Jens Eliasson

Integration of Wireless Sensor and Actuator Nodes With IT Infrastructure Using Service-Oriented Architecture

A large number of potential applications for Wireless Sensor and Actuator Networks (WSAN) have yet to be embraced by industry despite high interest amongst academic researchers. This is due to various factors such as unpredictable costs related to development, deployment and maintenance of WSAN, especially when integration with existing IT infrastructure and legacy systems is needed. Service-Oriented Architecture (SOA) is seen as a promising technique to bridge the gap between sensor nodes and enterprise applications such as factory monitoring, control, and tracking systems where sensor data is used. To date, research efforts have focused on middleware software systems located in gateway devices that implement standard service technology, such as Devices Profile for Web Services (DPWS), for interacting with the sensor network. This paper takes a different approach-deploying interoperable Simple Object Access Protocol (SOAP)-based web services directly on the nodes and not using gateways. This strategy provides for easy integration with legacy IT systems and supports heterogeneity at the lowest level. Twofold analysis of the related overhead, which is the main challenge of this solution, is performed; Quantification of resource consumption as well as techniques to mitigate it are presented, along with latency measurements showing the impact of different parts of the system on system performance. A proof-of-concept application using Mulle-a resource-constrained sensor platform-is also presented.

A SOA-based architecture for empowering future collaborative cloud-based industrial automation

The last years we are witnessing of rapid advances in the industrial automation domain, mainly driven by business needs towards agility and supported by new disruptive technologies. Future factories will rely on multi-system interactions and collaborative cross-layer management and automation approaches. Such a factory, configured and managed from architectural and behavioural viewpoints, under the service-oriented architecture (SOA) paradigm is virtualized by services exposed by its key components (both HW and SW). One of the main results of this virtualization is that the factory is transformed into a “cloud of services”, where dynamic resource allocation and interactions take place. This paper presents a view on such architecture, its specification, the main motivation and considerations, as well as the preliminary services it may need to support.

A survey of commercial frameworks for the Internet of Things

In 2011 Ericsson and Cisco estimated 50 billion Internet connected devices by 2020, encouraged by this industry is developing application frameworks to scale the Internet of Things. This paper presents a survey of commercial frameworks and platforms designed for developing and running Internet of Things applications. The survey covers frameworks supported by big players in the software and electronics industries. The frameworks are evaluated against criteria such as architectural approach, industry support, standards based protocols and interoperability, security, hardware requirements, governance and support for rapid application development. There is a multitude of frameworks available and here a total 17 frameworks and platforms are considered. The intention of this paper is to present recent developments in commercial IoT frameworks and furthermore, identify trends in the current design of frameworks for the Internet of Things; enabling massively connected cyber physical systems.

Enabling Cloud Connectivity for Mobile Internet of Things Applications

The number of small embedded devices connected to the Internet is increasing. This growth is mostly due to the large number of Internet of Things (IoT) deployments, with applications such as: industrial monitoring, home automation, and others. One common aspect with the majority of application areas is the lack of mobility. Most IoT devices are stationary and often use IEEE 802.15.4/6LoWPAN solutions. When a high level of mobility is required, the use of IEEE 802.15.4 is not possible without adding additional hardware for the user to carry. In this article, a holistic network architecture consisting of heterogeneous devices is presented. The architecture is composed of Embedded Internet Systems (EIS) and uses standard communication protocols. One important feature is the use of the Service-oriented architecture (SOA) paradigm. The use of SOA, by utilization of the CoAP protocol and standard services, enables the proposed architecture to exchange sensor- and actuator data with an Internet-based cloud as well as a users local cloud consisting of sensor IoT devices, smart phones and laptops. Another component of the architecture is a web-based human-machine interface for configuration, monitoring and visualization of sensor and actuator data using emerging web technologies for structured data processing. Results from experiments and real-world tests show that the proposed architecture can support sample rates of up to several kHz while enabling sensor data to be transmitted to SOA services in real time. This proves that the use of SOA, and Restful web services in particular, is feasible on resource-constrained platforms while supporting true mobility.

The arrowhead approach for SOA application development and documentation

The Arrowhead project aims to address the technical and applicative issues associated with cooperative automation based on Service Oriented Architectures. The problems of developing such kind of systems are mainly due to the lack of adequate development and service documentation methodologies, which would ease the burden of reusing services on different applications. The Arrowhead project proposes a technical framework to efficiently support the development of such systems, which includes several tools for documentation of services and to support the development of SOA-based installations. The work presented in this paper describes the approach which has been developed for the first generation pilots to support the documentation of their structural services. Each service, system and system-of-systems within the Arrowhead Framework must be documented and described in such way that it can be implemented, tested and deployed in an interoperable way. This paper presents the first steps of realizing the Arrowhead vision for interoperable services, systems and systems-of-systems.

Technologies for SOA-based distributed large scale process monitoring and control systems

In a SOA-based system the applications are organized in a manner such that interoperable services can be used from different domains. In a process industry context, different domains can refer to, for example, process instrumentation and monitoring, execution of process control, data acquisition, etc. Large process industry systems are a complex and potentially very large sets of multi-disciplinary, heterogeneous, networked distributed systems. Current industrial process control systems are typically vendor specific; in addition the different domains are associated with different layers, different standards and different technologies. In the paper the authors report about the investigations and assessments performed to find answers for four major critical questions that arise as key when technologies have to be selected and used in a true Service Oriented Architecture (SOA) based distributed large scale Process Monitoring and Control system: (1) Real-time SOA (what are the limits of bringing SOA into high performance control loops?); (2) Management of large scale industrial distributed control systems (is it feasible to manage up to tens of thousands of service-oriented devices?); (3) Distributed event-based systems are asynchronous (what are the limits compared to traditional periodic scanning systems?) and (4) Service specification (which semantics are the most suitable for specifying process control and monitoring services?).

A migration approach towards a SOA-based next generation process control and monitoring

Interest in Service Oriented Architectures (SOA) in the automation domain has seen a rapid increase both from the academia as well as the industry recent years. Since green field plants today are not common, the partial migration of plant automation to SOA design is needed to introduce new functionalities. Thus strategies and approaches for migration from legacy to SOA architectures becomes of vital interest. This paper discusses different views on partial migration of a process monitoring and control system from legacy to SOA. The discussion includes a global top down view, a bottom up view, hardware/software considerations and a hint on training of personnel.

An Infrastructure for Service Oriented Sensor Networks

Emerging wireless technologies enable ubiquitous access to networked services. Integration of wireless technologies into sensor and actuator nodes provides the means for remote access and control. However, ad hoc deployment of nodes complicates the process of finding, selecting and using these in a meaningful way. The use of a service discovery framework enables nodes to present themselves and the resources they hold. In this paper, we review the applicability of a number of well-known service discovery protocols in the context of networked nodes. Multicast DNS and Service Discovery (mDNS-SD) stands out with its auto-configuration, distributed architecture, sharing of resources, and wide area access. For wireless battery operated and resource constrained nodes, we seek to integrate SD and power management techniques. This leads us to a standards based infrastructure for service oriented sensor networks where; 1) nodes collaborate in an ad hoc fashion by using SD techniques to discover (and announce) resources locally and over the public Internet, 2) nodes preserve power through aggressive utilization of low power (sleep) modes, while yet being reachable for clients according to defined schemas, and 3) clients may access and configure nodes, and (if possible) access sleeping nodes by implicit wake-up procedures. To demonstrate the proposed infrastructure a complete experimental setup has been devised featuring; Bluetooth enabled nodes, lightweight implementations of mDNS-SD and communication stacks, Internet access through cellular/wired gateways, together with a public DNS server. Our experiments verify that mDNS-SD can be effectively deployed on small wireless sensor and actuator nodes and provides the basis of a service oriented infrastructure for low power sensor networks.

An authentication and access control framework for CoAP-based Internet of Things

Internet of Things (IoT) and Cyber-physical Systems (CPS) are two very hot research topics today, and more and more products are starting to appear on the market. Research has shown that the use of Service Oriented Architecture (SOA) can enable distributed application and devices to device communication, even on very resource constrained devices, and thus play an important role for IoT and CPS. In order to realize the vision of Internet of Things, communication between devices must be secured. Security mechanisms for resource constrained devices has attracted much interest from the academic community, where research groups have shown solutions like IPsec, VPN-tunnels, (D)TLS, etc. are feasible to use on this type of networks. However, even though the use of well-known security mechanisms are vital for SOA-based IoT/CPS networks and systems to be protected, they do not provide any fine-grain access control. In this paper, a CoAP-based framework for service-level access control on low-power devices is presented. The framework allows fine grain access control on a per service and method basis. For example, by using this approach a device can allow read/write access to its services to one group of users while only allowing read access to another group. Users without the right credentials are not even allowed to discover available services. To demonstrate the validity of the proposed approach, several implementations are presented together with test results. The aim is to provide a holistic framework for secure SOA-based low power networks comprise by resource constrain devices.

Efficient structured data processing for web service enabled shop floor devices

State of the art factory automation systems are now using Service Oriented Architecture (SOA) in order to increase flexibility and lower complexity of process monitoring and control. However, the service technology has not yet penetrated into the lower levels of plant-wide automation processes i.e. throughout shop floor devices such as programmable controllers, embedded sensors and actuators. Different techniques to adapt the web service technology to the specific requirements of embedded systems domain are intensively investigated by researchers and yet real-time properties, limited resources and wireless links are still posing immense challenges. The most promising solutions proposed are based on a newly emerging structured data format - Efficient XML Interchange (EXI). It is designed to compensate for the inefficiency of widely used throughout service implementations XML format. This paper investigates the design of EXI processor targeted at highly resource constrained embedded devices found at the shop floor level. The EXI processor is proposed as an alternative to the XML parsers and serializers currently used in web service implementations. Among the results presented are a novel low level processor interface and measurements quantifying the gained efficiency compared to traditional XML-like interfaces. Reference open source implementation equipped with the new interface is also provided.