Reliable data delivery over deep space networks: Benefits of long erasure codes over ARQ strategies

Achieving reliable communications in deep space environments poses formidable networking challenges because of the extreme physical medium peculiarities. In this view, two possible approaches can be considered to carry out reliable data transfers over deep space channels: automatic repeat request schemes and packet layer coding algorithms applied with long erasure codes. In this respect, this article surveys the mechanisms currently available from the Consultative Committee for Space Data Systems protocol stack, by reserving special attention, on one hand, to the ARQ schemes currently implemented at the application layer and, on the other hand, to the potential offered by erasure coding schemes. A comparative analysis gives some insights about the performance improvements the packet layer coding methodology can bring. In particular, the results show that the use of erasure coding is able to attain more satisfactory performance results than ARQ-based schemes in terms of reliability, data transfer delay, resource network utilization, and power consumption.