## 4 Avinomics Assessment
### Communication  
Between the UAV and external entities (e.g., Ground Control System (GCS)), a bidirectional data exchange is enabled by means of the communication subsystem. For applications involving a swarm of drones, it also enables mutual communication and data exchange between each UAV, transmitting control commands, captured images, and other data. It might be the case that the computing subsystem processes the data from sensors through the communication subsystem; however, the focus in this paper took into consideration only remote communication with external parties. Based on this approach, the communication modules/protocols were found to include Long Range (LoRa), Wi-Fi, Bluetooth Low Energy (BLE), and Long-Term Evolution for Machine-Type Communication (LTE-M). LoRa  
LoRa refers to long-range low-power wireless communication technology allowing for telemetry between a UAV and an external party [221]. Its physical layer employs a private Chirp Spread Spectrum (CSS), with LoRaWAN as its MAC layer [222]. Within the framework of UAVs, the identifier of a UAV is transmitted with real-time status tracking through LoRa [223], as well as other data concerning cases of environmental disasters [224]. From a different perspective, LoRa is utilized along with UAV-embedded IoT devices to track merchandise and increase their location accuracy in [225], whereas in [226], LoRa was employed to link a UAV with air pollution monitoring stations. Although LoRa presents the capability to transmit for up to 15 Km in rural areas [227], over unlicensed bands at frequencies ranging from 433 MHz to 923 MHz, it suffers from a low data rate, ranging between 0.3 and 5.5 kilobytes per second (kbps) [228]. This communication technology can be enabled inside a UAV through different modules, for example, SX1278 [229] supporting the frequency range from 137 MHz to 525 MHz. Alternatively, RN2483 [230] can also enable LoRa inside a UAV with a data rate of 300 kbps, similar to HOPERF RFM95W-868S2 [231], which works on a frequency of 868 MHz. Wi-Fi  
In lieu of LoRa, Wi-Fi enables remote control in UAVs, in addition to real-time data transmission, telemetry with GCS, and communication with other UAVs [232]. Wi-Fi communication in UAVs usually follows the Open System Interconnection (OSI) model, consisting of seven layers [233]. Within the framework of UAVs, the wireless systems' range (i.e., coverage zone) is extended through an intel Galileo board installed in a UAV, where Wi-Fi is configured in ad hoc mode [234]. A regional inspection and monitoring system based on Wi-Fi is established in reference [235], in which the signal strength model based on the Wi-Fi directional gain antenna is introduced. The leader-follower trajectory scheme in [236], on the other hand, implements a Robot Operating System (ROS) based communication system for a swarm of UAVs via Wi-Fi and MavLink serial forwarding. Tests result in fast responses between workstation-leader and leader-follower communication (0.2 S and 0.42 S, respectively). Unlike LoRa, which is featured by a coverage zone in kilometers, Wi-Fi technology has a limited range (maximum of 300 m outdoors). From another perspective, Wi-Fi presents an elevated throughput data rate, which varies according to each protocol (e.g., 802.11 ax, 802.11 ac wave2, 802.11 ac wave1, 802.11n, 802.11g, 802.11a, 802.11b, [237]). Different modules exist that enable Wi-Fi communication on a UAV, of which ESP8266 [238] enables the SBC/SoM to connect to 2.4 GHz via the 802.11 bgn. A better alternative to ESP8266 is ESP32 [239], which presents a Bluetooth connectivity, also featuring a dual-core processor allowing for better multitasking. CC3000 [240] can alternatively add Wi-Fi functionality to a UAV, supporting the 802.11b/g protocol, but, on the other hand, it does not support the AP mode.