Memory and communication efficient algorithm for decentralized counting of nodes in networks

PLoS One. 2021 Nov 22;16(11):e0259736. doi: 10.1371/journal.pone.0259736. eCollection 2021.

Abstract

Node counting on a graph is subject to some fundamental theoretical limitations, yet a solution to such problems is necessary in many applications of graph theory to real-world systems, such as collective robotics and distributed sensor networks. Thus several stochastic and naïve deterministic algorithms for distributed graph size estimation or calculation have been provided. Here we present a deterministic and distributed algorithm that allows every node of a connected graph to determine the graph size in finite time, if an upper bound on the graph size is provided. The algorithm consists in the iterative aggregation of information in local hubs which then broadcast it throughout the whole graph. The proposed node-counting algorithm is on average more efficient in terms of node memory and communication cost than its previous deterministic counterpart for node counting, and appears comparable or more efficient in terms of average-case time complexity. As well as node counting, the algorithm is more broadly applicable to problems such as summation over graphs, quorum sensing, and spontaneous hierarchy creation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms*
  • Memory
  • Quorum Sensing

Grants and funding

All the authors (A. S., J. A. R. M. and A. R.) acknowledge funding from the Office for Naval Research Global under grant no. 12547352 (the “Swarm Awareness” project; url:https://www.onr.navy.mil/Science-Technology/ONR-Global.aspx). A. R.also acknowledges support from the Belgian F.R.S.-FNRS, of which he is a Charge de Recherches. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.