Title
Space-Optimal Counting in Population Protocols.
Abstract
In this paper, we study the fundamental problem of counting, which consists in computing the size of a system. We consider the distributed communication model of population protocols of finite state, anonymous and asynchronous mobile devices agents communicating in pairs according to a fairness condition. This work significantly improves the previous results known for counting in this model, in terms of exact space complexity. We present and prove correct the first space-optimal protocols solving the problem for two classical types of fairness, global and weak. Both protocols require no initialization of the counted agents. The protocol designed for global fairness, surprisingly, uses only one bit of memory two states per counted agent. The protocol, functioning under weak fairness, requires the necessary $$\\log P$$ bits P states, per counted agent to be able to count up to P agents. Interestingly, this protocol exploits the intriguing Gros sequence of natural numbers, which is also used in the solutions to the Chinese Rings and the Hanoi Towers puzzles.
Year
DOI
Venue
2015
10.1007/978-3-662-48653-5_42
DISC
Field
DocType
Volume
Dynamic network analysis,Asynchronous communication,Population,Natural number,Computer science,Mobile agent,Population protocol,Counting problem,Theoretical computer science,Initialization,Distributed computing
Conference
9363
ISSN
Citations 
PageRank 
0302-9743
7
0.52
References 
Authors
17
4
Name
Order
Citations
PageRank
Joffroy Beauquier144853.52
Janna Burman212313.55
Simon Clavière3131.63
Devan Sohier48013.40