Sorting multisets in anonymous rings

An anonymous ring network is a ring where all processors (vertices) are totally indistinguishable except for their input value. Initially, to each vertex of the ring is associated a value from a totally ordered set; thus, forming a multiset. In this paper we consider the problem of sorting such a distributed multiset and we investigate its relationship with the election problem. We focus on the computability and the complexity of these problems, as well as on their interrelationship, providing strong characterizations, showing lower bounds, and establishing efficient upper bounds.