# Multi-Connectivity-Based Adaptive Fractional Packet Duplication in Cellular Networks
## 5 Simulation Results
### SINR-Threshold-Based Packet Duplication  
The activation and deactivation of packet duplication requires control signaling, and if this is performed many times, a great deal of radio resources are used for the control signaling, which is against our goal of efficient utilization of RF resources. If the instantaneous SINR is to be considered to make decisions on PD, we observed that the activation-deactivation operation happens multiple times over a single data communication session. Thus, we average out the SINR over a certain sample size and then use the average SINR value for PD. This helps to reduce the number of switches and, hence, the signaling overhead. We show two sample sizes, 500 and 50, to average out the instantaneous SINR from both the BS. PD activation and deactivation for multiple delta threshold values for a average SINR sample size of 500 are shown in Figures 8 and 9. Similarly, the same is shown in Figures 10 and 11 for an average SINR sample size of 50, showing many more ON-OFF PD transitions. Regarding the difference in SINR values, the smaller the delta threshold, the less likely is the PD as the RF channel conditions for the two base stations are different. Furthermore, a higher delta threshold means more PD. The PD will not toggle more often with higher delta but will have more switching for a smaller delta threshold, clearly showing that even an average SINR has many fluctuations over time given the unpredictable RF conditions. Figure 12 shows, for the delta SINR on the \(x\)-axis, how much reduction in corrupt packets can be achieved with PD. We also show how much of the actual packet duplication is required to reach this number. For example, 35.38% packet duplication is required to have 5.45% corrupt packets in the overall communication. This amount of PD increases in order to achieve minimum corrupt packets. In contrast to the average SINR with a sample size of 500, we simulate the environment using an average SINR with a sample size of 50, and the chart is shown in Figure 13. The average SINR with a sample size of 50 has more fluctuations than the average SINR with a 500 sample size, and the PD switching happens many more times. Figure 14 shows the number of times that packet duplication was triggered for the average SINR with sample sizes of 500 and 50 for the two base stations. Figure 10: Packet Duplication with an average (50 sample size) SINR difference of \(<\)=10 dB. Figure 9: Packet Duplication with an average (500 sample size) SINR difference of \(<\)=20 dB. Our results above can be used to understand the wireless channel conditions in regard to the re-transmissions involved for the corrupt packets versus the packet duplication rate required to compensate for the corrupt or the lost packets. A service provider or an operator can then decide what action to take based on the available resources. We provided an approach to find the optimal PD rate given the reduction in the percentage of the corrupt packets. Figure 11: Packet Duplication with an average (50 sample size) SINR difference of \(<\)=20 dB. Figure 12: Difference in the average SINR-based (500 sample size) Packet Duplication. As shown in Table 1, for every SINR difference in dB, we have columns for 500 samples and 50 samples. Each of these values are the difference of the 10-times relative decrease in corrupt packets and the percentage increase in packet duplication. For example, from 5 to 10 dB for a 50 sample size, a 1.77% decrease in corrupt packets was observed for 14.48% of additional packet duplication. This gives us -3.22%, which is the difference of 14.48% and 17.70%. Similarly, we calculated values for all others to determine the pattern where this difference then becomes positive. Figure 14: Actual number of times that Packet Duplication is triggered. Figure 13: Difference in the average SINR-based (50 sample size) Packet Duplication.