The MPI standard is often used in parallel applications for communication needs. Most of them are designed for homogeneous clusters but MPI implementations for grids have to take into account heterogeneity and long distance network links in order to maintain a high performance level. These two

To provide a long-distance communication device that would appeal to college students and recent graduates, the Rüüg team researched long-distance and face-to-face communication in more than 70 potential users. This research (consisting of surveys, observation, and directed storytelling) revealed

A class of low nonlinearity dispersion-shifted and dispersion-flattened fibers for broadband and long haul applications is presented. The refractive index profiles of these fibers assume a depressed-core multi-clad geometry in order to achieve effective-areas much larger than those in conventional optical fibers.

et amélioration des performances d’une implémentation MPI pour la grille

An ad hoc network is a collection of wireless computers (nodes), communicating among themselves over possibly multihop paths, without the help of any infrastructure such as base stations or access points. Although many previous ad hoc network routing protocols have been based in part on distance

An ad-hoc network is the cooperative engagement of a collection of (typically wireless) mobile nodes without the required intervention of any centralized access point or existing infrastructure. To provide optimal communication ability, a routing protocol for such a dynamic self-starting network

simple, light-weight algorithm that assigns synthetic coordinates to hosts such that the distance between the coordinates of two hosts accurately predicts the communication latency between the hosts.

We consider routing problems in ad hoc wireless networks modeled as unit graphs in which nodes are points in the plane and two nodes can communicate if the distance between them is less than some fixed unit. We describe the first distributed algorithms for routing that do not require duplication

in these networks. In this paper, we review localization techniques and evaluate the effectiveness of a very simple connectivity-metric method for localization in outdoor environments that makes use of the inherent radio-frequency (RF) communications capabilities of these devices. A fixed number of reference points

Wireless Sensor Networks have been proposed for a multitude of location-dependent applications. For such systems, the cost and limitations of hardware on sensing nodes prevent the use of range-based localization schemes that depend on absolute point-to-point distance estimates. Because coarse