Lots of mobile nodes in Digimesh network

For a project I need to make a system where a lot (100-500 nodes) will be moving through a 200x200meter facility. There will be one ‘main’ node which sends out a heartbeat signal to each of the nodes.

Because the nodes are moving around, I would like to know how long it takes to discover a new route. Also I would like to know if there is a way to register new nodes on the network. Because not all nodes will be active all the time. Only the active nodes need to be sent a heartbeat signal.