Design and performance evaluation of the layer 2 signalling protocol in the ESA OBP network

The paper presents the results of a simulation study, performed under contract for the European Space Agency (ESA), which evaluated the performance of the layer 2 signalling protocol in the ESA On-Board Processing Network (OBP). Two layer 2 design options were compared in the study: a general protocol based on the HDLC family, and a simplified protocol tailored to the OBP environment. In the first option, several retransmission mechanisms were considered, including go-back-N, selective reject, and preventive cyclic retransmission (PCR). These mechanisms were simulated for different system parameter values, for example: number of earth stations, signalling channel capacity, and bit error rates. In most cases, the PCR method with an adequate spacing of the retransmissions provided the lowest transit delay. The smaller overhead introduced by the OBP-specific protocol did not result in significant performance improvements with respect to HDLC