Efficient scheduling for sensor networks

Abstract — Sensor networks opened new opportunities to monitor the environment. In order to retrieve the desired data, sensors are usually organized into a hierarchy and synchronize when transmitting the data towards the base station. Many scheduling schemes have been proposed with the goal of allowing sensors to sleep as much as possible and ultimately save energy. In this paper, we propose two new scheduling algorithms that assign predefined slots to each sensor. These algorithms are distributed, need very little global information and do not need knowledge about the location of sensors or the network topology. As others, we also assume that loose clock synchronization is available. The experimental results confirm our expectations. They show a significant reduction in the average time awake per node of at least three times compared to more traditional routin

Abstract Node Mobility in Unstructured P2P Networks

P2P networks research is mainly focused on techniques for efficiently finding files to download from the network. Problems like churn and robustness have been thoroughly analyzed. Mobility in P2P networks is still an open topic. In this paper, we address the problem of deciding what to do in the case of node mobility. A node which knows that it is going to move in another part of the network wants to take the best decision what to do with its documents in the interest of the overall network performance. This problem is particularly challenging in the special case of a node which is the primary source for its documents, because of update costs and privacy issues. In this paper we identify possible decisions and circumstances in which a particular decision becomes the “best decision ” for the special case mentioned above. We also provide some experimental cases and results that compare the options with regard to different performance metrics.

ABSTRACT Efficient Handling of Sensor Failures ∗

Sensors provide unprecedented access to a wealth of information from the physical environment in real-time. However, they suffer from a variety of resource limitations, most importantly power consumption and communication bandwidth. Additionally, environmental conditions can contribute to sensor failures, disrupting the flow of query results. In this paper, we propose new techniques to deal with sensor failures based on the principles of partition and single path redundancy. Our experimental results confirm the efficiency of our techniques with respect to different performance metrics in general, and, in particular, high quality of data

LSynD: Localized Synopsis Diffusion

Wireless sensor networks represent an extremely fastgrowing emerging technology, but still suffer from several limitations. The state of the art in sensor networks focuses on optimizing the existing protocols to address the two main challenges affecting the sensors: failures and energy consumption. Our contributions in this paper include: analyzing most relevant protocols that attempt to address these two problems, presenting methods to achieve local reconstruction for a sensor network that uses multi-path routing and proposing a new protocol, called LSynD, an extension of the Tributaries and Deltas approach. LSynD achieves a faster, more localized and energy efficient reconstruction than its predecessor protocols by creating multiple adaptive multi-path routing regions