Dirk Timmermann

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This paper focuses on reducing the power consumption of wireless microsensor networks. Therefore, a communication protocol named LEACH (Low-Energy Adaptive Clustering Hierarchy) is modified. We extend LEACH’s stochastic clusterhead selection algorithm by a deterministic component. Depending on the network configuration an increase of network lifetime by(More)
Localization in wireless sensor networks gets more and more important, because many applications need to locate the source of incoming measurements as precise as possible. Weighted centroid localization (WCL) provides a fast and easy algorithm to locate devices in wireless sensor networks. The algorithm is derived from a centroid determination which(More)
For future application scenarios of resource constrained and low cost smart cooperating objects, miscellaneous technologies for wireless connectivity are existing or upcoming in the near future. But further cross domain middleware and dedicated communication protocols to provide syntactic and semantic interoperability and not only technical interoperability(More)
The usage of the Service Oriented Architecture (SOA) paradigm currently changes the view on many enterprise applications. SOA allows the creation of modular and clearly defined software architectures that ensure a high grade of interoperability and reusability. As even small, resource-constraint networked devices get more and more powerful it is common(More)
Localization of sensor nodes is one of the key issues in Wireless Sensor Networks. It is a precondition for a variety of scenarios as well as geographic clustering and routing. A simple approach for coarse grained localization is Weighted Centroid Localization (WCL), which, unfortunately, comes with some drawbacks. Therefore, we present the “Adaptive WCL”(More)
− Software development for wireless sensor networks requires novel programming paradigms and technologies. This article describes the concept of a new service oriented software architecture for mobile sensor networks. With this architecture, a flexible, scalable programming of applications based on an adaptive middleware is possible. The middleware supports(More)
This article describes the new concept of service oriented software architecture for mobile sensor networks. By the use of this architecture, a flexible, scalable programming of applications based on an adaptive middleware is possible. The middleware supports mechanisms for cooperative data mining, self-organization, networking, and energy optimization to(More)
Autonomous localization of nodes in wireless sensor networks is essential to minimize the complex self organization task consequently enhancing the overall network lifetime. Recently, precise indoor localization is impeded by multi path propagation of signals due to reflections at walls or objects. In this paper we partly overcome some of these problems by(More)
Leakage power dissipation is one of the most critical factors for the overall current dissipation and future designs. However, design techniques for the reduction of leakage power should not decrease design performance. Therefore, an enhanced Dual Vth/Dual Tox CMOS ap-proach is presented which applies mixed gates consisting of different transistor types.(More)