On the Minimization of Communication in Networked Systems with a Central Station

Abstract

The problem of minimizing communication in a distributed networked system is considered in a discrete-event formalism where the system is modeled as a finite-state automaton. The system consists of a central station and a set of N local agents, each observing a set of local events. The central station needs to know exactly the state of the system, whereas local agents need to disambiguate certain pre-specified pairs of states for purposes of control or diagnosis. This requirement is achieved by communication, which occurs only between the central station and the local agents but not among the local agents. A communication policy is defined as a set of event occurrences to be communicated between the central station and the local agents. A communication policy is said to be minimal if any removal of communication of event occurrences will affect the correctness of the solution. Under an assumption on the absence of cycles (other than self-loops) in the system model, this paper presents an algorithm that computes a minimal communication policy in polynomial time in all parameters of the system. These results improve upon previous algorithms for solving minimum communication problems.