# A Modular Experimentation Methodology for 5G Deployments: The 5 GENESIS Approach
## 4 Formalization of the Experimentation Methodology
### Test Case
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**Test Case: TC\_THR\_UDP** & **Metric: Throughput** \\ \hline
**Target KPI**: UDP Throughput & The UDP Throughput test case aims at assessing the maximum throughput achievable between a source and a destination. \\ \hline
* Source of packets: Measurement probe acting as traffic generator. \\
* Destination of packets: Measurement probe acting as recipient. \\
* Underlying SUT: Network components between the source and destination. \\
* Measurement conducted at layer: Application. Complementary measurement are collected at lower layers. \\ \hline
**Methodology**: For measuring UDP Throughput, a packet stream is emitted from a source and received by a data sink (destination). The amount of data (bits) successfully transmitted per unit of time (seconds), as measured by the traffic generator, shall be recorded. A UDP-based traffic stream is created between the source and destination while using the iPerf201. The test case shall include the consecutive execution of several iterations, according to the following properties: \\
* Duration of a single iteration: at least three minutes. \\
* Records throughput over one-second intervals within an iteration. \\
* Number of iterations (\(l\)): at least 25. \\ \hline
**iPerf configuration**: & **SiPerf option** & **Suggested value** \\ \hline Throughput measurement interval & –interval & 1 \\ Number of simultaneously transmitting probes/processes/threads & –parallel & –4 (in order to generate high data rate in the source) \\ Bandwidth limitation set to above the maximum bandwidth available & –b & Depends on the maximum theoretical throughput available in the network \\ Format to report iPerf results & –format & m [Mbps] \\ \hline
**Calculation process and output**: Once the KPI samples are collected, time-stamped (divided by iteration), and stored, evaluate relevant statistical indicators, e.g., average, median, standard deviation, percentiles, minimum, and maximum values, as follows: \\
* Evaluate the statistical indicators separately for each iteration. \\
* Evaluate the average of each indicator over the iterations, thus obtaining that same indicator for the test case. \\
* Evaluate and add a Confidence Interval (CI)
* to the obtained indicator, which denotes the precision of the provided outcome. \\
* A 95\% CI is suggested and it should be evaluated while assuming a Student T-distribution for the data sample, with \(l-1\) degrees of freedom. This accounts for non-Gaussian distributions of values collected at each iteration. \\ \hline
**Complementary measurements (if available)**: Throughput at Packet Data Convergence Protocol (PDCP) and Medium Access Control (MAC) layers, Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Channel Quality Indicator (CQI), Adopted Modulation, Rank Indicator (RI), Number of MIMO layers, MAC, and Radio Link Control (RLC) Downlink Block Error Rate (BLER). \\ For each measurement (or selected ones), provide the average per iteration and for the entire test case, following the procedure in “Calculation process and output”. \\
**Note**: packet loss rate is not recorded because constant traffic in excess of the available capacity will be injected and the excess will be marked as lost packets, as could be expected. \\ \hline
**Preconditions**: The scenario has been configured. In case of network slicing, the slice must be activated. The traffic generator should support the generation of the traffic pattern defined in “Methodology”. Connect a reachable UE (end point) in the standard 3 GPP interface SGI or No (depending on whether the UE is connected to EPC or 5 GC, respectively). Employ the monitoring probes to collect throughput and complementary measurements. Ensure that, unless specifically requested in the scenario, no unintended traffic is present in the network. \\ \hline
**Applicability**: The measurement probes should be capable of injecting traffic into the system as well as determining the throughput of the transmission. \\ \hline
**Test case sequence**: \\
1. Start monitoring probes. \\
2. Start the traffic generator for transmitting from the client to the server probe, as described in “Methodology”. \\
3. Record the throughput for each time interval within a trial. \\
4. Stop the traffic generator. \\
5. Stop monitoring probes. \\
6. Calculate and record the KPIs as needed per iteration as defined in “Calculation process and output”. \\
7. Repeat steps 1 to 6 for each one of the 25 iterations. \\
8. Compute the KPIs as defined in “Calculation process and output”. \\ \hline \hline \end{tabular}
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