Cross-layer organization of wireless sensor networks using sense-sleep trees

Because of their pervasiveness and autonomy in operation, wireless sensor networks (WSNs) are an ideal candidate in offering sustained monitoring functions at reasonable cost over a wide area. However, devising an energy-efficient, cost-effective and reliable communication strategy for WSNs requires tight collaboration of all of the sublayers, which introduces new technical challenges in the areas of data, network and power management. This paper proposes a cross-layer organizational approach, called sense-sleep trees (SS-Trees), that aims to harmonize the various engineering issues and provides a method of increasing monitoring coverage and operational lifetime of mesh WSNs engaged in wide-area surveillance applications. A computational approach based on integer linear programming (ILP) is suggested to determine the optimal SS-Tree structures for achieving the design goals.