## 1 Introduction  
SpaceFibre is a high data-rate communication protocol specifically designed for on-board data-handling space applications [PERSON] _et al._ (2019); its standardisation process by the European Cooperation for Space Standardization (ECSS) is at its final steps ([PERSON] _et al._, 2019) and is to be published in 2019 (ECSS-E-ST-50-11C). SpaceFibre protocol development has been promoted by the European Space Agency (ESA), which also developed the SpaceWire standard ([PERSON] _et al._, 2019), with SpaceFibre representing its evolution. SpaceWire is a full-duplex, low error rate line with low resources utilisation (5-8 Kgates) ([PERSON] _et al._, 2019) and a data-rate up to 400 Mbps. It has already been adopted in several ESA, National Aeronautics and Space Administration (NASA), and Japan Aerospace eXploration Agency (JAXA) missions, such as Rosetta, Mars-Express, Galileo and many others, making it a highly reliable solution. A wide set of COder-DECoders (CODECs) and routers is available on the market, both with Application Specific Integrated Circuit (ASIC) and Field Programmable Gate Array (FPGA) ([PERSON] _et al._, 2019), as well as a large choice of support equipment ([PERSON] _et al._, 2019). SpaceWire also implements fault tolerance mechanisms that automatically switches from one link to another in case of failure with very small loss of information. The protocol itself has been designed for easier integration and to improve and promote equipment reuse across different missions, making it also a competitive choice in terms of costs. SpaceWire adoption by different space agencies is therefore well motivated by the above considerations. Nevertheless, most recent applications require several Gbps data-rate, which cannot be achieved by a single SpaceWire node. In the near future, ESA upcoming missions (i.e., FLEX [6] and BIOMASS [7]) will mount Synthetic Aperture Radars (SARs) and hyper-spectral imagers which will require high speed on-board communication. In current missions, the lack of a standardised high-speed communication protocol led system integrators to adopt not optimised solutions such as WizardLink interfaces (not standardised) [8] with customised protocol on top or more SpaceWire CODECs in parallel (more components, cables and connectors required). These reasons fostered SpaceFibre development, starting from the same basic concepts of SpaceWire and adding functionalities such as greater bandwidth, the concept of Virtual Channels (VCs), Quality of Service (QoS) and Fault Detection Isolation and Recovery (FDIR). In fact, SpaceFibre features meet the data-rate requirement of future missions: a single lane SpaceFibre link can achieve 6.25 Gbps bandwidth, which is necessary to support data-rate requirements of most advanced payloads. Other solutions are currently under evaluation by the space community to be selected as the next standardised high-speed communication protocol for space applications: in particular, RapidIO [9] and TTEthernet [10]. Nevertheless, the adoption of these solutions is not straight forward. In fact, even if they fulfil system requirements, they have several disadvantages: they are not based on an open ECSS standard, and the structure of the protocol itself is not developed aiming at optimisation for spacecraft usage but rather it is an adaptation of commercial technology to space requirements. SpaceFibre instead is based on an open standard and could be easily implemented by different entities, increasing its reliability. Even if the standard has not been released yet, a wide range of SpaceFibre based product is available, both as research project or commercial product, from CODEC Intellectual Property (IP) (from IngeniArs [11], ESA [12] and StarDundee [1]) to routing switch (IngeniArs [13] and StarDundee [14]) and network simulator (IngeniArs [15]). Moreover, it has been developed specifically for space applications, resulting in a highly optimised solution. However, in particular cases, SpaceFibre may also be over-specified.