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— Instrumenting the physical world through large networks of wireless sensor nodes, particularly for applications like marine biology, requires that these nodes be very small, light, un-tethered and unobtrusive, imposing substantial restrictions on the amount of additional hardware that can be placed at each node. Practical considerations such as the small(More)
greatly extend our ability to monitor and control the physical world. The availability of microsensors and low-power wireless communications enables the deployment of densely distributed sensor/actuator networks for a wide range of biological and environmental monitoring applications, from marine to soil and atmospheric contexts. Networked sensors can(More)
A noise map facilitates monitoring of environmental noise pollution in urban areas. It can raise citizen awareness of noise pollution levels, and aid in the development of mitigation strategies to cope with the adverse effects. However, state-of-the-art techniques for rendering noise maps in urban areas are expensive and rarely updated (months or even(More)
Experience with wired networks has provides guidance about what level of detail is appropriate for simulation-based protocol studies. Wireless simulations raise many new questions about approriate levels of detail in simulation models for radio propagation and energy consumption. This paper describes the trade-offs associated with adding detail to(More)
Spatial localization or the ability to locate nodes is an important building block for next generation pervasive computing systems, but a formidable challenge, particularly, for very small hardware and energy constrained devices , for noisy, unpredictable environments and for very large ad hoc deployed and networked systems. In this paper, we describe,(More)
Embedded networked sensors promise to revolutionize the way we interact with our physical environment and require scalable, ad hoc deployable and energy-efficient node localization/positioning.This paper describes the motivation, design, implementation, and experimental evaluation (on sharply resource-constrained devices) of a <i>self-configuring</i>(More)
We present a novel scheme for node localization in a delay-tolerant sensor network (DTN). In a DTN, sensor devices are often organized in network clusters that may be mutually disconnected. Some mobile robots may be used to collect data from the network clusters. The key idea in our scheme is to use this robot to perform location estimation for the sensor(More)
It is an undeniable fact that people want information. Unfortunately, even in today's highly automated society, a lot of the information we desire is still manually collected. An example is fuel prices where websites providing fuel price information either send their workers out to manually collect the prices or depend on volunteers manually relaying the(More)
Ensuring that every sensor node has the same code version is challenging in dynamic, unreliable multi-hop sensor networks. When nodes have different code versions, the network may not behave as intended , wasting time and energy. We propose and evaluate DHV, an efficient code consistency maintenance protocol to ensure that every node in a network will(More)