## 3 Results and Discussions
### MaxJitter
In highway scenarios, where vehicles are typically positioned in straight lines with wider transmission ranges and fewer intersections, the risk of collision is inherently lower. In such conditions, introducing larger jitter values leads to unnecessary delays between packet transmissions without significantly improving collision mitigation. Consequently, the PDR decreases with increasing MaxJitter, as the added delay between packet transmissions outweighs the need to prevent collisions. This results in lower packet delivery efficiency at higher MaxJitter values, similar to the drop in throughput seen in these scenarios. The comparative performance of AODV and GPSR in both environments also underscores the importance of selecting an appropriate MaxJitter value based on network topology. In cities where collisions are a more prominent concern, higher MaxJitter values are beneficial for both throughput and PDR, as they help reduce packet losses due to simultaneous transmissions. Conversely, on highways, where collision is less of a concern, smaller MaxJitter values are preferable as they minimize transmission delays, leading to better overall performance. Thus, the observed PDR trends reinforce the idea that MaxJitter should be carefully tuned according to environmental conditions, with higher values more suitable for collision-prone urban settings and lower values for more straightforward, less congested highway scenarios. Figure 5 presents the delay behavior of AODV and GPSR in city and highway environments, plotted against varying MaxJitter values. AODV shows an increase in delay with rising MaxJitter on highways, whereas its delay decreases in city environments with higher MaxJitter. Conversely, GPSR exhibits an increased delay in city environments as MaxJitter increases, but this delay decreases in highway environments with larger MaxJitter values. This behavior can be attributed to the effect of MaxJitter on packet transmission intervals. Increasing MaxJitter introduces additional random delays between consecutive packets, increasing the probability of a back-off period [24]. This back-off helps reduce collisions,  
Figure 4: PDR comparison between VANET scenarios and MaxJitter. which explains the performance improvement seen in GPSR in city environments and AODV in highway settings. For AODV in city environments, where vehicle density is high, and transmission ranges overlap frequently, higher MaxJitter reduces the likelihood of packet collisions. Collisions typically result in packet retransmissions, which contribute to increased delays. By introducing greater spacing between packet transmissions, a higher MaxJitter helps mitigate these collisions, leading to fewer retransmissions and, therefore, a reduction in overall delay. The delay reduction observed for AODV in city scenarios with higher MaxJitter values confirms that this protocol benefits from a collision-mitigation mechanism when operating in densely populated, dynamic environments. On highways, however, the network topology differs, with vehicles typically spaced farther apart and collisions being less frequent. In this environment, the increased transmission intervals caused by a higher MaxJitter introduce unnecessary delays without providing significant benefits in collision avoidance. This explains the proportional increase in AODV delay on highways as MaxJitter rises. The protocol's reliance on route discovery packets adds to this delay, as higher MaxJitter also increases the time required for these control packets to reach their destination. For GPSR, the delay in city environments increases with MaxJitter due to the protocol's reliance on geographic information rather than route discovery mechanisms. In city settings, where packet collisions are more frequent, a higher MaxJitter increases the back-off time, leading to longer delays in packet transmission. This is because GPSR benefits less from randomized intervals between packets, as its transmission paths are more direct and require continuous updates.