# An Experimental Framework for 5G Wireless System Integration into Industry 4.0 Applications
## 3 Experimental Framework for 5G Integration
### 5G Hardware and Software Prototyping Tools
To achieve enough statistical confidence at such reliability levels, more than 100,000 samples were collected per realization, fulfilling the requirements set by normal approximation of the Binomial distribution [36]. Further, the results illustrate the statistical distribution when considering all samples from all realizations as well as the difference between best/worse realizations to give an overview of the variability of the system. As the NTS is typically used in connection with operational industrial machinery, it is important to verify that its use does not impact excessively the performance of the underlying industrial control communication processes while the data traffic is being logged. As illustrated in Figure 5, the processing delay introduced by the NTS device in operational conditions is bounded to 0.45 ms, which would not affect significantly the analyzed control traffic as the introduced latency is deterministic (with small jitter <33 \(\upmu\)s). This jitter sets the practical limitation to what the minimum possible PIAT measured in with the NTS is. Based on the calibrated performance, it can be concluded that industrial operational machines, over which our NTS box is used, will continue to operate reliably as long as the survival-time of the underlying control protocols can tolerate a small misalignment when our device starts to function. In the case of the 5 GE, as the device will be used to emulate the performance of a 5G link between two devices, apart from the processing delay of the device itself, the correctness of the generated delay outputs needs to be validated. Figure 6 displays the results of the latency tests for two different configurations: one where no delay was added, so that the processing delay could be determined, and another one where a 1 ms constant offset delay distribution is configured (i.e., values are read from a file containing 100.000 delay samples of equal value of 1 ms), in order to confirm the correct performance at the output over a constant reference. The calibrated processing delay of this device is very similar to the one observed for the NTS. This is, essentially, due to the fact that both devices are built over a similar HW configuration with a slightly different SW implementation due to their different functionalities. When the specific 1 ms delay distribution was applied to the emulator, the output was shifted by 1 ms, as expected, validating the main functionality of the device. A similar deterministic behavior was observed with/without input, although a slightly larger best/worse case variability was observed in the case the specific delay distribution was applied. This is mainly due to the extra SW execution time introduced by the implemented uniform sampling mechanisms at configured delay re-configuration intervals (100 ms in this test case). In any case, this variability is limited (<80 \(\upmu\)s), which ensures that no excessive artificial jitter is introduced, limiting the potential distortion of the device over the input delay distributions, and resulting in a reliable delay emulation. Figure 5: CCDF of the processing delay introduced by the NTS device in operational conditions. Finally, the performance experienced when utilizing the WMAGW devices for transmitting data traffic over the configurable L2-tunnel was examined. The total processing delay introduced by the two devices that set up the ends of the tunnel is considered in Figure 7. In this case, despite of having the combined effect of the processing delay introduced by the encapsulating and decapsulating devices, the delay is bounded by 0.4 ms at the 99.5 percentile (\(10^{-25}\)). This reduced delay as compared to the one in the NTS and 5 GE devices is explained mainly by the different HW choice as, as indicated in Table 1, the WMAGW (v3) is implemented over a Gateworks Newport GW6404 [30] single board computer, with higher processing power capabilities than the one of the Raspberry Pi Model 4B [27] over which the NTS (v2) and the 5 GE (v2) operate.