Taming the interoperability challenges of complex IoT systems

of communication protocols and data formats; hence ensuring diverse devices can interoperate with one another remains a significant challenge. Model-driven development and testing solutions have been proposed as methods to aid software developers achieve interoperability compliance in the face of this increasing complexity. However, current approaches often involve complicated and domain specific models (e.g. web services described by WSDL). In this paper, we explore a lightweight, middleware independent, model-driven development framework to help developers tame the challenges of composing IoT services that interoperate with one another. The framework is based upon two key contributions: i) patterns of interoperability behaviour, and ii) a software framework to monitor and reason about interoperability success or failure. We show using a case-study from the FI-WARE Future Internet Service domain that this interoperability framework can support non-expert developers address interoperability challenges. We also deployed tools built atop the framework and made them available in the XIFI large-scale FI-PPP test environment

Enabling High-Level Application Development for the Internet of Things

Application development in the Internet of Things (IoT) is challenging because it involves dealing with a wide range of related issues such as lack of separation of concerns, and lack of high-level of abstractions to address both the large scale and heterogeneity. Moreover, stakeholders involved in the application development have to address issues that can be attributed to different life-cycles phases. when developing applications. First, the application logic has to be analyzed and then separated into a set of distributed tasks for an underlying network. Then, the tasks have to be implemented for the specific hardware. Apart from handling these issues, they have to deal with other aspects of life-cycle such as changes in application requirements and deployed devices. Several approaches have been proposed in the closely related fields of wireless sensor network, ubiquitous and pervasive computing, and software engineering in general to address the above challenges. However, existing approaches only cover limited subsets of the above mentioned challenges when applied to the IoT. This paper proposes an integrated approach for addressing the above mentioned challenges. The main contributions of this paper are: (1) a development methodology that separates IoT application development into different concerns and provides a conceptual framework to develop an application, (2) a development framework that implements the development methodology to support actions of stakeholders. The development framework provides a set of modeling languages to specify each development concern and abstracts the scale and heterogeneity related complexity. It integrates code generation, task-mapping, and linking techniques to provide automation. Code generation supports the application development phase by producing a programming framework that allows stakeholders to focus on the application logic, while our mapping and linking techniques together support the deployment phase by producing device-specific code to result in a distributed system collaboratively hosted by individual devices. Our evaluation based on two realistic scenarios shows that the use of our approach improves the productivity of stakeholders involved in the application development

Rewriting Semantics of Meta-Objects and Composable Distributed Services1 1Supported by DARPA through Rome Laboratories Contract F30602-97-C-0312, by DARPA and NASA through Contract NAS2-98073, by Office of Naval Research Contract N00014-99-C-0198, and by National Science Foundation Grants CCR-9505960 and CCR-9633363, and CCR-9900334.

AbstractCommunication between distributed objects may have to be protected against random failures and malicious attacks; also, communication timeliness may be essential or highly desired. Therefore, a distributed application often has to be extended with communication services providing some kind of fault-tolerance, secrecy, or quality-of-service guarantees. Ideally, such services should be defined in a highly modular and dynamically composable way, so that the combined assurance of several services can be achieved by composition in certain cases, and so that services can be added or removed from applications at runtime in response to changes in the environment. To reason about the formal properties of such composable communication services one first needs to give them a precise semantics. This paper proposes a rewriting logic semantics for the so-called “onion skin” model of distributed object reflection, in which different meta-objects, providing different communication services, can be stacked on top of a basic application object. Since the correct behavior of a service depends on the type of hostile environment, against which the service must protect the application, rewriting logic should also be used to specify such hostile environments. The service guarantees are then guarantees about the behavior specified by the union of the rewrite theories specifying the basic application, the services, and the hostile environment

PrimitiveC-ADL: Primitive Component Architecture Description Language

In this paper, we introduce an architecture descrip- tion language (ADL) for PCOMs (a context oriented component model). The language is described at three levels: (1) Building blocks (PCOMs context oriented components types) (2) Connec- tors, which connect components externally and internally, and (3) Architectural Configuration, which includes a full description of composition and decomposition mechanisms. The contribution is designing ADL. That supports context- orinted component by providing new architecture elements, which fulfil the requirements of designing context oriented component based applications. Context oriented component is a behavioural unit composed of static parts and dynamic parts. A PCOMs component model design was introduced in our previous work. PCOMs proposes a component model design to compose context-aware system by capturing context condition at runtime. The model is a component-based one that modifies the application architecture by subdividing components into subsystems of static and dynamic elements. We map each context condition to a composable template architectural configuration. Each context condition acts to select behavioural patterns, which combine to form application architectures. Different types of architecture elements are proposed in this work. We focus in defining the following new elements: Com- ponents’ dynamic and static parts, components’ layers, decision policies, and composition plan. Finally we introduce an ADL that fully supports context aware applications, by supporting the definition of a component as a unit of behaviour. Our ADL clearly defines the composition mechanisms, and provides proper definition for the composition’s design Patterns and composition plan. A Context oriented component is a behavioural unit composed with static parts and dynamic parts. A PCOMs component model design was introduced in our previous work. PCOMs proposes a component model design to compose context-aware system by capturing context condition at runtime. The model is a component-based one that modifies the application architecture by subdividing components into subsystems of static and dynamic elements. We map each context condition to a composable tem- plate architectural configuration. Each context condition acts to selected behavioural patterns, which combine to form application architectures

Atomic service-based scheduling for web services composition

With the rapid development of Internet technologies and widespread of Internet applications, Web Services has become an important research issue of World Wide Web Consortium (W3C). In order to cope with various requirements from service users, services need to be thoroughly and precisely described, thus improvement needs to be made in describing services as more properties should be added to the current service description model based on OWL-ร, an ontology structure consisting of service profiles and operations. Semantics is widely considered as one of the core supplements, which is able to provide the metadata of services, so as to better match requirements with services in the service repository. On the other hand, Web Services has attracted people from various fields to perform relevant experiments on how to cope with users' requirements. Service providers tend to coordinate service implementation by means of interacting with available resources and reconstructing existing service modules. The integration of self-contained software components becomes a key step to meet service demands. This thesis makes contributions to current service description. The introduction of the term "Atomic Service" is not only considered to be a more refined service structure, but also serves as the fundamental component for all service modules. Based on this, the thesis will discuss issues including composition and scheduling, with the purpose of building interoperations among composable service units and setting up the mechanism of realising business goals with composite services under the guidance of the service scheduling language. This notion is illustrated in a demonstration system to justify the manageable interrelationship between service modules and the way of composition

An ontology-based framework for semantic grid service composition

The Semantic Grid aims at enhancing Grid architectures by knowledge engineering techniques. The service notion is central in this approach. Service-level agreements, called contracts, are formed to define the service usage conditions. Ontology technology can form the framework to capture semantical conditions for contracts. Often, applications of Grid services involve a combination of several services. We present an ontology-based framework for service composition for the Semantic Grid. We take a process-oriented view of services, achieving an intrinsic representation of services and their composition in an ontology

Ontological Problem-Solving Framework for Dynamically Configuring Sensor Systems and Algorithms

The deployment of ubiquitous sensor systems and algorithms has led to many challenges, such as matching sensor systems to compatible algorithms which are capable of satisfying a task. Compounding the challenges is the lack of the requisite knowledge models needed to discover sensors and algorithms and to subsequently integrate their capabilities to satisfy a specific task. A novel ontological problem-solving framework has been designed to match sensors to compatible algorithms to form synthesized systems, which are capable of satisfying a task and then assigning the synthesized systems to high-level missions. The approach designed for the ontological problem-solving framework has been instantiated in the context of a persistence surveillance prototype environment, which includes profiling sensor systems and algorithms to demonstrate proof-of-concept principles. Even though the problem-solving approach was instantiated with profiling sensor systems and algorithms, the ontological framework may be useful with other heterogeneous sensing-system environments

Towards an aspect weaving BPEL engine

This position paper proposes the use of dynamic aspects and the visitor design pattern to obtain a highly configurable and extensible BPEL engine. Using these two techniques, the core of this infrastructural software can be customised to meet new requirements and add features such as debugging, execution monitoring, or changing to another Web Service selection policy. Additionally, it can easily be extended to cope with customer-specific BPEL extensions. We propose the use of dynamic aspects not only on the engine itself but also on the workflow in order to tackle the problems of Web Service hot deployment and hot fixes to long running processes. In this way, composing aWeb Service "on-the-fly" means weaving its choreography interface into the workflow