# A Method for the Rapid Propagation of Emergency Event Notifications in a Long Vehicle Convoy
## 5 Results
### Outliers  
Occasionally, there will be a node with a reception delay that is approximately 0.05 s to 0.10 s higher than that of its nearby peers. This occurs when an SM is transmitted but the skipped node does not receive it while a further node does. The further node then retransmits the SM, but againn the skipped node does not receive it while the original transmitter does, causing the original transmitter to recognize it as having propagated rearward. In assuming the skipped node does not receive the SM from any further rearward nodes' transmissions, it must now wait until a node hears its VS, which indicates that it has not heard the SM. At this point, the nearby nodes will begin transmitting the SM again, allowing it to be received. Because the VS is transmitted every 0.10 s, this situation will incur, on average, 0.05 s of extra delay. A more common outlier is node 0 transmitting SMs much more than its followers (see Figure 12). When any node transmits more than 5 SMs, it is usually a consequence of hearing a VS message and scheduling uncancelable delayed SM transmissions. This is especially prevalent with node 0 because of simulation timing consistency. Node 0 always sends the SM on the exact 5 s division (20.000 s, 25.000 s, 30.000 s, etc.). If another node schedules its VS before the minimum delay afforded by the retransmission system, then node 0 will schedule several uncancelable SM retransmissions (see Section 3.4.3). Other nodes do not exhibit this behavior as consistently because the time at which they first receive an SM is largely random, as opposed to node 0's perfect consistency. This issue is not as prevalent with far spacing due to the lower reception reliability of VS messages, meaning only one node may trigger it semi-consistently instead of two or three. There is no mechanism in place to recognize the minimum amount of time needed before a confirmation of reception may be received (see Future Work, Section 7). While this issue may not be realistic, it was left in because it illustrates the main shortcoming of the system: the use of uncancelable SM retransmissions. Figure 3: Standard spacing, doubled delays. (**Left**): SM reception delay for every vehicle. (**Right**): Number of SM transmissions for every vehicle. Figure 2: Standard spacing, standard delays. Number of SM transmissions per event for every vehicle given the SM transmission time. Figure 4: Standard spacing, doubled delays. Number of SM transmissions per event for every vehicle, given the SM transmission time. Figure 5: Standard spacing, doubled delay randomness. (**Left**): SM reception delay for every vehicle. (**Right**): Number of SM transmissions for every vehicle. Figure 6: Standard spacing, doubled delay randomness. Number of SM transmissions per event for every vehicle given the SM transmission time. Figure 7: Close spacing, standard delays. (**Left**): SM reception delay for every vehicle. (**Right**): Number of SM transmissions for every vehicle. Figure 8: Close spacing, standard delays. Number of SM transmissions per event for every vehicle given the SM transmission time. Figure 9: Close spacing, doubled delays. (**Left**): SM reception delay for every vehicle. (**Right**): Number of SM transmissions for every vehicle. Figure 11: Close spacing, doubled delay randomness. **(Left)**: SM reception delay for every vehicle. (Right): Number of SM transmissions for every vehicle. Figure 10: Close spacing, doubled delays. Number of SM transmissions per event for every vehicle given the SM transmission time. Figure 2:0 Close spacing, doubled delay randomness. Number of SM transmissions per event for every vehicle given the SM transmission time. Figure 2:1 Far spacing, standard delays. (**Left**): SM reception delay for every vehicle. (**Right**): Number of SM transmissions for every vehicle. Figure 2:2 Far spacing, standard delays. Number of SM transmissions per event for every vehicle, given the SM transmission time. Figure 2:3 Far spacing, doubled delays. (**Left**): SM reception delay for every vehicle.