Tobias Farrell

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Moving objects databases (MODs) have been proposed for managing trajectory data, an important kind of information for pervasive applications. To save storage capacity, a MOD generally stores simplified trajectories only. A simplified trajectory approximates the actual trajectory of the mobile object according to a certain accuracy bound.
In location-based services, continuous queries are often employed to monitor the locations of mobile objects that are determined by sensing devices like GPS receivers. Due to limited battery resources, it is important for these objects to acquire and report location data only if necessary. We study how these energy- consuming operations can be reduced with(More)
Continuous queries are often employed to monitor the locations of mobile objects (MOs), which are determined by sensing devices like GPS receivers. In this paper, we tackle two challenges in processing continuous range queries (CRQs): coping with data uncertainty inherently associated with location data, and reducing the energy consumption of(More)
Many location-based systems rely on fine-grained tracking of mobile objects that determine their own locations with sensing devices like GPS receivers. For these objects, energy is a very valuable and limited resource. A distance-based reporting protocol can be employed to reduce the energy they consume by sending position updates. However, the energy(More)
The management of positions of mobile objects is an essential prerequisite for many context-aware systems such as advanced traffic management systems or personal assistance systems. In this paper, we present two approaches for the scalable tracking of mobile object trajectories and the efficient processing of continuous spatial range queries, respectively.(More)
The IEEE 802.11g physical layer is based on coded orthogonal frequency division multiplexing (COFDM) using the industry standard [133 171] binary convolutional code. In the presence of Bluetooth interference this code struggles to provide good packet error rate (PER) performance. In this paper Turbo coding is considered as an alternative to convolutional(More)
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