The Freeze Tag Problem How to Wake Up a Swarm of Robots

The Freeze-Tag Problem: How to Wake Up a Swarm of Robots⁄ Esther M. Arkiny Michael A. Benderz S¶andor P. Feketex Joseph S. B. Mitchelly Martin Skutella

http://www.ams.sunysb.edu/~jsbm/papers/freezetag-algorithmica.pdf