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[ES] El objetivo principal de este proyecto es realizar una virtualización de la máquina de cálculo Millionaire. En el inicio de esta memoria, se estudia el lenguaje de programación Scratch, explicando sus orígenes y su funcionamiento, así como sus características, sus ventajas y sus limitaciones. Para este capítulo se ha hecho uso de las guías de referencia de Scratch. A continuación, se realiza un repaso histórico de la evolución de las distintas herramientas de cálculo, analizando también el contexto socioeconómico que propició la invención de la calculadora Millionaire. La memoria continúa haciendo un exhaustivo análisis del funcionamiento de la máquina y sus orígenes, explicando cada una de las operaciones que puede realizar el aparato y el mecanismo interno que lo permite. Por último, con los conocimientos adquiridos en Scratch y en la máquina, se ha programado y documentado el código de la calculadora., [CA] El objectiu principal d’aquest projecte es realitzar una virtualització de la màquina de càlcul Millionaire. En l’inici d’aquesta memòria, s’estudia el llenguatge de programació Scratch, explicant el seus orígens i el seu funcionament, així com les seues característiques, els seus avantatges y les seues limitacions. Per a este capítol s’ha fet ús de les guíes de referència de Scratch. A continuació, es realitza un repàs històric de l’evolució de les distintes eines de càlcul, tot analitzant també el context socioeconòmic que va propiciar la invenció de la calculadora Millionaire. La memòria continua fent un exhaustiu anàlisi del funcionament de la màquina i els seus orígens, explicant cadascuna de les operacions que pot realitzar l’aparell i el mecanisme intern que ho permet. Finalment, amb els coneixements adquirits en Scratch i en la màquina, s’ha programat i documentat el codi de la calculadora., [EN] The main objective of this project is to realize virtualization of the Millionaire calculation machine. IV At the beginning of this report, the Scratch programming language is studied, explaining its origins and operation, as well as its features, advantages and limitations. This chapter was written with the help of the Scratch reference guides. The next part is a historical review of the evolution of the different calculation tools and the economic context that led to the invention of the Millionaire calculator. The report continues with an exhaustive analysis of the operation of the machine and its origins, explaining each of the operations that the device can make and the internal mechanism that allows it. Finally, with the knowledge acquired in Scratch and the machine, the calculator code has been programmed and documented.

[EN] Riding a bicycle is a great manner to contribute to the preservation of our ecosystem. Cycling helps to reduce air pollution and traffic congestion, and so, it is one of the simplest ways to lower the environmental footprint of people. However, the cohabitation of cars and vulnerable road users, such as bikes, scooters, or pedestrians, is prone to cause accidents with serious consequences. In this context, technological solutions are sought that enable the generation of alerts to prevent these accidents, thereby promoting a safer city for these road users, and a cleaner environment. Alert systems based on smartphones can alleviate these situations since nearly all people carry such a device while traveling. In this work, we test the suitability of a smartphone based alert system, determining the most adequate communications architecture. Two protocols have been designed to send position and alert messages to/from a centralized server over 4G cellular networks. One of the protocols is implemented using a REST architecture on top of the HTTP protocol, and the other one is implemented over the UDP protocol. We show that the proposed alarm system is feasible regarding communication response time, and we conclude that the application should be implemented over the UDP protocol, as response times are about three times better than for the REST implementation. We tested the applications in real deployments, finding that drivers are warned of the presence of bicycles when closer than 150 m, having enough time to pay attention to the situation and drive more carefully to avoid a collision.

© 2016 Jorge E. Luzuriaga et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., MQTT is being widely used for data delivery in IoT applications but its architecture does not properly handle mobility when disconnection periods tend to be large. In this paper we describe an experimental evaluation, made in a real environment, of a solution that guarantees that there is no information loss when variable length hand-offs appear due to the movement of a node. Our proposal modifies the classical publish/subscribe scheme by introducing an intermediate buffer that takes care of message transfer. Finally, we study the impact related to the connectivity of mobile devices of the use of the standard Linux Network Manager. We propose a cross-layer solution that improves the device connectivity in conjunction with the data layer management. We show that our solution improves the data delivery guaranteeing that no information is lost.

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising 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., Connectivity clearly plays an important role in Internet of Things (loT) solutions, and the efficient handling of mobility is crucial for the overall performance of loT applications. Currently, the most widely adopted protocols for loT and Machine to Machine (M2M) environments, namely MQTT, CoAP or LWM2M, are directly dependent on the TCP/IP protocol suite. This suite is highly reliable when using wired networks, but it is not the best solution in the presence of intermittent connections. In this work we provide a solution to improve MQTT with an emphasis on mobile scenarios. The advantage of the solution we propose is making the system more immune to changes in the point of attachment of mobile devices. This way we avoid loT service developers having to explicitly consider this issue. Moreover, our solution does not need extra support from the network through protocols like MobilelP or LISP. The obtained results show that our proposal, based on intermediate buffering, guarantees that there is no information loss during hand-off periods due to node mobility; furthermore, based on discrete event simulation results, we determine the maximum number of sources and the required amount of buffers for a mobile node.

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising 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., Message oriented middleware (MOM) refers to the software infrastructure supporting sending and receiving messages between distributed systems. AMQP and MQTT are the two most relevant protocols in this context. They are extensively used for exchanging messages since they provide an abstraction of the different participating system entities, alleviating their coordination and simplifying the communication programming details. These protocols, however, have not been thoroughly tested in the context of mobile or dynamic networks like vehicular networks. In this paper we present an experimental evaluation of both protocols in such scenarios, characterizing their behavior in terms of message loss, latency, jitter and saturation boundary values. Based on the results obtained, we provide criteria of applicability of these protocols, and we assess their performance and viability. This evaluation is of interest for the upcoming applications of MOM, especially to systems related to the Internet of Things.

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising 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., Message Oriented Middleware (MOM) refers to the software infrastructure that support ubiquitous information delivery among software and hardware systems. Two of the most relevant protocols in this context are AMQP and MQTT. Lately, they have been extensively used to exchange messages conserving network bandwidth, device memory and batteries. These protocols provide an abstraction of the communication programming details of the different participating system entities, alleviating their coordination and collaboration. However, these protocols have not been thoroughly tested focused on studying the impact of node mobility. In this paper we present an experimental evaluation of both protocols quantifying the effect of the node mobility in terms of message loss, latency, jitter and saturation boundary values. Based on the results obtained, we provide criteria of applicability of these protocols. This evaluation is of interest for the upcoming applications that can be supported by MOM, and in especial for communication in Machine to Machine (M2M) and Internet of Things (IoT).

The final publication is available at Springer via http://dx.doi.org/ 10.1007/978-3-319-11692-1_22, AMQP is a middleware protocol extensively used for exchanging messages in distributed applications. It provides an abstraction of the different participating parts and simplifies communication programming details. AMQP provides reliability features and alleviates the coordination of different entities of an application. However, implementations of this protocol have not been well tested in the context of mobile or unstable networks. This paper is the starting point of an experimental evaluation of AMQP protocol in such kind of scenarios. Our goal is to identify the limits of applicability of this middleware, assessing its the capacity in terms of message losses, latencies or jitter, when wireless devices are interrupted and reconnected. This evaluation is of interest for the upcoming applications in which personal devices and vehicles will collaborate, forming part of large complex systems.

©ACM 2014. This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in ACM, In Proceedings of the 11th ACM symposium on Performance evaluation of wireless ad hoc, sensor, & ubiquitous networks (pp. 85-92). .http://dx.doi.org/10.1145/2653481.2655235 ., Routing metrics commonly used nowadays in large wireless community networks (WCN), do not seem appropriate since they are generally not based on the real link capacity but on choosing the shortest path. Routing protocols such as OSPF or BGP use static metrics, while wireless links should be evaluated frequently because their bandwidth varies dynamically. Ad hoc routing protocols use more complex metrics, however they are better suited for sporadic or mobile nodes than for static nodes placed in house roofs to create the backbone infrastructure. In this work, we compare several metrics which might be of interest in realistic WCN scenarios. To do this, we have performed routing studies over real topologies extracted from a specific WCN, namely “guifi.net”. The routes obtained using different metrics are compared in terms of length, capacity, and alternative paths. We show that, when using metrics based on real link bandwidth, the amount of routes with low bandwidth could be halved and the capacity of the network could be increased up to a 25%.

El proyecto pretende romper con el concepto tradicional de estación como un espacio acotado enfocado en un único programa. Para ello organiza una serie de recorridos y usos que favorecen la comunicación. El espacio público funciona como soporte para múltiples actividades y, al mismo tiempo, sirve de nexo entre el barrio y el vecindario. Se propone conformar un espacio público activo utilizando el arte. También las zonas de espera son consideradas como generadoras de comunicación.