Context Aware Session Management for Services in Ad Hoc Networks

The increasing ubiquity of wireless mobile devices is promoting unprecedented levels of electronic collaboration among devices interoperating to achieve a common goal. Issues related to host interoperability are addressed partially by the service-oriented computing paradigm. However, certain technical concerns relating to reliable interactions among hosts in ad hoc networks have not yet received much attention. We introduce ”follow-me sessions”, where interaction occur between a client and a service, rather than a specific provider or server. We allow the client to switch service providers if needed. The redundancy offers scope for reliable communication in the presence of mobility induced disconnections. We exploit strategies involving the use of contextual information, strong process migration, context-sensitive binding, and location-agnostic communication protocols. We show how follow-me sessions mitigate issues related to proxy-based service-oriented architectures in ad hoc networks, making them more reliable

Technical considerations towards mobile user QoE enhancement via Cloud interaction

This paper discusses technical considerations of a Cloud infrastructure which interacts with mobile devices in order to migrate part of the computational overhead from the mobile device to the Cloud. The aim of the interaction between the mobile device and the Cloud is the enhancement of parameters that affect the Quality of Experience (QoE) of the mobile end user through the offloading of computational aspects of demanding applications. This paper shows that mobile user’s QoE can be potentially enhanced by offloading computational tasks to the Cloud which incorporates a predictive context-aware mechanism to schedule delivery of content to the mobile end-user using a low-cost interaction model between the Cloud and the mobile user. With respect to the proposed enhancements, both the technical considerations of the cloud infrastructure are examined, as well as the interaction between the mobile device and the Cloud

Towards Predictable Service Provision in Mobile Ad Hoc Networks

This paper considers the technical challenges associated with the development of applications designed to work over mobile ad hoc net-works (MANETs). The setting is one in which a miniature application core residing on a mobile host with limited resources is able to support a complex application in a changing open environment by exploiting ser-vices made available by other hosts it encounters. The proposed solution extends in a novel way the applicability of the service provision paradigm to the ad hoc wireless setting. The novelty of the approach rests with the accumulation and management of knowledge about the service structure and the mobility of hosts to ensure a degree of predictability during the service exploitation process

Context Aware Service Oriented Computing in Mobile Ad Hoc Networks

These days we witness a major shift towards small, mobile devices, capable of wireless communication. Their communication capabilities enable them to form mobile ad hoc networks and share resources and capabilities. Service Oriented Computing (SOC) is a new emerging paradigm for distributed computing that has evolved from object-oriented and component-oriented computing to enable applications distributed within and across organizational boundaries. Services are autonomous computational elements that can be described, published, discovered, and orchestrated for the purpose of developing applications. The application of the SOC model to mobile devices provides a loosely coupled model for distributed processing in a resource-poor and highly dynamic environment. Cooperation in a mobile ad hoc environment depends on the fundamental capability of hosts to communicate with each other. Peer-to-peer interactions among hosts within communication range allow such interactions but limit the scope of interactions to a local region. Routing algorithms for mobile ad hoc networks extend the scope of interactions to cover all hosts transitively connected over multi-hop routes. Additional contextual information, e.g., knowledge about the movement of hosts in physical space, can help extend the boundaries of interactions beyond the limits of an island of connectivity. To help separate concerns specific to different layers, a coordination model between the routing layer and the SOC layer provides abstractions that mask the details characteristic to the network layer from the distributed computing semantics above. This thesis explores some of the opportunities and challenges raised by applying the SOC paradigm to mobile computing in ad hoc networks. It investigates the implications of disconnections on service advertising and discovery mechanisms. It addresses issues related to code migration in addition to physical host movement. It also investigates some of the security concerns in ad hoc networking service provision. It presents a novel routing algorithm for mobile ad hoc networks and a novel coordination model that addresses space and time explicitly

Context aware session management for services in ad hoc networks,

Abstract-The increasing ubiquity of wireless mobile devices is promoting unprecedented levels of electronic collaboration among devices interoperating to achieve a common goal. Issues related to host interoperability are addressed partially by the service-oriented computing paradigm. However, certain technical concerns relating to reliable interactions among hosts in ad hoc networks have not yet received much attention. We introduce follow-me sessions, where interactions occur between a client and a service, rather than a specific provider or server. We allow the client to switch service providers, if needed. We exploit strategies involving the use of contextual information, strong process migration, context-sensitive binding, and locationagnostic communication protocols. We show how follow-me sessions mitigate issues related to proxy-based service-oriented architectures in ad hoc networks

Desempenho de QoS e mobilidade de sessões multicast em redes dinâmicasMes

Mestrado em Engenharia Electrónica e TelecomunicaçõesThe increasing demand in multimedia group services, contextawareness and seamless mobility implies strict requirements that cannot be satisfactorily addressed by the traditional transport control architectures for session content delivery. Moreover, context-aware networks introduce personalized concepts: any change in context can change the overall services and network environments, requiring the network and multicast sessions to be completely restructured in a very dynamic way. Regarding the complexity of maintaining scalability in context-aware networks, this Thesis has as main goal the development of an intelligent module, included in C-CAST architecture, capable of managing the entire network scheme. This mechanism depending on the scenario and the context of users and sources, and in cooperation with other network entities, must decide the most suitable network transport path in order to provide the best multiparty content delivery to the users, and manage the dynamicity of the network whenever changes occur. To perform its implementation, it was used an approach based in the interaction of different network components, exchanging context information between them. The intelligent module, using the updated network information, decides the better network connection to serve each user. In order to simulate the network behaviour in various situations, several scenarios were tested to evaluate its performance. The network is evaluated according to the several configured parameters, evaluating the improvements achieved in the network performance concerning different metrics, e.g. delay, lost packets ratio, overhead introduced by the architecture signalling. Through the implemented simulation setup, it is possible to conclude that the deployment of the solution proposed effectively provides an enhanced service to the users, distributing the multiparty content with QoS assurance using context information.O aumento da exigência em serviços de grupo, redes baseadas em contexto e mobilidade transparente implicam requisitos rígidos que não podem ser satisfeitos pelas arquitecturas tradicionais de controlo de transporte para entrega de conteúdos de sessão. Não obstante, redes baseadas em contexto introduzem conceitos personalizados: qualquer mudança no contexto pode mudar completamente os serviços e a própria rede, sendo necessário que a rede e as sessões multicast sejam completamente reestruturadas de uma forma dinâmica. Tendo em conta a complexidade de manter a escalabilidade em redes baseadas em contexto, esta Tese tem como principal objectivo o desenvolvimento de um módulo inteligente, que faz parte da arquitectura do projecto C-CAST, capaz de gerir toda a rede. Este mecanismo, dependendo do cenário da rede e do contexto dos utilizadores e das fontes, e em cooperação com outras entidades da rede, deve seleccionar a o caminho mais apropriado da rede de modo a fornecer da melhor forma o conteúdo aos utilizadores, e gerir a dinâmicidade da rede sempre que ocorrem mudanças. Para o implementar foi usada um método baseado na interacção de vários componentes, que trocam informação sobre contextos entre eles. O componente inteligente, usando informação actualizada da rede decide qual a melhor conexão da rede para servir cada utilizador. De forma a simular o comportamento da rede em várias situações, foram testados diversos cenários para avaliar a sua performance. A rede é avaliada de acordo com os vários parâmetros configurados, avaliando as melhorias conseguidas na performance da rede, por exemplo em termos de atrasos, rácio de pacotes perdidos e a carga imposta pelas mensagens de controlo da arquitectura. Através das simulações efectuadas é possível concluir que aplicando a arquitectura proposta, é fornecido de forma eficiente um serviço melhorado aos utilizadores, distribuindo o serviço de grupo com garantias de Qualidade de Serviço e usando informação de contexto