Dipl. Inf. Torsten Teubler
|Adresse||Fachhochschule Lübeck, Fachbereich Elektrotechnik und Informatik
Mönkhofer Weg 239
D-23562 Lübeck, Deutschland
|Telefon||+49 (0)451 300-5348|
Seit dem 1. September 2009 bin ich wissenschaftlicher Mitarbeiter im Fachbereich Elektrotechnik und Informatik an der Fachhochschule Lübeck. Ich beschäftige mich im Rahmen des Real-World G-Lab-Projektes mit verteilten Algorithmen in Sensornetzen.
Geboren am 21. Februar 1978
Abitur 1999 am Fachgymnasium technischer Zweig, Kiel
Ausbildung zum IT-Systemkaufmann 2000-2003
- Studium der Informatik mit dem Nebenfach Medizinische Informatik 2003-2009 an der Universität zu Lübeck
- Seit 01. September 2009 wissenschaftlicher Mitarbeiter an der Fachhochschule Lübeck
|||Memory Efficient Forwarding Information Base for Content-Centric Networking , In International Journal of Computer Networks & Communications (IJCNC), volume 9, 2017. [bib] [pdf] [abstract]|
Content-Centric Networking (CCN) is a new paradigm for the future Internet where content is addressed by hierarchically organized names with the goal to replace TCP/IP networks. Unlike IP addresses, names have arbitrary length and are larger than the four bytes of IPv4 addresses. One important data structure in CCN is the Forwarding Information Base (FIB) where prefixes of names are stored together with the forwarding face. Long prefixes create problems for memory constrained Internet of Things (IoT) devices. In this work, we derive requirements for a FIB in the IoT and survey possible solutions. We investigate, design and compare memory-efficient solutions for the FIB based on hashes and Bloom-Filters. For large number of prefixes and an equal distribution of prefixes to faces we recommend a FIB implementation based on Bloom-Filters. In all other cases, we recommend an implementation of the FIB with hashes.
|||Transparent Integration of Non-IP WSN into IP Based Networks , In International Conference on Distributed Computing in Sensor Systems and Workshops IEEE Computer Society, 2012. [bib] [abstract]|
Embedded devices connected to the Internet will start an increasing growth of the Internet in near future. Wireless Sensor Networks (WSN) will play a major role in that growth. In the past several solutions were proposed to make sensor networks IP capable. Today there are IPv6-Stacks available including web servers running on sensor nodes. However, a gateway is always needed to convert the routing protocols and MAC-Layer Protocols including compression of IP packets to run on these devices. The overhead using IPv6 on the nodes is very high in respect of code size and message overhead. Therefore, in our approach we design and implement a system based on simple protocols target for sensor network nodes and a flexible gateway working in a hybrid fashion for our sensor network testbed. We successfully integrated this non-IP WSN in the Internet and our testbed is productive available from any computer connected to the Internet for reference. In this paper we present the architecture of our solution and present the implementation details of a standard WSN application that can be used for evaluation.
|||Verborgenes Rechencluster im neuen Studienarbeitsraum der Elektrotechnik und Informatik , In Impulse, volume 16, 2012. [bib] [pdf]|
|||Cooperative Virtual Memory for Sensor Nodes , Chapter in Real-World Wireless Sensor Networks Springer Berlin / Heidelberg (Pedro Marron, Thiemo Voigt, Peter Corke, Luca Mottola, eds.), volume 6511, 2010. [bib] [pdf] [abstract]|
Wireless sensor networks (WSN) have unique challenges and constraints. Sensor nodes e.g. have tough memory limitations. However, the latest advances in WSN research direct for an implementation of lightweight versions of Internet protocols like IPv6, TCP, and HTTP on sensor nodes. These protocols have challenging requirements. Especially, memory consumption of these protocols is often higher than the physical RAM that microcontrollers have integrated. Therefore, we suggest an approach for virtual memory providing more memory than the available RAM. As microcontrollers do not include a memory management unit the usage of memory is implemented in cooperative fashion based on the C standard library function malloc and free. We suggest an underlying file system and a hardware abstraction layer to support various external or internal memory devices like Flash or EEPROM. In this work in progress we present an API, some implementation details and preliminary results including future work.
|||Name-Centric Services for the Internet of Things , In 3rd International Conference on Networked Systems (NetSys), 2017. [bib] [abstract]|
Today, we see the development of the Internet of Things (IoT). Latest IoT devices are embedded, single-board computers (SBC) equipped with Ethernet and WiFi. Those SBCs are run an operating system and have network interfaces and use standard Internet protocols like IP, TCP, and so on. Compared to the envisioned devices for the future IoT these SBCs are still large and connected to a steady power supply. The next step in evolution towards the future IoT will be smaller, microcontroller driven devices which will operate for years on small batteries. Such small devices communicating via lowpower radios and also equipped with sensors are known as wireless sensor nodes. Ad-hoc networks formed by multiple wireless sensor nodes are so called wireless sensor networks (WSN).
|||Testbed for Development of Networked Autonomous Underwater Vehicles , In Oceans'16 MTS/IEEE Shanghai, 2016. [bib] [abstract]|
Development of underwater vehicles is a complex and challenging task. Especially the integration of components like sensors and actuators in a control loop is difﬁcult and costly and requires many experiments. One of the difﬁculties is the lack of debugging facilities underwater. In this paper, we suggest a distributed system architecture and a testbed concept for the development of networked autonomous underwater vehicles. Our approach is based on standard Ethernet and TCP/IP enabling use of industrial hardware like single board computers and switches. Furthermore, we suggest a mesh network with a layer 2 ad-hoc routing for wireless interconnection of underwater vehicles and infrastructure like base stations. The suggested mesh network integrates WiFi for communication on the surface and under- water electrical ﬁeld communication. To support the integration process of sensors and actuators we suggest external components for our testbed. We implement an external component including a remotely operated underwater vehicle. This remotely operated underwater vehicle serves as a carrier for sensors and allows the implementation of a control loop in underwater environments. We set up a testbed and present an evaluation of the ad-hoc routing and a dedicated control application with the remotely operated vehicle in a water tub.
|||Design of Expert Systems for Autonomous Underwater Vehicle Control , In Oceans'16 MTS/IEEE Monterey, CA, USA, 2016. [bib] [abstract]|
The development process of an intelligent autonomous underwater vehicle (AUV) is based on experiential knowledge leading to uncertainty in the software development for the intelligent AUV control. In this work we suggest an expert system to implement the AUV control software because expert systems handle uncertainty during the development process better than conventional, procedural programming languages. Furthermore, we provide design principles for the system architecture and the expert system. Finally, we present preliminary evaluation results on our designated computer hardware for the AUV we develop in a joint research project.
|||Architecture and Message Processing for Name-Centric Services in Wireless Sensor Networks , In 2016 Advances in Wireless and Optical Communications (RTUWO) (RTUWO2016), 2016. [bib] [abstract]|
Name-centric approaches provide maximum flexibility for applications, as a result, the future of Internet services is heading towards the increased importance of name-centric approaches. However, for the Internet of Things to become more name-centric, implementations of resource-constrained devices are required. Although there have been advances in the Internet of Things, such as CoAP and DPWS (Devices Profile for Web Services), these are not considered name-centric. A key to successful name-centric solutions for wireless sensor networks, is efficient handling and processing of names. In this paper we address architectural level communication and implementation for resource constraint devices. Finally, we evaluate the processing times and memory consumption of our implementation.
|||Embedded Multibeam Sonar Feature Extraction for Online AUV Control , In Oceans'16 MTS/IEEE Shanghai, 2016. [bib] [abstract]|
For development of an intelligent unmanned au- tonomous underwater vehicle (AUV), sensor data needs to be processed online for navigation and mission planning. In this work, we suggest a complete workﬂow and a processing chain to retrieve multibeam sonar data for AUV control. Our approach is based on the well-known image processing library OpenCV which provides sophisticated image recognition algorithms. We implement a processing chain for feature extraction on multibeam sonar acoustic image which retrieves contours of objects and coordinate points of the contours. Coordinate points are discrete data which can be easily processed further with additional algorithms. E.g. size of objects can be determined with the coordinate points or an expert system can classify objects with help of the coordinate points. Our solution will be embedded in an online control of an AUV. We evaluate the performance of our feature extraction approach using pre-recorded sonar data.
|||Integrating Expert System CLIPS into DUNE for AUV Control , In Oceans'15 MTS/IEEE Genova, 2015. [bib] [abstract]|
In this paper, we motivate the need for a flexible and robust system architecture for autonomous underwater vehicles. We present a novel concept for integrating the expert system CLIPS into an AUV navigation environment DUNE. Our approach provides complete tool support for automatic source code generation and therefore allows fast and target-oriented development of control software for AUVs. We present the design of the architecture comprised of DUNE and CLIPS. In an application example we describe each step of the software development with implementation details. We show the benefits of such an expert system for a flexible AUV control. For evaluation we measure the execution time of the system and the number of fired rules of our expert system. By that we demonstrate that the approach is suited for embedded hardware of an AUV.
|||A Solution for the Naming Problem for Name-Centric Services , In 12th International Conference on Wired & Wireless Internet Communications (WWIC 2014), 2014. [bib] [abstract]|
In recent past name-centric or content-centric networking (CCN) has gained substantial attention in the networking community. In a further development step name-centric service architecture enables the flexible placement and distribution of services in the network especially in a heterogeneous environment of wired and wireless (sensor) networks. However, the problem of structuring and creating hierarchies for names in name-centric networks is not solved yet. E.g. there is no configuration of service names in name-centric service WSN, no concept of unsolicited names or link-local names in CCN. In IP networks, DHCP or IPv6 auto- configuration is available, but no equivalent technique exists for CCN. We analyze the naming problem in the software development life cycle for name-centric services in WSN and propose a structure, hierarchy, and configuration mechanism for names. The paper introduces the overall concept and preliminary steps of implementation.
|||Wiseman - A Management and Deployment Approach for WSN Testbed Software , In 2013 IEEE INFOCOM Student Poster Session (INFOCOM'2013 Student Posters), 2013. [bib] [pdf] [abstract]|
Wireless Sensor Networks (WSNs) are an emerging technology. Today research in this field focuses on WSN testbeds to evaluate algorithms under realistic conditions. Numerous WSN testbed platforms allow remote deployment of WSN code and control of WSN experiments. However, one major aspect for testbeds was not addressed until now, namely the deployment and management of the testbed software itself. By deployment we mean installation and configuration of software. Once deployed on the testbed machines executables or services need maintenance and management. During testbed lifetime, periodic redeployment of testbed software is necessary due to new software versions, configuration changes, or an extension of the testbed. In this work, we present Wiseman a management and deployment approach and an implementation of Wiseman for the Wisebed WSN testbed software.
|||Name-Centric Service Architecture for Cyber-Physical Systems (Short Paper) , In Service-Oriented Computing and Applications (SOCA), 2013 6th IEEE International Conference on, 2013. [bib] [abstract]|
The goal of Service-Oriented Architectures (SOA) is to enable easy cooperation of a large number of computers and orchestration of services that are connected via a network. However, SOA for wireless senor networks (WSN) and cyber-physical systems (CPS) is still a challenging task. Consequently, for design and development of large CPS like WSNs connected to clouds, SOA has not yet evolved as an integral technology. One of the limiting issues is service registration and discovery. In large CPS discovery of services is tedious, mostly due to the fact that services are often semantically bound to a region or an application function while SOA forces service endpoints to be based on addresses of nodes. Also, today, SOA technologies are not used for service composition within sensor nodes and between sensor nodes, and even worse, different methods exist for service access in a WSN and in the backend. Therefore, service development differs largely in WSN and cloud. To overcome this limitation, we suggest a name-centric service architecture for cyber-physical systems. Our architecture is based on (a) using URNs instead of URLs to provide a service-centric architecture instead of service- or location-centric networking, (b) using the well-known CCNx protocol as a basis for our architecture which supports location and access transparency, and (c) employing CCN-WSN as the resource-efficient lightweight implementation for WSNs to build a name-based service bus for CPS. We evaluate the architecture by implementing an example application for facility management.
|||GAAP - Generic Android Application Programming , In Proceedings of WWW/Internet 2011 (Bebo White, Pedro Isaías, Flávia Maria Santoro, eds.), 2011. [bib] [pdf] [abstract]|
Today, smartphones are one of the fastest growing markets in the world where Android is receiving more and more attention. In the beginning when users of smartphones use Internet applications with generic WWW-Browsers recently there is a trend that they are been replaced by special applications. For each service in the Internet e.g. Android users need to download, install and maintain individual applications. However, there are too many service providers that have their own application that need to be updated regularly because new functionality is added. Many users lose control of this administrative process which bears additionally security risks. In this paper, we suggest a generic android application programming (GAAP) comparable to a middleware where the application logic and presentation layer is placed on the server. By this approach users do not need to update their installed application. Additionally, we suggest using android-like syntax and message format for layout and GUI following the KISS-principle (Keep it simple and stupid). For evaluation purpose we developed an application providing typical GUI elements for users to demonstrate the effectiveness of GAAP approach.
|||Poster Abstract: Real-World G-Lab: Integrating Wireless Sensor Networks with the Future Internet , In TridentCom 2010: The 6th International ICST Conference on Testbeds and Research Infrastructures for the Development of Networks & Communities, 2010. [bib] [pdf] [abstract]|
Today's Internet is approaching architectural limits that are set up by its legacy architecture. It is based on technologies and algorithms that were developed about 30 years ago. Thus intensive research is done in the field of new protocols and algorithms fulfilling the needs of the Future Internet. We believe that wireless sensor networks (WSNs), sensor-equipped devices such as cellphones and other embedded systems will have a vital part in this context, providing a way to obtain information about the real world. All of these new devices will produce a huge amount of data by sensing and interacting with their environment. At present, complex low-level sensor node programming and algorithm knowledge is necessary to access sensor data, and only a few mature techniques exist to integrate heterogeneous WSNs with the Internet. The goal of Real-World G-Lab, which is part of the German-Lab (G-Lab) project, is to overcome these obstacles by working on the different levels of protocols, services and applications. We will enable developers to write applications that rely on sensor data input, without knowledge of the underlying hardware platform and the network communication algorithms. This implies that sensors are able to participate in the Future Internet as peer hosts. This enables new fields of applications but likewise opens a set of new challenges in the context of efficient request processing by WSNs. Efficiency here means the optimization of query-latency, energy efficiency and general service-guarantees regarding the access to sensor nodes. Beyond this we need the ability to scale to a large amount of requests from the Internet while maintaining low latencies. We will verify our concepts and applications inside the controllable environment of the G-LAB research network, by adding several outdoor WSN deployments to the experimental facility of the G-LAB project. In summary, Real-World G-LAB will contribute to the integration of resource-constrained (wireless) sensor devices into the Future Internet by investigating several key challenges, ranging from low-level energy efficiency to improved high-level application development.
|||Tool Chain for Application Development with Name-Centric Services , In The 12th IEEE International Workshop on Managing Ubiquitous Communications and Services, 2015 (MUCS'15), 2015. [bib] [abstract]|
Regarding service oriented architectures various tool chains evolved in the last decades. However, in terms of content-centric approaches tools and middleware are in an early stage. Especially tool support for name-centric services in future heterogeneous networks is not available. Future networks will cover future Internet, wireless sensor networks and cyber-physical systems. Existing content-centric networking provides powerful, flexible, but heavyweight APIs to the developers but does not cover middleware and tool chains for services. Therefore, we implement a solution for application development with name-centric services based on an existing content-centric networking protocol. We design a lightweight service description based on JSON which is short and can be easily understood. We implement a complete tool chain for automatic code generation for server and client applications. We demonstrate the workflow, the convenience for the application developer and the effectiveness of our approach in a convincing application example. A first evaluation of the code generation reveals a prediction of logical lines of code and illustrates the complexity of the problem that is now solved automatically. Our approach is proven to simplify and advance the application development process for name-centric services.
|||Efficient Data Aggregation with CCNx in Wireless Sensor Networks , In 19th EUNICE Workshop on Advances in Communication Networking (EUNICE 2013), 2013. [bib] [abstract]|
CCNx is the reference implementation for a content centric networking (CCN) protocol developed by the Palo Alto Research Center CCNx group. It serves also as reference for our CCN-WSN, a CCNx implementation for wireless sensor networks (WSN). Efficient data aggregation with CCN-WSN is a challenge. In order to collect data from source in the network data sinks have to poll data sources with interests and exclude fields in interests are necessary bloating the interest messages. We solve the problem by introducing three building blocks in CCN-WSN: unicast faces for packet filtering and ``link'' abstraction, a forwarding service for creating network overlay structures used by applications and an intra-node protocol providing an API for applications to interact with the forwarding service. For evaluation purpose we implement an application using a forwarding service implementing a tree topology to collect data in the WSN.
|||A Reusable and Extendable Testbed for Implementation and Evaluation of Cooperative Sensing , In The 8th ACM International Workshop on Performance Monitoring, Measurement and Evaluation of Heterogeneous Wireless and Wired Networks PM2HW2N'13, 2013. [bib] [abstract]|
Cooperative sensing has been identi?ed as a potential improvement for cognitive radios to perceive their radio environment. In the past, algorithms have been developed by analysis and simulations exclusively. With cheaper hardware experimental platforms have been used for evaluation purpose recently. Simulations lack realistic propagation models for radio transmission but are reproducible compared to experimental evaluation done by hand. The effects of reduced detection probability and false alarms are not realistic in these simulations. In this paper, we suggest a reusable and extendable automated testbed software and instructions for deployment of own testbeds. Primary users as well as secondary users with cooperating cognitive radios can be flexibly deployed in the testbed within seconds. The advantage is that a series of even long lasting measurements including automatic logging of results can be easily repeated. Results can be assessed on the fly during the ongoing evaluation by accessing debug output remotely. The testbed supports stationary, portable, and in the future mobile radio devices for flexible scenarios as well as monitoring devices for debugging. The testbed and the radio devices are validated by deploying primary and secondary user in a small scenario whose outcome was analyzed beforehand. The results are as predicted and show the usefulness of this approach.
|||RoombaNet - Testbed for Mobile Networks , In Proceedings of the Workshops der wissenschaftlichen Konferenz Kommunikation in verteilten Systemen 2011 (WowKiVS 2011) Electronic Communications of the EASST (Tiziana Margaria, Julia Padberg, Gabriele Taentzer, eds.), volume 37, 2011. [bib] [abstract]|
The design and deployment of wireless networks needs careful planning including various tools for analysis, simulation and evaluation. Therefore, development of software to support deployment of wireless networks has been subject of intensive research for several years. In particular the evaluation of the influence of mobility remains a challenging task. For deployment of mobile communication networks operators perform simulations and measurements during the planning process with large efforts. In the past the research community based their decisions on development of new protocols on simulations exclusively. While network simulators provide fast investigation of huge and also mobile networks they rely on theoretical models which are often considered as inaccurate and too optimistic. Therefore, more and more real wireless network environments called testbeds are established worldwide most of them with static nodes. Testbeds dedicated towards mobile networks remain a challenge as the effort to build such a network increases with mobility. The work here presents an approach for a fully automated real-world mobile network testbed where nodes are piggybacked on mobile robots. The platform with up to 30 mobile nodes and additional 30 static nodes can emulate various scenarios especially suited for pedestrian scenarios or for slow car movements. In this paper we introduce this testbed which is integrated into the larger Real-World GLab Internet testbed facility. We provide first details of the hardware and software components and provide first evaluations as well as present application examples.
|||EZgate - A Flexible Gateway for the Internet of Things , In Proceedings of the Workshops der wissenschaftlichen Konferenz Kommunikation in verteilten Systemen 2011 (WowKiVS 2011) Electronic Communications of the EASST (Tiziana Margaria, Julia Padberg, Gabriele Taentzer, eds.), volume 37, 2011. [bib] [abstract]|
Two years ago a survey of the wireless world research forum predicted that in the year 2017 there will be seven trillion wireless devices for seven billion humans which is equivalent to 1000 devices per human being on the average. The future will show if this incredible number will be reached but for sure we will see an increasing number of wireless devices forming the Internet of the future. The new evolving ``Internet of Things'' is one of the challenging research topics today. With many wireless resource constraints devices, smart gateways integrating these small battery-powered devices into the future Internet will play a major role for the success of the Internet of Things. These gateways will work as a communication endpoint or proxy enabling transparent services including mechanisms for semantic service discovery, Quality of Service (QoS), and performance enhancing proxies (PEPs). In this work we will introduce a fully operable TCP/IP-Stack EZgate written in Java that allows designing and implementing such gateways for wireless networks in a flexible and fast approach and compare it with related work. We will demonstrate how the protocols in this stack can be assembled in a flexible manner, creating various types of gateways and can be easily extended to implement cross layer techniques. Finally, we evaluate the performance of the implementation for delay and throughput performance to show that EZgate is suitable for use in a productive environment.
|||Middleware for Smart Gateways Connecting Sensornets to the Internet , In MidSens'10: The fifth international workshop on Middleware Tools, Services and Run-Time Support for Sensor Networks, 2010. [bib] [pdf] [abstract]|
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 syntactic approach to wreck pattern recognition in sonar images , GRIN (T. M. Buzug et. al., ed.), 2017. [bib]|