# A Review of Flying Ad Hoc Networks: Key Characteristics, Applications, and Wireless Technologies
## 2 UAV Classification
According to Figure 2, box \(B\), they have been used for search and rescue when a natural disaster suddenly happens, for transport and delivery of medications, first aid kits, and laboratory samples, and for remote telemedicine and teleradiology services [29; 30; 31; 32; 33]. The most promising UAVs for near-future applications in healthcare are Seattle's _VillageReach_ ([[https://www.villagereach.org/](https://www.villagereach.org/)]([https://www.villagereach.org/](https://www.villagereach.org/)) accessed on 21 July 2022), used for transportation of blood samples from one hospital to another; _Flirty_ ([[https://getskydrop.com/](https://getskydrop.com/)]([https://getskydrop.com/](https://getskydrop.com/)) accessed on 21 July 2022), used for delivery of first aid kits; _EHang_ ([[https://www.ehang.com/index.html](https://www.ehang.com/index.html)]([https://www.ehang.com/index.html](https://www.ehang.com/index.html)) accessed on 21 July 2022), used to transport donated organs to people for use in emergency situations; _ZipLine_ ([[https://flyzipline.com/](https://flyzipline.com/)]([https://flyzipline.com/](https://flyzipline.com/)) accessed on 21 July 2022), used for blood transportation; _TU Delft_ ([[https://www.tudelft.nl/io/onderzoek/research-labs/applied-labs/ambulance-drone](https://www.tudelft.nl/io/onderzoek/research-labs/applied-labs/ambulance-drone)]([https://www.tudelft.nl/io/onderzoek/research-labs/applied-labs/ambulance-drone](https://www.tudelft.nl/io/onderzoek/research-labs/applied-labs/ambulance-drone)) accessed on 21 July 2022), which is an ambulance UAV sent to bystanders near a patient to teach them how to perform CPR and use its in-built automatic defibrillator until emergency services arrive to take over; and _Google Drones_, which can provide people in distress with medical aid before an ambulance can arrive there; other autonomous UAVs for use in healthcare applications include _Project Wing_ ([[https://x.company/projects/wing/](https://x.company/projects/wing/)]([https://x.company/projects/wing/](https://x.company/projects/wing/)) accessed on 21 July 2022), _Healthcare Integrated Rescue Operations_ (_HiRO_) ([[https://ieee-aess.org/hiro-healthcare-integrated-rescue-operations](https://ieee-aess.org/hiro-healthcare-integrated-rescue-operations)]([https://ieee-aess.org/hiro-healthcare-integrated-rescue-operations](https://ieee-aess.org/hiro-healthcare-integrated-rescue-operations))  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Type** & **Size (inch)** & **Weight (gram)** & **Max Altitude** & \begin{tabular}{c} **Coverage Range** \\ **(kilometer)** \\ \end{tabular}  & **Endurance (hour)** \\ \hline Nano & around 3 & W \(\leq\) 0.2 & h \(\leq\) 15 & 0.05 \(<\) r \(<\) 0.1 & E \(<\) 0.6 \\ \hline Micro & s \(\leq\) 4 & 0.2 \(<\) W \(\leq\) 2 & h \(\leq\) 15 & 0.1 \(<\) r \(<\) 0.5 & E \(<\) 1 \\ \hline Mini & 4 \(\leq\) s \(\leq  
accessed on 21 July 2022), and _Vayu Drones_ ([[https://www.engineeringforchange.org/solutions/product/vayu-drones-for-medical-delivery/](https://www.engineeringforchange.org/solutions/product/vayu-drones-for-medical-delivery/)]([https://www.engineeringforchange.org/solutions/product/vayu-drones-for-medical-delivery/](https://www.engineeringforchange.org/solutions/product/vayu-drones-for-medical-delivery/)) accessed on 21 July 2022). * _Agriculture (Figure 2, box C)_: Recently, UAVs integrated with the IoT paradigm have found wide use in intelligent agriculture. As shown in to Figure 2, box C, UAVs are employed in many agriculture applications. UAVs equipped with flight planning software automatically take pictures using onboard sensors and the built-in camera to allow users to perform mapping analyses of an area. UAVs are capable of planting seeds and seedlings, harvesting crops, and detecting infestations and weed. In addition, they can spray crops more accurately than a traditional tract [34; 35; 36].