# An Efficient Mobility Model for Improving Transmissions in Multi-UAVs Enabled WSNs
## 3 Literature Review
\begin{table}
\begin{tabular}{l l l l l l} \hline \hline
**Approach** & **Author** & **Motivation** & **Fundamental Process** & **Features** & **Analysis** \\ \hline UAV Group & [PERSON] and & & & & Visited Areas Marked by Pheromone & \\ Reconnaissance & [PERSON] [21] & Reconnaissance, Search, Acquisition & Random Movement, Pheromone Driven & Trails, Banking Decisions by & Real Time \\  & & & & & Pheromone Small Index & \\ \hline Fleet Mobility Model & [PERSON] et al. [22] & Area Surveillance, Target Detection, & Nature Based Mobility using Ant & Marking Area using Repulsive & \\  & & Global UAV Connectivity, Tracking & Cheore Optimization (ACO) & Pheromone, Attraction Pheromone to & Simulated \\ \hline Public Infrastructure & & Reconnaissance, Surveillance, & & & \\ for UAV & Daniel & Communication, Concept of & Public Wireless Infrastructure Driven, & High and low Altitude Coverage, Air & Proposed \\ Remote Sensing & and [PERSON] [23] & Operations (CONOPS), Chemical, Radiological, Biological and & Wireless UAS Backbone & & Approach \\  & & Nuclear (CBBN) & & & \\ \hline Paparazzi & & Development of a Realistic & & Improved Geometric (Clustering, & \\ Mobility Model & [PERSON] et al. [24] & Model based on Paparazzi & Paparazzi Movements: Stay-at, & Frequency, Meeting, Neighbor) & \\  & & UAV Movements & & Measures as well as & \\  & & UAV Movements & & Network Parameters & \\ \hline Semi-Random & & & & & \\ Circular & & Mobility Model Capsule of & Smooth Transition Movements, & Scanning Large Areas in less Time, & \\ Movement (SRCM) & & Adapting to the Spatial Randomnes & Constant Radial Turns & Potentially Increased Flight Time, & NS2 \\ \hline Ground Node Based & & & & & \\ UAV deployment & [PERSON] et al. [25] & Optimized Mobile Ad Hoc Network & Heuristic UAV Placement Algorithm & Increased Probable Message & \\  & & (MANET) Connectivity & Margaud Velocity and Movement & Propagation, Decreased Probable & \\  & & Direction for Increased Connectivity & Network Division & \\ \hline Minimized & & & Dimensions of State Information & & \\ Trajectory Deviation & Kharchenko and & & & (vertical, horizontal or three & \\  & & & dimensional), Conflict Detection & \\  & & & Threshold, Conflict Resolution Method & & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: UAV Mobility Models. [PERSON] et al. (2018) proposed that a nature-inspired algorithm can solve the problem of optimized routing and congestion control as well. The authors presented an optimized fruit fly based routing protocol for aerial and ground ad hoc networks. The algorithm also includes enhanced congestion control mechanisms. The algorithm relies on the principle that all nodes playing food sources should calculate their smell index, which, in turn, is used by source nodes to calculate the fruit fly index. The base of the protocol is that the node acting as a source is called the fly and the relays for path formation are considered as a food source, thus a node when evaluating itself is a fly and when evaluating others is a food source. The route discovery, route maintenance, and route recovery are the three stages of the protocol. The route discovery phase starts more or less like a link state protocol by broadcasting hello messages. However, this is it for the link state. The hello messages are generated by each node acting as a fly. When receiving a hello message, the node with the help of modeling equations calculates the smell index and the sender node on receiving the acknowledgment calculates a fruit fly index. The greater the value of this index, the more chances of the node getting selected as a relay point. The feedback mechanism also exists which has beacons to keep everyone updated about the network state. Each node maintains a forward connectivity and a flash feedback table. The route maintenance takes into account the acknowledgments and periodic updates. The proposed mechanism employs the estimation and prediction of the proposed window size. A watchdog policy is also employed to have a check on a maximum number of interacting food sources.