Download or read book Allongement de la durée de vie des réseaux sans fils de capteurs par l'optimisation des protocoles de routage et d'accès au canal written by Abdelmalik Bachir and published by . This book was released on 2007 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extending the lifetime of a sensor network requires optimizations at two complementary scopes: local and global. At the scope front, each node should optimize its own energy consumption to maximize its life span. At the global scope, nodes should cooperate to optimize the global usage of energy resources. ln this thesis, we have addressed both problems through the optimization of communication protocols. Our contribution mainly concerns MAC and Routing protocols. At the MAC layer, we have tackled the problem of reduction two major sources of energy waste: collisions and overhearing. We have differentiated two types of collisions: those caused by hidden nodes and those caused by visible nodes, and two forms of overhearing: that resulting from the reception of irrelevant messages and that resulting from the reception of useless signais. For ail of these identified sources of energy waste, we have proposed solutions that improve the networks lifetime. At the routing layer, we have proposed a protocol capable of combining two lifetime extension techniques: reducing protocols' overhead and load balancing among nodes to avoid their premature death Our contribution in this thesis not only provides more energy-efficient MAC and routing protocols that are optimized independently from each other, but also a cross layer design in which MAC and routing protocols are jointly optimized.