## 7 Experimental Results
From the graph, it can be seen that doubling the length of the message results in a loss in terms of send width equal to 6 percentage points. The mean data throughput observed during performance evaluation trials is illustrated in Figures 9 and 10. These graphics contrast the efficiency of various TLSv1.2 encryption protocols across MQTT iterations 3.x and 5.0, utilizing IEEE 802.3 ab network links. The data highlight performance discrepancies between the protocol versions, with newer features in MQTT 5.0 sometimes introducing additional overhead that can reduce bandwidth efficiency compared to MQTT 3.x. Actual performance also varies depending on how MQTT protocols are implemented by clients and brokers, with some implementations optimizing bandwidth use more effectively than others. For instance, while AES128-GCM-SHA256 in MQTT version 3.11 shows subpar performance, MQTT 5.0 generally exhibits improved performance metrics. Figures 11 and 12 illustrate trends in IEEE 802.11n/ac connections, while Figures 13 and 14 depict average bandwidth usage over 3 GPP-4G links, comparing TLSv1.2 cipher suites and MQTT versions 3.x and 5.0. Figure 10: Performance Analysis of Data Throughput: MQTT V5.0 over IEEE 802.3 ab Connections with TLSv1.2 Encryption Protocols across Quality of Service Tiers. Figure 9: Performance Analysis of Data Throughput: MQTT V3.11 over IEEE 802.3 ab Connections with TLSv1.2 Encryption Protocols across Quality of Service Tiers. Figure 11: Performance Analysis of Data Throughput: MQTT V3.11 over IEEE 802.11n/ac Connections with TLSv1.2 Encryption Protocols across Quality of Service Tiers. Figure 12: Performance Analysis of Data Throughput: MQTT V5.0 over IEEE 802.11n/ac Connections with TLSv1.2 Encryption Protocols across Quality of Service Tiers. Figure 13: Performance Analysis of Data Throughput: MQTT V3.11 over 3 GPP-4G Connections with TLSv1.2 Encryption Protocols across Quality of Service Tiers. Notably, certain cipher suites, particularly those ranked lower in performance on the left side of Figure 13, show improved performance transitioning from MQTT 3.x to 5.0, as evident in Figure 14. Similar observations regarding performance enhancements with MQTT 5.0 can be seen in the results for both IEEE 802.11n/ac and 3 GPP-4G connections, especially for cipher suites initially demonstrating poorer performance. Bandwidth performance is influenced by various network conditions such as latency, available bandwidth, and network congestion, which can significantly impact MQTT performance, particularly in 3 GPP-4G environments. The delay distribution for TLS v1.2 cipher suites at QoS0 level on a 3 GPP-4G network with MQTT V3 is shown in Figure 6:0 The boxplot illustrates the latency distribution for various cipher suites over a 4G network. Notable variability is observed with suites like ECDHE-RSA-AES256-GCM-SHA384 and DHE-RSA-CHACHA20-POLY1305, which show larger boxes and longer whiskers, indicating a wider range of latency values. Outliers, particularly visible for these suites, suggest occasional extreme latency spikes. Conversely, suites such as AES128-SHA and ECDHE-ECDSA-AES128-SHA exhibit more stable performance with smaller boxes and fewer outliers, indicating more consistent latency. Overall, the cipher suite chosen significantly impacts the latency performance, with some suites being more prone to variability than others. Figure 6:1 Performance Analysis of Data Throughput: MQTT V5.0 over 3 GPP-4G Connections with TLSv1.2 Encryption Protocols across Quality of Service Tiers. Figure 6:2 Latency Patterns Analysis for MQTT V3.11 over 3 GPP-4G Connection: Examining TLS v1.2 Encryption Protocols at QoS0 Priority Level. \(\times\) represents the median value. By comparison, the average bandwidth used for benchmarks with TLSv1.3 cipher suites and MQTT versions 3.x and 5.0 over IEEE 802.11n/ac connections is shown in Figures 16 and 17. Figures 18 and 19 display the average bandwidth utilization during benchmarks using TLSv1.3 cipher suites and MQTT versions 3.x and 5.0 over 3 GPP-4G connections.