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Despite availability of multiple orthogonal communication channels on common sensor network platforms, such as MicaZ motes, and despite multiple simulation-supported designs of multi-channel MAC protocols, most existing sensor networks use only one channel for communication, which is a source of bandwidth inefficiency. In this work, we design, implement,(More)
Most currently deployed sensor networks use the same channel to communicate information among nodes. This is a source of great inefficiency as it poorly utilizes the available wireless spectrum. This paper takes advantage of radio capabilities of MicaZ motes that can communicate on multiple frequencies as specified in the 802.15.4 standard. We consider the(More)
1. Background The use of control-based methods for resource management in real-time computing and communication systems has gained a substantial interest recently. Applications areas include performance control of web-servers, dynamic resource management in embedded systems, traffic control in communication networks, transaction management in database(More)
The paper presents some preliminary results on dynamic scheduling of model predictive controllers (MPC's). In model predictive control, the control signal is obtained by optimization of a cost function in each sample, and the MPC task may experience very large variations in execution time. Unique to this application, the cost function also offers an(More)
The increased complexity of performance-sensitive software systems leads to increased use of automated adaptation policies in lieu of manual performance tuning. Composition of adaptive components into larger adaptive systems , however, presents challenges that arise from potential incompatibilities among the respective adaptation policies. Consequently,(More)
This tutorial describes experiences with applying a control theoretical approach to achieving performance guarantees in Web servers, with emphasis on delay control. A model for the server is formulated and translated into a control problem formulation. Limitations of the control theoretic approach are identified that arise due to system non-linearities and(More)
In vision-based feedback control systems, the time to obtain sensor information is usually non-negligible, and these systems thereby possess fundamentally different timing behavior compared to standard real-time control applications. For many image-based tracking algorithms, however, it is possible to trade-off the computational time versus the accuracy of(More)