A capable, high-level scheduling concept for application-specific wireless sensor networks

The primary objective of wireless sensor networks is the monitoring of a system or area by measuring different kinds of sensor data. Dependent on the application scenario, a specific measurement scheduling scheme is preferred. Based on this scheduling, an optimisation of the available energy resources in each sensor node and accordingly in the whole network topology is possible. At the same time, an application-specific synchronisation of the measurement points ensures a maximum quality for the merged sensor information. One essential requirement for any kind of scheduling scheme is a synchronised time base in the entire network topology. In order to define capable measurement schemes for any kind of available sensor node hardware, lightweight synchronisation concepts are necessary. In this paper we present a scheduling concept for distributed, resource-limited sensor networks based on a capable time synchronisation approach. The concepts operate on the application layer and enable application-specific, energy-efficient sensor measurement schemes. For proof of concept, the approaches were implemented on a sensor node hardware platform. Several test scenarios evaluate the feasibility and clarify an excellent usability in wireless sensor network environments.