# Wake-Up Receiver-Based Routing for Clustered Multihop Wireless Sensor Networks
## 5 Experimental Setup and Measurement
### Performance Evaluation  
For experimental acquisition of the measurement data and the subsequent evaluation of the results, the energy consumption in ampereseconds and the time in active mode in milliseconds of all sensor nodes was measured using an oscilloscope. The technical setting \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Strategies & proposed approach CWM, SBS, NTN \\ Hardware & AS3933 (WuRx), SPIRIT1 (Transceiver), MSP430 \\  & (MCU), Raspberry Pi 4 \\  & Manchester Bits (S Carrier Burst, 6.5 Preamble, 16 Address) \\ DataPkt & size 107 Byte (8 Byte Preamble, 4 Byte Sync, 1 Byte \\  & Length, 1 Byte Address, 92 Byte Payload, 1 Byte CRC) \\ REQ & size 18 Byte (8 Byte Preamble, 4 Byte Sync, 1 Byte \\  & Length, 1 Byte Address, 3 Byte Payload, 1 Byte CRC) \\ Frequency band & 868.0 MHz \\ Bit-rate & AS3933 (1.16 kbit/s), SPIRIT (8.4 kbit/s), MSP430 \\ Modulation & AS3933 (OOK), SPIRIT1 (FSK) \\ Area & Indoor 30 m \(\times\) 30 m \\ Transmission power Sink and Fog Node & WuPt and DataPt (+12 dBm) \\ Transmission power Cluster Nodes & WuPt (\(-\)6 dBm) and DataPt (\(-\)34 dBm) \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Parameter values used in this experimental measurement. Figure 9: Sequence diagram of NTN approach. for the analysis as shown in Figure 10 also includes a shunt resistor of \(1\,\Omega\) and a low noise amplifier to amplify the signal by a factor of 100. In order to better understand the results of the energy consumption measurement of each sensor node, a measurement of the active times of each individual node was carried out. The measurement results represent the energy consumption and time each node sends, waits or receives an REQ, WuPt, or DataPt. The measurement carried out using the described measurement setup and the resulting outcomes follow subsequently. In Figure 11, the energy consumption of every single node within the communication route when using \(1\) cluster node as relay at the different strategies is shown. The results show, that when using our proposed approach, almost each individual sensor node consumes the least energy compared to the other two strategies. It is noticeable that the Destination Node consumes almost the same amount of energy in our approach and the strategy named SBS. Based on the previous description of the different strategies by means of the sequence diagram, it is evident that this relay is identical in terms of the activities and also in terms of the time in active mode. Both nodes receive a WuPt followed by transmitting a DataPt to the Cluster Node acting as relay. Since the actions are the same, they should consume the same amount of energy and take the same amount of time. This minimal difference can be attributed to a variety of reasons. Indoors, wireless sensors are generally more difficult to use due to signal fading and reflections. It should also be noted that these are real measurements using prototypes that are not entirely identical to each other, which leads to minimal deviations in the collected measurement data. Since this minimal difference cannot be eliminated, and the variation is that minimal and has no significant influence on the overall assessment of the different scenarios, this deviation can be regarded as not significant. Even if this anomaly is noticeable here in this scenario with one relay, it does not have much effect in the following measurements with several relays. The total active-mode time for each individual sensor node is shown in Figure 12. When considering our approach and SBS, it is noticeable that according to the sequence diagrams in Figures 7 and 8, the destination node performs the same actions. As already stated, differences between the individual nodes can also be determined in these results. The specific results can be found in Tables 2 and 3. Figure 10: Set up used for measurements.