Sistemas y Telemática Vol. 6 No. 11

URI permanente para esta colecciónhttp://hdl.handle.net/10906/1720

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    Ítem
    Proceso de consultas móviles adaptables a diferentes tipos de negocios basados en telefonía celular (Metamorf)
    (Universidad Icesi, 2008-07-24) Montes Hurtado, Diana Patricia
    Metamorfis a research Project, introducing the development of a process centered in a mobile solution under a service-oriented architecture, with the capacity of adapting to all different business contests, providing a system that, with the use of Web Services through TCP/IP connections, allows for execution of queries in mobile environments.
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    Ítem
    Vol. 6 No. 11, Enero/Junio 2008 / SISTEMAS y TELEMATICA
    (Universidad Icesi, 2008-01-01) Universidad Icesi
    Esta edición incluye: Caracterización del consumo de energía y el desempeño de las aplicaciones streaming sobre redes inalámbricas WLAN; Estimación de capacidad en una red IE 802.11e para entornos outdoor multicelda; Descubrimiento e interacción de servicios móviles ubicuos utilizando Bluetooth y WiFi; Capacidad de una red inalámbrica en malla, para el transporte de voz sobre IP y datos en un entorno rural; Propuesta para la interconexión WLAN multicelda basada en el estándar IE 802.11e y Diff Serv; Desempeño de redes de múltiple salto ante ataque de denegación de servicio basado en tráfico; Arquitectura para la interconectividad de la tecnología Bluetooth con redes IP cableadas para transporte de voz; Propuesta de arquitectura para facturación y pago por proximidad de servicios ubicuos en el contexto colombiano; y Proceso de consultas móviles adaptables a diferentes tipos de negocios basados en telefonía celular (Metamorf).
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    Ítem
    Desempeño de redes de múltiple salto ante ataque de denegación de servicio basado en tráfico
    (Universidad Icesi, 2008-07-24) Peña, Néstor Misael
    The Multi-hop wireless networks or ad hoc networks are build on MAC IEEE 802.11 DCF protocol, which was originally designet for wireless LAN. This adaptation have revealed problems and vulnerabilities that a buased on traffic DoS attack might take advantage, avoiding normal clients to access or provide its services. In wired networks, hardware devices and preventive measures like encryption and authentication are used to the defense against the attacks, but some-times due of ad hoc networks physical conditions, this measures could not be applied, then the network performance falls. For the simulations of base on traffic DoS consequences on MAC layer protocol, Qualnet@ simulation tool was used. To improve the performance of the multi-hop network in presence of a based on traffic DoS, we propose as a preventive measure to increase and setup the default retry limits of MAC layer and a modification of BEB algorithm. These changes, reduce the effects of the DoS and improve the network performance in terms of throughput and packet delivery ratio.
  • No hay miniatura disponible
    Ítem
    Arquitectura para la interconectividad de la tecnología Bluetooth con redes IP cableadas para transporte de voz
    (Universidad Icesi, 2008-07-24) Reinoso R., Daryan F.
    En el presente documento se estudian los criterios y requerimientos tecnológicos necesarios para la construcción de una arquitectura que permita la interconectividad de Bluetooth con redes Ethernet como base para la prestación de servicios de VoIP; adicionalmente se detallan los resultados obtenidos a partir de un proceso de validación de la arquitectura con base en la simulación de una serie de scenarios y un análisis de desempeño de un prototipo funcional para la prestación de dichos servicios.
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    Ítem
    Propuesta de arquitectura para facturación y pago por proximidad de servicios ubicuos en el contexto colombiano
    (2008-07-24) Solarte, Zeida
    Ubiquitous services pretend to interact proactively with the user, proposing solutions to some problems. Those services must to be billed in a secure and efficient form in order to guarantee confidence between customer new services that fulfill the customer’s expectation. For this reason, ubiquitous computing is a new research area that looks for the provision of services in a transparent way for the user in mobile environments. However, ubiquitous services have the problem of a non-existent protocol that fulfills all the mobility, identity and context requirements of such services. This paper describes the development of ubiquitous services pilot that pretends to fulfill such requirements.
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    Ítem
    Caracterización del consumo de energía y el desempeño de las aplicaciones streaming sobre redes inalámbricas WLA N
    (Universidad Icesi, 2008-07-24) Garnica, Juan Pablo; Marín, Andrés; Aedo Cobo, José Edinson
    Today’s society requires people to be connected anyplace, anytime, thorough different media, such as test, audio and video. This requirement explains the high adoption rate of streaming applications and wireless LANSs (WLANs), and the increasing research in these topics. This article presents the power consumption characterization for a laptop computer running a streaming multimedia application over a WLAN, as well as the profile for the WLAN performance while the multimedia application is running. We found that the laptop power consumption changes depending of the network adapter in use, and the network performance is related to the type of media being transmitted over the network, to the communication channel conditions, and the protocol stack implementation.
  • No hay miniatura disponible
    Ítem
    Propuesta para la interconexión WLA N multicelda basada en el estándar IE 802.11e y Diff Serv
    (Universidad Icesi, 2008-07-24) Gómez Ordóñez, Javier Andrés
    Nowadays, the convergence of services as video, voice and data over a common infrastructure has become an important issue that requires special treatment in order to achieve an optimum Quality of Service (QoS) level. This is the case of the IEEE standard 802.11 MAC layer providing a fair medium access treatment according to the application needs. In addition, the deployment of WLANs in public places (hotspots) has been made in a one-cell oriented way and the network design over an outdoor environment involving more than one cell has not been considered. This fact leads to our proposal of an “Outdoor Multicell WLAN supporting 802.11e” design based on the solutions provided by special techniques commonly used by cellular telephony in order to solve problems related to outdoor scenarios. Our design is complemented by an integrated wired/wireless network architecture in order to achieve end to end QoS. This integration uses the Differentiated Services (DiffServ) QoS architecture which maps its traffic classification into the 802 11e and 802.1D link layer technologies.
  • No hay miniatura disponible
    Ítem
    Capacidad de una red inalámbrica en malla, para el transporte de voz sobre IP y datos en un entorno rural
    (Universidad Icesi, 2008-07-23) Hurtado, Julián Andrés
    This paper analyzes the effectiveness of VoIp in fixed mesh Wireless networks considering the study of the standardization and performance of these types of networks and taking into account the instability of medium conditions from one node to another one which could affect the communication. The network capacity analysis is specifically focused in VoIP transport because it as an application that demands greater quality requirements that the ones required by data transmission. This is validated throughout a specific that is implemented for one of the micronetworks of the EHAS-Silvia Project and simulated on the National Chiao Tung University Network Simulator, NCTUns 3.0 that allows to verify its correct operation and to establish the maximum network capacity considering specific factors of mesh networks as the amount of jumps, increase of traffic and fall and establishment of routes.
  • No hay miniatura disponible
    Ítem
    Descubrimiento e interacción de servicios móviles ubicuos utilizando Bluetooth y WiFi
    (Universidad Icesi, 2008-07-23) Caicedo, Oscar Mauricio
    Wireless Communications, especially cellular systems have an important role in actual communication systems. Mobility is an intrinsic characteristic for people that motivate the creation of and commerce. This architecture pretends to adapt some existent technologies for electronic billing and payment to the Colombian context.
  • No hay miniatura disponible
    Ítem
    Estimación de capacidad en una red IE 802.11e para entornos outdoor multicelda
    (Universidad Icesi, 2008-07-23) Benavides, Christian
    The convergence of services as video, voice and data over a common infrastructure achieving a certain Quality of Service (QoS) level lead to the cration of the IEEE 802.11e standard which enhances the original IEEE 802.11 MAC layer by providing a fair medium access treatment according to the application needs. In addition, the deployment of WLANs in public places (hotspots) has been made in a one-cell oriented way and the behavior of parameters such as throughput, delay and loss packet in voice and data traffic over an outdoor environment involving more than one cell has not been analized.