Network protocol architectures for future deep-space internetworking

In the next two decades, humans are going to experience a grand age of deep-space exploration, especially in Mars and Lunar spaces. These relatively frequent and long-term activities provide the opportunity, and at the same time, demands the necessity for a true interplanetary network as an essential infrastructure for future deep-space exploration. In this study, we try to provide a picture and a perspective in the current network protocol architectures for future deep-space internetworking. We first investigate the recent technical advances for deep-space internetworking and the challenges to their network protocol architecture. Detailed technical characteristics of three effective network protocol architectures are presented. A special focus is casted on delay tolerant networking (DTN), which is a dedicated network protocol architecture for deep-space internetworking. Finally, several open questions in DTN for future deep-space internetworking are proposed for further study.