Daniel Bimschas

SPITFIRE: toward a semantic web of things

The developed world is awash with sensors. However, they are typically locked into unimodal closed systems. To unleash their full potential, access to sensors should be opened such that their data and services can be integrated with data and services available in other information systems, facilitating novel applications and services that are based on the state of the real world. We describe our vision and architecture of a Semantic Web of Things: a service infrastructure that makes the deployment and use of semantic applications involving Internet-connected sensors almost as easy as building, searching, and reading a web page today.

Flexible experimentation in wireless sensor networks

Virtual testbeds model them by seamlessly integrating physical, simulated, and emulated sensor nodes and radios in real time.

Using and operating wireless sensor network testbeds with WISEBED

Current surveys and forecast predict that the number of wireless devices is going to increase tremendously. These wireless devices can be computers of all kinds, notebooks, netbooks, Smartphones and sensor nodes that evolve into real-world scenarios forming a “Real-World-Internet” in the future. In our work we focus on the Future Internet with small battery driven devices forming the “Internet of Things”. In recent networking research, testbeds gain more and more attention, especially in the context of Future Internet and wireless sensor networks (WSNs). This development stems from the fact that simulations and even emulations are not considered sufficient for the deployment of new technologies as they often lack realism. Experimental research on testbeds is a promising alternative that can help to close the gap. The deployment of testbeds is challenging and user and operator requirements need to be considered carefully. Therefore, the goal is to design an architecture that allows operators of WSN testbeds to offer numerous users access to their testbeds in a standardized flexible way that matches these requirements. In this paper we first identify some of the requirements, then introduce the architecture and general concepts of our WISEBED approach and show how this architecture meets the requirements of both groups. We give an overview of existing WISEBED-compatible WSN testbeds that can be used for experimentation today. Main focus in this paper compared to previous work is to address the perspective of both users and operators on how to experiment or respectively operate a WSN testbed based on WISEBED technology.

Middleware for smart gateways connecting sensornets to the internet

There is an increasing trend to integrate sensor networks into the Internet, eventually resulting in an Internet of Things. Recent efforts of porting IPv6 to sensor networks turn sensor nodes into equitable Internet peers and RESTful Web Services on sensor nodes allow a distribution of the application logic among sensor nodes and more powerful Internet nodes. The touching point between a sensor network and the Internet is the gateway which translates between the link-layer protocols used in the Internet (Ethernet, Wi-Fi) and sensor networks (IEEE 802.15.4). So far, the functionality of those gateways was fixed and simple. We propose to turn these gateways into smart gateways by enabling them to execute application code. As only the gateway has full knowledge of and control over both the sensor network and the Internet, smart gateways can act as performance-enhancing proxies and intelligent caches to preserve the limited resources of the sensor network. Also, the smart gateway can perform application-specific protocol conversion between highly optimized but non-standard protocols in the sensor network and standardized, but less efficient protocols in the Internet. In this paper we present the design of a middleware for smart gateways that allows the execution of application code on the gateway by offering simplified interfaces to the sensor network and the Internet. We also report preliminary performance results for key functions of the middleware.

A P2P Semantic Query Framework for the Internet of Things

The Internet of Things (IoT) will connect billions of embedded computers that can sense and influence their environment. By integrating perception and control of the real world with data and services available on the Web, a wide range of novel applications can be realized, including Smart Cities, Smart Homes, or Smart Grids. A prerequisite for integrating sensor data with other data on the Web is a common data format that is not constrained to a specific domain, such that joint queries over diverse data sources can be efficiently performed. The SemanticWeb offers such a data format called RDF,which essentially consists of subject-predicate-object triples to formulate arbitrary facts, as well as a query language called SPARQL to pose queries over setsof such triples. Inorder to scale to thehugeamount of sensor data being produced in the IoT, RDF databases and SPARQL query engines need to be implemented in a distributed fashion, in particular using peer-to-peer (P2P) techniques. Existing solutions in that space offer only limited functionality andcannotbeeasily extended. Therefore, after surveying the state of the art, we propose a generic framework that fullysupportsSPARQL,butallowsplugging indifferentP2P systemsanddistribution strategies.Wealso presentandevaluateanovelprobabilisticdistributionstrategy that supports non-uniformly distributed RDF triples. *Dipl.-Inf. Richard Mietz: E-Mail: mietz@iti.uni-luebeck.de PDDr. rer.nat. habil SvenGroppe: E-Mail: groppe@ifis.uni-luebeck.de Oliver Kleine, M.Sc.: E-Mail: kleine@itm.uni-luebeck.de Daniel Bimschas,M.Sc.: E-Mail: bimschas@itm.uni-luebeck.de Prof. Dr. Stefan Fischer: E-Mail: fischer@itm.uni-luebeck.de Prof. Dr. Kay Römer: E-Mail: roemer@iti.uni-luebeck.de PD Dr.-Ing. habil. Dennis Pfisterer: E-Mail: pfisterer@itm.uni-luebeck.de

Hybrid underwater environmental monitoring

Many underwater monitoring tasks, such as submarine life studies and pipeline inspections, are usually performed manually. Automated underwater monitoring has the potential to increase safety, improve timeliness, and decrease costs. We propose a hybrid solution of stationary sensor buoys and swarms of autonomous underwater vehicles (AUV) and report on our current progress of its realization. Our solution is based on sensor network technology and a small mobile underwater robot developed in our institute.

Topology Virtualization for Wireless Sensor Network Testbeds

In recent years Wireless Sensor Networks (WSNs) have enjoyed a growing amount of attention. One particularly promising prospect is to employ WSNs as an extension of the future internet into the real world; this motivates experimentally driven research to evaluate and benchmark new concepts on WSNs. With our poster we will show our approach to virtualizing Wireless Sensor Network testbeds. With this technique we are able to reconfigure the topology of a WSN testbed without changing the physical location of nodes; it even allows building virtual topologies on top of federated testbeds.

Demo abstract: bridging the gap between simulated sensor nodes and the real world

We present an architecture for the interconnection of simulated sensor nodes and real node hardware. The simulator is therefore running in real-time, and the simulated nodes are able to exchange messages with real sensor nodes as if they were sent over the radio. This runs fully transparent for the application--and is well suitable for debugging purposes and general algorithm development. It is even possible to use exactly the same algorithm implementation for both simulated nodes and real sensors.

Testbed Runtime – The WISEBED WSN Testbed Infrastructure Software

In the Internet of Things (IoT) tiny embedded devices, equipped with sensors and actuators, extend the Internet into the physical world and allow to sense and influence the current state of the realworld in real time. These devices typically have unstable and high-latency multi-hop wireless Internet connectivity. In order to make those networks robust, experimental validation in testbeds is imperative [4] as simulations and emulations often lack realism and are therefore not considered sufficient. In this extended abstract,wedescribe “TestbedRuntime” (TR, cf. [1]), aBSDlicensed open-source framework for the operation, use and management of IoT testbeds, originally created in the EUproject WISEBED [5]. TR has been and is being used in various German and European research projects (such as Real-World G-Lab, WSNLAB, MOVEDETECT, Spitfire and SmartSantander) as well as various smalland large-scale testbeds at research institutions around the world (including Argentina, New Zealand, England and Germany). It has seen 20 releases since June 2010 and has proven to be extremely versatile and efficient. It is a unique piece of software that encompasses a variety of features that sets it apart fromsimilar solutions. TR provides a unified API-based and interactive way of remote experimentation with wireless sensor network testbeds, allowing users to choose from awide variety of available clients (e.g. the scriptableWeb-based “WiseGui” [2] or Java-based automation scripts [3]) or to develop their own use-case-tailored clients. TR can be used to either set up a Desktop/small-scale personal or a large-scale private or public testbed, the latter typically being composed of sensor nodes attached to gateway hosts having Ethernet connectivity with the “portal host” running the public APIs. TRs extensible architecture currently supports 5 different sensor node types. TheWISEBEDAPI andwith it Testbed Runtimewas the first WSN testbed infrastructure solution to allow bidirectional communication over a sensor nodes’ serial port at experiment runtime, providing a first class out-of-band logging and debugging infrastructure. All functionality (message exchange, reprogramming, resetting, etc.) is APIbased, allowing to fully script and automate experiments and their repeated execution. Scripts and experiment configurations can be published and shared for additional validation or repeated execution on the same or on other API-compatible testbeds, resulting in higher credibility of results. Our demonstration atNetSys 2013 showcases a realistic use case in which the user evaluates and debugs a largescale WSN running CoAP services (a lightweight HTTP-like service abstraction) based on IPv6/6LoWPAN. Using the WiseGui, we will program the network and trigger one of the nodes to issue a CoAP request to another node in the network. The user will then be able to see the node logging outputs of every network hop from source to destination and a graphical visualization reconstructs the requests’ path throughout the network. By manually disabling/enabling individual nodes the user can see how the routing adapts to node failure.

Experimentalumgebungen für das Internet der Dinge: Überblick, Taxonomie und praktische Nutzung

Zusammenfassung Die experimentelle Validierung neuartiger Ansätze hat, besonders im Kontext des Internet der Dinge, stark an Bedeutung gewonnen. Dieser Beitrag identifiziert Anforderungen an Experimentaleinrichtungen für das Internet der Dinge, gibt einen Überblick über aktive und öffentlich zugängliche Experimentaleinrichtungen und stellt verschiedene Plattformen auf Basis dieser Anforderungen qualitativ gegenüber. Es wird beispielhaft auf eine der Plattformen (WISEBED) näher eingegangen, um den Lesern einen Eindruck zu vermitteln, welche Möglichkeiten der experimentellen Forschung heute bereits zur Verfügung stehen. Des Weiteren wird besprochen, wie eigene Testbeds auf Basis der WISEBED Software betrieben und – falls gewünscht – mit anderen föderiert werden können.