Our research can be divided into the areas quality-of-service (QoS)-oriented system design and autonomic networking. In QoS-oriented system design we focus on the systematic design of networked and embedded systems. The vision is to provide model-based tool support over the whole engineering cycle in a seamless way to yield systems optimized with respect to QoS issues. Quality-of-service is understood as an umbrella covering various aspects such as traditional performance measures (e.g., throughput of a network, system response time, loss rate, etc.) and dependability measures (e.g., reliability of a network, availability of a server system, etc.) but also real time, energy efficiency, security, and economics.
For the QoS-oriented system design, modeling in its various aspects plays a key role and is complemented by measurements and tests. Models are used for system specification (the group is experienced in using SDL, MSC, and UML and related tools), stochastic analysis and simulation (experience exists in using queuing networks, stochastic Petri nets, UML models, and several simulation tools), real-time analysis, HW/SW co-design (synthesis and optimization starting from high-level models such as SDL and graph models) and modular software engineering for mobile and reconfigurable components (driven by UML models). Test cases are also generated from high-level models and provide information about the functional and QoS-related system behavior. Measurements are performed for selected experimental networks (e.g., a cluster-based Web-server, a soccer robot team, a WLAN, a sensor network) and are used to validate and calibrate the models.
The autonomic networking research primarily focuses on autonomous sensor/actuator networks that consist of a large number of small and cheap sensor nodes and a team of mobile robots. Sensor nodes contain a sensing unit, a processor, energy supply, and a wireless communication adapter; sensor networks can be used to collect, process, and communicate measurement data. Such systems provide many design challenges on several abstraction layers, including medium access control, ad-hoc routing, self-organization, large-scale distributed information processing in the presence of severe resource restrictions, dynamic topologies and frequent failures. Mobile robots extend the possibilities of stationary sensor networks by the abilities of locomotion and real interaction with the environment. Important research questions in both stationary as well as mobile sensor networks are QoS aspects such as energy efficiency, performance, dependability, and security. We also investigate how concepts from cellular and molecular biology (e.g., cellular signaling pathways) can be applied in autonomous sensor/actuator networks. Finally, we work on new concepts for network monitoring and intrusion detection in the area of network security.

The group is organized into three teams which focus on the following research areas:

Quality-of-Service (Coordination: Armin Heindl)
Methods for the measurement, simulation, and analysis are developed and investigated in experimental network scenarios. A GPS-based measurement infrastructure has been developed for highly precise and high-volume measurements. Simulation models are built either with commercial UML tools or with WinPEPSY, a tool allowing for queuing network models. Special emphasis is given on innovative analysis methods for models with a large state space and with general distributions (non-Markovian models), analysis of large queuing networks by traffic-based decomposition and matrix-analytic techniques, as well as deterministic analysis based on network calculus (for providing QoS guarantees).
In late 2006 we started two cooperations with AUDI AG Ingolstadt on the topics

• Software-in-the-Loop Simulation and Testing of Highly Dependable Distributed Automotive Applications
• Transmission of Safety-Relevant Sensor Data in Intra-Car Communication Systems.

• GPS-based measurement infrastructure for a Web cluster
• online and offline clock synchronization
• UML simulation models
• analysis of queuing networks by traffic-based decomposition and matrix-analytic methods
• correlated input modeling by Markovian arrival processes
• WinPEPSY: a modeling tool based on queuing networks
• analysis of large non-Markovian models by iterative rate adjustments
• network calculus and optimization
• performance impact factors in WLANs
• QoS of mechanisms for distributing traffic control messages

• statistical testing based on scenario descriptions
• enhancement of statistical scenario-based testing for QoS testing using UML
• tool development for statistical sceanario-based testing
• modular software development for reconfigurable mobile systems driven by UML patterns
• software development in a mobile commerce scenario

• Sensor and Actor Networks
• Bio-inspired Networking
• Wireless Networking
• Network Monitoring and Attack Detection

The group has a PC cluster which can operate as a distributed Web server for both static or dynamic content or as an e-commerce system (a bookshop as specified by the TPC-W benchmark) and which has a measurement infrastructure for recording one-way delays, resource usages, and other relevant events. The infrastructure consists of a roof-mounted GPS antenna, several GPS receiver cards, additional hardware to distribute the PPS pulse, and modifications in the operating system kernels. It is possible to conduct measurements with high data volume and microsecond precision. A WLAN has the same measurement infrastructure. A robot assisted sensor network is available and consists of three Robertino robots and a number of sensor motes. The group also develops a soccer robot configuration close to the RoboCup F180 rules which includes an adapted measurement infrastructure.

• AUDI AG, Ingolstadt
• BMW, Science and Traffic Policy, München
• Computer Systems and Networks Group (University of Turin, Prof. G. Balbo, Dr. M. Gribaudo)
• Computer Networks and Internet Group (University of Tübingen, Prof. G. Carle)
• Fraunhofer Institut Integrierte Schaltungen (several departments, Erlangen Tennenlohe)
• Inchron GmbH
• method park Software AG
• Prozeßdatenverarbeitung und Robotik (TU Berlin, Prof. G. Hommel)
• Performability Engineering Research Group (University of Illinois, Prof. W. Sanders)
• Siemens A & D
• Siemens Medical Solutions
• Vodafone Group R&D Germany, München
• Carnegie Mellon University, Prof. O. Tonguz

In 2009 we organized the following conferences and workshops:

• IEEE ISWCS 2009 (The Sixth International Symposium on Wireless Communication Systems)
• IEEE WSNS 2009 (The Fifth IEEE International Workshop on Wireless and Sensor Networks Security)
• IEEE VNC 2009 (The First IEEE Vehicular Networking Conference)
• PMCCS 2009 (The International Workshop on Performability Modeling of Computer and Communication Systems)

• ACOOWEE - Activity Oriented Programming of Wireless Sensor Networks
  
• Analysis Methods for Non-Markovian Models
  
• Conceptual design of a UML-based tool for the simulation and test of wireless sensor networks
  
• CoopNet
  
• Data Quality and the Control of Car Manufacturing
  
• GeTTeMo - Systematische Generierung von Testszenarien aus benutzungsorientierten Testmodellen
  
• Integrated Modeling Platforms for Computer Infrastructures
  
• Modellierung, Emulation und Vorhersage der Charakteristika drahtloser Kanäle in heterogenen Netzen
  
• Network Calculus and Optimization
  
• ProHTA- Prospektive Bewertung von Gesundheitstechnologien
  
• Quality of Service of Networked Embedded Systems
  
• Requirements oriented testing with Markov chain usage models in the automotive domain
  
• Sensitivity Analysis of Queueing Networks
  
• Support for inter-domain routing and data replication in virtual coordinate based networks
  

• Automatische Verifikation von Qualitätsmerkmalen verteilter Systeme
  
• BioNeting - Bio-inspired Networking
  
• Co-Design and Rapid-Prototyping System for Applications with Real-Time Constraints (CORSAIR)
  
• CoCar - Cooperative Cars
  
• Constraint-based Testing of Communication Protocols with Time Requirements
  
• Effiziente Leistungsbewertung mit Hilfe von Entscheidungsdiagrammen
  
• Energy-Efficient System-Level Co-design for Real-Time Distributed Embedded Systems
  
• HISTORY - HIgh Speed neTwork mOnitoRing and analYsis
  
• ITS²SSU
  
• MaTeLo (Markov Test Logic)
  
• Methodik und Werkzeuge zur Entwicklung optimierter Echtzeitsysteme im Kontext von SDL/MSC und VHDL
  
• Mo.S.I.S. (Modular Software Engineering for Interoperative Systems)
  
• Modeling of External and Internal Impact Factors on the Performance of Wireless Local Area Networks
  
• monk-it - Efficient distributed monitoring, attack detection, and event correlation
  
• p2p4wsn - Efficient Data Management in Mobile Sensor Networks using Peer-to-Peer Technologies
  
• Q.E.D. (QoS Enhanced Development Using UML2.0 and TTCN-3)
  
• ROSES - RObot assisted SEnsor networkS
  
• Security and Quality of Service and Aspects in ZigBee-based Wireless Communication
  
• Self-organization of SN-MRS systems
  
• Sichere intelligente Mobilität - Testfeld Deutschland
  
• Software-in-the-Loop Simulation and Testing of Highly Dependable Distributed Automotive Applications
  
• Stochastic Modelling and Verification
  
• Telematics Services in Hybrid Networks
  
• Transmission of Safety-Relevant Sensor Data in Intra-Car Communication Systems
  
• Validation of Stochastic Systems
  
• Veins - Vehicles in Network Simulation
  
• Web Cluster Laboratory