# Evaluation of IEEE802.15.4g for Environmental Observations
## 4 Analysis
### Smart Agriculture Scenario
#### 4.2.2 RX at 615 m  
At this distance, the overall performance of the radio settings is poor. Figure 10a shows the PDR of all radio settings for short frames, where the majority of OFDM and FSK radio settings are not able to get any frames across. Only O-QPSK PHYs, 2-FSK-FEC-50 and OFDM2-100 have a PDR over 80%. The reference 2 FSK-50 has a negligible PDR, only 5%. PDR values for long packets are shown in Figure 10b. Only OQPSK PHYs maintain a high PDR. 2 FSK-FEC-50 drops to 64% and the reference is only 11%. Therefore, if the potential user wants to have radio links with similar length, 2 FSK-FEC-50, OFDM2-100 and any O-QPSK radio setting are useful for such requirement with short packets. For long packets, any O-QPSK radio setting is useful. It can be seen in Table 8 that the PDR values at 538 m are lower than at 615 m. This seems counterintuitive since at further distance, lower should be the power of the received signal and thus, the PDR. This assumption is correct in environments where the attenuation of the radio signals are only due to distance, without obstacles located between the transmitter and receiver. But this is not our case. The obstacles surrounding the RX node located at 538 m and its relative position to the TX node cause this shadowing effect, affecting its PDR. At 615 m, the surroundings of the RX node did not have this effect and therefore, the PDR values are higher. The maximum amount of short packets that can be sent under the 0.1% duty cycle regulation are shown in Figure 10c. Even though OFDM1-200 has only 52% PDR, its high data rate allows it to send just over 300 packets per hour. Not far behind, OFDM2-100 has the possibility of sending up to 251 packets per hour. 2 FSK-50 only 8 packets, and OQPSK-50 below 100 packets of 127 B. Now considering long packets, Figure 10d shows the maximum amount each PHY can correctly send within an hour. 2 FSK-50 can send one long packet per hour, whereas OQPSK-50 just 10. For a potential user, if it is wanted to maximize the amount of transmitted packets, OFDM1-200 is the best option for short packets. For long packets, OQPSK-50 is the best option but just a few packets possible. Figure 10e shows the electric charge consumed on average per short packet transmitted to this node. 2 FSK-50 has a poor PDR, thus the eventual need for retransmissions makes energetically expensive to get a packet across. It consumes 36 mC, whereas OFDM1-200 and OFDM2-100 consume 895 \(\upmu\)C and 1095 \(\upmu\)C respectively. Therefore, we highlight these last two as the more efficient in electric charge consumption. For long packets, Figure 10f shows the average consumption. The reference 2 FSK-50 consumes 250 mC per packet of 2047 B. We can observe that the less consuming PHY is OQPSK-50, with 29.5 mC. In both cases, for short and long packets, 2 FSK-50 is at least one magnitude higher than the most electric charge-efficient PHYs. Figure 10: Smart Agriculture, 615 m. The radio link is very close to the maximum distance where it can deliver connectivity. High data rates OFDM radio settings are unable to get any packet across. Maximum data rate that can provide connectivity is 200 kbps, but with PDR of 52% with short packets. (**a**) PDR values for all radio settings with short packets. Only 2 FSK-FEC-50, OFDM2-100 and all the O-QPSK radio settings have a PDR over 80%. The reference has a poor PDR, only 5%; (**b**) PDR values considering long packets. Only O-QPSK PHYs have PDR values over 85%, against the reference with 11%; (**c**) Maximum amount of TXs with short packets under 0.1% duty cycle. Despite its PDR of 52%, OFDM1-200 is able to transmit up to 300 short packets. The reference can send just 8 packets; (**d**) Maximum amount of TXs with long packets within one hour. OQPSK-50 can send up to 10 long packets while the reference roughly 1 packet per hour; (**e**) Energy consumed per 127 B packet transmitted. OFDM1-200 and OFDM2-100 are the most electric charge-efficient, consuming 895 \(\upmu\)C and 1095 \(\upmu\)C respectively. The reference consumes 36 mC.