Comparison of low-power wireless communication technologies for wearable health-monitoring applications

Health monitoring technologies such as Body Area Network (BAN) systems has gathered a lot of attention during the past few years. Largely encouraged by the rapid increase in the cost of healthcare services and driven by the latest technological advances in Micro-Electro-Mechanical Systems (MEMS) and wireless communications. BAN technology comprises of a network of body worn or implanted sensors that continuously capture and measure the vital parameters such as heart rate, blood pressure, glucose levels and movement. The collected data must be transferred to a local base station in order to be further processed. Thus, wireless connectivity plays a vital role in such systems. However, wireless connectivity comes at a cost of increased power usage, mainly due to the high energy consumption during data transmission. Unfortunately, battery-operated devices are unable to operate for ultra-long duration of time and are expected to be recharged or replaced once they run out of energy. This is not a simple task especially in the case of implanted devices such as pacemakers. Therefore, prolonging the network lifetime in BAN systems is one of the greatest challenges. In order to achieve this goal, BAN systems take advantage of low-power in-body and on-body/off-body wireless communication technologies. This paper compares some of the existing and emerging low-power communication protocols that can potentially be employed to support the rapid development and deployment of BAN systems.

Análise de desempenho experimental de redes IEEE 802.3.

The Ethernet technology dominates the market of computer local networks. However, it was not been established as technology for industrial automation set, where the requirements demand determinism and real-time performance. Many solutions have been proposed to solve the problem of non-determinism, which are based mainly on TDMA (Time Division Multiple Access), Token Passing and Master-Slave. This work of research carries through measured of performance that allows to compare the behavior of the Ethernet nets when submitted with the transmissions of data on protocols UDP and RAW Ethernet, as well as, on three different types of Ethernet technologies. The objective is to identify to the alternative amongst the protocols and analyzed Ethernet technologies that offer to a more satisfactory support the nets of the industrial automation and distributed real-time application

Sistema de ensino à distância sobre toxinologia: implantando um novo paradigma

The author suggests a long-distance teaching on toxinology using the following media: conventional printed book, scientific electronic journal, video library and the Internet. These new media are discussed as new alternatives for long-distance learning without the teacher.

Unveiling fieldbus network technology through project-based learning

Fieldbus communications networks are a fundamental part of modern industrial automation technique. This paperwork presents an application of project-based learning (PBL) paradigm to help electrical engineering students grasp the major concepts of fieldbus networks, while attending a one-term long, elective microcontroller course. © 2012 IEEE.

Planejamento de redes de comunicação sem fio para ambiente indoor considerando os efeitos da polarização das antenas: abordagem baseada em medições

Uma das principais aplicações de ondas eletromagnéticas, na atualidade, na área de telecomunicações trata dos enlaces em sistemas móveis sem fio. Sejam estes terrestres (indoor/outdoor) ou via satélites, o projetista do sistema de telecomunicações tem que ser capaz de determinar os sistemas irradiantes, as potências envolvidas, a frequência de operação do sistema, a área de cobertura e os parâmetros de qualidade do serviço. O planejamento das novas redes de comunicações sem fio representa um grande desafio ao incluir serviços cada vez mais avançados com diferentes requisitos de qualidade, suporte a mobilidade, altas taxas de transmissão e capacidades elevadas de tráfego. Os diversos ambientes nos quais essas redes operam, os fenômenos associados produzem diversos efeitos no comportamento do sinal recebido e, consequentemente, uma variação no desempenho do enlace de comunicação entre os pontos de acesso, a rede e os usuários. Por conseguinte, esses efeitos devem ser avaliados corretamente, de tal forma que o dimensionamento da rede atenda aos requisitos de qualidade regulamentados. O presente trabalho objetiva estabelecer uma metodologia para o planejamento de redes de comunicação sem fio para ambientes indoor, considerando os parâmetros de qualidade de serviços e os efeitos da polarização das antenas. Foi proposto um modelo empírico para determinar a área de cobertura desse ambiente a partir de uma abordagem baseada em medições. Como resultado de campanhas de medições, foram identificados os principais parâmetros que interferem nas perdas no enlace de propagação, destacando-se os materiais envolvidos no ambiente bem como os efeitos da polarização das antenas transmissora, entre outros. Tais efeitos, avaliados corretamente, permitirão ao projetista da rede, de uma forma crítica e com base em dados obtidos em campo, definir a melhor configuração de parâmetros e critérios de projeto para a implantação de uma rede móvel de acesso sem fio. As medições para determinação dos parâmetros de cobertura e de qualidade de serviços foram realizadas no prédio do Laboratório de Engenharia Elétrica e de Computação e no prédio de aulas do Instituto de Tecnologia da Universidade Federal do Pará. Nas campanhas de medição foram utilizadas algumas frequências, escolhidas devido à importância dos serviços disponibilizados: 2,4 GHz - redes locais sem fio (WLAN’s); 3,5 GHz - Wimax licenciado; 5,85 GHz - Wimax livre e 10 GHz (a faixa de 9,8 a 10 GHz não está ainda regulamentada, de 10 - 10,15 GHz-radioamador (Resolução Anatel, Nº 452/2006 - D.O.U. de 20.12.2006) ou serviços de comunicações multimídias (SCM) para sistemas em banda larga). Os principais resultados obtidos com o modelo proposto foram avaliados e comparados com os principais modelos da literatura e mostraram que a metodologia adotada para o planejamento de redes de comunicação sem fio em ambientes indoor teve um bom desempenho.

Scoping Electronic Communication Privacy Rules: Data, Services and Values

We use electronic communication networks for more than simply traditional telecommunications: we access the news, buy goods online, file our taxes, contribute to public debate, and more. As a result, a wider array of privacy interests is implicated for users of electronic communications networks and services. . This development calls into question the scope of electronic communications privacy rules. This paper analyses the scope of these rules, taking into account the rationale and the historic background of the European electronic communications privacy framework. We develop a framework for analysing the scope of electronic communications privacy rules using three approaches: (i) a service-centric approach, (ii) a data-centric approach, and (iii) a value-centric approach. We discuss the strengths and weaknesses of each approach. The current e-Privacy Directive contains a complex blend of the three approaches, which does not seem to be based on a thorough analysis of their strengths and weaknesses. The upcoming review of the directive announced by the European Commission provides an opportunity to improve the scoping of the rules.

El núcleo de red en redes de nueva generación

El presente proyecto fin de carrera tiene como objetivo realizar un estudio del núcleo de red en las de redes de nueva generación (NGN) y de cómo la evolución de las redes actuales hacia estos conceptos producirá un cambio en la forma de pensar y desarrollar las redes de comunicaciones del futuro. El estudio esta desglosado en tres grandes partes y se inicia con el análisis de la evolución que ha sufrido el núcleo de red en las redes de comunicaciones móviles digitales desde la implantación de las primeras redes digitales hasta la actualidad abarcando tanto la evolución de las redes troncales como de las redes de acceso así como los cambios que han tenido lugar tanto dentro de las propias estructuras de red de los operadores como la forma de interconectarse entre sus redes. Una segunda parte que constituye el cuerpo teórico del trabajo donde se estudia a nivel funcional y de arquitectura de red el desarrollo de los nuevos modelos de red proporcionados por los organismos de estandarización que dan lugar a la aparición de las redes de nueva generación (NGN) y que constituirán el siguiente paso en la evolución de las redes de comunicaciones hacia una infraestructura de red común para todas las redes de acceso actuales. Y una tercera parte que tiene como objetivo el estudio del grado de transformación que tienen que sufrir el núcleo de red en actuales redes troncales de comunicaciones móviles y terrestres, así como una valoración del estado actual de dicha integración, de las dificultades que están encontrando fabricantes y proveedores de servicio para la implementación de dichas redes en el contexto tecnológico y económico actual y su respectivo análisis de como afectará este cambio a los modelos de negocio de los proveedores de servicios de telecomunicaciones. Finalmente se estudia como se esta llevando a cabo este proceso por medio de un caso práctico de implantación e interconexión de la solución propuesta por un fabricante de equipamiento basándose en los modelos anteriormente expuestos en una red comercial de un operador en España y todas las implicaciones asociadas a esta caso concreto. The object of this work is to provide a deep view about the core network inside next generation network (NGN) and how the evolution of the current comunications networks towards the concepts introduced by these new networks brings a change in the way of think and develop communications networks of the future. This work is composed of three blocks and one real case and it starts with the analysis of the evolution of the core network in digital mobile comunications networks since the beginning of the digital mobile comunications networks deployments until nowadays both in core network side and access network side and how the providers have made changes inside their comunications infrastructure and how they interconnect them with other networks. A second part which is the central theoretical part of this work where it is studied the next generation network models stablished by telecomunications associations and how they will be the next step in the evolution of comunications networks towards a common network infrastructure for all existing access networks. A third part where it is studied the level of transformation that core network in mobile and terrestrial comunications networks have to experienced since current situation up to next generation scenarios and what it is the impact of these changes, the issues that are arising for developers, manufactures and service providers in this process, the way that these changes will improve and shift telecomunications business models and how the current economic and technological context is influencing in the whole process. Finally it is studied a actual case about a proposed solution by a manufacturer that based on the models exposed in second part take place a integration and interconection process in a the comercial network of one telecomunication service providers in Spain. This final part regards to all implications associated with this specific case.

A component library to improve the reusability in the development of converged services

The evolution of communications networks to Next Generation Networks (NGN) has encouraged the development of new services. Nowadays, several technologies are being integrated into telecommunications services in order to provide new functionalities, resulting in what are known as converged services. The objective is to adapt the behavior of the services to the necessities of different users, generating customized services. Some of the main technologies involved in their development are those related to the Web. But due to this type of services implies the combination of different technologies, their development is a very complex process that has to be improved to reduce the time and cost required, with the aim of promoting the success of such services. This paper proposes to apply software reuse through the utilization of a component library and presents one focused on ECharts for SIP Servlets (E4SS). It is a framework, based on the SIP Servlet specification, which uses finite state machines for the definition of converged communications services. Also, to promote the use of the library, a methodology is proposed in order to facilitate the integration between the library operations and the software development cycle.

Research challenges for cross-cloud application

Federated clouds can expose the Internet as a homogeneous compute fabric. There is an opportunity for developing cross-cloud applications that can be deployed pervasively over the Internet, dynamically adapting their internal topology to their needs. In this paper we explore the main challenges for fully realizing the potential of cross-cloud applications. First, we focus on the networking dimension of these applications. We evaluate what support is needed from the infrastructure, and what are the further implications of opening the networking side. On a second part, we examine the impact of a distributed deployment for applications, assessing the implications from a management perspective, and how it affects the delivery of quality of service and non-functional requirements.

Optimization and evaluation in space conditions of multi-GHz optical modulators

Among the different optical modulator technologies available such as polymer, III-V semiconductors, Silicon, the well-known Lithium Niobate (LN) offers the best trade-off in terms of performances, ease of use, and power handling capability [1-9]. The LN technology is still widely deployed within the current high data rate fibre optic communications networks. This technology is also the most mature and guarantees the reliability which is required for space applications [9].In or der to fulfil the target specifications of opto-microwave payloads, an optimization of the design of a Mach-Zehnder (MZ) modulator working at the 1500nm telecom wavelength was performed in the frame of the ESA-ARTES "Multi GigaHertz Optical Modulator" (MGOM) project in order to reach ultra-low optical insertion loss and low effective driving voltage in the Ka band. The selected modulator configuration was the X-cut crystal orientation, associated to high stability Titanium in-diffusion process for the optical waveguide. Starting from an initial modulator configuration exhibiting 9 V drive voltage @ 30 GHz, a complete redesign of the coplanar microwave electrodes was carried out in order to reach a 6 V drive voltage @ 30GHz version. This redesign was associated to an optimization of the interaction between the optical waveguide and the electrodes. Following the optimisation steps, an evaluation program was applied on a lot of 8 identical modulators. A full characterisation was carried out to compare performances, showing small variations between the initial and final functional characteristics. In parallel, two similar modulators were submitted to both gamma (10-100 krad) and proton irradiation (10.109 p/cm²) with minor performance degradation.

Estudio sobre un sistema de radiocomunicaciones ferroviarias de acuerdo al paradigma 4G

No hay duda de que el ferrocarril es uno de los símbolos del avance tecnológico y social de la humanidad, y su imparable avance desde el primer tercio del Siglo XIX así lo atestigua. No obstante, a lo largo de gran parte de su historia se ha mostrado algo renuente a abrazar ciertas tecnologías, lo que le ha causado ser tachado de conservador. Sin embargo, en los últimos años, coincidiendo con el auge masivo de los trenes de alta velocidad, los metropolitanos y los tranvías, muchas tecnologías han ido penetrando en el mundo del ferrocarril. La que hoy nos ocupa es una de las que mayor valor añadido le ha proporcionado (y que probablemente le proporcionará también en el futuro): las comunicaciones móviles. Actualmente el uso de este tipo de tecnologías en el entorno ferroviario puede calificarse como de inicial o, por seguir la nomenclatura de las comunicaciones móviles públicas, de segunda generación. El GSM-R en las líneas de alta velocidad es un caso (aunque de éxito al fin y al cabo) que define perfectamente el estado del arte de las comunicaciones móviles en este entorno, ya que proporcionó un gran valor añadido a costa de un gran esfuerzo de estandarización; ha supuesto un importante salto adelante en el campo de la fiabilidad de este tipo de sistemas, aunque tiene unas grandes limitaciones de capacidad y graves problemas de escalabilidad. Todo hace pensar que en 2025 el sustituto de GSM-R deberá estar en el mercado. En cualquier caso, se debería abandonar la filosofía de crear productos de nicho, que son extraordinariamente caros, y abrazar las filosofías abiertas de las redes de comunicaciones públicas. Aquí es donde LTE, la última gran estrella de esta familia de estándares, puede aportar mucho valor. La idea subyacente detrás de esta Tesis es que LTE puede ser una tecnología que aporte gran valor a las necesidades actuales (y probablemente futuras) del sector del ferrocarril, no solamente en las líneas y trenes de alta velocidad, sino en las denominadas líneas convencionales y en los metros y tranvías. Dado que es un campo aún a día de hoy que dista bastante de estar completamente estudiado, se ha explorado la problemática de la propagación electromagnética en los diferentes entornos ferroviarios, como pueden ser los túneles de metro y la influencia de las estructuras de los trenes. En este sentido, se ha medido de forma bastante exhaustiva en ambos entornos. Por otro lado, dado que los sistemas multiantena son uno de los pilares fundamentales de los modernos sistemas de comunicaciones, se ha verificado de forma experimental la viabilidad de esta tecnología a la hora de implementar un sistema de comunicaciones trentierra en un túnel. Asimismo, de resultas de estas medidas, se ha comprobado la existencia de ciertos fenómenos físicos que pueden suponer una merma en la eficiencia de este tipo de sistemas. En tercer lugar, y dado que uno de los grandes desafíos de las líneas de alta velocidad está provocado por la gran celeridad a la que se desplazan los trenes, se ha explorado la influencia de este parámetro en la eficiencia global de una red completa de comunicaciones móviles. Por supuesto, se ha hecho especial hincapié en los aspectos relacionados con la gestión de la movilidad (traspasos o handovers Por último, a modo de cierre de la Tesis, se ha tratado de identificar los futuros servicios de comunicaciones que aportarán más valor a las explotaciones ferroviarias, así como los requisitos que supondrán para las redes de comunicaciones móviles. Para los casos antes enunciados (propagación, sistemas multiantena, movilidad y desafíos futuros) se proporcionan las contribuciones ya publicadas en revistas y congresos internacionales, así como las que están enviadas para su revisión. ABSTRACT There is almost no doubt that railways are one of the symbols of the technological and social progress of humanity. However, most of the time railways have been somewhat reluctant to embrace new technologies, gaining some reputation of being conservative. But in the last years, together with the massive boom of high speed lines, subways and trams all over the world, some technologies have broken through these conservative resistance. The one which concerns us now is one of the most value-added (both today and in the future): mobile communications. The state-of-the-art of these technologies in the railway field could be called as incipient, or (following the mobile communications’ notation) ‘second generation’. GSM-R, the best example of mobile communications in railways is a success story that shows perfectly the state-of-the-art of this field: it provided a noticeable mark-up but also required a great standardization effort; it also meant a huge step forward in the reliability of these systems but it also needs to face some scalability issues and some capacity problems. It looks more than feasible that in 2025 the alternative to GSM-R should be already available. Anyway, the vision here should be forgetting about expensive niche products, and embracing open standards like public mobile communications do. The main idea behind this Thesis is that LTE could be a technology that provides a lot of added value to the necessities of the railways of today and the future. And not only to highspeed lines, but also to the so-called conventional rail, subways and tramways. Due to the fact that even today, propagation in tunnels and influence of car bodies is far from being full-studied, we measured in a very exhaustive way the EM propagation in these two environments. Also, multiantenna systems are one of the basic foundations of the modern communications systems, so we experimentally verified the feasibility of using such a system in a train-towayside in a tunnel. Moreover, from the measurements carried out we proved the existence of some physical phenomena that could imply a decrease in the performance of these multiantenna systems. In third place, we have explored the influence of high-speed in the whole performance of the network, from the mobility management point-of-view. This high-speed movement is one of the most relevant challenges for the mobile communications networks. The emphasis was placed on the mobility aspects of the radio resource management. Finally, the Thesis closure is an identification of the future communication services that could provide a bigger addition of value to railways, and also the requirements that imply to mobile communications networks. For all the previous for scenarios depicted before (propagation, multiantenna systems, mobility and challenges) we provide some contributions already published (or submitted for revision or still in progress) on publications and international conferences.