12 research outputs found

    Universal Mobile Service Execution Framework for Device-To-Device Collaborations

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    There are high demands of effective and high-performance of collaborations between mobile devices in the places where traditional Internet connections are unavailable, unreliable, or significantly overburdened, such as on a battlefield, disaster zones, isolated rural areas, or crowded public venues. To enable collaboration among the devices in opportunistic networks, code offloading and Remote Method Invocation are the two major mechanisms to ensure code portions of applications are successfully transmitted to and executed on the remote platforms. Although these domains are highly enjoyed in research for a decade, the limitations of multi-device connectivity, system error handling or cross platform compatibility prohibit these technologies from being broadly applied in the mobile industry. To address the above problems, we designed and developed UMSEF - an Universal Mobile Service Execution Framework, which is an innovative and radical approach for mobile computing in opportunistic networks. Our solution is built as a component-based mobile middleware architecture that is flexible and adaptive with multiple network topologies, tolerant for network errors and compatible for multiple platforms. We provided an effective algorithm to estimate the resource availability of a device for higher performance and energy consumption and a novel platform for mobile remote method invocation based on declarative annotations over multi-group device networks. The experiments in reality exposes our approach not only achieve the better performance and energy consumption, but can be extended to large-scaled ubiquitous or IoT systems

    Interoperabilidad dinámica de servicios mediante comunicaciones inalámbricas bluetooth en entornos urbanos y sistemas inteligentes de transporte

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    La evolución en la capacidad de los sistemas empotrados y, en particular, de aquellos sistemas embarcados en terminales móviles, hace posible que hoy en día puedan ofrecer servicios avanzados que antes sólo se concebían para redes y sistemas de mayor envergadura tales como PCs conectados a través de Internet. En el nuevo escenario de los servicios en movilidad las tecnologías inalámbricas juegan un papel fundamental, y se complementan con tecnologías procedentes de otros ámbitos, como el middleware, para dar soporte a los servicios. El uso de estas tecnologías en entornos urbanos y sistemas de transporte inteligente conlleva una serie de ventajas que se manifiestan, por ejemplo, en la posibilidad de ofrecer servicios dependientes del contexto o en la interoperabilidad de servicios. Entre esas tecnologías destacan Bluetooth, como base para las comunicaciones inalámbricas y CORBA, como plataforma middleware. Si bien, las características de ambas tecnologías son bastante adecuadas al tipo de entornos mencionado, es necesario acomenter ciertas adaptaciones que tengan en cuenta las particularidades y situaciones que se dan en estos entornos y que garanticen un correcto acceso a los servicios y una gestión inteligente de las conexiones. Sobre la base de Wireless CORBA, una de las iniciativas que une Bluetooth y CORBA, en esta Tesis se plantean modificaciones y se definen nuevos elementos que permiten su utilización en entornos urbanos y sistemas inteligentes de transporte. La definición del sistema se acompaña de estudios y recomendaciones que ayudan a optimizar el rendimiento en función del tipo de servicio y las condiciones del entorno. El sistema planteado supone una base común para el desarrollo de nuevos servicios, y prueba de ello lo constituyen las aplicaciones implementadas, que demuestran la viabilidad práctica del mismo

    IP Mobility in Wireless Operator Networks

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    Wireless network access is gaining increased heterogeneity in terms of the types of IP capable access technologies. The access network heterogeneity is an outcome of incremental and evolutionary approach of building new infrastructure. The recent success of multi-radio terminals drives both building a new infrastructure and implicit deployment of heterogeneous access networks. Typically there is no economical reason to replace the existing infrastructure when building a new one. The gradual migration phase usually takes several years. IP-based mobility across different access networks may involve both horizontal and vertical handovers. Depending on the networking environment, the mobile terminal may be attached to the network through multiple access technologies. Consequently, the terminal may send and receive packets through multiple networks simultaneously. This dissertation addresses the introduction of IP Mobility paradigm into the existing mobile operator network infrastructure that have not originally been designed for multi-access and IP Mobility. We propose a model for the future wireless networking and roaming architecture that does not require revolutionary technology changes and can be deployed without unnecessary complexity. The model proposes a clear separation of operator roles: (i) access operator, (ii) service operator, and (iii) inter-connection and roaming provider. The separation allows each type of an operator to have their own development path and business models without artificial bindings with each other. We also propose minimum requirements for the new model. We present the state of the art of IP Mobility. We also present results of standardization efforts in IP-based wireless architectures. Finally, we present experimentation results of IP-level mobility in various wireless operator deployments.Erilaiset langattomat verkkoyhteydet lisääntyvät Internet-kykyisten teknologioiden muodossa. Lukuisten eri teknologioiden päällekkäinen käyttö johtuu vähitellen ja tarpeen mukaan rakennetusta verkkoinfrastruktuurista. Useita radioteknologioita (kuten WLAN, GSM ja UMTS) sisältävien päätelaitteiden (kuten älypuhelimet ja kannettavat tietokoneet) viimeaikainen kaupallinen menestys edesauttaa uuden verkkoinfrastruktuurin rakentamista, sekä mahdollisesti johtaa verkkoteknologioiden kirjon lisääntymiseen. Olemassa olevaa verkkoinfrastruktuuria ei kaupallisista syistä kannata korvata uudella teknologialla yhdellä kertaa, vaan vaiheittainen siirtymävaihe kestää tyypillisesti useita vuosia. Internet-kykyiset päätelaitteet voivat liikkua joko saman verkkoteknologian sisällä tai eri verkkoteknologioiden välillä. Verkkoympäristöstä riippuen liikkuvat päätelaitteet voivat liittyä verkkoon useiden verkkoyhteyksien kautta. Näin ollen päätelaite voi lähettää ja vastaanottaa tietoliikennepaketteja yhtäaikaisesti lukuisia verkkoja pitkin. Tämä väitöskirja käsittelee Internet-teknologioiden liikkuvuutta ja näiden teknologioiden tuomista olemassa oleviin langattomien verkko-operaattorien verkkoinfrastruktuureihin. Käsiteltäviä verkkoinfrastruktuureita ei alun perin ole suunniteltu Internet-teknologian liikkuvuuden ja monien yhtäaikaisten yhteyksien ehdoilla. Tässä työssä ehdotetaan tulevaisuuden langattomien verkkojen arkkitehtuurimallia ja ratkaisuja verkkovierailujen toteuttamiseksi. Ehdotettu arkkitehtuuri voidaan toteuttaa ilman mittavia teknologisia mullistuksia. Mallin mukaisessa ehdotuksessa verkko-operaattorin roolit jaetaan selkeästi (i) verkko-operaattoriin, (ii) palveluoperaattoriin ja (iii) yhteys- sekä verkkovierailuoperaattoriin. Roolijako mahdollistaa sen, että kukin operaattorityyppi voi kehittyä itsenäisesti, ja että teennäiset verkkoteknologiasidonnaisuudet poistuvat palveluiden tuottamisessa. Työssä esitetään myös alustava vaatimuslista ehdotetulle mallille, esimerkiksi yhteysoperaattorien laatuvaatimukset. Väitöskirja esittelee myös liikkuvien Internet-teknologioiden viimeisimmän kehityksen. Työssä näytetään lisäksi standardointituloksia Internet-kykyisissä langattomissa arkkitehtuureissa

    Selección de socios en las Empresas Virtuales Dinámicas

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    En el presente documento se describen los aspectos más importantes asociados a la aplicación software DVEBreeder. Esta herramienta ha sido creada expresamente para facilitar el proceso de selección de socios en las Empresas Virtuales Dinámicas utilizando, para ello, dos tecnologías procedentes del ámbito de la Inteligencia Artificial, como son los Sistemas Multiagente y los Sistemas Expertos. En dicha aplicación el proceso de selección se realiza en base a un modelo que engloba y amplía las posibilidades de los distintos enfoques existentes en la literatura, y en el que se hace uso del reciente concepto de Entornos de Gestación.Departamento de Informátic

    Supporting Disconnected Operation in Mobile CORBA

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    CORBA has been used successfully for a number of years as a way of building and connecting distributed applications. Normally this has been in the context of a wired network with static hosts. With recent developments in wireless technology, such as GSM and wireless LANs, a new potentially lucrative domain opens itself to the development of distributed applications. As the use of wireless technology becomes more widespread the applications that use it will become more complex. The CORBA architecture could be used to develop applications for this domain. However, CORBA does not yet take into account the problems associated with mobile computing such as limited processing resources on the mobile host and unreliable and low bandwidth wireless links. The Architecture for Location Independent CORBA Environments (ALICE), went some way to addressing the problems associated with ensuring that CORBA applications could operate successfully within a wireless network. ALICE defines a layered architecture, which takes into account the movement of mobile hosts and ensures that client-server connections remain established transparently to the user. This dissertation describes how ALICE could be extended to support disconnected operation for applications in a wireless network. The goal was to allow clients residing on a mobile device to continue operation without having to be in contact with remote servers. In this way the unreliability of the wireless link is avoided. This is achieved through the introduction of a new layer in the architecture called the Disconnected IIOP (D/IIOP) layer. The D/IIOP layer provides the additional functionality necessary to allow disconnected operation. The concept of disconnected operation is not new but is more generally associated with file systems such as Coda. One possible CORBA compliant way of implementing this behaviour was to use Object by Value. Object by Value is part of the CORBA 2.3 standard and enables the passing of an object by value rather than by reference. A prototype of the D/IIOP layer functionality was implemented using the Object by Value approach for moving CORBA objects. This approach was evaluated by enhancing a distributed scheduling application to allow it to work in a disconnected mode by using D/IIOP functionality. Object by Value did provide a mechanism to move CORBA servant functionality from the server side to the mobile host, and this did allow a client to operate without having to connect to the remote server. This added functionality however, came at a cost of changing both the server and client implementations quite extensively
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