Terminating population protocols via some minimal global knowledge assumptions

Othon Michail, Paul G. Spirakis
2015 Journal of Parallel and Distributed Computing  
We extend the population protocol model with a cover-time service that informs a walking state every time it covers the whole network. This represents a known upper bound on the cover time of a random walk. The cover-time service allows us to introduce termination into population protocols, a capability that is crucial for any distributed system. By reduction to an oracle-model we arrive at a very satisfactory lower bound on the computational power of the model: we prove that it is at least as
more » ... trong as a Turing Machine of space log n with input commutativity, where n is the number of nodes in the network. We also give a log n-space, but nondeterministic this time, upper bound. Finally, we prove interesting similarities of this model to linear bounded automata.
doi:10.1016/j.jpdc.2015.02.005 fatcat:aiqc6rdeebdefebexmlt3bmsme