963 resultados para Communication services packets


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This study investigates the extent to which the digital boom has had repercussions on productive activity, in terms of both manufacturing (ict goods) and services (ict services), in addition to its potential ramifications in the rest of the Mexican economy. Input-output matrices are used and compared to those of Brazil and the United States. Mexico has fallen behind, particularly in the production of ict goods, and the productive chains of this activity have weakened. The ict services sector offers much greater potential than has been exploited thus far, with the advantage that it involves comparatively more value added and has major diversification possibilities. It is considered essential to find more effective industrial policies targeted on the ict goods and services sectors; but the experience of countries such as Brazil, which have applied more proactive approaches with mixed results, suggests that this will be challenging.

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Consider a communication system in which a transmitter equipment sends fixed-size packets of data at a uniform rate to a receiver equipment. Consider also that these equipments are connected by a packet-switched network, which introduces a random delay to each packet. Here we propose an adaptive clock recovery scheme able of synchronizing the frequencies and the phases of these devices, within specified limits of precision. This scheme for achieving frequency and phase synchronization is based on measurements of the packet arrival times at the receiver, which are used to control the dynamics of a digital phase-locked loop. The scheme performance is evaluated via numerical simulations performed by using realistic parameter values. (C) 2011 Elsevier By. All rights reserved.

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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.

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Linking the physical world to the Internet, also known as the Internet of Things, has increased available information and services in everyday life and in the Enterprise world. In Enterprise IT an increasing number of communication is done between IT backend systems and small IoT devices, for example sensor networks or RFID readers. This introduces some challenges in terms of complexity and integration. We are working on the integration of IoT devices into Enterprise IT by leveraging SOA techniques and Semantic Web technologies. We present a SOA based integration platform for connecting WSNs and large enterprise business processes. For ensuring interoperability our platform is based on Linked Services. These are thoroughly described, machine-readable, machine-reasonable service descriptions.

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Objectives: The purpose of this study is to understand the perceived effects of patient-dental staff communication and cultural diversity on the utilization of dental services in the U.S. by Saudi Arabian students who live in the U.S. and enrolled into the King Abdullah Scholarship program. Methods: The study design was an analytical cross-sectional study. Data for this study was obtained from the Saudi Dental Servicers Utilization Survey, a voluntary internet survey available online for one month through Facebook. Ordered logistic regression analyses and multinomial logistic regression analyses were used to measure the relationships between patient-dental staff communication and cultural diversity on the utilization of dental services. Results: Eight hundred and forty-seven responses were analyzed for this study. Overall, the majority of Saudi students reported having excellent communication experience with dental providers in the U.S. More than 58% of respondents reported at least one regular dental visit last year. Factors that influenced the use of regular dental care were: dentist's explanation of treatment plan, response of dental staff to patient's needs, respectful and polite dental staff, dental staff kindness, availability of up-to-date equipment, and overall communication with dentist. However, the utilization of emergency dental care was not associated with any measurement of patient-dental provider communication. Overall future utilization of dental care is associated with all aspects of patient-dental staff communication measured in this survey. Furthermore, more utilization of regular dental care was related to respondent's perception of the importance of trustworthiness dental staff and the importance of a dentist's reputation was only marginally associated. Respondent's perception of dentist's reputation was associated with more use of emergency dental services. Respondents are more likely to anticipate using dental care in the future if they perceived trustworthiness dental staff, and the dentist's reputation as influencing factors to their usage of dental services. Conclusions: Patient-dental staff communication was partially associated with utilization of regular dental care, not associated with utilization of emergency dental care, and broadly associated with anticipated future utilization of dental care. In addition, trustworthy dental staff, and a dentist's reputation were considered to be strong influencing factors towards utilization of dental services.^

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Any new hospital communication architecture has to support existing services, but at the same time new added features should not affect normal tasks. This article deals with issues regarding old and new systems’ interoperability, as well as the effect the human factor has in a deployed architecture. It also presents valuable information, which is a product of a real scenario. Tracking services are also tested in order to monitor and administer several medical resources.

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Digital services and communications in vehicular scenarios provide the essential assets to improve road transport in several ways like reducing accidents, improving traffic efficiency and optimizing the transport of goods and people. Vehicular communications typically rely on VANET (Vehicular Ad hoc Networks). In these networks vehicles communicate with each other without the need of infrastructure. VANET are mainly oriented to disseminate information to the vehicles in certain geographic area for time critical services like safety warnings but present very challenging requirements that have not been successfully fulfilled nowadays. Some of these challenges are; channel saturation due to simultaneous radio access of many vehicles, routing protocols in topologies that vary rapidly, minimum quality of service assurance and security mechanisms to efficiently detect and neutralize malicious attacks. Vehicular services can be classified in four important groups: Safety, Efficiency, Sustainability and Infotainment. The benefits of these services for the transport sector are clear but many technological and business challenges need to be faced before a real mass market deployment. Service delivery platforms are not prepared for fulfilling the needs of this complex environment with restrictive requirements due to the criticism of some services To overcome this situation, we propose a solution called VISIONS “Vehicular communication Improvement: Solution based on IMS Operational Nodes and Services”. VISIONS leverages on IMS subsystem and NGN enablers, and follows the CALM reference Architecture standardized by ISO. It also avoids the use of Road Side Units (RSUs), reducing complexity and high costs in terms of deployment and maintenance. We demonstrate the benefits in the following areas: 1. VANET networks efficiency. VISIONS provide a mechanism for the vehicles to access valuable information from IMS and its capabilities through a cellular channel. This efficiency improvement will occur in two relevant areas: a. Routing mechanisms. These protocols are responsible of carrying information from a vehicle to another (or a group of vehicles) using multihop mechanisms. We do not propose a new algorithm but the use of VANET topology information provided through our solution to enrich the performance of these protocols. b. Security. Many aspects of security (privacy, key, authentication, access control, revocation mechanisms, etc) are not resolved in vehicular communications. Our solution efficiently disseminates revocation information to neutralize malicious nodes in the VANET. 2. Service delivery platform. It is based on extended enablers, reference architectures, standard protocols and open APIs. By following this approach, we reduce costs and resources for service development, deployment and maintenance. To quantify these benefits in VANET networks, we provide an analytical model of the system and simulate our solution in realistic scenarios. The simulations results demonstrate how VISIONS improves the performance of relevant routing protocols and is more efficient neutralizing security attacks than the widely proposed solutions based on RSUs. Finally, we design an innovative Social Network service based in our platform, explaining how VISIONS facilitate the deployment and usage of complex capabilities. RESUMEN Los servicios digitales y comunicaciones en entornos vehiculares proporcionan herramientas esenciales para mejorar el transporte por carretera; reduciendo el número de accidentes, mejorando la eficiencia del tráfico y optimizando el transporte de mercancías y personas. Las comunicaciones vehiculares generalmente están basadas en redes VANET (Vehicular Ad hoc Networks). En dichas redes, los vehículos se comunican entre sí sin necesidad de infraestructura. Las redes VANET están principalmente orientadas a difundir información (por ejemplo advertencias de seguridad) a los vehículos en determinadas zonas geográficas, pero presentan unos requisitos muy exigentes que no se han resuelto con éxito hasta la fecha. Algunos de estos retos son; saturación del canal de acceso de radio debido al acceso simultáneo de múltiples vehículos, la eficiencia de protocolos de encaminamiento en topologías que varían rápidamente, la calidad de servicio (QoS) y los mecanismos de seguridad para detectar y neutralizar los ataques maliciosos de manera eficiente. Los servicios vehiculares pueden clasificarse en cuatro grupos: Seguridad, Eficiencia del tráfico, Sostenibilidad, e Infotainment (información y entretenimiento). Los beneficios de estos servicios para el sector son claros, pero es necesario resolver muchos desafíos tecnológicos y de negocio antes de una implementación real. Las actuales plataformas de despliegue de servicios no están preparadas para satisfacer las necesidades de este complejo entorno con requisitos muy restrictivos debido a la criticidad de algunas aplicaciones. Con el objetivo de mejorar esta situación, proponemos una solución llamada VISIONS “Vehicular communication Improvement: Solution based on IMS Operational Nodes and Services”. VISIONS se basa en el subsistema IMS, las capacidades NGN y es compatible con la arquitectura de referencia CALM estandarizado por ISO para sistemas de transporte. También evita el uso de elementos en las carreteras, conocidos como Road Side Units (RSU), reduciendo la complejidad y los altos costes de despliegue y mantenimiento. A lo largo de la tesis, demostramos los beneficios en las siguientes áreas: 1. Eficiencia en redes VANET. VISIONS proporciona un mecanismo para que los vehículos accedan a información valiosa proporcionada por IMS y sus capacidades a través de un canal de celular. Dicho mecanismo contribuye a la mejora de dos áreas importantes: a. Mecanismos de encaminamiento. Estos protocolos son responsables de llevar información de un vehículo a otro (o a un grupo de vehículos) utilizando múltiples saltos. No proponemos un nuevo algoritmo de encaminamiento, sino el uso de información topológica de la red VANET a través de nuestra solución para enriquecer el funcionamiento de los protocolos más relevantes. b. Seguridad. Muchos aspectos de la seguridad (privacidad, gestión de claves, autenticación, control de acceso, mecanismos de revocación, etc) no están resueltos en las comunicaciones vehiculares. Nuestra solución difunde de manera eficiente la información de revocación para neutralizar los nodos maliciosos en la red. 2. Plataforma de despliegue de servicios. Está basada en capacidades NGN, arquitecturas de referencia, protocolos estándar y APIs abiertos. Siguiendo este enfoque, reducimos costes y optimizamos procesos para el desarrollo, despliegue y mantenimiento de servicios vehiculares. Para cuantificar estos beneficios en las redes VANET, ofrecemos un modelo de analítico del sistema y simulamos nuestra solución en escenarios realistas. Los resultados de las simulaciones muestran cómo VISIONS mejora el rendimiento de los protocolos de encaminamiento relevantes y neutraliza los ataques a la seguridad de forma más eficientes que las soluciones basadas en RSU. Por último, diseñamos un innovador servicio de red social basado en nuestra plataforma, explicando cómo VISIONS facilita el despliegue y el uso de las capacidades NGN.