On distributed computation of information potentials

Abstract

A common task of mobile wireless ad-hoc networks is to distributedly extract information from a monitored process. We define process information as a measure that is sensed and computed by each mobile node in a network. For complex tasks, such as searching in a network and coordination of robotic swarms, we are typically interested in the spatial distribution of the process information. Spatial distributions can be thought of as information potentials that recursively consider the richness of information around each node. This paper describes a localized mechanism for determining the information potential on each node based on local process information and the potential of neighboring nodes. The mechanism allows us to distributedly generate a spectrum of possible information potentials between the extreme points of a local view and distributed averaging. In this work, we describe the mechanism, prove its exponential convergence, and characterize the spectrum of information potentials. Moreover, we use the mechanism to generate information potentials that are unimodal, i.e., feature a single extremum. Unimodality is a very valuable property for chemotactic search, which can be used in diverse application tasks such as directed search of information and rendezvous of mobile agents.

Walk globally, act locally

“…Loukas et al [9] [8] propose a localized mechanism for determining the information potential on each node based on local process and the potential of neighboring nodes. They also analyze the convergence of information potentials for static networks, and provide a mechanism for reshaping the information landscape.…”

“…Different from previous studies, we focus on utilizing the user mobility while requiring little network overhead. Our work is inspired by information potential scheme proposed by Loukas et al [8] [9]. Information potential Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page.…”

Think globally, act locally

“…Nevertheless, unimodal potentials are particularly useful in specific tasks, such as robot coordination. Our previous paper demonstrated how unimodal potentials solve the problem of multi-agent rendezvous [16]. …”

“…Even though their paper concerns the processing of images, it is a special case of our method as they consider only the case of xi = di and do not identify the property of unimodality. A preliminary version of this work was presented in [16]. The previous study focused on the analysis of the unimodality property and on its application to the multi-agent rendezvous problem.…”

“…The mobile entities can be packets, people, robots, cars, etc. In a preliminary version of this study [16], we showed through simulations how our algorithm is used for rendezvous coordination, where a swarm of mobile entities identify the nodes with the largest potentials, and the rest of the swarm moves towards their closest high-potential node in real time. Below, we describe two applications that can benefit from our work on information potentials.…”