High-bandwidth technologies for next-generation launcher networks: a comparative analysis between TTethernet and Time Sensitive Networking (TSN)

With the emergence of new space technologies, there is a need for more flexible and cost-effective aerospace intra-communication systems for both launchers and satellites. Traditional protocols like MILSTD-1553B are facing bandwidth limitations, while other alternatives like TTEthernet are expensive and inflexible. In this context, the use of Ethernet technologies is gaining popularity due to their high bandwidth and compatibility with Commercial Off-The Shelf (COTS) components, enabling cost savings and increased interoperability. This trend is particularly relevant for micro-launchers, where the payload size is relatively small, and the launching vehicles' reusability and quick production are key factors. As a result, manufacturers are attempting to adopt COTS components and the industry is shifting towards Ethernet-based intra-communication systems, as they offer a viable alternative to traditional protocols. Time Sensitive Networking (TSN) is a new technology that offers a promising alternative to these protocols, providing low-latency and high-bandwidth tailored to meet the needs of aerospace applications. One of the primary challenges of incorporating TSN into launchers networks is the configuration of the Quality of Service (QoS) parameters. QoS is essential for ensuring that critical data is prioritized and delivered with low latency and zero jitter, while non-critical data is transmitted with lower priority. TSN provides a variety of QoS mechanisms, including Time Aware Shaper (TAS) and Queue-Based Scheduling (Qbv), which specify the queue-based scheduling mechanism to support the determinism required by applications such as aerospace. The TAS feature introduces time-controlled gating mechanisms to the egress port queues, but TSN does not immediately provide the same good temporal features as TTEthernet. Our study contributes significantly by introducing TSN-Lite, which incorporates only two Time Sensitive standards (IEEE 802.1ASrev and IEEE 802.1Qbv), optimizing them specifically for aerospace applications. We assess the TSN-Lite solution in a real network context using VEGA, a small launcher developed jointly by the Italian Space Agency and the European Space Agency. Furthermore, we perform a performance evaluation comparing the optimized TSN-Lite schedule with the optimized schedule of state-of-the-art solutions in the VEGA case study, demonstrating capability of TSN-Lite to approach TTethernet performance.