In the '70s while I was still in school I imagined computers costing a few hundred dollars controlling amateur radios similarly priced to provide a message delivery service nationwide. I modeled this in operation between 173 locations. It worked. And it exhibited unexpected behavior that interests me to this day. site 
YOUTUBE hqnhNOlbc5s Published March 18, 2013.
The model remains an object of study as a self-contained complex system. The exact configuration of stations and the logic they use to communicate have been duplicated now in three implementations offering progressively improved means of study.
As we undertake renewed explorations based on this now historic model we will here note aspects that run through all implementations and improvements we have or will make in the most recent incarnation.