Embedded Sensor Network Control:
The DESAL Project

Funded by Microsoft Research
Principal Investigator Anish Arora anish@cis.ohio-state.edu
Other Team Members Jason Hallstrom hallstro@cis.ohio-state.edu
William Leal leal@cis.ohio-state.edu
Nigamanth Sridhar nsridhar@cis.ohio-state.edu

Project Description

A smart sensor is a computationally powerful, feature-rich device that detects and processes environmental stimuli. An embedded smart sensor network (ESSN) is a collection of these high-powered sensors that collaborate to control processes in the system in which they are embedded. These networks play a central role in a number of application domains, including manufacturing industries, the health care industry, and the military, to name a few. As ESSNs are increasingly central to business-critical and safety-critical applications, the uptime of these networks should be maximized.

This project is intended to develop frameworks for evolving ESSNs and for continuous testing that take into account the critical nature of such networks. The evolution framework will make it possible to change an ESSN when sensors have to be replaced or upgraded, when new processing algorithms are developed, and when the network’s mission changes. With a framework to provide for continuous, safe testing, data to support confidence in the ESSN can be gathered, and problems in dependability can be identified. Microsoft .NET is an appropriate environment for the project, providing a rich and productive environment for framework development as well as for subsequent ESSN developers and managers. The frameworks we propose to develop can be deployed on an ESSN that is running Windows Embedded XP, along with the specific components necessary for the ESSN. Hence .NET on Windows XP provides a natural development environment targeted for .NET on Windows Embedded XP.

Dynamic Embedded Sensing and Actuation Language (DESAL)

 

We are defining a language in which to develop control modules for embedded sensor and actuator networks. The language is a variant of UNITY: a program written in DESAL is a collection of guarded commands that read from the sensors and control the actuators. Key features of the language include:

  1. The system is soft state. State that is not refreshed sufficiently often disappears. This means that applications build on DESAL are inherently self-stabilizing.

  2. Sensors and actuators are anonymous. They are accessed by attributes that give their characteristics. If a sensor or actuator fails, another satisfying the required attributes will be substituted, if available. In this case, the application will not notice that a failure occurred.

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