Marcio E. F. Maia

Requirements and challenges for building service-oriented pervasive middleware

The dinamicy and uncertainness of resources in mobile networks ask for novel uncoupled, adaptable and autonomous programming abstractions. Although applications are built upon a middleware layer that encapsulates some of that complexity, there is a lot left to fully explore the potential of ubiquitous and pervasive systems. To provide an insight on the challenges to develop interoperable middleware systems, this paper highlights the requirements to build service-oriented ubiquitous and pervasive middleware. These requirements are divided into primary and cross-cutting requirements. Primary requirements are Message Exchange, Mobility Support, Service Description, Discovery and Coordination, and Security. While Cross-cutting requirements are Context-Awareness and Adaptability, Autonomy, and QoS Requirements.

MobiLine: A Nested Software Product Line for the domain of mobile and context-aware applications

Mobile devices are multipurpose and multi-sensor equipments supporting applications able to adapt their behavior according to changes in the users context (device, location, time, etc.). Meanwhile, the development of mobile and context-aware software is not a simple task, mostly due to the peculiar characteristics of these devices. Although several solutions have been proposed to facilitate their development, reuse is not systematically used throughout the software development life-cycle. In this paper, we discuss an approach for the development of mobile and context-aware software using the Software Product Line (SPL) paradigm. Furthermore, a Nested SPL for the domain of mobile and context-aware applications is presented, lessons learned in the SPL development are discussed and a product for a context-aware visit guide is shown.

A software product line for the mobile and context-aware applications domain

The mobile and context-aware application domain presents challenging requirements to software development. Although several solutions have been proposed for this type of application, reuse is not systematically used throughout the software development lifecycle. Then, in this paper we propose an approach for the development of a mobile and context-aware Software Product Line (SPL). A SPL for the mobile and context-ware mobile guide domain is presented in order to illustrate the steps of the proposed approach. Furthermore, the lessons learned in the SPL development are discussed. Both approach and SPL are the main contributions of this paper.

LOCCAM - loosely coupled context acquisition middleware

Sensors of all kinds are being integrated with mobile and portable devices (tablets, smartphones). This opens up the possibility of context-aware applications to effectively be able to adapt their behavior, user interfaces and content according to the current users situation. Frequently, context-aware applications require an infrastructure for acquisition, aggregation and reasoning of contextual information. However, existing context management infrastructures are not always appropriated to the heterogeneous and particular environment of mobile devices. In this paper, we present a context management middleware called LoCCAM (Loosely Coupled Context Acquisition Middeware) to provide self-adaptive acquisition of contextual information. It can execute both locally, on a single device, or distributed among nearby devices. The middleware proposes a model for publication, and notification of contextual information based on tuple spaces. As consequence, it offers a lower coupling among applications and the context acquisition layer. In this paper, we also present a performance evaluation of the adaptation mechanism.

An adaptive context acquisition framework to support mobile spatial and context-aware applications

The increasing number of mobile devices allows users to access applications anytime and anywhere. In such applications, location is a key information to improve the interaction between user and services. Existing applications combine location with other context information, such as weather, users activity, temperature, among others. However, developing context-aware applications is still a non-trivial task due to the complexity to implement context management. Additionally, existing context management infrastructures are too brittle to handle changes in the underlying execution infrastructure. In this scenario, this work proposes a context acquisition framework, which tries to reduce the development complexity of mobile spatial and context-aware applications. The framework uses tuples space and OSGi to promote uncoupling and to adapt itself according to application requirements. A proof of concept was developed in order to show how spatial and context filters can be easily implemented during the development of a tracking application.

An Aspect-Oriented Programming Model for Bag-of-Tasks Grid Applications

This paper presents a novel programming model for explicitly separating parallelization and middleware-specific concerns in bag-of-tasks (BoT) grid applications. The model uses Java threads for application decomposition, and aspect-oriented programming to dynamically (and transparently) convert the applications thread objects into independent grid tasks, using the services of a specific grid middleware API. This paper also describes early experimental results showing the models modularity gains and performance overhead, when applied to implement BoT grid applications using OurGrid.

What Changes from Ubiquitous Computing to Internet of Things in Interaction Evaluation

Internet of Things (IoT) is a new paradigm that includes a network of smart objects, which are embedded sensors, communicating using the Internet. One of the areas that are leading up to IoT is Ubiquitous Computing (UbiComp). There are thus solutions such as frameworks, middlewares, and other development artifacts that come from the UbiComp community and can be used for IoT applications. On the other hand, the interaction evaluation of the applications can be more complex in IoT than in UbiComp systems, once we have two different perspectives: Human-Thing and Thing-Thing interactions. In this paper, based on the literature, our experience in these two domains, and case studies with Ubicomp and IoT applications, we discuss how we can benefit from the UbiComp move towards IoT, focusing on the main differences and similarities related to interaction evaluation. These differences open a set of questions that are also presented and discussed in this paper.

USABle -- A Communication Framework for Ubiquitous Systems

The widespread use of mobile devices is reshaping the way users interact, allowing applications to explore physical proximity of devices to offer intelligent services. Although there are several communication technologies available (e.g., Wi- Fi, Wi-Fi Direct, LTE, UMTS, Bluetooth, NFC), building an application from scratch considering both communication and application requirements is not a trivial task. In order to help developers to implement communication primitives, this paper presents a communication framework for ubiquitous systems called USABle. Two important contributions of this framework can be highlighted: i) a set of technology-independent interfaces to handle communication requirements; and ii) a modular and extensible layer-based architecture that permits developers to implement new communication technologies and message dissemination strategies. The outcome of using this communication framework is a simpler way to build applications that explore physical proximity. To validate the claims presented in this paper, a performance evaluation using real devices is done, analyzing two multi-hop and three carry-and-forward implementations of routing algorithms that were implemented using the USABle framework.

A coordination framework for dynamic adaptation in ubiquitous systems based on distributed tuple space

The evolution of mobile technologies allows the emerging of ubiquitous systems, able to anticipate user needs and to seamlessly adapt to context changes. These systems present the problem of dynamic adaptation in a highly distributed, heterogeneous and volatile environment, since it may be difficult to collect and process context information from distributed unknown sources. In order to facilitate the development of such systems, this paper extends an existing coordination framework based on tuple spaces, aiming at the management of distributed information. Hence, a decentralized coordination framework was created, offering primitives to developers to create ubiquitous systems able to interact and cooperate in scenarios of total decentralization. This paper reports some experimental results obtained in a testbed of smartphones and tablets which demonstrate the practical feasibility of our approach and pointed out how our solution can grant context data dissemination in ad hoc and infrastructured networks.

Detecting Malicious Manipulation in Grid Environments

Malicious manipulation of jobs results endangers the efficiency and performance of grid computing applications. The presence of nodes interested in depreciating jobs results may be detected and minimized with the usage of fault tolerance techniques. In order to detect this kind of nodes, this paper presents a distributed and hierarchical diagnosis model based on comparison and reputation, which can be applied to both public and private grids. This strategy defines the status of a node according to its level of confidence, measured through its behavior. The proposed model was submitted to simulations to evaluate its effectiveness under different quota of malicious nodes. The results reveals that 8 test rounds can detect practically all malicious nodes and even with less rounds, the correctness remains high without a significant overhead increase