On scalability of Fractionated Satellite Network architectures

Fractionated Satellite Networks are a popular concept in space systems. On these networks, several satellites cooperate and collaborate by exchanging resources wirelessly in order to obtain an aggregated network capability higher than the sum of the individual capabilities of the different satellites that compose it. Fractionated Satellite Networks are a generalization of Fractionated Satellites. Scalability is defined as the ability of a system to maintain its performance and function, and retain all its desired properties when its scale is increased greatly without having a corresponding increase in the systems complexity. The whole concept of fractionation (both at spacecraft level and network level) is based on the use of multiple satellites that jointly perform a function that can be further expanded by adding new satellites to the system. Because of this expandable nature of Fractionated Satellite Networks, the concept of scalability is critical on these architectures, as systems that do not scale well present a very poor performance when adding new agents, increasing costs and harming quality of service and stakeholder satisfaction. This paper presents a model and a framework for analyzing scalability of fractionated networks. Our model includes descriptions of the system at the resource, satellite, network and mission level. Connections and resource transfer among nodes are modelled using graphs whereas the study is approached from a resource allocation problem perspective. Finally, the utility and applications of the developed methodology is demonstrated through the analysis of a case study of a potential fractionated network.