# Satellite-Assisted Disrupted Communications: IoT Case Study
## 2 Related Work
Various protocols and mechanisms have been tested in the context of satellite communications such as the IEEE 802.15.4 standard for WSN devices [24], the Digital Video Broadcasting standards (DVB-RCS and DVBS2) [25], Carrier-sense multiple access with collision avoidance (CSMA/CA) back-off distribution functions [26] and novel (MAC and MANET) routing solutions [27; 28]. In addition, the authors in [29] introduced a Satellite Network Simulation Platform for testing communication protocols such as DTN concepts. Furthermore, network jamming scenarios have been evaluated by implementing prevention algorithms for defense, as explored in [30], as well as the trade-offs associated with the satellite-to-ground and satellite-to-satellite communications, specifically focusing on their impact on the energy consumption [28]. Subsequently, certain studies investigated the impact of space design parameters on metrics such as the delay, without employing simulations in OMNeT++. In [4; 31], the system architecture of constellation designs was analyzed, estimating the total throughput and minimizing the required ground stations, while [31] attempted to optimize the number of satellites in ultra-dense LEO constellations to satisfy backhaul requirements. In addition, existing studies examined the effect of satellite design parameters and challenges. In particular, the authors of [32; 33; 34] analyzed the architecture of inter-satellite link paths with [33] focusing on Mega-constellation networks and [34] outlining trends and future prospects in the space laser communication scheme. In [35; 36; 37] the impact of different constellation sizes and orbit inclinations have been explored, regarding hop-count metrics and comparing them with the ground fiber networks. Finally, the work by [38] investigated certain routing issues in a Starlink constellation, evaluating the end-to-end latency with multi-path options, while [39] provided an overview of integrating LEO constellations into 5G and B5G systems. Moreover, in the challenging networking scenarios characterized by disruptive communications and delay, DTN has demonstrated its value as a valuable solution [3; 40; 41]. Addressing a spectrum of inter-networking challenges, DTN protocols have been comprehensively explored in [32]. Some notable scenarios included the Ring Road Network approach [42] and a multi-hop DTN relay system [7]. These scenarios utilized LEO satellites as \"data mules\" to efficiently transfer data during overflights to areas lacking Internet connectivity on Earth or beyond. Hence, any unsent data was stored for future flights to reduce the end-to-end latency of the delivered message. Focusing on urban environments, authors in [43] introduced a reference routing protocol for DTN-capable nodes, aiming to extend the Internet coverage in highly-dense environments, while in [44], DTN applications in existing infrastructure of public transport networks were investigated. Moreover, the work by [45] concentrated on practical experimentation to validate the effectiveness of DTN solutions in different scenarios, considering the routing in space. Finally, the SPICE testbed is presented in [46], serving as a state-of-the-art DTN testbed for satellite and space communications, relying on the Bundle Protocol to support multiple DTN implementations and various underlying and overlying protocols. While certain literature studies focus on simulating and analyzing space-terrestrial communication scenarios with OMNeT++, they exhibit a limited emphasis on the incorporation of real-world testbed data into the simulation environment. This distinction is essential to ensure the accuracy of simulation results, as real-world measurements provide valuable insights into the practical performance of communication systems. In the context of IoT Case Study scenarios, the evaluation of various parameters impacting the reliability of space-terrestrial communications is crucial.