Project 5 Examples

Example 1

Suppose you wanted to simulate the following network of 3 nodes. The on/off patterns of the nodes are as follows:

• Node 1
  • time 0 - node turns on
  • time 10 - node turns off
• Node 2
  • time 0 - node turns on
  • time 5 - node turns off
  • time 10 - node turns on
• Node 3
  • time 5 - node turns on

The initial message queues are as follows:

• Node 1
  • message addressed to node 2 - send time 3
  • message addressed to node 3 - send time 3
• Node 2
  • message addressed to node 3 - send time 3
• Node 3
  • message addressed to node 2 - send time 3

The simulation would proceed as follows:

Time 0:

• Node 1 turns on
• Node 2 turns on

• Node 1 starts transfer of message to node 2
• Node 2 cannot start transfer because the only message in its queue is destined for node 3, which is offline

Time 1 - 2: transfer in progress, no new event

Time 3:

• Node 1 completes transfer of message to node 2
• Node 1 cannot start a new transfer because the only message in its queue is destined for node 3, which is offline

Time 4: no new event

Time 5:

• Node 3 turns on
• Node 2 turns off

• Node 1 starts transfer of message to node 3
• Node 3 cannot start transfer because the only message in its queue is destined for node 2, which is offline

Time 6-7: transfer in progress, no new event

Time 8:

• Node 1 completes transfer of message to node 3
• Node 1 has completed all message transfers

Time 9: no new event

Time 10:

• Node 1 turns off
• Node 2 turns on

• Node 2 starts transfer of message to node 3
• Node 3 starts transfer of message to node 2

Time 11 - 12: transfers in progress, no new event

Time 13:

• Node 2 completes transfer of message to node 3
• Node 3 completes transfer of message to node 2

Example 2

Suppose you wanted to simulate the following network of 3 nodes. The on/off patterns of the nodes are as follows:

• Node 1
  • time 0 - node turns on
  • time 10 - node turns off
  • time 15 - node turns on
• Node 2
  • time 0 - node turns on
  • time 5 - node turns off
  • time 10 - node turns on
• Node 3
  • time 5 - node turns on
  • time 15 - node turns off

The initial message queues are as follows:

• Node 1
  • message addressed to node 2 - send time 6
  • message addressed to node 3 - send time 3
• Node 2
  • message addressed to node 3 - send time 3
• Node 3
  • message addressed to node 2 - send time 3

The simulation would proceed as follows:

Time 0:

• Node 1 turns on
• Node 2 turns on

• Node 1 starts transfer of message to node 2
• Node 2 cannot start transfer because the only message in its queue is destined for node 3, which is offline

Time 1 - 4: transfer in progress, no new event

Time 5:

• Node 3 turns on
• Node 2 turns off

• Node 1 transfer to node 2 interrupted
• Node 1 starts transfer of message to node 3
• Node 3 cannot start transfer because the only message in its queue is destined for node 2, which is offline

Time 6-7: transfer in progress, no new event

Time 8:

• Node 1 completes transfer of message to node 3
• Node 1 cannot start transfer because the only message in its queue is destined for node 2, which is offline

Time 9: no new event

Time 10:

• Node 1 turns off
• Node 2 turns on

• Node 2 starts transfer of message to node 3
• Node 3 starts transfer of message to node 2

Time 11 - 12: transfers in progress, no new event

Time 13:

• Node 2 completes transfer of message to node 3
• Node 3 completes transfer of message to node 2

Time 14: no new event

Time 15:

• Node 1 turns on
• Node 3 turns off

• Node 1 starts transfer of message to node 2

Time 16 - 20: transfer in progress, no new event

Time 21:

• Node 1 completes transfer of message to node 2