# Resource- and Neighbor-Aware Observation Transmission Scheme in Satellite Networks
###### Abstract  
The observation satellite can exploit its own storage and computational resources to reduce the transmission delay. However, too excessive usage of these resources can have negative effects on the queuing delay at the relay satellite and/or on conducting other tasks at each observation satellite. In this paper, we proposed a new resource- and neighbor-aware observation transmission scheme (RNA-OTS). In RNA-OTS, each observation satellite decides whether to use its resources and the resources of the relay satellite at each time epoch by considering its resource utilization and transmission policies of neighbor observation satellites. For the optimal decision of each observation satellite in a distributed manner, the operation of observation satellites is modeled by means of a constrained stochastic game, and a best-response-dynamics-based algorithm is devised to find the Nash equilibrium. The evaluation results demonstrate that RNA-OTS can decrease the delay to deliver the observation to the destination by up to 87% compared to a relay-satellite-based scheme while guaranteeing a sufficiently low average utilization of the resources of the observation satellite. s 2023234889 202323 23  
Then, the observation satellite can compress the observation to reduce the transmission delay by using its computational resources. However, when using excessive storage and computational resources, the observation satellite cannot store and conduct other tasks (e.g., image processing for environmental monitoring) in a timely manner. To sum up, the resources of two types of satellites should be appropriately utilized. Even though a centralized approach may aid in coordinating the utilization of two types of resources, a significant signaling overhead can arise and a centralized entity can become overburdened owing to a high computation overhead. In this paper, we propose a resource- and neighbor-aware observation transmission scheme (RNA-OTS). In RNA-OTS, to avoid the excessive simultaneous transmissions to the relay satellite (i.e., to avoid the increased queuing delay at the relay satellite), each observation satellite decides whether or not to transmit its observation to the relay satellite (or to the ground station) (i.e., whether or not to use the resources of the relay satellite) by considering the neighbor observation satellites' transmission policies. Additionally, to conduct other tasks (e.g., image processing for environmental monitoring) in a timely manner, each observation satellite decides whether or not to delay the transmission and to compress the observation before the transmission (i.e., whether or not to use its own resources) with a consideration of its current resource utilization. For the distributed optimal decision of each observation satellite by considering the transmission policies of neighbor observation satellites and its resource utilization, the operation of observation satellites is modeled by means of a constrained stochastic game. Then, a best-response-dynamics-based algorithm is devised to find the Nash equilibrium of the game. The Nash equilibrium indicates the status where the best performance (i.e., minimized delay) can be achieved and no players can profit from arbitrarily deviating from the equilibrium [5,6]. The evaluation results demonstrate that RNA-OTS can decrease the delay to deliver the observation to the destination by up to 87% compared to a relay-satellite-based scheme while guaranteeing a sufficiently low average utilization of the resources of the observation satellite. Moreover, it can be found that RNA-OTS can adaptively operate according to its operating environments.