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Environmental monitoring is one of the driving applications in the domain of sensor networks. The lifetime of such systems is envisioned to exceed several years. To achieve this longevity in unattended operation it is crucial to minimize energy consumption of the battery-powered sensor nodes. This paper proposes Dozer, a data gathering protocol meeting the(More)
Topology control in ad-hoc networks tries to lower node energy consumption by reducing transmission power and by confining interference, collisions and consequently retransmissions. Commonly low interference is claimed to be a consequence to sparseness of the resulting topology. In this paper we disprove this implication. In contrast to most of the related(More)
Among the foremost goals of topology control in wireless ad-hoc networks is interference reduction. This paper presents a receiver-centric interference model featuring two main advantages over previous work. First, it reflects the fact that interference occurs at the intended receiver of a message. Second, the presented interference measure is robust with(More)
The continuous miniaturization process of computing devices featuring wireless technologies influences our everyday life. Besides well-established communication paradigms such as GSM or WLAN which are based on a fixed network infrastructure, unattended and self-organizing networks are envisioned. These so-called wireless ad hoc and sensor networks open a(More)
Among the most critical issues of wireless ad hoc and sensor networks are energy consumption in general and interfer-ence in particular. The reduction of interference is consequently considered one of the foremost goals of topology control. Almost all of the related work however considers this issue implicitly: Low interference is often claimed to be a(More)
While several important problems in the field of sensor networks have already been tackled, there is still a wide range of challenging, open problems that merit further attention. We present five theoretical problems that we believe to be essential to understanding sensor networks. The goal of this work is both to summarize the current state of research(More)
The infrastructure for mobile distributed tasks is often formed by cellular networks. One of the major issues in such networks is interference. In this paper we tackle interference reduction by suitable assignment of transmission power levels to base stations. This task is formalized introducing the Minimum Membership Set Cover combinatorial optimization(More)
Wireless ad hoc and sensor networks need to deal with unstable links. In practice the link quality between neighboring nodes fluctuates significantly over time. In this paper we evaluate the impact of topology control on routing performance. We propose a dynamic version of the XTC topology control algorithm. This simple and strictly local protocol removes(More)
— The inherent trade-off between energy-efficiency and rapidity of event dissemination is characteristic for wireless sensor networks. Scarcity of energy renders it necessary for nodes to spend a large portion of their lifetime in an energy-efficient sleep mode during which they do neither receive nor send messages. On the other hand, the longer nodes stay(More)