Design and Analysis of Communication Systems (DACS)

ACS 2011

Faculty of Electrical Engineering, Mathematics and Computer Science (EEMCS)

Section head: Dr.ir. A. Pras (ad interim)

Keywords: dependability, performance modelling, quantitative analysis, measurements, wireless communication, communication systems, network management.

DACS focuses on dependable networked systems. A (networked) system is called dependable, whenever reliance can justifiably be placed on the services it delivers. Tailored to communication systems, which can be wired, wireless, or embedded in other systems, this means that we aim to contribute to the design and implementation of dependable networked systems, as well as to methods and techniques to support the design and dimensioning of such systems, such that they are dependable, in all phases of their lifecycle. We thereby interpret the term dependability as encompassing availability, reliability, performance (quality of service) and security.

Three phases in system design

We distinguish three phases in the design of dependable networked systems. In the first (exploratory) phase the emphasis lies on the development of system models and the model-based evaluation of key system characteristics. In the second, more concrete phase the emphasis lies on designing and/or standardizing systems architectures, protocols, and algorithms, as well as on implementing prototype systems. In the third, operational phase the systems have been implemented and the emphasis lies on operationally managing them. As an example of these three phases, consider the internet backbone. During 1965-1985, research concentrated on a variety of networking models (circuit-switching vs. packet-switching, various local area access mechanisms). In the period 1980-1995, research focus shifted toward designing, implementing and standardizing protocols (TCP/IP, Ethernet). Since the beginning of the 1990s, an ever more important challenge is to keep the internet up and running, and solve problems related to (performance) management, security and scalability. A similar transition in focus can be seen for wireless data communication system, although for such systems, we are yet in the second phase (design, prototype implementation, and so on). Since more and more of these systems become operational, the importance of operational management in this area will steadily increase. For embedded communication systems, like car-to-car communications, or wireless sensor network based systems, research is still more in the exploratory phase, meaning, largely modelling and evaluation based. The figure below illustrates, through a horizontal structuring, the above three phases in system design.

Three technologies for dependable networked systems

Within DACS, research on wired networks (primarily internet) focuses on operational aspects, like managing and optimizing configurations, as well as on intrusion detection. Taking and interpreting measurements plays an important role in this research. In this area DACS also performs work on the design and standardization of new protocols, like NSIS (QoS signalling protocols for the internet).

Research on wireless systems focuses on the design, evaluation and prototype implementation of new protocols and algorithms, such as algorithms for context- and power-aware routing in ad-hoc networks, personal network architectures, security in personal networks, as well as on service discovery architectures and algorithms.

Finally, research on embedded networked systems focuses primarily on system specification and evaluation techniques to describe such systems and the resource constraints they have to operate under. This includes the development of new stochastic model checking techniques and the application thereof to predict dependability and performance properties.

The figure above also shows, through a vertical structuring, the three technology domains (where a clear cut separation can, of course, never be made). When technologies mature over time, a shift in phase and type of activity is foreseen. Inherent to university research, DACS moves on the increasing side of the wave (to the right).

Programme development

The view toward the research within DACS as explained above, has been developed over the last year. Each of the three areas has as coordinator a full or associate professor: Pras for dependable operational network systems, Heijenk for (protocol) design of dependable network systems, and Haverkort for model-based issues in dependable networked system design. Each of these area coordinators has a very clear presence in the respective international scientific community (e.g., as regular conference organiser, PC chair, and journal editorial board member). These three focal points will be further developed and emphasized in the years to come. More than in the past, we will ask the question how new activities fit in, before we take them up. Notice that the presented structure is a structure based on technical content, not an organisational sub-structuring of the group. Group members participate in a variety of projects, in which all the above issues might play a role.

Currently, the group is actively involved in the CTIT strategic research orientations (SROs) on Dependable Systems and Networks (DSN), Wireless and Sensor Systems (WiSe), and Integrated Security and Privacy in a Networked World (Istrice). For the near future, we envisage (and will strive for) an SRO on “dependability for ICT”, in which a larger share of our current work can be put forward.

Key persons: dr. ir. A. Pras,, prof. dr. ir. B.R. Haverkort, prof. dr. J.L. van den Berg, dr. ir. G.J. Heijenk, dr. ir. G. Karagiannis, dr. ir. P.T. de Boer, dr. A. Remke

Projects:

European funding:

o	UNIVERSELF (EU/FP7 IP)

o	COST TMA: Traffic Measurements and Analysis (COST)

o	GEODES: Global Energy Optimization for Distributed Embedded Systems (ITEA2)

National funding:

o	MATMaM: Mean-Field Approximation Techniques for Markov Models (NWO)

o	McStores: Model Checking Stochastic Systems using Rare Event Simulation (NWO)

o	Connect & Drive (HTAS)

o	MIDAS: Intrusion detection for SCADA (Ministry of Interior)

o	NGENMon: Next Generation Ethernet Network Monitoring

o	Sequal: Service Optimization and Quality (IOP GENCOM)

o	Rocks: Rigorous Dependability Analysis using Model Checking Techniques for Stochastic Systems (DFG/NWO)

o	E-Quality: Expertise Centre on Performance and Quality of Service in ICT (TNO-ICT)

o	SPITS: Strategic Platform for Intelligent Traffic Systems (HTT)

o	TENETS: Towards efficient simulation of non-Markovian queueing networks (NWO)

Publications DACS

Presentations DACS (CTIT visit 24 February 2012)

Movie: Car-to-Car Communication