Reliable Deep-Space File Transfers: How Data Transfer Can Be Ensured Within a Single Round-Trip Interval

The challenging problem of mission control and data delivery in deep-space explorations is a typical application scenario of delay-/disruption-tolerant networking (DTN) technology. The development of protocols and efficient data transmission mechanisms for space-vehicle networks and deepspace-vehicle communications is presently underway. In this article, we show how to ensure successful file transfers in deep-space-vehicle communications within a single round-trip interval using a bundle protocol (BP), the main protocol of DTN, despite the high rate of data loss, long signal propagation delay, and highly asymmetric channel rates that characterize deepspace channels. The key concept is anticipatory retransmission: bundles are proactively retransmitted, long before the round-trip interval elapses, based on expected transmission failure rather than detected transmission failure.