks such as a Hamiltonian ring or a tree, OFAR outperforms former proposals with distance-based deadlock avoidance. Additionally, although long paths are allowed in theory, in practice packets arrive at their destination in a small number of hops. Altogether, OFAR-CM constitutes the first practicable mechanism to the date that supports both local and global misrouting in Dragonfly networks.The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n. ERC-2012-Adg-321253- RoMoL, the Spanish Ministry of Science under contracts TIN2010-21291-C02-02, TIN2012-34557, and by the European HiPEAC Network of Excellence. M. García participated in this work while affiliated with the University of Cantabria.Peer ReviewedPostprint (author's final draft

Kalman filter applied to Thevenin’s modeling of a lead-acid battery

This article determines the internal parameters of a battery analyzed from its circuit equivalent, reviewing important information that can help to identify the battery’s state of charge (SOC) and its state of health (SOH). Although models that allow the dynamics of different types of batteries to be identified have been developed, few have defined the lead-acid battery model from the analysis of a filtered signal by applying a Kalman filter, particularly taking into account the measurement of noise not just at signal output but also at its input (this is a novelty raised from the experimental). This study proposes a model for lead-acid batteries using tools such as MATLAB® and Simulink®. First, a method of filtering the input and output signal is presented, and then a method for identifying parameters from 29 charge states is used for a lead-acid battery. Different SOCs are related to different values of open circuit voltage (OCV). Ultimately, improvements in model estimation are shown using a filter that considers system and sensor noise since the modeled and filtered signal is closer to the original signal than the unfiltered modeled signal

The health from the humanist perspective of Blas Álvarez de Miraval

A pesar de que existen diferentes estudios en las Ciencias de la Actividad Física y del Deporte sobre autores humanistas, el objetivo del presente trabajo es poner en valor la obra de una de las figuras más importantes del humanismo español, Blas Álvarez de Miraval, insigne médico y teólogo, a través del análisis pormenorizado de su obra cumbre, titulada De la conservación de la salud del cuerpo y el alma, cuyos resultados arrojan una visión única y diferente de lo que ha de ser la conservación de la salud desde una perspectiva integral por parte del individuoIn spite of the fact that there are different studies in the Sciences of the Sport on humanist authors, the aim of the present work is to put of relevancy the work of one of the most important figures of the Spanish humanism, Blas Álvarez de Miraval, celebrated doctor and theologian, with regard to the Sciences of the Physical Activity and of the Sport by means of the study detailed of his greatest work, "Of the conservation of the health of the body and the soul", which results throw an only and different vision from what has to be the conservation of the health from the integral care of the individua

El servicio en Bogotá y el dilema paradigmático entre lo público y lo privado

Desde el año 2005 en lo público y desde siempre en lo privado, se ha tratado, en la ciudad de Bogotá el tema del servicio, tema que ha dado mucho que hablar puesto que en él, subyacen un sinnúmero de aspectos, situaciones, momentos, estrategias, problemas, argumentos, soluciones que, en su totalidad, han generado todo un discurso en torno al servicio mismo, a sus componentes, a su dinámica y hasta a su correcto proceder implícito, es decir, han despertado entre los diseñadores y desarrolladores de la idea de servicio una gran polémica en torno al concepto de servicio, visto, tanto como la acción y el efecto de servir, como la tarea de estar disponible al servicio del otro pero también, como aquello de querer o tener a bien atender a otro partiendo de una necesidad, de la necesitad de ser entendido, escuchado, tenido en cuenta y como si fuera poco respetado. Respetado obviamente, por quienes dinamizan el concepto de servicio en la práctica y en el diario servir

Banca ética y banca cooperativa. Un análisis comparativo a través del estudio de Caixa Popular y de Fiare Banca Ética

Social banks now represent an alternative to conventional banking, especially for those customers who demand a socially responsible consumption. Social banking consists of two different types of credit institutions: cooperative banks and ethical banks. The first are active since more than a century through a proximity banking model focused on the territory. The latter have three decades approximately operation, addressing the realization of socially responsible investment (social and environmental projects). In this paper the similarities and differences between the two models of social banking are analyzed by conducting a consistent analysis of cases in a comparative study between the credit union Caixa Popular and the ethical bank Fiare Banca Etica. The analysis concludes that both social banking models are based on a participatory and democratic system in which employees and customers are actively involved in their operation and both contribute to financial inclusion. Instead, the cooperative banking model is a model based on community banking and direct customer relations through bank branches, while the model of ethical banking is based on electronic banking with few branches.Los bancos sociales representan en la actualidad una alternativa a la banca convencional, sobre todo para aquellos clientes que demandan un consumo socialmente responsable. La banca social está formada por dos tipos diferentes de entidades de crédito: los bancos cooperativos y los bancos éticos. Los primeros desarrollan su actividad desde hace ya más de un siglo a través de un modelo de banca de proximidad enfocada al territorio. Los segundos llevan tres décadas aproximadamente de funcionamiento, dirigiéndose a la realización de inversiones socialmente responsables (proyectos sociales y medioambientales). En el presente trabajo se analizan las similitudes y diferencias entre ambos modelos de banca social mediante la realización de un ánalisis de casos consistente en un estudio comparativo entre la cooperativa de crédito Caixa Popular y el banco ético Fiare Banca Ética. Del análisis se concluye que ambos modelos de banca social se basan en un sistema democrático y participativo en el que trabajadores y clientes participan activamente en su funcionamiento y ambos contribuyen a la inclusión financiera. En cambio, el modelo de la banca cooperativa es un modelo de proximidad basado en el trato personalizado y directo al cliente a través de las oficinas bancarias, mientras que el modelo de banca ética está basado en la banca electrónica con escasas sucursales

Never retreat, never surrender: the bargaining power of commitment in the Hawk-Dove game

This paper studies experimentally the conditions that improve bargaining power using threats in a negotiation process. Following Schelling’s (1960) ideas we choose the hawk-dove game because is the simplest negotiation environment with inequity distribution in equilibrium. The analysis is focused on three essential elements of commitment: the possibility of a player to announce his own actions, the credibility of these messages and the experience acquired in the negotiation process. The empirical evidence shows that, in the first period, subjects do not realize the bargaining power of commitment. When the game is repeated and experience increases, subjects gradually understand the advantages of a threat, turning the payoffs into their favor. Credibility is also relevant for the relation, if subjects can choose their message, it is common to find strategic liars, and their rivals punish this behavior

Integration of Apache Mesos over GPUs resources in the DEEP Hybrid DataCloud project

Trabajo presentado a IBERGRID: Delivering Innovative Computing and Data services to Researchers, celebrado en Santiago de Compostela (España) del 23 al 26 de septiembre de 2019.DEEP Hybrid DataCloud project was proposed with the necessity to support different amount of intensive computing techniques over specialized hardware, like HPC or GPUs. The project focus on the integration of this specialized, and expensive, hardware under a Cloud Platform as OpenStack that can be used on-demand by researchers of different areas. Within this project, a set of building blocks whose solution is called >DEEP as a Service> was implemented to make the application deployment more easier for the user. For this development, it is necessary to provide the researchers with access to these technologies as friendly but powerful services able to exploit very large datasets. On the one hand we have the gpu resources and on the other hand the users and their applications to run over those resources. DEEP needs to provide a service that controls how users can use those resources in an efficiently way. Although there are multiple technologies that address this problem as a queuing system, Apache Mesos has been developed to do it in an effective and controlled manner. Apache Mesos is a technology that abstracts the resources from different machines, like cpu, gpu, ram and storage to provide a scheduling and distributed system across the whole cloud environment. Mesos is easily to deploy over cpu-based systems but gpu needs a more tricky configuration as it is shown in this solution. As an added value, this solution provides an apache2 configuration for authenticate users from different communities by the current AAI service in DEEP. The proposed presentation will show the design and deployment of Mesos to work over gpus resources inside the Deep Hybrid DataCloud Project scope.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 777435