Cross-Layer Organization ofWireless Sensor Networks UsingSense-Sleep Trees

Becauseoftheir pervasiveness andautonomy in operation, wireless sensor networks (WSNs) areanideal candidate inoffering sustained monitoring functions at reasonable cost overawidearea. However, devising an energy-efficient, cost-effective andreliable communication strategy forWSNsrequires tight collaboration ofallofthe sublayers, whichintroduces newtechnical challenges in theareas ofdata, network andpowermanagement. This paperproposes a cross-layer organizational approach, called Sense-Sleep Trees (SS-Trees), that aimstoharmonizethevarious engineering issues andprovides amethod ofincreasing monitoring coverage andoperational lifetime ofmeshWSNsengaged inwide-area surveillance applications. A computational approach based oninteger linear programming (ILP) issuggested todetermine the optimal SS-Tree structures forachieving thedesign goals.