# Mobile Network Operators' Assessment Based on Drive-Test Campaign in Urban Area for iPerf Scenario
## 2 Drive Test Campaign
### Measured QoS and Signal Metrics  
In the analyzed scenario, we evaluated QoS and radio signal quality measures for UL and DL, using the iPerf application for two protocols, TCP and UDP. As basic QoS metrics, we use the following:  
* Th-Sx (Mbps)--Throughput from the sender is defined as an average throughput measure on the sender side. Basically, in [43], throughput is defined as an average UL or DL throughput over the configured active transfer duration. In the tests, Th-Sx was calculated separately for UL and DL. * Th-Rx (Mbps)--Throughput at the receiver is defined as an average throughput measured on the receiver side. Similarly to Th-Sx, throughput is defined as an average UL or DL throughput over the configured active transfer duration [43]. In this research, Th-Rx was calculated separately for UL and DL. * Th-Rate (%)--Throughput at Receiver Rate, which is calculated based on the following formula: \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **TCP** & **UDP** \\ \hline Target throughput (Mbps) & 8 for UL/40 for DL & 100 \\ Total target throughput (Mbps) & 24 for UL/120 for DL & 100 \\ Parallel streams & 3 & 10 \\ Buffer size & 8192 & 1200 \\ Transfer duration (s) & 5 for UL/7 for DL & 3 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Parameters of iPerf tests for TCP and UDP. \[\text{Th-Rate}=100\%\cdot\frac{\text{Th-Rx}}{\text{Th-Sx}}, \tag{2}\]
* JT (ms)--Jitter is a measure of the Internet Protocol (IP) packet jitter reported by the iPerf application. It is usually equal to or more than 0 on the sender or receiver sides, respectively. Only available as an intermediate result for UDP [43]. * LDR (%)--Lost Datagrams Rate is the percentage of lost datagrams in relation to the number of total datagrams. Lost Datagrams are defined as the number of datagrams that did not reach the receiver before the end of the active transfer duration and count as lost. Total Datagrams is the number of datagrams sent on the sender side. If the datagram size is smaller than one Ethernet frame, this usually corresponds to the number of IP packets. The parameters mentioned above are usually analyzed for UDP [43]. * RDR (%)--Received Datagrams Rate, which is determined as follows: \[\text{RDR}=100\%-\text{LDR},\] (3) Additionally, using the R&S TSME6 scanner, the following radio signal quality parameters are measured:
* RSRP (dBm)--reference signal received power (RSRP) is utilized mainly to rank among different candidate cells in accordance with their signal strength. Generally, the reference signals on the first antenna port are used to determine this parameter. However, the reference signals sent on the second port can also be used in addition to the radio stations on the first port if UE can detect that they are being transmitted [47]. Basically, RSRP is defined as the linear average over the power contributions (in watts) of the resource elements that carry cell-specific reference signals within the considered measurement frequency bandwidth [48; 49]. * SINR (dB)--Signal-to-interference-plus-noise ratio (SINR) is defined as the linear average over the power contribution (in watts) of the resource elements carrying cell-specific reference signals divided by the linear average of the noise and interference power contribution (in watts) over the resource elements carrying cell-specific reference signals within the same frequency bandwidth [47]. In fact, it is only measured for the reference signal. Therefore, it is called a Reference Signal-SINR (RS-SINR) [48; 49]. * RSRP-5G (dBm)--RSRP for 5G NR is widely named as a Second Synchronization-RSRP (SS-RSRP) [50; 51]. It is defined as the linear average over the power contributions (in watts) of the resource elements that carry secondary synchronization signals. It represents the quantitative measure of SS-RSRP. The RSRP-5G range is from -156 to -31 dBm [52]. This parameter gives possibilities to compare the strengths of signals from individual cells in 5G networks, which is key for cell selection or handover.