## 4 Results and Discussions
### Mean Packet Delay Comparison  
In this section, an examination of the mean packet delay versus the system load is presented. It should be noted that, for these purposes, the measurement of the packet delay starts from the time when a given packet arrives into the classifier shown in Figure 1 and then lasts until the transmission of the packet is fully completed. However, it should be noted that the packet processing time in the classifier itself is assumed to be ignored. Given these conditions, Figures 5 and 6 present comparisons between the proposed algorithm and the baseline algorithm of the mean packet delay for RT and NRT packets, respectively.  
As can be seen from both Figures 5 and 6, the proposed algorithm provided better performance than the baseline algorithm in terms of the mean packet delays for both RT and NRT packets. It can also be seen that for both the proposed algorithm and the baseline algorithm, the system performance in terms of the RT packet delay was better than the performance in terms of the NRT packet delay.  
Figure 4: Comparison between the proposed algorithm and the baseline algorithm for the system throughput versus the system load.  
This explains why the proper setting of \(\eta\) can effectively protect RT packets from competition by NRT packets.  
Furthermore, Figure 5 also shows that there was no monotonic increase in the mean RT packet delay for either the proposed algorithm or the baseline algorithm. Rather, for high system loads, the maximum of the mean RT packet delay was always equal to 0.1 s because the RT packet would be dropped if it violated the threshold of \(\delta_{\text{RT}}=20\) rounds (i.e., 0.1 s).  
Additionally, Figure 6 further shows that the proposed algorithm yielded a significant overall improvement over the baseline algorithm in terms of the mean NRT packet delay, particularly when the system load was high. This is because under the proposed algorithm, when the mechanism of multiple CCs being aggregated for transmission is enabled, the loads of the RT users can be distributed over the two CCs for parallel transmissions, which in turn provides the NRT users with more opportunities to transmit their packets via the 1 st CC.  
Finally, as shown in Table 1, we used values of the parameter \(\eta=1/4\), \(1/2\) and \(3/4\), respectively, in order to determine the effects that these different values would have on the mean RT packet delay and mean NRT packet delay when using the proposed algorithm with the system load set at  
Figure 5: Comparison between the proposed algorithm and the baseline algorithm for the mean RT packet delay versus the system load.  
Figure 6: Comparison between the proposed algorithm and the baseline algorithm for the mean NRT packet delay versus the system load.  
respective values of 0.3, 0.5, 0.7 and 0.9. The effects of the different values on the mean RT packet delay were observed first. In that regard, the results did not actually differ significantly when different \(\eta\) values were used under the various system loads noted above. This lack of variability in the results presumably resulted from the fact that the number of available RBs that could be reserved for RT packets remained nearly the same under a given system load value even with different values of \(\eta\). As for the mean NRT packet delay, the differences in the observed results were increasingly significant as the system loads were increased, with the best, middle, and worst performances for any given system load being at \(\eta=3/4\), \(1/2\) and \(1/4\), respectively. This order from best to worst performance was due to the fact that by adjusting \(\eta=1/4\) to \(\eta=3/4\), 50% more resources could be reserved by the system for NRT packets.