# Improved Road Segment-Based Geographical Routing Protocol for Vehicular Ad-hoc Networks
## 3 Improved Road Segment-Based Geographical Routing Protocol
### Routing Process, Flowchart and Algorithms
On the other hand, the TASR protocol steeply increased the delay because this protocol initiated the decision based on distance, direction, and vehicle density. although the more vehicle nodes centric congestion on roads results in stronger signal strength for vehicular communication. However, the scenario might lead to longer delay in communication due to the channel congestion for accessing the wireless channel during vehicular communication. Data throughput was analyzed in the presence of different vehicle velocities, as shown in Figure 11. The data throughput of the proposed ISR protocol consistently decreased due to its routing metric calculations and greater amount of nodes in network. However, the existing protocols had lesser data throughput than the proposed protocol. This result also indicated that the data throughput decreased when the network had a greater data load with different vehicle velocities in the network. The TASR protocol steeply decreased throughput because this protocol initiated the decision based on distance, direction, and signal strength. Although more vehicle nodes centric congestion on roads sometimes

Figure 10: Comparison of end-to-end delay with increasing vehicle speed. Figure 6.0 Comparison of packet delivery ratio with increasing vehicle speed. show stronger signal strengths for communication. However, longer delay and lesser throughput are some other network challenges due to the different vehicle velocities on roads. The proposed protocol addressed this issue by selecting the maximum traffic density road segments, and it had better data throughput results. One hop disconnection, as shown in Figure 12, was analyzed in the presence of different vehicle velocities. It can be clearly observed that the one hop link disconnection of ISR was nominal, as compared to other two existing protocols. It was also observed that with different vehicle node speeds, the one hop disconnection increased. However, the one hop disconnection of the proposed ISR protocol consistently increased due to its routing metric calculations and greater amount of nodes in the network. However, the ISR protocol has shown lesser one-hop disconnections than the other two existing protocols. This result also indicated that one hop disconnection increased when the network had a greater data load in different vehicles speeds. The TASR protocol had a steeply increased one hop disconnection because this protocol initiated the decision based on distance, direction, and signal strength. Although the more vehicle nodes centric congested roads have strong signal strengths for communication, however, in this network environment longer delay and more one-hop disconnections are other issues considering different vehicle speeds. The proposed protocol addressed this issue by selecting the maximum traffic density road segments, and it had a lower percentage of one hop disconnections. Figure 6.1 Comparison of data throughput with increasing vehicle speed. Figure 6.2 Comparison of one-hop link disconnection with increasing vehicle speed. It is noteworthy, as shown in Table 4, that the ISR protocol outperformed by 0.68% in terms of the PDR, 5.6% in delay, 16% in throughput, and 18% in one hop disconnections in the presence of different numbers of nodes. On the other hand, in the consideration of higher vehicle speed, the ISR protocol outperformed by 71% in terms of PDR, 5.8 % terms of delay, 38% in data throughput, and 24% in one hop disconnections, as shown in Tables 4 and 5. We agree that performance of the proposed framework was very close to the considered literature techniques. However, it can be highlighted that the overall performance benefits of the proposed framework are significant and visible for larger network sizes or with higher numbers of nodes and increasing vehicles speeds. Therefore, we believe that these performance improvements will be considerable in realistic traffic environments.