A loosely-stabilizing leader election protocol with polylogarithmic convergence time in the population protocol model is presented in this paper. In the population protocol model, which is a common abstract model of mobile sensor networks, it is known to be impossible to design a self-stabilizing leader election protocol. Thus, in our prior work, we introduced the concept of loose-stabilization, which is weaker than self-stabilization but has similar advantage as self-stabilization in practice. Following this work, several loosely-stabilizing leader election protocols are presented. The loosely-stabilizing leader election guarantees that, starting from an arbitrary configuration, the system reaches a safe configuration with a single leader within a relatively short time, and keeps the unique leader for an sufficiently long time thereafter. The convergence times of all the existing loosely-stabilizing protocols, i.e., the expected time to reach a safe configuration, are polynomial in n where n is the number of nodes (while the holding times to keep the unique leader are exponential in n). In this paper, a loosely-stabilizing protocol with polylogarithmic convergence time is presented. Its holding time is not exponential, but arbitrarily large polynomial in n.
@InProceedings{sudo_et_al:LIPIcs.OPODIS.2018.30, author = {Sudo, Yuichi and Ooshita, Fukuhito and Kakugawa, Hirotsugu and Masuzawa, Toshimitsu and Datta, Ajoy K. and Larmore, Lawrence L.}, title = {{Loosely-Stabilizing Leader Election with Polylogarithmic Convergence Time}}, booktitle = {22nd International Conference on Principles of Distributed Systems (OPODIS 2018)}, pages = {30:1--30:16}, series = {Leibniz International Proceedings in Informatics (LIPIcs)}, ISBN = {978-3-95977-098-9}, ISSN = {1868-8969}, year = {2019}, volume = {125}, editor = {Cao, Jiannong and Ellen, Faith and Rodrigues, Luis and Ferreira, Bernardo}, publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl, Germany}, URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.OPODIS.2018.30}, URN = {urn:nbn:de:0030-drops-100901}, doi = {10.4230/LIPIcs.OPODIS.2018.30}, annote = {Keywords: Loose-stabilization, Population protocols, and Leader election} }