# Cross-Technology Interference-Aware Rate Adaptation in Time-Triggered Wireless Local Area Networks
## 5 Results and Analysis
### Performance of CTINet based on the \(\alpha\).
#### 5.2.3. Latency  
To compare performance in terms of latency, Figure 7 presents latency boxplots for each algorithm at WLAN SNRs of 8, 18, and 30 dB. The measured latency pertains to data packets generated by all WLAN STAs in the network during a 10 s simulation. In our experiment, lost packets are considered retransmitted, causing delays to accumulate until the packet is successfully transmitted without loss; these appear as outliers in the boxplots. In the time-triggered network considered, if an STA fails to complete packet transmission within its assigned time duration, the packet is sent in the next cycle, resulting in additional delays equivalent to \(N\times T_{\text{slot}}\), where \(N\) is the number of STAs. Since time-triggered networks prioritize not exceeding specific delay thresholds, the proportion of delays exceeding 1 ms is also examined in Table 7.  
At 8 dB, the median latency values are [0.354, 0.662, 0.662, 0.5] ms, indicating low delays below 1 ms, but some packets experience delays accumulating up to over 9 ms. Notably, M-CARA, through appropriate MCS selection, has no packets with delays exceeding  
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**WLAN SNR** & **M-CARA** & **M-Base** & **P-CARA** & **P-Base** \\ \hline
8 dB & 7.857\% & 8.789\% & 10.912\% & 11.191\% \\
13 dB & 1.040\% & 1.354\% & 5.465\% & 5.556\% \\
18 dB & 0.212\% & 0.267\% & 3.597\% & 3.920\% \\
25 dB & 0.051\% & 0.175\% & 2.077\% & 2.398\% \\
30 dB & 0.023\% & 0.166\% & 0.111\% & 0.254\% \\ \hline \hline \end{tabular}
\end{table}
Table 7: Percentage of packets exceeding 1 ms latency for each algorithm.  
Figure 6: Comparison of goodput under different WLAN SNRs with CTI.  
Figure 7: Comparison of latency under different WLAN SNRs with CTI.  
7 ms. According to Table 7, the proportion of packets with delays over 1 ms for M-CARA is 7.857%, the lowest among the algorithms, confirming its superior latency performance.  
At 18 dB, where the channel condition is relatively good, the total packet transmissions are higher, and the overall PER is lower, resulting in median latency values of 0.146 ms across all algorithms. However, the P-Base algorithm exhibits packets with delays around 6 ms, and a higher proportion of delays exceeding 1 ms at 3.92%, indicating poorer performance.  
At 30 dB, the median latency values are [0.106, 0.106, 0.094, 0.094] ms, with packet-based algorithms showing slightly lower latency. This is because, in this condition, packet error-based algorithms transmitted most packets at the data rate corresponding to MCS index 8, whereas measurement-based algorithms used MCS index 7. The proportion of packets with delays exceeding 1 ms is lowest for M-CARA at 0.023%. This indicates that only the M-CARA approach meets the latency requirements of 99.9% compliance in networks where all transmitted packets must satisfy stringent latency constraints (e.g., wireless time-sensitive networking [7]). M-CARA uniquely achieved a compliance rate of 99.977%. M-Base shows a higher proportion of outliers exceeding 1 ms compared to P-CARA, demonstrating that the CARA framework significantly improves latency performance.