Resource Consumption of a Hybrid Bundle Retransmission Approach on Deep-Space Communication Channels

Bundle protocol (BP) is the core protocol of delay/disruption-tolerant networking, which has been recognized as the only candidate networking technology that approaches the level of maturity required for deep-space mission communications. BP is intended to establish an overlay network for reliable data transfer over highly unreliable space links. A hybrid reliability strategy based on combining “proactive” retransmission and “reactive” retransmission of BP bundles is presented in this article as a means of achieving highly reliable file/data delivery in deep-space communication networks. Available electrical power on spacecraft is widely recognized as a scarce resource, especially for spacecraft in deep space where energy consumption is an important consideration for communications. In this article, the hybrid bundle retransmission approach is studied by means of a file transfer experiment over a PC-based testbed. The study focuses on variation in the transmission overhead and energy consumption of BP as a function of file size and retransmission timeout interval length.