Spacewire and Ieee 1355 Revisited Session: Standardization Long Paper

The ECSS (European Cooperation for Space Standardization) SpaceWire standard includes a list of changes from the standard from which it was derived, IEEE 1355. Several of these changes are improvements, for example fixing the initialization state machine, adding Time Codes, and adding a network layer. The list in the SpaceWire standard does not include a number of aspects of 1355 that SpaceWire has discarded, yet which are being requested by user missions — sometimes where the need is so strong that the missions are already using adaptations from the SpaceWire standard. This paper considers these user needs, with reference to where they were covered, at least in part, by IEEE 1355. It concludes that as SpaceWire is evolving to include SpaceFibre, it should also evolve in other directions to form a family of standards, all sharing the common link, ‘exchange’ and packet layers of the 1355/SpaceWire standards.