Attempts to generalize the Internet's point-to-point communication abstraction to provide services like multicast, anycast, and mobility have faced challenging technical problems and deployment barriers. To ease the deployment of such services, this paper proposes an overlay-based Internet

Habitat and environmental monitoring is a driving application for wireless sensor networks. We present an analysis of data from a second generation sensor networks deployed during the summer and autumn of 2003. During a 4 month deployment, these networks, consisting of 150 devices, produced unique datasets for both systems and biological analysis. This paper focuses on nodal and network performance, with an emphasis on lifetime, reliability, and the the static and dynamic aspects of single and multi-hop networks. We compare the results collected to expectations set during the design phase: we were able to accurately predict lifetime of the single-hop network, but we underestimated the impact of multihop traffic overhearing and the nuances of power source selection. While initial packet loss data was commensurate with lab experiments, over the duration of the deployment, reliability of the backend infrastructure and the transit network had a dominant impact on overall network performance. Finally, we evaluate the physical design of the sensor node based on deployment experience and a post mortem analysis. The results shed light on a number of design issues from network deployment, through selection of power sources to optimizations of routing decisions.

14,000 authors.

CarTel is a mobile sensor computing system designed to collect, process, deliver, and visualize data from sensors located on mobile units such as automobiles. A CarTel node is a mobile embedded computer coupled to a set of sensors. Each node gathers and processes sensor readings locally before

The spectre of climate change that is unfolding now is undeniably a cumulative impact of anthropogenic interference in the climate system over the last two centuries. The science is clear and the policy community is being increasingly convinced and galvanised into action to address this emergent challenge in light of the associated economic and human dimensions. The impacts of climate change ranging from sea level rise, melting ice caps and glaciers, severe weather events, drought, flooding, warming, subtle changes in ecosystems – will impinge on every aspect of society and economic life. The costs of inaction will more than outweigh the costs of action. There is only a narrow window of opportunity to redress the situation. The Intergovernmental Panel on Climate Change (IPCC) in its Fourth Assessment Report has

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This document (ns Notes and Documentation) provides reference documentation for ns. Although we begin with a simple simulation script, resources like Marc Greis's tutorial web pages (at http://titan.cs.uni-bonn.de/~greis/ns/ ns.html) or the slides from one of the ns tutorials are problably better places to begin for the ns novice.

The impressive penetration of 802.11-based wireless networks in many metropolitan areas around the world offers, for the first time, the opportunity of a “grassroots ” wireless Internet service provided by users who “open up ” their 802.11 (Wi-Fi) access points in a controlled manner to mobile

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A common problem facing mobile computing is disconnected operation, or computing in the absence of a network. Hoarding eases disconnected operation by selecting a subset of the user's files for local storage. We describe a hoarding system that can operate without user intervention