  The minimum spanning tree (MST) construction is a classical problem in
Distributed Computing for creating a globally minimized structure
distributedly. Self-stabilization is versatile technique for forward recovery
that permits to handle any kind of transient faults in a unified manner. The
loop-free property provides interesting safety assurance in dynamic networks
where edge-cost changes during operation of the protocol. We present a new
self-stabilizing MST protocol that improves on previous known ap- proaches in
several ways. First, it makes fewer system hypotheses as the size of the
network (or an upper bound on the size) need not be known to the participants.
Second, it is loop-free in the sense that it guarantees that a spanning tree
structure is always preserved while edge costs change dynamically and the
protocol adjusts to a new MST. Finally, time complexity matches the best known
results, while space complexity results show that this protocol is the most
efficient to date.
