## 7 Simulation Results Discussion: Analysis and Evaluation
### Evaluating RSU Availability and Overnight Connectivity
#### 7.2.2 Evaluating RSU Deployment in Rural Areas  
This section presents the outcomes of our simulation study focusing on RSU deployment in a rural setting, exemplified by the Peak District. The simulation explores the impact of RSU density on communication patterns within two different range scenarios--300 m, representing limited coverage, and 900 m, for extended coverage. The RSU deployment strategy commences with nothing and progressively increases the number of units, reflecting a realistic expansion towards 15 RSUs. Figures 16-18 show an analysis of vehicular communication efficacy by RSU density and range (300-900 m). These figures offer insights into how different types of vehicular communications perform in scenarios where the overnight connectivity factor varies at 30%, 50%, and 70%, respectively. The analysis delineates three principal communication categories--Online Available, Reputable, and Offline Reputable. The RSU densities are varied to simulate different deployment stages:  
* 0 RSUs: Represents an absence of RSU presence. * 1 RSU: Indicates a very low RSU density, with minimal coverage. * 3 RSUs: Depicts a low RSU density, offering limited communication capabilities. * 5 RSUs: Corresponds to a medium RSU density, reflecting an improving infrastructure. * 7 RSUs: Demonstrates a high RSU density, nearing effective coverage. * 15 RSUs: Signifies a very high RSU density, with a robust communication network. Figure 16: Analysis of Vehicular Communication Efficacy under 30% Overnight Connectivity Across Various RSU Densities, with Comparisons at 300 m Range (**Left**) and 900 m Range (**Right**). Figure 15: Time-Based Analysis of Communications Metrics for RSU 1 with 0% Overnight Connectivity. Figures 16-18 (left) show that, for the 300 m range, RSU density has a small impact on online communications, while the number of reputable communications generally increases with increasing RSUs. At the 900 m range (right graphs), both online and reputable communications experience a slight enhancement at lower RSU densities with diminishing gains as density increases. The line for ORC is fairly close to RC in all the graphs, meaning that our scheme is the primary contributor to the availability of reputation in the rural scenario. In Figure 18 (right), we can see ORC decreasing a bit, suggesting a unimodal curve, where a very high RSU density allows for increasingly more reputation to be available online, diminishing the need for our scheme. Note that, in an urban scenario, the density of RSUs may be orders of magnitude higher, allowing the ONRC to overtake the ORC--which would imply that our scheme has less benefit in such an environment. However, as long as ORC is larger than zero, the impact is positive (and if zero, the impact is nil). Overall, RSU impact is more significant at lower densities and diminishes with greater range and density. Our analysis indicates that deploying even a single RSU can significantly enhance communication patterns in rural areas. As RSU density increases, the efficiency of our Pre-Signature scheme improves, particularly within the RSU range. This improvement is evidenced by the increase in reputable communications, both online and offline. However, the most notable enhancement is observed in the online reputable communications, highlighting the benefits of RSU proximity. Notably, even in the absence of RSU presence ('None'), the graph denotes a substantial count of ORC. This phenomenon accentuates the Pre-Signature scheme's strength in fostering trust and reliability in vehicular communications devoid of centralized infrastructure support. The scheme's resilience is further corroborated by the consistent level of ORC observed across all RSU densities, which is critical for the autonomous management of Reputation Values. These findings articulate the Pre-Signature scheme's critical role in enhancing vehicular network resilience, particularly under the stringent different cases of overnight connectivity.