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Technological progress in integrated, low-power, CMOS communication devices and sensors makes a rich design space of networked sensors viable. They can be deeply embedded in the physical world and spread throughout our environment like smart dust. The missing elements are an overall system architecture and a methodology for systematic advance. To this end,(More)
The dynamic and lossy nature of wireless communication poses major challenges to reliable, self-organizing multihop networks. These non-ideal characteristics are more problematic with the primitive, low-power radio transceivers found in sensor networks, and raise new issues that routing protocols must address. Link connectivity statistics should be captured(More)
We study the problem of media access control in the novel regime of sensor networks, where unique application behavior and tight constraints in computation power, storage, energy resources, and radio technology have shaped this design space to be very different from that found in traditional mobile computing regime. Media access control in sensor networks(More)
Real-time wireless link reliability estimation is a fundamental building block for self-organization of multihop sensor networks. Observed connectivity at low-power is more chaotic and unpredictable than in wireless LANs, and available resources are severely constrained. We seek estimators that react quickly to large changes, yet are stable, have a small(More)
The constraints of sensor networks, an emerging area of network research, require new approaches in system design. We study the evolution of abstractions and techniques in TinyOS, a popular sensor network operating system. Examining CVS repositories of several research institutions that use TinyOS, we trace three areas of development: single-hop networking,(More)
A new class of networked systems is emerging that involve very large numbers of small, low-power, wireless devices. We present findings from a large scale empirical study involving over 150 such nodes operated at various transmission power settings. The instrumen-tation in our experiments permits us to separate effects at the various layers of the protocol(More)
This paper presents a study of how empirical ranging characteristics affect multihop localization in wireless sensor networks. We use an objective metric to evaluate a well-established parametric model of ranging called <i>Noisy Disk:</i> if the model accurately predicts the results of a real-world deployment, it sufficiently captures ranging(More)
Miniaturization, integration, and customization make it possible to combine sensing, processing, and communications to produce a smart, network-enabled wireless sensor. Here's how it works. New technology is changing the nature of sensors and the way they interface with data acquisition and control systems. Researchers at U.C. Berkeley have developed an(More)
The ability to incorporate low-power, wireless communication into embedded devices gives rise to a new genre of embedded software that is distributed, dynamic, and adaptive. This paper describes the network-centric approach to designing software for highly constrained devices embodied in TinyOS. It develops a tiny Active Message communication model and(More)