Performance analysis of SCPS-TP SNACK in space communication

TCP has been a robust and efficient protocol for terrestrial networks, but it does not fare very well in the space environment because of the long-link delay, high bit-error-rate, asymmetric bandwidth, intermittent links compare with the terrestrial networks. However, it does provide an excellent base for extension. The Space Communications Protocol Standards (SCPS) has proposed Transport Protocol (SCPS-TP) which is a popular modification of TCP that is very efficient for space environments. The Selective Negative Acknowledgement (SNACK) is an important option provided by SCPS-TP. The focus of this paper is to investigate the performance of SCPS-TP SNACK in hybrid networks with space segments. The paper proposes a new mode, which is IP over CCSDS AOS, to integrate the space network with the ground network at first, based on this mode; it designs the topology for the hybrid networks; then, the paper analyses the performance of the SCPS-TP SNACK in the hybrid networks. The results show that SCPS-TP SNACK has a better performance than the regular TCP in space communication.