Using of non-stationary networks in monitoring problems

In recent years, researchers in many countries have been paying attention to the networks with a non-stationary topology with nodes on vehicles (VANET, Vehicle ad-hoc network), on flying vehicles (FANET, Flying ad-hoc networks). The method of collecting data using these networks is increasingly being used, especially in monitoring problems: transport monitoring, environmental monitoring, etc. Smart sensors are used, which, in addition to collecting data, perform the function of processing information and transmitting it to the GPRS module for uploading to a web server. Similar projects are carried out in different countries China, Canada, Sweden. For example, observations of the state of air in an urban environment using wireless sensors were carried out in Uppsala (Sweden). This work is part of the Swedish Green IoT project, which uses the Internet of Things to measure urban air pollution. In publications about FANET, much attention is paid to the use of unmanned aerial vehicles (UAVs) for monitoring large territories, hard-to-reach areas. The main investigations are devoted to the development of algorithms for controlling the routes and optimizing the process of transmitting information collected by mobile nodes. The goal of similar projects is to collect information in real time and upload data to a web server for users to view.UAV are equipped with environmental monitoring sensors (gas sensor, air quality sensor, humidity sensor, temperature sensor), as well as a microcontroller and a GPRS module. The nodes are distributed in space and transmit data wirelessly. The microcontroller performs the function of processing the data received from the sensors and transmits the processed information to the base station, where it is open to users in real time. The limited battery life of the UAV narrows their functioning, therefore, various possibilities for recharging are used for example, recharging stations.When the critical level of the remaining energy is reached, the path to the nearest station must be denoted for UAV. In the case of a swarm of drones, there should be a flight schedule for recharging, because with a very large number of UAV, queues to stations are possible. Thus, the problem of optimal placement of charging stations in a territory is urgent: the total number of stations is not more than a given one, and the lifetime of the network is not less than a given one. To solve optimization problems, it is necessary to have convenient simulation tools in order to test algorithms on various models. For the optimizing monitoring problem, it is convenient to use a system to simulate the movement of nodes, the transfer of information between them, as well as to determine the possible parameters of devices for collecting and transmitting data. Well-known systems are used to simulate data transmission from nodes on moving objects for example, Network Simulator, Any Logic. However, these systems mainly simulate the movement, as well as the process of collecting information by nodes. Such urgent problems as ensuring monitoring of the entire given territory, recharging drones during network operation are not in the attention of simulation. In order to complete the simulation possibilities, the authors developed a UAV-monitoring simulation system, in which some urgent problems were solved by adapting well-known algorithms.