,
Naoki Kitamura
,
Ryota Eguchi
,
Yuichi Sudo
,
Junya Nakamura
,
Yonghwan Kim
,
Yoshiaki Katayama
,
Toshimitsu Masuzawa
,
Quentin Bramas
,
Sébastien Tixeuil
Creative Commons Attribution 4.0 International license
In this paper, we address the problem of uniformly deploying mobile robots in complete bipartite graphs. Specifically, when n robots are positioned arbitrarily at distinct nodes in a complete bipartite graph K_{n,n}, which consists of two n-node sets V_L and V_R, the uniform deployment problem requires the robots to achieve one of the following configurations: (a) each node in V_L is occupied by exactly one robot, with no robots in V_R, or (b) each node in V_R is occupied by exactly one robot, with no robots in V_L. In either configuration, the distance between any two robots is 2, ensuring that the robots are uniformly deployed. In this paper, we explore the relationship between the visibility range of robots and the solvability of the uniform deployment problem. First, we characterize solvable and unsolvable initial configurations under the assumption that robots have an infinite visibility range. Next, we demonstrate that visibility range 1 (meaning robots can only observe nodes at a distance of 1 and the robots positioned on them) is insufficient, proving the impossibility of solving the problem under this constraint. Conversely, we show that visibility range Θ(log n) is sufficient by presenting an algorithm that solves the uniform deployment problem in O(1) rounds, starting from any solvable initial configuration. Finally, we briefly introduce an example showing that robots with a constant visibility range (which is 3 in this example) cannot solve the problem in a native way.
@InProceedings{shibata_et_al:LIPIcs.OPODIS.2025.34,
author = {Shibata, Masahiro and Kitamura, Naoki and Eguchi, Ryota and Sudo, Yuichi and Nakamura, Junya and Kim, Yonghwan and Katayama, Yoshiaki and Masuzawa, Toshimitsu and Bramas, Quentin and Tixeuil, S\'{e}bastien},
title = {{Uniform Deployment of Mobile Robots in Complete Bipartite Graphs}},
booktitle = {29th International Conference on Principles of Distributed Systems (OPODIS 2025)},
pages = {34:1--34:17},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-409-3},
ISSN = {1868-8969},
year = {2026},
volume = {361},
editor = {Arusoaie, Andrei and Onica, Emanuel and Spear, Michael and Tucci-Piergiovanni, Sara},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.OPODIS.2025.34},
URN = {urn:nbn:de:0030-drops-252075},
doi = {10.4230/LIPIcs.OPODIS.2025.34},
annote = {Keywords: mobile robots, uniform deployment, complete bipartite graphs}
}