Applicability of delay tolerant networking to distributed satellite systems

Abstract

interacting small satellites to realize distributed missions. There are various fields of application for distributed satellite systems (DSS), such as earth observation missions, distributed sensor networks and communication relays for remote locations. Also the combination of traditional large monolithic satellites with distributed small satellite systems is promising. In such distributed architectures, inter-satellite communication is one of the key aspects and, therefore, potential approaches need to be investigated. Hence, intersatellite communication is currently one of the hot topics in the satellite community. Adequate networking solutions are required to allow for efficient data exchange within challenging networks such as DSS in earth orbits. Therefore, the benefit of delay tolerant networking (DTN) for DSS is investigated, a promising approach for communication in challenging networks. Within the scope of this article, extensive simulations for typical scenarios have been performed to investigate the benefit of using DTN in those systems.To define the scope of our investigation an introduction to DSS is given in the following section. In Sect. 3, the DTN concept is introduced and its differences compared to traditional approaches are characterized followed by an overview of available implementations and in-orbit test results. Subsequently, in Sect. 4 a description of the simulated scenarios and our simulation framework follows, in Sect. 5 the results of the simulations are discussed. Section 6 concludes with derived statements about the applicability of the DTN approach to DSS and an outlook on future developments. Communication in distributed satellite systemsIn the last decade, many small satellites were launched into low earth orbits. Space vehicles are considered as small Abstract Currently, a trend towards distributed small satellite missions is emerging using cooperating satellites to achieve joint mission objectives, e.g. for earth observation. Communication is a key feature when cooperation between satellites is desired. Typically those satellite networks are affected by slow data rates, high packet loss and intermittent connectivity. To address these challenges the storeand-forward approach of the delay tolerant networking (DTN) concept is investigated in this article. Network simulations of typical scenarios were carried out and evaluated to derive statements about the applicability of the DTN approach to networks in low earth orbits.