# Evaluation of IEEE802.15.4g for Environmental Observations
It is used a 50 node deployment using the 433 MHz frequency band, connecting to a gateway embedded inside a wooden birdhouse with solar panels on the top. The antenna of the gateway was left inside the box. This choice reduced drastically the quality of the radio links between gateway and sensor nodes, allowing communication ranges only up to 70 m.  
[PERSON] et al. (2018) presented SCALE, a measurement visualization tool that allow the collection of packet delivery statistics and can help to engineers to determine data capacity and latency of the system. They used the same micro-controller with two types of radios, an RFM TR1000 and a Chipcon CC1000. The former working at 916 MHz, 13.3 kbps with an Amplitude Shift Keying (ASK) modulation and the latter at 433 MHz, 19.2 kbps and FSK. They show that radio links of 50 m with Packet Delivery Ratio (PDR) over 60% are achieved in outdoor environments, with a 0 dBm TX power with the TR1000 radio. Due to the lack of more hardware, they could not test over longer distances. They conclude that there is no evident correlation between PDR and distance for more than 50% communication range. The IEEE802.15.4 standard continuously evolves. In 2012, the \"g\" amendment to the standard ([PERSON], 2018) added a new physical layer, with three modulations (FSK, OFDM and O-QPSK), and a maximum frame size of 2047 B. Most importantly, IEEE802.15.4g is designed to operate in sub-GHz bands (such as 863-870 MHz in Europe, 902-928 MHz band in the US), increasing communication range for the output power, when compared to 2.4 GHz. Nonetheless, it can also be used at 2.4 GHz. The Wi-Smart Utility Network (SUN) industrial alliance (www.wi-sun.org) has adopted this amendment, specifically the 2-FSK 50 kbps option. This is one of the most frequently implemented options in smart metering applications (other sub-GHz solutions are popular, such as wireless M-Bus, LoRa, Sigfox.). As a result, most \"IEEE802.15.4g compliant\" chips only implement that option. In opposition to the 2.4 GHz band, license-free sub-GHz bands are at different frequencies in different countries, and are subjected to regional regulations. This means that devices compliant in one region may not be suitable to be deployed in another. One example is the European regulation,that imposes a duty cycle of <0.1%, or 3.6 s of transmit time over one hour while The United States imposes a duty cycle of <2%. This study explores the entire \"g\" amendment, i.e., all three modulations techniques with their further parametrization. The result is that IEEE802.15.4g contains 31 different radio settings, with data rates ranging from 6.25 kbps to 800 kbps, and channel bandwidth from 200 kHz to 1.2 MHz in the European sub-GHz band. Some studies of IEEE802.15.4g already exist. [PERSON] et al. [13] evaluate the performance of a WPAN when using the IEEE802.15.4/4e/4g for SUNs through simulations. [PERSON] et al. [14] deploy a WSN in office/canteen/warehouse buildings in a smart grid application, and evaluate the performance of a single radio setting (O-QPSK, 250 kbps, 2 MHz channel bandwidth). [PERSON] et al. [15] propose an enhancement to a conventional Wi-SUN system by increasing the transmission power of the downlink communication, and using a 2-FSK 100 kbps setting for their system tested in the city of Kyoto. [PERSON] et al. [16] study the communication and interference range for deployments for IEEE802.15.4g SUN devices in low and high dense environments (from 10 up to 2500 devices per square kilometer). Based on realistic channel models and assuming FSK modulation with \(-90\) dBm sensitivity, they conclude that the communication range in urban environments (PER \(\leq 1\%\)) for SUN devices is 33 m, 65 m and 104 m when using 2.4 GHz, 915 MHz and 460 MHz frequency bands respectively. [PERSON] et al. [17] deployed six sensor nodes and two dedicated routing nodes in the Cairngorm Mountains in Scotland. The Zolertia Z1 sensor more with a CC1120 radiochip was the hardware choice for the nodes.