# OPMSS: Optimal Producer Mobility Support Solution for Named Data Networking
## 5 Performance Evaluations
### Simulation Evaluation
The results shown in Figures 7b  
Figure 6: (**a**) Inter- and intra-domain handoff latencies (**b**) Average hop count vs. speed in the grid scenario. Figure 7: (**a**) Average hop count vs. speed in the Abilene scenario, (**b**) Signaling overhead vs. speed in the Abilene scenario. and 8a reveal that OPMSS has nearly equal or less handoff signaling overhead than the Kite solution, with about 4% signaling overhead compared to the Kite upload and pull pattern. The OPMSS results can be considered good, even though there is no significant improvement against the Kite solution. The average delay refers to the time it takes for a packet transmitted from the mobile producer to reach the consumer, which is measured across the number of consecutive hops. The average packet delay describes the significant effect of path stretching and the handoff latency of the proposed OPMSS and the Kite solution. In the Kite solution, the handoff delay is accumulated between the distances that the producer moves to an anchor or RS point. However, the mobile producer moves in a random direction; even if the consumer and producer are nearby, the interest packet must pass through the RS, thus causing the path to stretch. In the proposed OPMSS, by broadcasting the \(MI\) update message, the consumer interest packet can reach the mobile producer via a single hop. Figure 8b shows the overall average packet delay in OPMSS compared to the Kite solution. The vertical \(y\)-axis of the graph represents average packet delay in milliseconds, and the horizontal \(x\)-axis represents the speed of the mobile consumer measured in seconds. By general observation, the OPMSS has 30% fewer average packet delays for Scenario I and 25% fewer average packet delays for Scenario II compared to the Kite solution. This indicates that OPMSS reduces the delay between half and three-quarters of the average packet delay and reduces the handoff latency compared to the Kite solution. These results prove the effectiveness of OPMSS in solving the path-stretching problem and providing data path optimization. Interest packet loss is one of the major concerns in solving producer mobility problems, especially when the movement frequency and speed is high. Figure 9 shows the performance of OPMSS in terms of controlling interest packet loss compared to the Kite solution. The OPMSS regulates and stabilizes the network by broadcasting \(MI\) packets to update the intermediate routers to reduce the number of lost interest packets. The overall results indicate that OPMSS regulates and minimizes the level of Interest packet loss from 15-40% compared to the Kite solution across the two scenarios. This result is observed when the speed of the mobile producer increases from 40 m/s to 100 m/s, which means that OPMSS performed better than the Kite solution. Figure 8: (**a**) Signaling overhead vs. speed in the grid scenario, (**b**) Average packet delay vs. speed. The two scenarios are compared based on equal data received for OPMSS and the Kite solution. Figure 9 shows the average amount of interest packets and data sent per scenario; OPMSS has minimal interest packets sent for an equal amount of data compared to the Kite solution. Specifically, the grid scenario shows that about 1500 interest packets were required to be sent for 1000 data packets, while more than 2500 interest packets were sent in the Kite solution. Therefore, controlling the loss of interest packets will improve the packet delivery level, reduce the signaling cost, and provide better packet throughput and bandwidth consumption. Throughput is the average number of packets received per unit simulation time, and a higher value of throughput indicates better performance in terms of producer mobility. Hence, the packet throughputs of OPMSS and the Kite solution are measured to determine the level of successful packet delivery after the handoff. Figure 10a shows that, from an earlier time point in the simulation, that is, between 20 and 50 s, the Kite solution has a higher throughput.