# Cooperative UAV Scheme for Enhancing Video Transmission and Global Network Energy Efficiency
## 2 Related Work
A distributed decision making is also adopted. In the second phase, the UAVs exchange information among them in order to locally calculate a better coverage position. A Hill Climbing algorithm is used, which requires less computational power, making it feasible to run on UAVs. However, it is not clear of what type of data will be retransmitted from the user by the UAVs. An excessive amount of transmitted information among the UAVs in the second phase might decrease the network lifetime. Another issue is that, in the real world, the proposal might not be feasible once it does not consider the lifetime of the battery. [PERSON] et al. [19] introduced a distributed solution for long duration area surveillance missions, which takes into account limitations in the communication between the nodes in a set of UAVs. Surveillance application must operate independently of the necessity of group presence and maintenance. In addition, in monitoring missions, the presence and maintenance of the group are necessary, without impacting the functionality of the surveillance application. Each node considers its own information and its neighbors, so it is more difficult to have a global view of the energy consumption of each device, and the choice of nodes that can replace the battery. However, the proposed approach does not maintain the UAV coordination regarding energy efficiency influence. The need for refueling or recharging in intrusion detection applications has been extensively analyzed. In this case, [PERSON] et al. [20] proposed a mechanism for the problem of scheduling the replacements of the UAVs, seeking to optimize the operation of the application. For this, the authors propose a scenario where there is a set of battery-operated UAVs, each one performing routes to maximize the probability of detecting an attacker. Once a UAV node leaves the detection area, another node is allocated with the battery fully charged. The work focuses on the scheduling of the recharges and does not consider the communication between the UAVs, to make the scheduling decisions of the substitution strategy. Moreover, the solution developed is an algorithm that has information of all the active and reloading nodes, which seems like a nearly unfeasible approach. A single UAV equipped with a camera has been used to support structural inspection, such as introduced by [PERSON] et al. [9]. As a UAV has a short time of autonomy and structural inspection usually requires a long period of time to accomplish a reasonable result, the solution attempts maintain the service by replacing the UAV node in a transparent manner. The basic infrastructure presented is composed of a Ground Control Station (GCS) and a UAV. A machine state approach protocol that runs in the network is developed and is in charge of sending a full recharged UAV to the place where the drained UAV is present, exchanges the service-sensitive information and then sends the drained UAV to the GCS in order to recharge it. However, the approach does not consider any aspects of cooperation to grant network stability and large area video service coverage. Based on our analysis of the state-of-the-art, we conclude that it is essential to provide energy-efficiency operations in video dissemination over FANETs, avoiding the premature death of66 nodes, network disconnections, route failures, void areas, and low-quality video transmissions. In this way, UAV replacement must be provided in order to avoid the premature death of nodes, network disconnections, route failures, void areas, and low-quality video transmissions. However, so far, not all of these key features have been provided in a unified cooperative UAV scheme for enhancing the video transmission. Cooperative UAV Scheme for Enhancing Video Transmission and Global Network Energy Efficiency (VOEI)  
VOEI aims to improve the cooperation of UAVs for enhancing video transmission and global network energy efficiency in global FANETs.