# Weight-Based PA-GPSR Protocol Improvement Method in VANET
## 6 Conclusions  
VANET is of great significance in practice, as it can improve traffic safety, optimize traffic efficiency, and support intelligent transportation systems. Efficient and reliable routing protocols play a crucial role in VANET, providing stable and reliable data transmission by selecting the best relay vehicle and adapting to dynamic topology changes. To improve the local optimality and routing loops of PA-GPSR in urban sparse networks, W-PAGPSR is proposed. Given the geographic location routing protocols in the VANET network, this paper applies weight-based improvement strategies to routing establishment and routing maintenance to improve the routing stability of data packet transmission. The main contributions of this paper can be summarized as follows:  
1. Firstly, in the routing establishment stage, the distance, reliable node density, cumulative communication duration, and node movement direction are used to establish a greedy forwarding weight strategy; secondly, in the routing maintenance stage, the packet delivery angle and reliable node density are used to establish a perimeter forwarding weight strategy, and the weight parameters are then calculated using the CRITIC method; and, finally, a highly reliable link is established as a communication route. 2. Based on the NS-3 and SUMO simulation platforms, the two strategies are simulated and compared to other geographic location routing protocols in urban scenarios with different traffic densities and CBR connections. Compared to GPSR, MM-GPSR, and PA-GPSR in 30-110 nodes and 5-20 CBR connections, the packet loss rate of the protocol is reduced by an average of 24.47%, 25.02%, respectively; and 14.12%, the average end-to-end delay is reduced by an average of 48.34%, 79.96%, and 21.45%, respectively; and the network throughput is increased by an average of 47.68%, 58.39%, and 20.33% respectively. 3. According to the time complexity analysis, compared to GPSR, MM-GPSR, and PA-GPSR, W-PAGPSR does not add to the time complexity. The simulation results show that W-PAGPSR has a lower average end-to-end delay, a higher packet transmission rate, and overall network throughput. The results indicate that W-PAGPSR has the potential to improve the routing performance of urban VANET under different network densities. The current research is based on the simulation of the urban Manhattan grid, though there are certain differences from the actual urban network. Future research can adjust and optimize the parameters of the proposed algorithm, consider applying the algorithm to dense urban and highway scenarios to more realistically simulate the urban traffic environment, and explore the application of the algorithm in other networks (such as underwater ad hoc and UAV ad hoc networks). The current research assumes that node position information is perfect, but, in practice, GPS positioning has errors. Future research can consider introducing GPS error models to more accurately simulate node position information, as well as investigate the impact of GPS errors on algorithm performance and how to respond to such error situations. [PERSON] and [PERSON], contributed to the improvement of research methods; [PERSON] performed the modeling, calculation, and manuscript writing. [PERSON] assisted in data analysis, code debugging, and experimental data processing. [PERSON] edited the manuscript and modified the English grammar in the manuscript. [PERSON] and [PERSON] put forward useful suggestions and participated in the preparation of the manuscript. [PERSON] reviewed the manuscript and oversaw the project. The results are discussed and analyzed by all authors. All authors have read and agreed to the published version of the manuscript. This work was supported by National Natural Science Foundation of China (No. 72071153), as well as by Natural Science Basic Research Plan in Shaanxi Province of China (Program No. S2023-JC-YB-0513). Not applicable. The authors declare no conflict of interest.