Multi-stakeholder Interactive Simulation for Federated Satellite Systems

Federated satellite systems (FSS) are a new class of space-based systems which emphasize a distributed architecture. New information exchanging functions among FSS members enable data transportation, storage, and processing as on-orbit services. As a system-of-systems, however there are significant technical and social barriers to designing a FSS. To mitigate these challenges, this paper develops a multi-stakeholder interactive simulation for use in future design activities. An FSS simulation interface is defined using the High Level Architecture to include orbital and surface assets and associated transmitters, receivers, and signals for communication. Sample simulators (federates) using World Wind and Orekit open source libraries are applied in a prototype simulation (federation). The application case studies a conceptual FSS using the International Space Station (ISS) as a service platform to serve Earth-observing customers in sun-synchronous orbits (SSO). Results identify emergent effects between FSS members including favorable ISS power conditions and potential service bottlenecks to serving SSO customers

Multi-objective resource optimization in space-aerial-ground-sea integrated networks

Space-air-ground-sea integrated (SAGSI) networks are envisioned to connect satellite, aerial, ground, and sea networks to provide connectivity everywhere and all the time in sixth-generation (6G) networks. However, the success of SAGSI networks is constrained by several challenges including resource optimization when the users have diverse requirements and applications. We present a comprehensive review of SAGSI networks from a resource optimization perspective. We discuss use case scenarios and possible applications of SAGSI networks. The resource optimization discussion considers the challenges associated with SAGSI networks. In our review, we categorized resource optimization techniques based on throughput and capacity maximization, delay minimization, energy consumption, task offloading, task scheduling, resource allocation or utilization, network operation cost, outage probability, and the average age of information, joint optimization (data rate difference, storage or caching, CPU cycle frequency), the overall performance of network and performance degradation, software-defined networking, and intelligent surveillance and relay communication. We then formulate a mathematical framework for maximizing energy efficiency, resource utilization, and user association. We optimize user association while satisfying the constraints of transmit power, data rate, and user association with priority. The binary decision variable is used to associate users with system resources. Since the decision variable is binary and constraints are linear, the formulated problem is a binary linear programming problem. Based on our formulated framework, we simulate and analyze the performance of three different algorithms (branch and bound algorithm, interior point method, and barrier simplex algorithm) and compare the results. Simulation results show that the branch and bound algorithm shows the best results, so this is our benchmark algorithm. The complexity of branch and bound increases exponentially as the number of users and stations increases in the SAGSI network. We got comparable results for the interior point method and barrier simplex algorithm to the benchmark algorithm with low complexity. Finally, we discuss future research directions and challenges of resource optimization in SAGSI networks

Proceedings of the Fifth International Mobile Satellite Conference 1997

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial communications services. While previous International Mobile Satellite Conferences have concentrated on technical advances and the increasing worldwide commercial activities, this conference focuses on the next generation of mobile satellite services. The approximately 80 papers included here cover sessions in the following areas: networking and protocols; code division multiple access technologies; demand, economics and technology issues; current and planned systems; propagation; terminal technology; modulation and coding advances; spacecraft technology; advanced systems; and applications and experiments

Network Neutrality, Consumers, and Innovation

In this Article, Professor Christopher Yoo directly engages claims that mandating network neutrality is essential to protect consumers and to promote innovation on the Internet. It begins by analyzing the forces that are placing pressure on the basic network architecture to evolve, such as the emergence of Internet video and peer-to-peer architectures and the increasing heterogeneity in business relationships and transmission technologies. It then draws on the insights of demand-side price discrimination (such as Ramsey pricing) and the two-sided markets, as well as the economics of product differentiation and congestion, to show how deviating from network neutrality can benefit consumers, a conclusion bolstered by the empirical literature showing that vertical restraints tend to increase rather than reduce consumer welfare. In fact, limiting network providers’ ability to vary the prices charged to content and applications providers may actually force consumers to bear a greater proportion of the costs to upgrade the network. Restricting network providers’ ability to experiment with different protocols may also reduce innovation by foreclosing applications and content that depend on a different network architecture and by dampening the price signals needed to stimulate investment in new applications and content. In the process, Professor Yoo draws on the distinction between generalizing and exemplifying theory to address some of the arguments advanced by his critics. While the exemplifying theories on which these critics rely are useful for rebutting calls for broad, categorical, ex ante rules, their restrictive nature leaves them ill suited to serve as the foundation for broad, categorical ex ante mandates pointing in the other direction. Thus, in the absence of some empirical showing that the factual preconditions of any particular exemplifying theory have been satisfied, the existence of exemplifying theories pointing in both directions actually supports an ex post, case-by-case approach that allows network providers to experiment with different pricing regimes unless and until a concrete harm to competition can be shown