A sensitivity analysis of two worst-case delay computation methods for SpaceWire networks

Abstract

SpaceWire is a standard of on-board networks for satellites promoted by the ESA. As the ESA plans to use SpaceWire as the sole network for both critical and non-critical traffics, network designers need tools to check that all the critical messages meet their deadlines. We proposed previously two such tools to compute an upper-bound on the worst-case end-to-end delay of a packet traversing a SpaceWire network. The main contribution of this paper is the comparison of those two methods on a realistic network configuration provided by Thales Alenia Space. The goal is to identify the key parameters that affect the bounds computed by the methods. We then conduct a sensitivity analysis on simpler network configurations to study the impact of those parameters on the methods and determine which method works better in different situations.