Hardwired sensor installations using proprietary protocols found in today’s district heating substations limit the potential usability of the sensors in and around the substations. If sensor resources can be shared and re-used in a variety of applications, the cost of sensors and installation can be reduced, and their functionality and operability can be increased. In this paper, we present a new concept of district heating substation control and monitoring, where a service oriented architecture (SOA) is deployed in a wireless sensor network (WSN), which is integrated with the substation. IP-networking is exclusively used from sensor to server; hence, no middleware is needed for Internet integration. Further, by enabling thousands of sensors with SOA capabilities, a System of Systems approach can be applied. The results of this paper show that it is possible to utilize SOA solutions with heavily resource-constrained embedded devices in contexts where the real-time constrains are limited, such as in a district heating substation.

The IMC-AESOP architecture has been used to implemente a smart house demonstration. Six different systems has been integrated with local (802.11, 802.15.4) and global (telecom) communication. The six systems integrated are: Car arrival detection system, Garage door opening system, House security system, External house lightning system, External electrical outlet system, House energy control system. The SOA technologies used are CoAP and EXI using SenML to encode the services. Engineering tools have been used to simulate the usage scenario and provide prediction of system behaviour.

As the number of Internet-connected devices rapidly grows, it has become ever more challenging to develop and maintain purpose-made tightly integrated distributed embedded systems. Instead, the Internet of Things (IoT) approach, based on standardized interfaces and open communication protocols, enables support for various applications with the possibility of extension to provide additional services that were not necessarily available at the initial deployment.This thesis presents methods and tools for the development of standard-based Web services for the Internet of Things. Some of the key challenges in using Web services on resource-constrained devices are due to the overhead of the communication protocols, which leads to the need for greater network bandwidth, processing power, and memory usage. A common solution to these problems is to use gateways that translate between the protocols used on one end of the connection (i.e. low-capability devices) and those on the other end (i.e. powerful Web servers). However, this increases the overall complexity of the system. The work presented herein answers the following research questions: 1) Is it feasible to deploy standard Web services on IoT systems without using application layer gateways? 2) What are the trade-offs in using Web services for end-to-end interoperability of resource-constrained embedded systems? 3) What levels of efficiency and functionality can be achieved using binary coding schemes for XML data exchange?The research questions are tested by building and evaluating several prototype IoT systems. These evaluations show that the use of Web services requires more powerful hardware (i.e. CPU and RAM) and a larger form factor in exchange for better interoperability compared to the use of ad hoc application protocols. The main challenge in employing embedded Web services is the large size of the messages, which is due to the use of verbose data formats such as XML. Although it is shown that it is possible to deploy XML-based Web services on low-capability devices without application layer gateways, this approach has severe performance limitations. Using the Efficient XML Interchange (EXI) binary coding scheme overcomes some of these limitations by substantially reducing the size of the XML messages. The main outcome of this thesis is the design and implementation of a software toolkit, called EXIP, for building EXI-based embedded Web services.The trade-offs in the use of embedded Web services are likely to change in the near future as the importance of application layer interoperability increases and IoT devices become faster, more energy efficient, and equipped with more memory. The dominating importance of interoperability can be seen in highly heterogeneous systems such as energy management systems (i.e. smart grids), where embedded Web services are already in use today. With this in mind, future research directions and extensions of this work include the development of performance optimization strategies for the EXIP toolkit to foster the expansion of embedded Web services to an even wider range of IoT applications.

Developing and deploying Web applications on networked embedded devicesis often seen as a way to reduce the development cost and time to marketfor new target platforms. However, the sizeof the messages and the processing requirements of today's Web protocols, such as HTTP and XML,are challenging for the most resource-constrained class of devicesthat could also benefit from Web connectivity.New Web protocols using binary representations have been proposedfor addressing this issue. Constrained Application Protocol (CoAP)reduces the bandwidth and processing requirementscompared to HTTP while preserving the core concepts of the Web architecture.Similarly, Efficient XML Interchange (EXI) format has been standardizedfor reducing the size and processing time for XML structured information.Nevertheless, the adoption of these technologies is lagging behind due to lack ofsupport from web browsers and current Web development toolkits.Motivated by these problems, this article presents the design and implementationtechniques for the EXIP framework for embedded Web development. The frameworkconsists of a highly efficient EXI processor, a tool for EXI data binding basedon templates, and a CoAP/EXI/XHTML Web page engine.A prototype implementation of the EXI processor is hereinpresented and evaluated. It can be applied to Web browsersor thin server platforms using XHTML and Web servicesfor supporting human-machine interactions with constrained hosts.This article contains four major results: (1) theoretical and practical evaluation of the use of binary protocolsfor embedded Web programming; (2) a novelmethod for generation of EXI grammars based on XML Schema definitions;(3) an algorithm for grammar concatenationthat produces normalized EXI grammars directly, and hence reducesthe number of iterations during grammar generation;(4) an algorithm for efficient representation of possible deviations from theXML schema.

IMC-AESOP investigations have been articulated around key use cases in order to better capture user needs and corresponding requirements. This particular use case explores how Service-Oriented Architecture (SOA) can ease the installation and maintenance of one of the lubrication system of the world’s largest underground iron mine run by LKAB in north Sweden, with a focus on migration aspects. We demonstrate that the loose coupling provided by the SOA approach combined with the eventing capabilities of Event Driven Architecture (EDA) can benefit to both engineering, installation and maintenance of an industrial process control system, with the exception of hard real-time based control loops.

As process control and monitoring systems based on a Service-Oriented Architecture (SOA) are maturing, the need increases for a systematic approach to migrate systems. The legacy systems are traditionally based on a strict hierarchy and in order to gradually allow additional cross-layer interaction, the migration procedure needs to consider both—functionality and architecture of the legacy system. The migration procedure proposed here aims to preserve the functional integration, organize the SOA cloud through grouping of devices, and maintain the performance aspects such as real-time control throughout the whole migration procedure.

In the last years service-oriented architectures have been extensively used to enable seamless interaction and integration among the various heterogeneous systems and devices found in modern factories. The emerging Industrial Automation Systems are increasingly utilising them. In the cloud-based vision of IMC-AESOP such technologies take an even more key role as they empower the backbone of the new concepts and approaches under development. Here we report about the investigations and assessments performed to find answers to some of the major questions that arise as key when technologies have to be selected and used in an industrial context utilizing Service-Oriented Architecture (SOA)-based distributed large-scale process monitoring and control system. Aspects of integration, real-timeness, distributeness, event-based interaction, service-enablement, etc., are approached from different angles and some of the promising technologies are analysed and assessed.

The combination of Service Oriented Architectures (SOAs) and Complex Event Processing (CEP) is gaining momen- tum for event centric management and processing of informa- tion in complex distributed systems (e.g., business automation). Whereas systems for factory automation have traditionally been deployed using dedicated buses and proprietary (often scan based) protocols, a recent trend in process automation is towards adopting open internet based technologies and event based communication. This trend is driven by the increasing number and capabilities of devices used for monitoring and control, and the increased flexibility, maintainability and price/performance gains expected from IP (potentially SOA/CEP) enabled systems.In this paper we discuss the challenges involved to apply SOA and CEP to the field of factory automation. In particular, real- time aspects are highlighted, both w.r.t. to accurate time-stamping of physical events in a distributed system, as well as end-to-end timing including communication and CEP processing.We approach the challenges by an architecture combining state-of-the-art synchronisation mechanisms for wired and wire- less networks together with real-time communication and dis- tributed query processing based on the notion of time constrained reactions. We discuss the impact of synchronisation inaccuracies and delays introduced by processing and communication, and present a method for implementation of safe potential- and certain matches.

The mining industry is seeing a bright future with a high demand for minerals and relatively high material prices. Much of this is driven by the rapid industrial expansion in countries such as China and others. However, even though the mining business seems promising, there are some important issues that must be addressed in order to maintain a cost-effective and competitive edge. Worker and environment safety, working conditions, are very important issues. Another issue is attracting skilled personal to work in the deep mines of the future.Today, the mining industry has problems hiring personnel, due to hazardous working environments and re-locating to the distant regions. If the workers’ safety could be increased, attracting skilled personnel would become one less problem. Rock bolts and shot-crete are in use today to reinforce tunnel walls, and expensive measurement devices are used in order to monitor seismic activity and rock stress. However, by not having real-time monitoring of rock bolts makes it difficult to monitor them. A better approach would be to make rock bolts intelligent and have them measure stress and seismic activity. Furthermore, by connecting the rock bolts to a network, real-time monitoring of them is made feasible. In this paper, we propose the merger of the Internet of Things (IoT) approach with traditional rock bolts, thereby allowing online monitoring of rock bolt status. This enables an increased possibility to enhance work safety by being able to detect anomalies on the rock earlier, thereby giving workers and machinery an earlier alarm to evacuate hazardous locations in the mine.