HoPP: Robust and Resilient Publish-Subscribe for an Information-Centric Internet of Things

This paper revisits NDN deployment in the IoT with a special focus on the interaction of sensors and actuators. Such scenarios require high responsiveness and limited control state at the constrained nodes. We argue that the NDN request-response pattern which prevents data push is vital for IoT networks. We contribute HoP-and-Pull (HoPP), a robust publish-subscribe scheme for typical IoT scenarios that targets IoT networks consisting of hundreds of resource constrained devices at intermittent connectivity. Our approach limits the FIB tables to a minimum and naturally supports mobility, temporary network partitioning, data aggregation and near real-time reactivity. We experimentally evaluate the protocol in a real-world deployment using the IoT-Lab testbed with varying numbers of constrained devices, each wirelessly interconnected via IEEE 802.15.4 LowPANs. Implementations are built on CCN-lite with RIOT and support experiments using various single- and multi-hop scenarios

A survey of communication protocols for internet of things and related challenges of fog and cloud computing integration

The fast increment in the number of IoT (Internet of Things) devices is accelerating the research on new solutions to make cloud services scalable. In this context, the novel concept of fog computing as well as the combined fog-to-cloud computing paradigm is becoming essential to decentralize the cloud, while bringing the services closer to the end-system. This article surveys e application layer communication protocols to fulfill the IoT communication requirements, and their potential for implementation in fog- and cloud-based IoT systems. To this end, the article first briefly presents potential protocol candidates, including request-reply and publish-subscribe protocols. After that, the article surveys these protocols based on their main characteristics, as well as the main performance issues, including latency, energy consumption, and network throughput. These findings are thereafter used to place the protocols in each segment of the system (IoT, fog, cloud), and thus opens up the discussion on their choice, interoperability, and wider system integration. The survey is expected to be useful to system architects and protocol designers when choosing the communication protocols in an integrated IoT-to-fog-to-cloud system architecture.Peer ReviewedPostprint (author's final draft

Social-aware Forwarding in Opportunistic Wireless Networks: Content Awareness or Obliviousness?

With the current host-based Internet architecture, networking faces limitations in dynamic scenarios, due mostly to host mobility. The ICN paradigm mitigates such problems by releasing the need to have an end-to-end transport session established during the life time of the data transfer. Moreover, the ICN concept solves the mismatch between the Internet architecture and the way users would like to use it: currently a user needs to know the topological location of the hosts involved in the communication when he/she just wants to get the data, independently of its location. Most of the research efforts aim to come up with a stable ICN architecture in fixed networks, with few examples in ad-hoc and vehicular networks. However, the Internet is becoming more pervasive with powerful personal mobile devices that allow users to form dynamic networks in which content may be exchanged at all times and with low cost. Such pervasive wireless networks suffer with different levels of disruption given user mobility, physical obstacles, lack of cooperation, intermittent connectivity, among others. This paper discusses the combination of content knowledge (e.g., type and interested parties) and social awareness within opportunistic networking as to drive the deployment of ICN solutions in disruptive networking scenarios. With this goal in mind, we go over few examples of social-aware content-based opportunistic networking proposals that consider social awareness to allow content dissemination independently of the level of network disruption. To show how much content knowledge can improve social-based solutions, we illustrate by means of simulation some content-oblivious/oriented proposals in scenarios based on synthetic mobility patterns and real human traces.Comment: 7 pages, 6 figure

Ambient-aware continuous care through semantic context dissemination

Background: The ultimate ambient-intelligent care room contains numerous sensors and devices to monitor the patient, sense and adjust the environment and support the staff. This sensor-based approach results in a large amount of data, which can be processed by current and future applications, e. g., task management and alerting systems. Today, nurses are responsible for coordinating all these applications and supplied information, which reduces the added value and slows down the adoption rate. The aim of the presented research is the design of a pervasive and scalable framework that is able to optimize continuous care processes by intelligently reasoning on the large amount of heterogeneous care data. Methods: The developed Ontology-based Care Platform (OCarePlatform) consists of modular components that perform a specific reasoning task. Consequently, they can easily be replicated and distributed. Complex reasoning is achieved by combining the results of different components. To ensure that the components only receive information, which is of interest to them at that time, they are able to dynamically generate and register filter rules with a Semantic Communication Bus (SCB). This SCB semantically filters all the heterogeneous care data according to the registered rules by using a continuous care ontology. The SCB can be distributed and a cache can be employed to ensure scalability. Results: A prototype implementation is presented consisting of a new-generation nurse call system supported by a localization and a home automation component. The amount of data that is filtered and the performance of the SCB are evaluated by testing the prototype in a living lab. The delay introduced by processing the filter rules is negligible when 10 or fewer rules are registered. Conclusions: The OCarePlatform allows disseminating relevant care data for the different applications and additionally supports composing complex applications from a set of smaller independent components. This way, the platform significantly reduces the amount of information that needs to be processed by the nurses. The delay resulting from processing the filter rules is linear in the amount of rules. Distributed deployment of the SCB and using a cache allows further improvement of these performance results

Self-managed cells and their federation

Future e-Health systems will consist of low-power, on-body wireless sensors attached to mobile users that interact with a ubiquitous computing environment. This kind of system needs to be able to configure itself with little or no user input; more importantly, it is required to adapt autonomously to changes such as user movement, device failure, the addition or loss of services, and proximity to other such systems. This extended abstract describes the basic architecture of a Self-Managed Cell (SMC) to address these requirements, and discusses various forms of federation between/among SMCs. This structure is motivated by a typical e-Health scenario

Conhecimento da mobilidade do consumidor em redes centradas em informação

Mobile data traffic is expanding significantly since the surge and evolution of wireless communication technologies, leading to the design and implementation of different types of mobile networks. Information Centric Network paradigms have been pointed as an alternative to bypass the restrictions imposed by the traditional IP Networks, such as the one imposed by the mobility of its users. Despite their potential advantages regarding mobile wireless environments, several significant research challenges remain to be addressed, more specifically the communication damage due to handover, causing loss of packets. The scope of this dissertation is the development of NDN-based mechanisms with support for Consumer mobility in two different communication approaches: single content request and publish-subscribe. The proposed schemes address a remote mobility predictor entity, whose purpose is to monitor and anticipate trajectories, while compelling the infrastructure to adjust to the new paths, resulting in an efficient way to manage the consumers’ mobility with the purpose of attaining a better quality of service to users. The implementation and evaluation of the proposed schemes were performed using ndnSIM, through functional and non-functional scenarios. The latter uses real traces of urban mobility and connectivity. The obtained results show that the proposed solution far surpasses the native NDN workflow and the traditional publish-subscribe solutions with respect to content delivery ratio and network overhead.O tráfego de dados móveis tem vindo a crescer significativamente, sobretudo devido à evolução das tecnologias de comunicação sem fios, o que tem vindo a implicar o desenho e implementação de novos e diferentes tipos de redes móveis. Os paradigmas de redes centradas em informação têm sido apontados como uma alternativa para contornar as restrições impostas pelas redes tradicionais IP, nomeadamente a mobilidade dos seus utilizadores. Apesar das potenciais vantagens em relação aos ambientes móveis sem fios, vários desafios de investigação ainda necessitam de ser resolvidos, mais especificamente aqueles relacionados com o processo de handover dos seus utilizadores móveis, levando por vezes à perda de informação. Esta dissertação tem como objetivo o desenvolvimento de mecanismos de suporte à mobilidade do Consumidor para redes ICN, utilizando duas abordagens distintas de comunicação: solicitação única de conteúdo e o modelo publish − subscribe. Os esquemas propostos exploram uma entidade remota de previsão de mobilidade, cujo objetivo é monitorizar e antecipar eventuais trajetórias de posição dos utilizadores móveis, obrigando a infraestrutura a ajustar-se aos novos caminhos do consumidor, resultando numa forma eficiente de gestão de mobilidade dos utilizadores com o objetivo de garantir uma melhor qualidade de serviço. A implementação e avaliação dos esquemas propostos foi realizada utilizando o ndnSIM, em cenários funcionais e não funcionais. Estes últimos utilizam registos reais de mobilidade e conetividade urbana. Os resultados obtidos mostram que a solução proposta ultrapassa significativamenta a versão nativa do NDN e as soluções tradicionais de publish − subscribe, considerando a taxa de entrega de conteúdos e sobrecarga da rede.Mestrado em Engenharia de Computadores e Telemátic