Screenshots from SONIC Simulator

This is a sequence of snap-shots from an example operation of SONIC self-organizing protocol, with a set of 41 mTs that are initialized at the same time. Each of the mTs are capable of satellite communication, and the goal is organize them into a small number of networks.

Each mT has a its own communication range. The mT can only communicate with other mTs within this range. Unidirectional communication links results in some cases when the communication ranges of two mTs are different. The protocol handles these situations.

Each network has:

In this example, we restricted the mT-server to serve mT-clients which are upto two hops away from it.

Time is shown in Hours.Minutes. This example models a very low speed environment having low data rates. The time delays in network adaptation is completely parameterized by the duty cycle periods that are used.

Click on the images to see an enlarged view
Time 0.0: All mTs start
Time 0.20: 5 mT-servers have appeared; few mTs have still to find an appropriate mT-server
Time 0.28:Only one mT yet to find a mT-server. If an mT is unable to find an appropriate mT-server, it chooses to be a mT-server itself. This is what happened with the two mT-servers at the bottom.
Time 0.35:All mTs have joined some network. Small networks merge together to form bigger networks with a single mT-server. This helps in reducing aggregate satellite communication. One of the two mT-servers at the bottom has detected the other mT-server and has changed itself to a mT-client.
Time 0.46: At this instant, one of the centrally located servers has moved (to the top right corner) so that it is out of range from all its mT-relays and mT-clients. Note, the moved mT-server's communication range being indicated by the large circle around it.

This would cause all these other mTs to find another appropriate mT-server.

Time 0.56: All the mTs connected to the network of the moved mT-server drops out of the network, and starts hunting for another mT-server.
Time 1.11: Most of the disconnected mTs find new servers.
Time 1.18: All mTs now connected to some network. Note that the moved mT (at top right corner) is out of communication range of all other mTs, and therefore, is in its own single mT network.

Last updated on Jan 2000 
-- Suman