LeWiz develops deterministic Ethernet bridge under NASA contract

LeWiz Communications has received a NASA Small Business Innovation Research (SBIR) Phase III contract to develop an avionics network bridge connecting Time-Triggered Ethernet (TTE) and Time-Sensitive Networking (TSN). The system is intended to exchange communications between existing spacecraft electronics and newer subsystems using different deterministic Ethernet approaches. Development will cover the protocols as well as a complete hardware architecture for future spaceflight applications.

LeWiz plans to deliver a chassis designed for the SOSA Space Appendix, a backplane, networking boards and the associated firmware and software. Bringing these elements into a single development programme ties traffic handling to physical interfaces, board integration and the environmental requirements of spacecraft equipment. The design is aimed at spacecraft, space stations and future lunar and Mars mission architectures; specific flight deployment and qualification milestones have yet to be established.

Time-Triggered Ethernet uses agreed transmission schedules to make the timing of critical traffic predictable across a configured network. Scheduled frames can be separated from less time-sensitive communications, with participating endpoints synchronised to the timing model. NASA’s Orion spacecraft provides an established application of TTE, giving the project a relevant installed technology base that cannot simply be replaced whenever a new payload or processing module is introduced.

TSN extends Ethernet through a collection of IEEE 802.1 mechanisms, including synchronisation and traffic scheduling functions selected for particular implementations. A spacecraft subsystem designed around TSN may therefore have different arrangements for clock distribution, message queues and prioritisation from one using TTE. Interoperability requires the bridge to preserve the traffic properties the receiving equipment expects while respecting both sides’ timing and management rules.

Packets crossing the boundary may need to be mapped between traffic classes and transmission windows, with buffering controlled so that predictable delivery is maintained. The required behaviour depends on the endpoints’ timing budgets and the permitted network topology. LeWiz’s development programme will have to turn those requirements into an implementable bridge architecture before tests can establish latency, jitter and failure handling for the selected configuration.

Long spacecraft development and service lives make protocol coexistence a practical integration problem. New imaging payloads, processors and control electronics can arrive after a mission’s core avionics network has been established and qualified. A defined bridge can reduce the need to redesign established network segments, although the resulting interface still needs engineering evidence for message integrity, fault containment and recovery in the intended mission.

The planned modular chassis and backplane introduce electrical and mechanical verification alongside the networking work. Board connectors, power distribution, thermal design and resistance to launch and orbital conditions influence the reliability of the whole assembly. Compliance with relevant aerospace standards will depend on the final hardware and its qualification programme. A reference to a modular architecture defines an integration approach rather than completing that testing.

The Phase III award builds on LeWiz’s earlier NASA and US Navy research into deterministic networking, including work pursued through SBIR Phases I and II. The new contract moves that technical programme towards an integrated system with specific hardware deliverables. The published scope names the major elements but leaves the final semiconductor selections, network topology and delivery milestones to the development effort.

LeWiz’s existing portfolio includes FPGA-based networking technology and radiation-hardened semiconductor work. Programmable logic is one possible means of implementing time-critical packet processing and interface handling, subject to the architecture chosen for the contract. Component selection also influences available resources for timestamping, buffering, diagnostics and error recovery, all of which can affect deterministic behaviour once the bridge is integrated.

Engineering progress will be measured through verified timing behaviour, robust exchange of traffic between TTE and TSN domains, and environmental assessment of the boards and enclosure. Those outcomes will determine whether the bridge can support newer spacecraft subsystems while retaining compatibility with established avionics networks.