We consider a communication system between a satellite and control station located on the ground. We assume there are two classes of messages that must be transmitted: (i) messages that contain data related to scientific experiences and (ii) messages that contain data related to satellite control and monitoring. For the first class, a computer program F1 is in charge of writing and formatting the message. Then if the channel C1 is free, the message is sent. For the second class, two cases can occur. The first case is the transmission of regular messages, while the second case is the transmission of alarm messages. The regular messages are written and formatted by a computer program called F2. They are sent through channel C1 when it is free. The alarm messages are formatted by a program called F3 and are transmitted through a special channel, called Ca.
Question 1: Develop a DEVS atomic model for each of F1, F2 F3, C1, and Ca (feel free to add other models if needed). For each atomic model, first describe its input & output ports, and then specify its initialization function, external transition function, internal transition functions, and output function in pseudo code. Note: only the pseudo code that shows the main logic is needed. You code does not need to show every detail.
Question 2: Couple the above models into a DEVS coupled model satelliteSys to model the above system. Describe models’ couplings and draw a diagram to show your coupled model. Also write a paragraph to briefly explain how the whole system works.
Question 3: Develop a petri net model for the communication system described above.
Question 4: Comparing the DEVS model and the petri net model, describe one advantage for the DEVS model and one advantage for the petri net model.
