Benedikt Ostermaier

Moving Application Logic from the Firmware to the Cloud: Towards the Thin Server Architecture for the Internet of Things

Unlike traditional networked embedded systems, the Internet of Things interconnects heterogeneous devices from various manufacturers with diverse functionalities. To foster the emergence of novel applications, this vast infrastructure requires a common application layer. As a single global standard for all device types and application domains is impracticable, we propose an architecture where the infrastructure is agnostic of applications and application development is fully decoupled from the embedded domain. In our design, the application logic of devices is running on application servers, while thin servers embedded into devices export only their elementary functionality using REST resources. In this paper, we present our design goals and preliminary results of this approach, featuring the Californium (Cf) CoAP framework.

A real-time search engine for the Web of Things

The increasing penetration of the real world with embedded and globally networked sensors leads to the formation of the Internet of Things, offering global online access to the current state of the real world. We argue that on top of this realtime data, a Web of Things is needed, a software infrastructure that allows the construction of applications involving sensor-equipped real-world entities living in the Internet of Things. A key service for such an infrastructure is a search engine that supports lookup of real-world entities that exhibit a certain current state as perceived by sensors. In contrast to existing Web search engines, such a real-world search engine has to support searching for rapidly changing state information generated by sensors. In this paper, we show how the existing Web infrastructure can be leveraged to support publishing of sensor and entity data. Based on this we present a real-time search engine for the Web of Things.

Enhancing the Security of Local DangerWarnings in VANETs - A Simulative Analysis of Voting Schemes

The upcoming deployment of vehicular ad-hoc networks does not only facilitate novel telematics applications, but also poses strong requirements on security. Especially the adoption of active safety applications may raise new threats to road safety if security issues are not properly handled, thus thwarting their initial purpose. In this paper, a special active safety application is considered that enables cooperative fore sighted driving through the exchange of local danger warnings, which are based on individual observations and refer to the current road condition. From a security point of view, the decision whether or not such an application should rely on a reported hazard, is a crucial issue, which cannot be completely protected by conventional security measures. We propose an additional security mechanism based on an information centric evaluation of the plausibility of received hazard messages. We developed four decision methods, which are based on voting schemes, and evaluated them by simulation using two attacks trying to manipulate the decision process by distributing false information. Our results indicate that the proposed information centric evaluation of remote observations is a reasonable means to increase the stability and security of a cooperative local danger warning service

First experiences using wireless sensor networks for noise pollution monitoring

The assessment of environmental pollution levels is a complex and expensive task that public administration and often also private entities are willing or forced to take over. Focusing on the assessment of environmental noise pollution in urban areas, we provide qualitative considerations and experimental results to show the feasibility of wireless sensor networks to be used in this context. We present a prototype for the collection and logging of noise pollution data based on the Tmote invent prototyping platform, using which we performed indoor and outdoor noise pollution measurements. We build upon these first experimental results to depict the potentials and limits of currently available wireless sensor networks prototyping platforms to be used as noise pollution sensors. Furthermore, we present tinyLAB, a Matlab-based tool developed in the context of this work, which enables real-time acquisition, processing and visualization of data collected in wireless sensor networks.

Real-Time Search for Real-World Entities: A Survey

We are observing an increasing trend of connecting embedded sensors and sensor networks to the Internet and publishing their output on the Web. We believe that this development is a precursor of a Web of Things, which gives real-world objects and places a Web presence that not only contains a static description of these entities, but also their real-time state. Just as document searches have become one of the most popular services on the Web, we argue that the search for real-world entities (i.e., people, places, and things) will become equally important. However, in contrast to the mostly static documents on the current Web, the state of real-world entities as captured by sensors is highly dynamic. Thus, searching for real-world entities with a certain state is a challenging problem. In this paper, we define the underlying problem, outline the design space of possible solutions, and survey relevant existing approaches by classifying them according to their design space. We also present a case study of a real-world search engine called Dyser designed by the authors.

Connecting things to the web using programmable low-power WiFi modules

We present first experiences of using programmable low-power WiFi modules for connecting things directly to the Web. Instead of relying on dedicated low-power radio technology and specialized protocols, we leverage the ubiquity of IEEE 802.11 access points and the interoperability of the HTTP protocol. Using a loosely coupled approach, we enable seamless association of sensors, actuators, and everyday objects with each other and with the Web. Our experimental results show that low-power WiFi modules can achieve long battery lifetime despite the fact that we are using HTTP over TCP/IP for communication.

WebPlug: A framework for the Web of Things

We present WebPlug, a framework for the emerging Web of Things. It consists of several building blocks which ease integration of things, including their sensors and actuators with the Web. For example, WebPlug supports versioning of and eventing for arbitrary Web resources, like sensor readings, thus simplifying the process of creating physical mash-ups. After providing an analysis that led to the development of WebPlug, we present selected aspects of its design.We complete the paper by presenting the application of our framework in a real-world scenario.

Dyser: towards a real-time search engine for the web of things

The increasing penetration of the real world with embedded and globally networked sensors leads to the formation of the Internet of Things, offering global online access to the current state of the real world. We argue that on top of this realtime data, a Web of Things is needed, a software infrastructure that allows the construction of applications involving sensor-equipped real-world entities living in the Internet of Things. A key service for such an infrastructure is a search engine that supports lookup of real-world entities that exhibit a certain current state as perceived by sensors. In contrast to existing Web search engines, such a real-world search engine has to support searching for rapidly changing state information generated by sensors. In this paper, we show how the existing Web infrastructure can be leveraged to support publishing of sensor and entity data. Based on this we present a real-time search engine for the Web of Things.

Creating Location-Based Services by Utilising a Web of Places

We present an open, decentralized, participatory system which realizes location-based services by gently extending the existing World Wide Web. Utilizing a geospatial search engine for such a Web of Places, users are able to consume location-based services generated by arbitrary parties using their mobile phones. Special care has been taken in order to foster the creation of places and services and their mobile usage by users. We further discuss that by using ranking algorithms based on place and service definitions, finding services relevant to the current location by searching only by geographic position might be feasible even in case of large numbers of relevant places.