# Mobile Network Operators' Assessment Based on Drive-Test Campaign in Urban Area for iPerf Scenario
## 4 Relationship between QoS Metrics  
### Analysis for TCP Results  
For TCP, we analyzed three QoS parameters, i.e., Th-Rx, Th-Rate, and RDR. From a practical viewpoint, Th-Rx is crucial. Th-Rx is generally moderately correlated with the signal metrics for the three MNOs, i.e., Orange, Play, and T-Mobile. For UL, the largest PCC (i.e., \(0.45<PCC<0.53\)) was obtained for RSRP (for Orange and Play) or RSRP-5G (for T-Mobile), while the more minor (i.e., \(0.29<PCC<0.4\)) was obtained for SINR or SINR-5G. For DL and the same three MNOs, higher correlations were obtained between Th-Rx and SINR or SINR-5G (i.e., \(0.54<PCC<0.62\)) than between Th-Rx and RSRP or RSRP-5G (i.e., \(0.28<PCC<0.45\)). For Plus, the highest Th-Rx correlation occurs for RSRQ-5G, and PCCs are equal to 0.35 or 0.57 for UL and DL, respectively.  
Considering the obtained results, we conclude that RSRP (or possibly RSRP-5G) should be used to estimate Th-Rx for UL TCP. It can be regarded as a similar approach to the one proposed by [PERSON] [29] and the Office of Electronic Communications, i.e., the Polish regulatory authority [30]. However, for DL TCP, we propose using SINR (or alternatively SINR-5G) for Th-Rx estimation. Figures 6 and 7 illustrate measured Th-Rx versus RSRP or SINR and appropriate regression lines for (a) UL and (b) DL, respectively.  
Figure 5: PCCs for UDP, UL/DL: (**a**) average of all MNOs, (**b**) Orange, (**c**) Play, (**d**) Plus, and (**e**) T-Mobile.  
Throughput measurement data for TCP are limited to 22.83 and 118.24 Mbps for UL and DL (see Figure 6a,b), respectively. It is due to the specificity of this protocol. The assessment of the throughput of individual MNOs is complex based on measurement data due to their spreading. This evaluation is facilitated by the regression lines presented in Figure 7a,b. Basically, we can see that, in UL, the lines for Orange and T-Mobile overlap, and the line for Play is close to them. In the DL case, the Orange and Play lines overlap, while the T-Mobile line has a similar slope. The similarity of the lines for Orange and T-Mobile may result from the mentioned RAN sharing and the same base station locations. Therefore, we may generally assume that the throughput versus radio signal parameters for these three MNOs can be modeled with one average curve. The Plus regression lines for both UL and DL are clearly different from other MNOs. The throughput at a given RSRP/SINR value is worse or better than the other MNOs for UL and DL, respectively. A more significant DL throughput may result from the use of the 40 MHz band at the 2.6 GHz frequency, which is used only by Plus in Poland.  
Figure 6: Measured Th-Rx versus (**a**) RSRP for four MNOs, TCP, and UL; or (**b**) SINR for four MNOs, TCP, and DL.  
Figure 7: Regression lines of Th-Rx versus (**a**) RSRP for four MNOs, TCP, and UL; or (**b**) SINR for four MNOs, TCP, and DL.  
Similar to the above, analyzing the measured parameters is difficult due to their spreading. Therefore, our assessment is based on appropriate regression lines. Generally, the results of the power and quality of reference signals measured according to the methodology for the LTE and 5G standards (see Figures 8 and 9 or Figures 10 and 11, respectively) are similar for all MNOs. In Figure 9, the lines of two MNOs, i.e., for Orange and T-Mobile, or Plus and Play, practically overlap. However, the differences between these two line groups are minor. However, in Figure 11, the lines of three MNOs (i.e., for Orange, T-Mobile, and Play) overlap. For RSRP-5G versus SINR-5G, there is a significant difference only for Plus. In this case, we can see that, with a lower RSRP-5G value, a higher quality, i.e., SINR-5G, may be obtained. It allows for this MNO to provide higher QoS, probably due to using the 2.6 GHz band for 5G technology.  
The parameters of all regression lines for TCP are listed in Table A3 in Appendix C.