جواد رنجبر

In delay-Tolerant networks (DTN), there is no possibility of continuous connection between nodes, and data transmission is done using a store-and-forward mechanism, where bundles (packets) are stored in nodes. Therefore, nodes use complex routing algorithms to calculate and predict data transmission routes. Different techniques have been proposed to calculate the route list in DTN networks. In space networks, these routing techniques are very useful and important because in these networks, knowing the network topology, the best routes with the best delivery time can be selected for routing in the network. Among the routing algorithms presented for delay-tolerant networks, cantact graph routing(CGR) has received much attention due to the analysis of data related to the physical topology of the network in space applications, such as the interplanetary Internet and near-Earth space networks . In previous researches in the field of space networks to eva‎luate the performance of cantact graph routing, problems such as the increase of fixed and temporary ground stations in different parts of the earth's surface, the result of which is the significant cost of setting up the network infrastructure. In addition, the division of network states with a high number of nodes based on consecutive intervals increases the time complexity and complexity in the calculation of contact plan states. In this research, reducing the time complexity and level of network state calculations in cantact graph routing in a constallation of Nanosatellites using real data with the aim of transmitting data packets to a single ground station has been done, which practically removes one layer of intermediary ground stations. And reducing the cost of network infrastructure. This goal is achieved by calculating physical topology changes based on different network states. The implementation of this scenario based on real data can be an introduction to space internet based on delay networks. The simulation results in the DtnSim environment show that this method of implementing cantact graph routing for systems with a larger number of nodes also shows good performance.

شبكه هاي تحمل تاخير , منظومه هاي نانوماهواره اي , بسته باندل , مسيريابي گراف تماس

Delay-Tolerant network , nanosatellite constellation‌‌‌ , Bundle‌‌‌ Protocol , Contact Graph Routing(CGR)

Javad Ranjbar

Dr. Mohammad Soleimani