# Enhancing Route Guidance with Integrated V2X Communication and Transportation Systems: A Review
## 6 Proposed Communication Network Architecture for RGS
Furthermore, this decentralized approach enhances the system's resilience by avoiding the need for single points of failure, ensuring that the network remains functional even if individual vehicles go offline. Moreover, such a decentralized approach not only enhances the resilience but also reduces costs and improves data privacy, as sensitive information is processed locally within each vehicle. Despite its advantages, there are limitations to this system. Specifically, vehicles have a limited view of the entire traffic network, relying only on data from nearby vehicles, which may not provide a  
Figure 3: Distributed V2V network. Figure 2: Integrated architecture of network communication and transportation systems for route guidance system. comprehensive picture of broader traffic conditions. Moreover, the constant exchange of data can create communication overhead, especially in dense traffic. The need for each vehicle to perform complex computations also increases costs and energy use. Without centralized coordination, vehicles may compute conflicting routes, leading to traffic inefficiencies. Additionally, localized errors can propagate through the network, resulting in incorrect routing decisions for multiple vehicles. Figure 4 illustrates the flow chart for a Distributed V2V Network. 2. Decentralized V2I Network: This decentralized model operates without a central processing unit; instead of relying solely on vehicles for computation, road side units (RSUs) take on the role of determining optimal paths. Vehicles periodically send status updates such as location, speed, direction, and observed traffic conditions to nearby RSUs, which also gather data from local infrastructure sensors, including traffic lights and cameras, to create a comprehensive view of the traffic environment. The RSUs aggregate and analyze these data to identify traffic patterns and potential obstacles, then compute the optimal routes for vehicles in their area, continuously updating these routes based on real-time information. These optimal routes are communicated back to the vehicles, enabling them to adjust their paths accordingly. As vehicles move through the network, they continue to update the RSUs, which refine their route recommendations. The model offers several key advantages. RSUs collect data from multiple vehicles and infrastructure sensors, providing a comprehensive view of traffic conditions within their respective regions (see Figure 5). Figure 4: Scenario 1: Distributed V2V network flow chart. Figure 5: Decentralized V2I network. This reduces the computational load on vehicles, conserving energy. Additionally, RSUs enhance traffic management by utilizing a broader set of data for more precise route guidance. The system's scalability is another advantage; adding more RSUs allows the network to adapt to various sizes and complexities while potentially reducing congestion by managing most data processing and communication. However, the model does have its drawbacks. It relies heavily on the availability and reliability of RSUs and sensors; if these are insufficient or fail, the system's effectiveness is diminished. RSUs' limited range could lead to less accurate guidance in areas with sparse coverage, particularly in rural regions. High-traffic areas might experience data overload, resulting in slower processing and delayed optimal route updates. Additionally, the system is vulnerable to network disruptions, which can impact the timeliness of route information. Finally, the high initial costs of deploying RSUs equipped with advanced computing processors and sensors may pose a barrier to widespread implementation. Figure 6 illustrates the flow chart for the Decentralized V2I Network scenario. 3. Hybrid V2V-Centralized Network: In this hybrid model, vehicles exchange information directly with one another through V2V communication, while also sending data to a centralized entity, like a Traffic Management Center (TMC).