NEST Project

Customizable Real-Time Coordination Services for Large-scale Network Embedded Systems

The goal of this project is to develop application independent services to coordinate scalable network embedded systems. In order to provide scalability and address the uncertainty in the environment, we are developing a stochastic model for network embedded software technology (NEST) systems. As a basis for defining algorithms, we use an operational model of actors with both probabilities on transitions and stochastic variables representing durations of transitions. Associating a duration with discrete events will facilitate the implementation of hybrid systems which require continuous variables and mode specific functions operating over given durations.

A repository of core coordination algorithms is being developed. The approach is to study probabilistic algorithms and guarantees. Some problems being studied are algorithms for approximate consensus (such as approximate synchrony), recovery, and hierarchical coordination. These algorithms will be implemented in middleware so that they can be used composed with applications to dynamically customize the behavior of embedded systems. A meta-architectural model provides the formal basis for middleware. This project is sponsored by U.S. DARPA Information Technology Office NEST program.