Метод оцінки зв’язності вузлів бездротових епізодичних мереж за умови застосування безпілотних літальних апаратів

Abstract

The paper considers a method for assessing the connectivity of nodes of wireless episodic networks (WEN) under the condition of using unmanned aerial vehicles (UAVs). It is proposed to perform an evaluation of the connectivity of a pair of nodes according to a method, which is based on: an evaluation of geometric connectivity, which is limited to the maximum range of radio visibility at the physical level and the vulnerability interval of a given multiple access protocol at the channel level; assessment of information connectivity, which takes into account the presence of not only a physical connection of a given reliability, but also the presence of a free channel resource, a given amount of transmission delay at a given traffic limit value; assessment of the duration of connectivity taking into account the mobility of network nodes. On the basis of analytical mathematical models, the duration of connectivity of mobile subscribers (nodes) (MS) of the WEN consisting of MS and UAVs in direct radio visibility conditions and taking into account relaying was investigated. The connectivity of a pair of nodes is determined by the characteristics of different levels of OSI information interaction, such as radio range, channel bandwidth, information transmission delay, etc. It is shown that the duration of connectivity is directly proportional to the size of the coverage zone and inversely proportional to the speed of movement of nodes. The nature (scenario) of node mobility also affects the duration of connectivity. The simulation of the movement of nodes was carried out under 4 scenarios: «march», «skirmish», «random wandering in the field» and «random wandering in the city». The largest values of the duration of connectivity correspond to the third scenario, and the smallest to the second (with a fixed radius of the coverage area and the speed of movement of nodes). Thus, the average connection duration of the UAV-pedestrian connection in the event of a «difference» will be of the order of 36 minutes, and the UAV-car connection of the order of 5 minutes. The obtained results can be used in the UAV network topology control method.