A Real-Time Service-Oriented Architecture for Industrial Automation

Industrial automation platforms are experiencing a paradigm shift. New technologies are making their way in the area, including embedded real-time systems, standard local area networks like Ethernet, Wi-Fi and ZigBee, IP-based communication protocols, standard service oriented architectures (SOAs) and Web services. An automation system will be composed of flexible autonomous components with plug & play functionality, self configuration and diagnostics, and autonomic local control that communicate through standard networking technologies. However, the introduction of these new technologies raises important problems that need to be properly solved, one of these being the need to support real-time and quality-of-service (QoS) for real-time applications. This paper describes a SOA enhanced with real-time capabilities for industrial automation. The proposed architecture allows for negotiation of the QoS requested by clients from Web services, and provides temporal encapsulation of individual activities. This way, it is possible to perform an a priori analysis of the temporal behavior of each service, and to avoid unwanted interference among them. After describing the architecture, experimental results gathered on a real implementation of the framework (which leverages a soft real-time scheduler for the Linux kernel) are presented, showing the effectiveness of the proposed solution. The experiments were performed on simple case studies designed in the context of industrial automation applications

Building Enterprise Architecture Agility and Sustenance with SOA

Service-Oriented Architecture(SOA) is primarily regarded as a technical architecture consisting of tools and service specification to build loosely coupled applications. At another level it is also a means to leverage flexibility and agility to system services as it offers a hierarchical framework to coordinate simultaneous business process design and implementations using loosely coupled service infrastructures. SOA has been debated both in the academy and industry and misinterpretations of its nature impede its adoption. We summarize its historical origins and current evolutions. We review technologies that underlie SOA. In particular, we address how to integrate SOA initiatives with current technology platforms, and how to enforce reuse during the design of loosely coupled systems. We also analyze SOA design methodologies and platforms, and what are their roles in the application integration. Finally we outline challenges and future research directions for SOA

Study of fault-tolerant software technology

Presented is an overview of the current state of the art of fault-tolerant software and an analysis of quantitative techniques and models developed to assess its impact. It examines research efforts as well as experience gained from commercial application of these techniques. The paper also addresses the computer architecture and design implications on hardware, operating systems and programming languages (including Ada) of using fault-tolerant software in real-time aerospace applications. It concludes that fault-tolerant software has progressed beyond the pure research state. The paper also finds that, although not perfectly matched, newer architectural and language capabilities provide many of the notations and functions needed to effectively and efficiently implement software fault-tolerance

Context-aware Authorization in Highly Dynamic Environments

Highly dynamic computing environments, like ubiquitous and pervasive computing environments, require frequent adaptation of applications. Context is a key to adapt suiting user needs. On the other hand, standard access control trusts users once they have authenticated, despite the fact that they may reach unauthorized contexts. We analyse how taking into account dynamic information like context in the authorization subsystem can improve security, and how this new access control applies to interaction patterns, like messaging or eventing. We experiment and validate our approach using context as an authorization factor for eventing in Web service for device (like UPnP or DPWS), in smart home security

Object access control to enable internet commerce

Object-Orientation defines components (objects) that encapsulate data and functionality. Modern 00 programming languages have features that specify the degree of encapsulation in much detail. This thesis extends the access control specification capabilities to objects and puts more emphasis on the objects of Internet commerce. A simple and flexible framework of access control is introduced based on the concept of token . A prototype implemented in Java demonstrates the feasibility of the ideas and related issues