# Evaluation of IEEE802.15.4g for Environmental Observations
## 4 Analysis
### Line of Sight Scenario
#### 4.1.1 RX at 420 m  
As shown in Figure 7a for a packet size of 127 B, most of the radio settings have a PDR close to 100%, including the reference 2 FSK-50. OFDM3-600 is the only exception, with a 26% PDR. The majority of the radio settings has a high reliability at 420 m with LoS. Increasing the packets size to 2047 B, Figure 7b shows that the performance of the radio settings is not much affected, with high data rates still having a PDR close to 100%, including the reference  
Figure 7: Line of Sight, 420 m. The radio link allows the transmission of packets with 2047 B even with the highest data rates available with a PDR very close to 100%. Within this distance, high data rates radio settings maintain high reliability while consuming less electric charge and allowing more data exchange than low data rates radio settings. (**a**) PDR of all radio settings at 420 m from TX with packets of 127 B. Except for OFDM3-600, all radio settings have a PDR close to 100%; (**b**) PDR of all radio settings at 420 m from TX with packets of 2047 B. OFDM2-800 and OFDM4-300 do not have PDR values close to 100%. OFDM3-600 has 0% PDR; (**c**) Maximum amount of 127 B packets that can be correctly sent per PHY under 0.1% duty cycle regulation. OFDM1-800 can send 1531 packets while 2 FSK-50 only 166; (**d**) Maximum amount of 2047 B packets that can be correctly sent per PHY under 0.1% duty cycle regulation. OFDM1-800 can send 167 packets while 2 FSK-50 roughly 11; (**e**) Average electric charge consumption per packet of 127 B correctly sent. OFDM1-800 is the most electric charge-efficient, consumes 178.6 \(\upmu\)C whereas the reference 2 FSK-50 consumes 1807 \(\upmu\)C; (**f**) Average electric charge consumption per packet of 2047 B correctly sent. OFDM1-800 consumes the lowest amount of electric charge per packet, with 1637 \(\upmu\)C whereas the reference 2 FSK-50 consumes 27.5 mC. 2 FSK-50. The exception in this case are OFDM2-800, OFDM3-600 and OFDM4-300, the highest data rates of OFDM options 2, 3 and 4. One of the reasons is that these PHYs present the lowest sensitivity (the lower the sensitivity value is, the higher sensitivity is. e.g., a device A with sensitivity of \(-110\) dBm and another device B with sensitivity of \(-120\) dBm, device B has a higher sensitivity than device A.) (\(-101\) dBm, \(-97\) dBm and \(-101\) dBm respectively) of the different OFDM radio settings. The poor performance of OFDM3-600 (with a 26% PDR) could be linked to its low sensitivity, being at least 4 dB lower than any other OFDM radio setting. The sensitivity for 4 FSK-200 is 1 dB lower but the TX power is 4 dBm higher. Therefore, the signal at the receiver is 4 dB higher for the 4 FSK-200 PHY, enough to present a PDR of 100%. On the other hand, the rest of the PHYs present high reliability. Thus, we do not highlight any particular PHY in Figure 7a,b since most of them have 100% PDR. Considering throughput, with 127 B packets, Figure 7c clearly shows that OFDM1-800 is the PHY than can have the maximum amount of correct packets transmitted within an hour (duty cycle of 0.1%), with 1531 packets. The reference value, 2 FSK-50, can transmit during the same time just 166 packets. This proportion is maintained with packets of 2047 B, as shown in Figure 7d. OFDM1-800 stands alone with the possibility of transmitting 167 packets against roughly 11 of 2 FSK-50 whilst having 0.1% duty cycle. Therefore, OFDM1-800 has the capability of transmitting more short and long packets than any other PHY within the standard, under the 0.1% duty cycle regulation and at 420 m from the TX. If it is the interest of the user to maximize the amount of packets that can be sent, OFDM1-800 or any other OFDM option with high data rate can be used, as Figure 7c,d show. Figure 7e shows the average electric charge consumption per packet transmitted for all radio settings. We can see that high data rates PHYs, mostly OFDM, consume several times less electric charge that the reference 2 FSK-50. The most electric charge-efficient is, again, OFDM1-800.