Proposal and Investigation of a Lite Time Sensitive Networking solution for the support of Real Time Services in Space Launcher Networks

Most launcher networks are based on proprietary buses such as MIL-STD-1553B whose low bandwidth limits the introduction of new services of suitable characteristics. Ethernet technology, because of its low cost and high performance, has been considered an excellent candidate for its use in launcher networks. The real time Ethernet solutions based on the Time Sensitive Networking (TSN) standards seem the most suitable because of its multi-vendor product characteristics. In this paper we propose a real time Ethernet solution for aerospace applications in which negligible jitter services has to be guaranteed. The proposed solution is based on the following TSN standards: IEEE 802.1AS/ASrev as synchronization protocol and 802.1Qbv-2015 for deterministic traffic scheduling. To improve both the bandwidth effective and the frame delay the solution is also based on a change in the management of the Priority Code Point field in IEEE 802.1Q standard. The optimal scheduling problem is formulated so as to minimize the makespan, defined as the time needed to deliver all of the messages of an elementary cycle. The problem has been resolved with the CPLEX solver and the proposed solution has been evaluated in terms of both delay and bandwidth effective by comparing its performance with the TTEthernet, FTTEthernet benchmark solutions. The obtained results in a real traffic scenario characterized by the set of messages of the VEGA launcher show how the proposed solution allows for the same performance of TTEthernet, i.e., the solution of proprietary and real-time Ethernet with better performance.