Reliable Proactive Retransmission of Bundle Protocol for Deep-Space Communications in Presence of Link Disruption

Reliable data transmission mechanisms of bundle protocol (BP) are presently under development for delay/disruption-tolerant networking (DTN). In this paper, a new transmission approach is proposed for BP for highly reliable data delivery in deep-space communications in presence of unpredictable or random link disruption. The main idea of the proposed approach is to employ a joint use of the proactive retransmission mechanism and active retransmission mechanism during file transfer. The performance of the approach is analyzed in four different cases according to different starting times of link disruption. Analytical models are built to estimate the effect of link disruption on BP transmission with focus on the number of transmission attempts and the total file delivery time affected by the link disruption. The models are validated by the file transfer experiment over a PC-based testbed.