Watch the detailed propagation of a single multicast message through an eight-node fragment of the network.

Notice how our intelligent MAC control - based on a Response Schedule in the packet header - minimizes channel contention and maximizes bandwidth utilization. 

• By scheduling the downstream channel access sequence, each node can avoid propagation collisions

• Does not incur bandwidth costs of fat contention windows and random backoff  periods.

• Simple annealing mechanisms shake out "colliding-cousin" nodes

• Annealing is automatically promoted up the hierarchy as needed.

• All transmissions are verified by handshake (ACK)

• Hub to hub propagation saves time by using the (overheard) forwarded message as a free ACK. 

This approach is a Big Fun Development innovation, designed especially for the SWARM requirements. It follows certain ideas of Fullmer and Garcia-Luna-Aceves (FAMA), though it tries to reach these through radically different means.

This addresses the problems of contention during the fan-out of a multicast message. There are other contention problems to be addressed as we move forward.