Stefan Rührup

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Beaconless georouting algorithms are fully reactive and work without prior knowledge of their neighbors. However, existing approaches can either not guarantee delivery or they require the exchange of complete neighborhood information. We describe two general methods for completely reactive face routing with guaranteed delivery. The Beaconless Forwarder(More)
Recently proposed beaconless georouting algorithms are fully reactive, with nodes forwarding packets without prior knowledge of their neighbors. However, existing approaches for recovery from local minima can either not guarantee delivery or they require the exchange of complete neighborhood information. We describe two general methods that enable(More)
Beaconless or contention-based geographic routing algorithms forward packets towards a geographical destination reactively without the knowledge of the neighborhood. Such algorithms allow greedy forwarding, where only the next hop neighbor responds after a timer-based contention using only 3 messages (RTS, CTS and DATA) per forwarding step. However,(More)
We have developed TakaTuka, a Java Virtual Machine optimized for tiny embedded devices such as wireless sensor motes. TakaTuka requires very little memory and processing power from the host device. This has been verified by successfully running TakaTuka on four different mote platforms. The focus of this paper is TakaTuka’s optimization of program memory(More)
Wireless sensor networks are formed by small sensor nodes communicating over wireless links without using a fixed network infrastructure. Sensor nodes have a limited transmission range, and their processing and storage capabilities as well as their energy resources are also limited. Routing protocols for wireless sensor networks have to ensure reliable(More)
Geographic routing algorithms use position information for making packet forwarding decisions. Unlike topological routing algorithms, they do not need to exchange and maintain routing information and work nearly stateless. This makes geographic routing attractive for wireless ad hoc and sensor networks. Most geographic routing algorithms use a greedy(More)
We consider the problem of routing a message in a mesh network with faulty nodes. The number and positions of faulty nodes is unknown. It is known that a flooding strategy like expanding ring search can route a message in the minimum number of steps h while it causes a traffic (i.e. the total number of messages) of O(h). For optimizing traffic a single-path(More)
This paper describes methodology, experiment configuration and final results from a set of measurements we executed in order to validate the interference model assumptions that are currently adopted when simulating OFDM-based wireless networks with NS-3, a widely used network simulation tool in academia. In order to do that we devised a measurement method(More)
We investigate distributed algorithms for mobile ad hoc networks for moving radio stations with adjustable transmission power in a worst case scenario. We consider two models to find a reasonable restriction on the worst-case mobility. In the pedestrian model we assume a maximum speed <i>v<sub>max</sub></i> of the radio stations, while in the vehicular(More)