A State Machine Sensor Network for Ephemeral Stream Detection

Abstract

Sensor networks based on the de facto standard Berkeley TinyOS platform are changing the way environmental information is collected in the field. One such network has been designed, deployed, and tested in order to determine where ephemeral streams (small, temporary channels of runoff) form during precipitation events. This small, proof-of-concept test network was designed around a generic nondeterministic finite state machine component, which was built to be re-used in later environmental sensor network applications. A simplistic broadcast mechanism was devised to provide collective sampling interval changes to adapt to environmental conditions. In this paper, the design and testing of the ephemeral stream detection network are discussed, along with design features that can be re-used in later applications. Improvements for a later deployment of a larger, operational ephemeral stream detection network are also described.

The authors would like to thank Pinky Tejwani, Don Lipscomb, and Dr. Tom Williams (Clemson University) for their assistance in network preparation and deployment. Thanks also to Dr. Howard Blair (Syracuse University) for his review of the finite state machine transition expressions.

Keywords:

• Environmental Sensor Network
• Finite State Machine
• Broadcast Network
• Sensor-Focused Design
• Mote
• TinyOS

Notes

The authors would like to thank Pinky Tejwani, Don Lipscomb, and Dr. Tom Williams (Clemson University) for their assistance in network preparation and deployment. Thanks also to Dr. Howard Blair (Syracuse University) for his review of the finite state machine transition expressions.

¹Calculated with n − 1 degrees of freedom.

²With only minor code changes, it would be possible to make α dynamic.