Race and Challenges for Developing Direct Satellite-to-Smartphone Communication Systems

Direct satellite-to-smartphone service is an emerging wireless market segment that synergizes satellite and terrestrial communications services. It can expand the reach for terrestrial services and increase the user-base for satellite services. In fact, several commercial services have already been started, and a few more have been announced. In this article, we classify direct satellite-to-smartphone systems into three types, and study the network architectures that support target services for each type of system. We also present candidate designs. We discuss their pros and cons from both technical and operational aspects. Then, we describe research questions that could become more important as the service expands. We hope they can provide some insights that could be the foundation for guiding future enhancements and evolutions of direct satellite-to-smartphone to deliver truly ubiquitous connectivity.